Materiały źródłowe

• #1 Amnesia: What It Is, Causes, Symptoms, Treatment & Types

  https://my.clevelandclinic.org/health/diseases/21455-amnesia

  Amnesia is when you have significant memory loss. There are many possible causes of it. Sometimes its a symptom of other conditions, but it can also happen on its own. It can involve past memories, or you can have trouble making and storing new memories. Treating the underlying cause may reverse it, but some causes are permanent. […] Amnesia can happen for many reasons. The causes fall broadly into two main categories: neurological causes and psychological causes. […] Neurological causes of amnesia all involve damage to your brain or disruptions in brain activity. The possible causes include (but arent limited to) the following: Alcohol intoxication (this can temporarily block the formation of new memories, causing a blackout). Alzheimers disease. Brain aneurysms. Brain tumors (including cancerous and noncancerous growths). Cerebral hypoxia (brain damage from lack of oxygen). Drugs and medications (especially certain sedatives and anesthesia medications), including nonmedical drug use. Epilepsy and seizures (especially temporal lobe epilepsy). Frontotemporal dementia. Head injuries like concussions or traumatic brain injuries (TBIs). Infections (especially ones that cause encephalitis like herpes simplex virus). Other degenerative brain diseases, like Parkinsons disease or multiple sclerosis (MS). Stroke. Toxins and poisons like carbon monoxide poisoning or heavy metal poisoning. Transient global amnesia. Wernicke-Korsakoff syndrome (this is a severe vitamin B1 deficiency that happens with long-term alcohol use disorder).

• #2 Amnesia – Wikipedia

  https://en.wikipedia.org/wiki/Amnesia

  Anterograde amnesia is the inability to create new memories due to brain damage, while long-term memories from before the event remain intact. The brain damage can be caused by the effects of long-term alcoholism, severe malnutrition, stroke, head trauma, encephalitis, surgery, WernickeKorsakoff syndrome, cerebrovascular events, anoxia or other trauma. […] Retrograde amnesia is inability to recall memories before onset of amnesia. One may be able to encode new memories after the incident. Retrograde is usually caused by head trauma or brain damage to parts of the brain besides the hippocampus. […] Korsakoff’s syndrome can result from long-term alcoholism or malnutrition. It is caused by brain damage due to a vitamin B1 deficiency and will be progressive if alcohol intake and nutrition pattern are not modified.

• #3 Amnestic disorders. Pathophysiology and patterns of memory dysfunction.

  https://pmc.ncbi.nlm.nih.gov/articles/PMC1002292/

  A wide variety of conditions seen in medical practice can produce memory impairment (amnesia). […] Systemic illnesses can impair memory by injuring vulnerable limbic regions sensitive to hypoxia or hypoglycemia. […] Recent studies suggest that immediate, recent, and remote memory functions have different neuroanatomic substrates, as do the processes of registration, retention, and retrieval. […] The neuropharmacology of memory now includes several peptides in addition to cholinergic and noradrenergic pathways. […] Critical limbic regions have been discovered that mediate memory consolidation, and neuronal mechanisms such as long-term potentiation are being implicated in the unique capacity of these areas to permit new learning to take place.

• #4 Amnesia – Wikipedia

  https://en.wikipedia.org/wiki/Amnesia

  Amnesia is a deficit in memory caused by brain damage or brain diseases, but it can also be temporarily caused by the use of various sedative and hypnotic drugs. The memory can be either wholly or partially lost due to the extent of damage that is caused. […] Case studies also show that amnesia is typically associated with damage to the medial temporal lobe. In addition, specific areas of the hippocampus (the CA1 region) are involved with memory. Research has also shown that when areas of the diencephalon are damaged, amnesia can occur. Recent studies have shown a correlation between deficiency of RbAp48 protein and memory loss. […] Individuals with amnesia also retain substantial intellectual, linguistic, and social skills despite profound impairments in the ability to recall specific information encountered in prior learning episodes.

• #5 Amnesia, memory and brain systems.

  https://pmc.ncbi.nlm.nih.gov/articles/PMC1692096/

  Bilateral damage to either the medial temporal lobe or the diencephalic midline causes an amnesic syndrome, i.e. a global impairment in the ability to acquire new memories regardless of sensory modality, and a loss of some memories, especially recent ones, from the period before amnesia began. […] The memory deficit can occur against a background of intact intellectual and perceptual functions. […] Two themes have been prominent in recent work. First, the amnesic syndrome is narrower than once believed in the sense that a number of learning and memory abilities are preserved (e.g. skill and habit learning, simple forms of conditioning and the phenomenon of priming). […] Second, the brain system damaged in amnesia has only a temporary role in memory. […] As time passes after learning, memory is reorganized and consolidated within neocortex, such that eventually medial temporal lobe and diencephalic structures are not needed for storage or retrieval.

• #6 Amnesia – Wikipedia

  https://en.wikipedia.org/wiki/Amnesia

  The loss of semantic information in amnesia is most closely related with damage to the medial temporal lobe or to the neocortex. […] One reason that patients could not form new episodic memories is likely because the CA1 region of the hippocampus has a lesion, and thus the hippocampus could not make connections to the cortex. […] There are three generalized categories in which amnesia could be acquired by a person. The three categories are head trauma (example: head injuries), traumatic events (example: seeing something devastating to the mind), or physical deficiencies (example: atrophy of the hippocampus). […] Among specific causes of amnesia are the following: Electroconvulsive therapy in which seizures are electrically induced in patients for therapeutic effect can have acute effects including both retrograde and anterograde amnesia.

• #7 Anterograde amnesia – Wikipedia

  https://en.wikipedia.org/wiki/Anterograde_amnesia

  In neurology, anterograde amnesia is the inability to create new memories after an event that caused amnesia, leading to a partial or complete inability to recall the recent past, while long-term memories from before the event remain intact. […] To a large degree, anterograde amnesia remains a mysterious ailment because the precise mechanism of storing memories is not yet well understood, although it is known that the regions of the brain involved are certain sites in the temporal cortex, especially in the hippocampus and nearby subcortical regions. […] Patients with anterograde amnesia may have episodic, semantic, or both types of explicit memory impaired for events after the trauma that caused the amnesia. This suggests that memory consolidation for different types of memory takes place in different regions of the brain.

• #8 Amnesia: Symptoms, Types, Causes, and More

  https://www.healthline.com/health/neurological-health/amnesia

  Amnesia refers to memory loss. There are many types of amnesia, each with different causes. While some types of amnesia are temporary, others can be permanent. […] Amnesia is a form of memory loss. […] Mild memory loss is a normal part of aging. Significant memory loss or the inability to form new memories may indicate the presence of an amnestic disorder. […] The primary symptom of amnesia is memory loss or the inability to form new memories. […] When you have anterograde amnesia, you can’t form new memories. […] It can also be permanent. You can experience it if the area of your brain known as the hippocampus is damaged. Your hippocampus plays an important role in forming memories. […] The hippocampus is the part of the brain and limbic system responsible for memory. Its activities include forming memories, organizing memories, and retrieving them when needed.

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• #10 Anterograde amnesia – Wikipedia

  https://en.wikipedia.org/wiki/Anterograde_amnesia

  The pathophysiology of anterograde amnesic syndromes varies with the extent of damage and the regions of the brain that were damaged. The most well-described regions indicated in this disorder are the medial temporal lobe (MTL), basal forebrain, and fornix. […] Neuropsychologists and scientists are still not in total agreement over whether forgetting is due to faulty encoding, accelerated forgetting, or faulty retrieval, although a great deal of data seem to point to the encoding hypothesis. […] Neuroscientists are in disagreement about the length of time involved in memory consolidation. […] The MTL memory system includes the hippocampal formation (CA fields, dentate gyrus, subicular complex), perirhinal, entorhinal, and parahippocampal cortices. It is known to be important for the storage and processing of declarative memory, which allows for factual recall.

• #11 Amnesias – Neurologic Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/neurologic-disorders/function-and-dysfunction-of-the-cerebral-lobes/amnesias

  Bilateral damage to the mediodorsal nuclei of the thalamus severely impairs recent memory and the ability to form new memories. […] Amnesia may be caused by Thiamin deficiency (by causing Wernicke encephalopathy or Korsakoff psychosis) in patients with chronic alcohol abuse or severe undernutrition, Traumatic brain injury, Seizures, Global brain anoxia or ischemia, Encephalitis, Embolic occlusion at the top of the basilar artery, causing ischemia in the anterior medial temporal lobes, Degenerative dementias such as Alzheimer disease, Various drug intoxications (eg, chronic solvent sniffing, amphotericin B or lithium toxicity), Hypothalamic tumors, Psychologic trauma or stress. […] Posttraumatic amnesias for the periods immediately before and after concussion or moderate or severe head trauma seem to result from medial temporal lobe injury.

• #12 Retrograde Amnesia: Causes, Symptoms, and Treatment

  https://www.healthline.com/health/retrograde-amnesia

  Amnesia is a type of memory loss that affects your ability to make, store, and retrieve memories. Retrograde amnesia affects memories that were formed before the onset of amnesia. Retrograde amnesia is caused by damage to the memory-storage areas of the brain, in various brain regions. This type of damage can result from a traumatic injury, a serious illness, a seizure or stroke, or a degenerative brain disease. […] Retrograde amnesia can result from damage to different parts of the brain responsible for controlling emotions and memories. These include the thalamus, which is deep in the center of the brain, and the hippocampus, which is in the temporal lobe. […] Most traumatic brain injuries are mild, resulting in concussion. But a severe injury, like a serious blow to the head, can damage the memory-storing areas of the brain and lead to retrograde amnesia.

• #13 Amnesias – Neurologic Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/neurologic-disorders/function-and-dysfunction-of-the-cerebral-lobes/amnesias

  Amnesia is partial or total inability to recall past experiences or inability to store new memories after the causative event. It may result from traumatic brain injury, degeneration, metabolic disorders, seizures, or psychologic disturbances. […] Deficits in any of these steps can cause amnesia. Amnesia, by definition, results from impairment of memory functions, not impairment of other functions (eg, attention, motivation, reasoning, language), which may cause similar symptoms. […] Amnesia can result from diffuse cerebral impairment, bilateral lesions, or multifocal injuries that impair memory-storage areas in the cerebral hemispheres. […] Predominant pathways for declarative memory are located along the medial parahippocampal region and hippocampus as well as in the inferomedial temporal lobes, orbital surface of the frontal lobes (basal forebrain), and diencephalon (which contains the thalamus and hypothalamus). Of these structures, the following are critical: Hippocampal gyri, Hypothalamus, Nuclei of the basal forebrain, Mediodorsal thalamic nuclei.

• #14 Amnesia pathophysiology – wikidoc

  https://www.wikidoc.org/index.php/Amnesia_pathophysiology

  Memory is the stored information in the hippocampal region of the brain. According to Richard Semon (1904), experiences cause some structural and functional changes in the neurons and these changes are referred to as engram and they form memory of that experience. Reactivation of these neurons occur when patient tries to recall those memories. […] Pathogenesis: Dissociative Amnesia Psychological origin. Transient global amnesia Precipitated by brain ischemia, migraine, epileptic seizure, venous congestion, psychological trauma. Post-traumatic Amnesia Amnesia that follows head trauma could be temporary or permanent. Infantile Amnesia Influenced by cultural norms and sexual repression. Drug-Induced Amnesia Benzodiazepine are the most common group of drugs that can cause drug-induced amnesia, especially if used with alcohol. Neurologically Derived Amnesia Brain regions involved are the hippocampus and the medial temporal lobes. Amnesia in Korsakoffs Syndrome Caused by thiamine deficiency due to prolonged alcohol use or severe malnutrition. Deficiency of thiamine damages medial thalamus, mammillary bodies and causes cerebral atrophy due to lack of pyruvate decarboxylation. […] Deficiency of RbAp48 protein encoded by RBBP4 gene have been co-related to memory loss.

• #15 Amnesia – Brain, Spinal Cord, and Nerve Disorders – Merck Manual Consumer Version

  https://www.merckmanuals.com/home/brain-spinal-cord-and-nerve-disorders/brain-dysfunction/amnesia

  Amnesia is total or partial loss of the ability to recall experiences or events that happened in the preceding few seconds, in the preceding few days, further back in time, or after the event that caused the amnesia. […] Because many areas of the brain are involved in memory, damage almost anywhere in the brain can cause amnesia. […] How amnesia is caused is only partly understood. […] How long memory loss lasts depends on the severity of the damage that caused it. […] The brains mechanisms for storing information and recalling it from memory are located primarily in the temporal lobe and frontal lobe, but many areas of the brain are involved in memory. For example, the hippocampus, located deep within the brain, is involved in the formation of new memories and retrieval of stored memories.

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• #17 Amnesia – Brain, Spinal Cord, and Nerve Disorders – Merck Manual Consumer Version

  https://www.merckmanuals.com/home/brain-spinal-cord-and-nerve-disorders/brain-dysfunction/amnesia

  Emotions originating from the limbic system can influence the storing of memories and their retrieval. […] How amnesia is caused is only partly understood. […] Depending on the cause, amnesia may be temporary, permanent and unchanging, or progressive. […] Most of these cures are dubious. […] Whether memories can be recovered depends on the severity and cause of the damage. Often, the damage is not severe, or the cause is temporary. […] If a cause of amnesia is identified, it is treated if possible. Such treatment may or may not lessen the amnesia.

• #18 A human memory circuit derived from brain lesions causing amnesia | Nature Communications

  https://www.nature.com/articles/s41467-019-11353-z

  By definition, functional connectivity with our region in the subiculum-retrosplenial continuum defines a human brain circuit that encompasses 95% of lesion locations causing amnesia. […] This connectivity profile was specific to lesions causing amnesia compared to generic lesions or lesions causing other non-memory symptoms. […] The hub of our human memory circuit is at the junction of the subiculum and the retrosplenial cortex, a region referred to as the subiculum-retrosplenial continuum. […] Connectivity to this single brain location defines a human brain circuit that encompasses over 95% of our 53 lesions causing amnesia. […] The fact that our circuit predicted memory scores in two independent datasets differing in lesion etiology and method of memory assessment is an important validation of our results and of lesion network mapping more generally.

• #19 Amnestic disorders. Pathophysiology and patterns of memory dysfunction.

  https://pmc.ncbi.nlm.nih.gov/articles/PMC1002292/

  A wide variety of conditions seen in medical practice can produce memory impairment (amnesia). […] Systemic illnesses can impair memory by injuring vulnerable limbic regions sensitive to hypoxia or hypoglycemia. […] Recent studies suggest that immediate, recent, and remote memory functions have different neuroanatomic substrates, as do the processes of registration, retention, and retrieval. […] The neuropharmacology of memory now includes several peptides in addition to cholinergic and noradrenergic pathways. […] Critical limbic regions have been discovered that mediate memory consolidation, and neuronal mechanisms such as long-term potentiation are being implicated in the unique capacity of these areas to permit new learning to take place.

• #20 Memory Loss Mechanism On Amnesia | International Journal of Scientific Development and Research

  https://www.ijsdr.org/viewpaperforall.php?paper=IJSDR2411002

  Neurological amnesia has been the focus of a lot of research because scientists want to better understand how memory works and how the brain is involved. […] There is now a general agreement that damage to the hippocampus (a part of the brain) or areas around it leads to problems with episodic memory, which is the ability to remember personal experiences, as well as issues with recalling things after some time and remembering details of events. […] However, there is still ongoing debate about how other types of memory, like general knowledge (semantic memory), recognizing things after a delay, short-term memory (working memory), and the ability to imagine, are affected by amnesia. […] This review highlights some recent advances in these discussions and what they tell us about amnesia and how the hippocampus works.

• #21

  https://link.springer.com/article/10.3758/s13423-024-02567-4

  This points to the effects of a continued process of consolidation on older memories long after their initial encoding. […] The use of retrograde amnesia as an indicator of long-lasting memory consolidation stems from Ribots (1882) early work on the retention and recovery of information following brain trauma. […] Historical data points towards a specific pattern of disruption and preservation that extends even decades into a person’s past, which implies that memory consolidation processes continue for decades, resulting in the temporal gradient that we often witness in the results of many experiments. […] Browns key finding was a large performance gap between patients and controls for more recent memories and a smaller gap for older memories. […] This was true for various causes of retrograde amnesia.

• #22 Amnesia after Repeated Head Impact Is Caused by Impaired Synaptic Plasticity in the Memory Engram | Journal of Neuroscience

  https://www.jneurosci.org/content/44/8/e1560232024

  Subconcussive head impacts are associated with the development of acute and chronic cognitive deficits. […] To better understand the mechanisms underlying HFHI-induced memory decline, we used TRAP2/Ai32 transgenic mice to enable visualization and manipulation of memory engrams. […] This lack of plasticity coincided with impaired activation of the engram network, leading to retrograde amnesia in HFHI mice. […] Our work shows that chronic cognitive impairment after HFHI is a result of deficiencies in synaptic plasticity instead of a loss in neuronal infrastructure, and we can reinstate a forgotten memory in the amnestic brain by stimulating the memory engram. […] Targeting synaptic plasticity may have therapeutic potential for treating memory impairments caused by repeated head impacts.

• #23 Anterograde amnesia – Wikipedia

  https://en.wikipedia.org/wiki/Anterograde_amnesia

  The pathophysiology of anterograde amnesic syndromes varies with the extent of damage and the regions of the brain that were damaged. The most well-described regions indicated in this disorder are the medial temporal lobe (MTL), basal forebrain, and fornix. […] Neuropsychologists and scientists are still not in total agreement over whether forgetting is due to faulty encoding, accelerated forgetting, or faulty retrieval, although a great deal of data seem to point to the encoding hypothesis. […] Neuroscientists are in disagreement about the length of time involved in memory consolidation. […] The MTL memory system includes the hippocampal formation (CA fields, dentate gyrus, subicular complex), perirhinal, entorhinal, and parahippocampal cortices. It is known to be important for the storage and processing of declarative memory, which allows for factual recall.

• #24 Amnesia after Repeated Head Impact Is Caused by Impaired Synaptic Plasticity in the Memory Engram | Journal of Neuroscience

  https://www.jneurosci.org/content/44/8/e1560232024

  Subconcussive head impacts are associated with the development of acute and chronic cognitive deficits. […] To better understand the mechanisms underlying HFHI-induced memory decline, we used TRAP2/Ai32 transgenic mice to enable visualization and manipulation of memory engrams. […] This lack of plasticity coincided with impaired activation of the engram network, leading to retrograde amnesia in HFHI mice. […] Our work shows that chronic cognitive impairment after HFHI is a result of deficiencies in synaptic plasticity instead of a loss in neuronal infrastructure, and we can reinstate a forgotten memory in the amnestic brain by stimulating the memory engram. […] Targeting synaptic plasticity may have therapeutic potential for treating memory impairments caused by repeated head impacts.

• #25 Amnesia after Repeated Head Impact Is Caused by Impaired Synaptic Plasticity in the Memory Engram | Journal of Neuroscience

  https://www.jneurosci.org/content/44/8/e1560232024

  The memory engram refers to the collection of changes that happen in the brain that hold the substrate for a specific memory. […] We report that HFHI does not alter the number of dentate gyrus neurons in the memory engram, but it does interfere with the ability of memory engram neurons to physiologically distinguish themselves from nonengram dentate gyrus neurons. […] HFHI prevents reactivation of the engram without affecting engram size. […] HFHI does not cause retrograde amnesia by interfering with memory consolidation, as we found that five head impacts delivered 15min after training (which is the same day 1 protocol for HFHI) does not cause a significant reduction in memory recall at 24h post-head impact. […] Rather, there was impaired reactivation of the engram in HFHI mice, as revealed by a reduction in the number of engram cells that were positive for c-Fos protein following presentation of natural recall cues.

• #26 Amnesia after Repeated Head Impact Is Caused by Impaired Synaptic Plasticity in the Memory Engram | Journal of Neuroscience

  https://www.jneurosci.org/content/44/8/e1560232024

  The memory engram refers to the collection of changes that happen in the brain that hold the substrate for a specific memory. […] We report that HFHI does not alter the number of dentate gyrus neurons in the memory engram, but it does interfere with the ability of memory engram neurons to physiologically distinguish themselves from nonengram dentate gyrus neurons. […] HFHI prevents reactivation of the engram without affecting engram size. […] HFHI does not cause retrograde amnesia by interfering with memory consolidation, as we found that five head impacts delivered 15min after training (which is the same day 1 protocol for HFHI) does not cause a significant reduction in memory recall at 24h post-head impact. […] Rather, there was impaired reactivation of the engram in HFHI mice, as revealed by a reduction in the number of engram cells that were positive for c-Fos protein following presentation of natural recall cues.

• #27 Amnesia pathophysiology – wikidoc

  https://www.wikidoc.org/index.php/Amnesia_pathophysiology

  Memory is the stored information in the hippocampal region of the brain. According to Richard Semon (1904), experiences cause some structural and functional changes in the neurons and these changes are referred to as engram and they form memory of that experience. Reactivation of these neurons occur when patient tries to recall those memories. […] Pathogenesis: Dissociative Amnesia Psychological origin. Transient global amnesia Precipitated by brain ischemia, migraine, epileptic seizure, venous congestion, psychological trauma. Post-traumatic Amnesia Amnesia that follows head trauma could be temporary or permanent. Infantile Amnesia Influenced by cultural norms and sexual repression. Drug-Induced Amnesia Benzodiazepine are the most common group of drugs that can cause drug-induced amnesia, especially if used with alcohol. Neurologically Derived Amnesia Brain regions involved are the hippocampus and the medial temporal lobes. Amnesia in Korsakoffs Syndrome Caused by thiamine deficiency due to prolonged alcohol use or severe malnutrition. Deficiency of thiamine damages medial thalamus, mammillary bodies and causes cerebral atrophy due to lack of pyruvate decarboxylation. […] Deficiency of RbAp48 protein encoded by RBBP4 gene have been co-related to memory loss.

• #28 Guideline “Transient Global Amnesia (TGA)” of the German Society of Neurology (Deutsche Gesellschaft für Neurologie): S1-guideline | Neurological Research and Practice | Full Text

  https://neurolrespract.biomedcentral.com/articles/10.1186/s42466-023-00240-0

  Functional and morphometric MRI studies and quantitative EEG analyses have demonstrated changes in functional connectivity in the limbic system and hippocampus. […] Larner developed a neural network model of memory function and suggested, among other things, that loss of fault tolerance of hippocampal neural networks leads to a failure of synaptic transmission in these networks and thus to memory impairment. […] In summary, these findings most likely suggest that TGA is based on a transient dysfunction, particularly of the hippocampus, based on a multifactorial etiology, such that several of the factors described above must interact for TGA to occur.

• #29 9.5: Brain Mechanisms of Memory Disorders – Social Sci LibreTexts

  https://socialsci.libretexts.org/Courses/Sacramento_City_College/Psyc_310%3A_Biological_Psychology_(Keys)/09%3A_Learning_and_Memory/9.05%3A_Brain_Mechanisms_of_Memory_Disorders

  According to this theory, an amnesiac patient like H. M. could remember events from his remote past because those memories were fully consolidated and no longer depended on the hippocampus, but instead had been transferred to other brain areas, primarily to particular areas of the cerebral cortex. […] Korsakoffs syndrome is similar to global amnesic syndrome, except that people with Korsakoffs are more prone to confabulation to cover up gaps in their memories of their own past. […] In Alzheimers disease, beta-amyloid, an insoluble toxic substance, forms clumps known as senile plaques around the neurons. […] The memory circuits that depend on them, especially those in the hippocampus, are thus permanently damaged. […] Certain encephalopathies due to anoxias, ischemias, hypoglycemias, carbon monoxide poisoning, or prolonged epileptic attacks can cause the loss of large numbers of neurons in both hippocampi.

• #30 Anterograde amnesia – Wikipedia

  https://en.wikipedia.org/wiki/Anterograde_amnesia

  In neurology, anterograde amnesia is the inability to create new memories after an event that caused amnesia, leading to a partial or complete inability to recall the recent past, while long-term memories from before the event remain intact. […] To a large degree, anterograde amnesia remains a mysterious ailment because the precise mechanism of storing memories is not yet well understood, although it is known that the regions of the brain involved are certain sites in the temporal cortex, especially in the hippocampus and nearby subcortical regions. […] Patients with anterograde amnesia may have episodic, semantic, or both types of explicit memory impaired for events after the trauma that caused the amnesia. This suggests that memory consolidation for different types of memory takes place in different regions of the brain.

• #31 Anterograde amnesia – Wikipedia

  https://en.wikipedia.org/wiki/Anterograde_amnesia

  The pathophysiology of anterograde amnesic syndromes varies with the extent of damage and the regions of the brain that were damaged. The most well-described regions indicated in this disorder are the medial temporal lobe (MTL), basal forebrain, and fornix. […] Neuropsychologists and scientists are still not in total agreement over whether forgetting is due to faulty encoding, accelerated forgetting, or faulty retrieval, although a great deal of data seem to point to the encoding hypothesis. […] Neuroscientists are in disagreement about the length of time involved in memory consolidation. […] The MTL memory system includes the hippocampal formation (CA fields, dentate gyrus, subicular complex), perirhinal, entorhinal, and parahippocampal cortices. It is known to be important for the storage and processing of declarative memory, which allows for factual recall.

• #32 Anterograde amnesia – Wikipedia

  https://en.wikipedia.org/wiki/Anterograde_amnesia

  An important finding in amnesic patients with MTL damage is the impairment of memory in all sensory modalities sound, touch, smell, taste, and sight. […] The key is the MTL is responsible for the learning of new materials. […] The data does not explain the dichotomy that exists in the MTL memory system between episodic memory and semantic memory. […] Another case described the onset of anterograde amnesia as a result of cell death in the fornix, another structure that carries information from the hippocampus to the structures of the limbic system and the diencephalon.

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• #34 Anterograde amnesia – Wikipedia

  https://en.wikipedia.org/wiki/Anterograde_amnesia

  An important finding in amnesic patients with MTL damage is the impairment of memory in all sensory modalities sound, touch, smell, taste, and sight. […] The key is the MTL is responsible for the learning of new materials. […] The data does not explain the dichotomy that exists in the MTL memory system between episodic memory and semantic memory. […] Another case described the onset of anterograde amnesia as a result of cell death in the fornix, another structure that carries information from the hippocampus to the structures of the limbic system and the diencephalon.

• #35 Amnesia, memory and brain systems.

  https://pmc.ncbi.nlm.nih.gov/articles/PMC1692096/

  Bilateral damage to either the medial temporal lobe or the diencephalic midline causes an amnesic syndrome, i.e. a global impairment in the ability to acquire new memories regardless of sensory modality, and a loss of some memories, especially recent ones, from the period before amnesia began. […] The memory deficit can occur against a background of intact intellectual and perceptual functions. […] Two themes have been prominent in recent work. First, the amnesic syndrome is narrower than once believed in the sense that a number of learning and memory abilities are preserved (e.g. skill and habit learning, simple forms of conditioning and the phenomenon of priming). […] Second, the brain system damaged in amnesia has only a temporary role in memory. […] As time passes after learning, memory is reorganized and consolidated within neocortex, such that eventually medial temporal lobe and diencephalic structures are not needed for storage or retrieval.

• #36

  https://link.springer.com/article/10.3758/s13423-024-02567-4

  This paper reports a reassessment of published literature on the question of whether retrograde amnesia data from patients with severe trauma supports the idea that there is ongoing consolidation of long-lasting memories. […] Our analysis was limited to patients with specific traumas rather than neurodegenerative conditions that can be complicated by the additional presence of significant anterograde amnesia. […] Our results revealed that the standard account of retrograde amnesia only fits part of the data, with more than half not conforming to this account. Specifically, damage to different brain areas was associated with different patterns of retrograde amnesia. […] Future directions to better understand the influence of retrograde amnesia and memory consolidation are suggested. […] Some evidence for long-term consolidation comes from reports of people who have sustained brain damage resulting in severe retrograde amnesia.

• #37

  https://link.springer.com/article/10.3758/s13423-024-02567-4

  This points to the effects of a continued process of consolidation on older memories long after their initial encoding. […] The use of retrograde amnesia as an indicator of long-lasting memory consolidation stems from Ribots (1882) early work on the retention and recovery of information following brain trauma. […] Historical data points towards a specific pattern of disruption and preservation that extends even decades into a person’s past, which implies that memory consolidation processes continue for decades, resulting in the temporal gradient that we often witness in the results of many experiments. […] Browns key finding was a large performance gap between patients and controls for more recent memories and a smaller gap for older memories. […] This was true for various causes of retrograde amnesia.

• #38

  https://link.springer.com/article/10.3758/s13423-024-02567-4

  Thus, the patient data that Brown (2002) included could reflect a combination of anterograde and retrograde amnesia. […] The classic Ribots gradient is more likely to be observed when areas traditionally associated with declarative memory are damaged. […] In comparison, other patterns of memory performance are more strongly associated with damage in other areas. […] These findings suggest that not only can retrograde amnesia result from damage to different brain areas, but also that the specific brain areas damaged can influence the resultant amnesia. […] The involvement of the thalamus in the production of retrograde amnesia is more ambiguous. […] Overall, going forward, these results suggest that further work is needed to understand the mechanisms that can result in retrograde amnesia.

• #39 Forgetting and Amnesia | Noba

  https://nobaproject.com/modules/forgetting-and-amnesia

  Patients with damage to the temporal lobes may experience anterograde amnesia and/or retrograde amnesia. […] The most widely studied amnesic patient was known by his initials H. M. (Scoville Milner, 1957). […] Anterograde amnesia provides evidence for the role of the hippocampus in the formation of long-lasting declarative memories, as damage to the hippocampus results in an inability to create this type of new memory. […] Similarly, temporally graded retrograde amnesia can be seen as providing further evidence for the importance of memory consolidation. […] The classic amnesiac syndrome we have considered here is sometimes referred to as organic amnesia, and it is distinct from functional, or dissociative, amnesia. […] Amnesiac patients allow us a glimpse into what life would be like if we suffered from profound forgetting and perhaps show us that our everyday lapses in memory are not so bad after all.

• #40

• #41 Guideline “Transient Global Amnesia (TGA)” of the German Society of Neurology (Deutsche Gesellschaft für Neurologie): S1-guideline | Neurological Research and Practice | Full Text

  https://neurolrespract.biomedcentral.com/articles/10.1186/s42466-023-00240-0

  Transient global amnesia (TGA) is characterized by a sudden onset of retrograde and anterograde amnesia for a period of one to a maximum of 24 h (with an average of 6 to 8 h). […] The cause of TGA is still unknown. Numerous findings in recent years point to a multifactorial genesis. Because the pathomechanism of TGA is not yet clearly known, no evidence-based therapeutic or prophylactic recommendations can be made. […] The cause of TGA is still unknown, but numerous findings in recent years point to a multifactorial genesis. […] Based on the clinical picture, as a common pathophysiological correlate a dysfunction of mediobasal temporal lobe components including both hippocampi is assumed, as these structures are involved in both memory consolidation and retrieval. […] TGA patients with and without DWI lesions do not differ in terms of clinical symptoms and cognitive functions over the long term.

• #42 Transient global amnesia – Symptoms & causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/transient-global-amnesia/symptoms-causes/syc-20378531

  Transient global amnesia is an episode of confusion that comes on suddenly in a person who is otherwise alert. […] During an episode of transient global amnesia, a person is unable to create new memory, so the memory of recent events disappears. […] The underlying cause of transient global amnesia is unknown. […] Another possible cause is the overfilling of veins with blood due to some sort of blockage or other problem with the flow of blood (venous congestion). […] The clearest risk factors are: Age. People age 50 and older have a higher risk of transient global amnesia than do younger people. […] If you have migraines, your risk of transient global amnesia is significantly higher than that of someone without migraines. […] Transient global amnesia has no direct complications. […] It’s possible to have a second episode of transient global amnesia, but it’s extremely rare to have more than two.

• #43 Transient Global Amnesia: Background, Pathophysiology, Epidemiology

  https://emedicine.medscape.com/article/1160964-overview

  Transient global amnesia (TGA) has been a well-described phenomenon for more than 40 years. Clinically, it manifests with a paroxysmal, transient loss of memory function. Immediate recall ability is preserved, as is remote memory; however, patients experience striking loss of memory for recent events and an impaired ability to retain new information. In some cases, the degree of retrograde memory loss is mild. […] The precise pathophysiology of transient global amnesia is not clear. The findings reported with positron emission tomography (PET), diffusion-weighted MRI (DWI), single photon emission computed tomography (SPECT) and MR spectroscopy (MRS) have indicated various brain regions that are affected in TGA. […] On PET and DWI, blood flow to specific brain areas that involve memory appears to be disrupted transiently during TGA. This includes the thalamus and/or mesial temporal structures (in particular the amygdala and hippocampus). […] Overall, the variety of findings on functional imaging studies may support the notion that TGA is a syndrome with not only a variety of precipitating causes but also of differing mechanisms.

• #44 Transient global amnesia – UpToDate

  https://www.uptodate.com/contents/transient-global-amnesia

  Transient global amnesia (TGA) is a clinical syndrome characterized by the acute onset of anterograde amnesia (the inability to form new memories). […] A single, definite etiology has not been determined, although epidemiologic and imaging data support several putative pathophysiologic processes, including vascular, migraine, epileptic, and psychogenic mechanisms.

• #45 :: DND :: Dementia and Neurocognitive Disorders

  https://dnd.or.kr/DOIx.php?id=10.12779/dnd.2014.13.2.46

  However, this has been reported in many studies that mild cognitive decline could be prolonged for certain times after the TGA events. […] The transient dysfunction of the hippocampus, especially Cornus Ammnonis 1 (CA 1) sector is known as the main mechanism. […] Cerebrovascular events are one of the most powerful one because of its abrupt onset and anatomical lesion. […] Most of imaging data revealed an involvement of memory circuits in TGA, which present high signal intensity at DWI correlating to restricted apparent diffusion coefficient. […] In the circuit, many reports points out the CA 1 sector as a critical lesion of TGA. […] Furthermore, Clinical and experimental data show that neurons of CA 1 sector are selectively vulnerable to hypoxemia and ischemia which cause glutmate- and calcium-induced neuronal death of affected neurons.

• #46 Transient Global Amnesia: Background, Pathophysiology, Epidemiology

  https://emedicine.medscape.com/article/1160964-overview

  Transient global amnesia (TGA) has been a well-described phenomenon for more than 40 years. Clinically, it manifests with a paroxysmal, transient loss of memory function. Immediate recall ability is preserved, as is remote memory; however, patients experience striking loss of memory for recent events and an impaired ability to retain new information. In some cases, the degree of retrograde memory loss is mild. […] The precise pathophysiology of transient global amnesia is not clear. The findings reported with positron emission tomography (PET), diffusion-weighted MRI (DWI), single photon emission computed tomography (SPECT) and MR spectroscopy (MRS) have indicated various brain regions that are affected in TGA. […] On PET and DWI, blood flow to specific brain areas that involve memory appears to be disrupted transiently during TGA. This includes the thalamus and/or mesial temporal structures (in particular the amygdala and hippocampus). […] Overall, the variety of findings on functional imaging studies may support the notion that TGA is a syndrome with not only a variety of precipitating causes but also of differing mechanisms.

• #47 Dissociative amnesia: Epidemiology, pathogenesis, clinical manifestations, course, and diagnosis – UpToDate

  https://www.uptodate.com/contents/dissociative-amnesia-epidemiology-pathogenesis-clinical-manifestations-course-and-diagnosis/print

  Dissociative amnesia is a potentially reversible memory impairment that primarily affects autobiographical memory. In dissociative amnesia, the patient cannot recall important autobiographical information, usually of a traumatic or stressful nature, although more extensive memory loss may be reported. […] Dissociative fugue, a subtype of dissociative amnesia in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR), is characterized by sudden unexpected travel or wandering in a dissociated state, with subsequent dissociative amnesia for the fugue episode, and often for some or all of the patient’s life history.

• #48 How Dissociative Amnesia Affects Daily Life and Ways You Can Help – BrightQuest Treatment Centers

  https://www.brightquest.com/blog/how-dissociative-amnesia-affects-daily-life-and-ways-you-can-help/

  Dissociative amnesia is a response to trauma. About one percent of men and 2.5 percent of women experience this forgetting of memories or identity in their lifetimes. […] The underlying cause of dissociative amnesia is a very stressful event or traumatic experience. Amnesia is an involuntary coping mechanism. The brain reacts to trauma by erasing certain memories for a period of time. Not everyone who experiences trauma will go through this, and why some people do is not well understood. […] The common term amnesia, a loss of memories, specific events, or aspects of one’s identity, is more correctly called dissociative amnesia. It is one of a few conditions categorized as dissociative disorders, mental illnesses that cause you to lose touch with reality in some way. In the case of amnesia, you lose touch by forgetting events, people, or identity and personal history.

• #49 Dissociative Amnesia | Charlie Health

  https://www.charliehealth.com/post/dissociative-amnesia-2

  Significant memory loss linked to trauma may be dissociative amnesia, a kind of dissociative disorder. […] One such condition is known as dissociative amnesia, a kind of significant memory loss that happens as an after-effect of a traumatic or stressful event. […] At its core, dissociative amnesia is a form of dissociative disorder, a category of mental health conditions that involve experiencing a loss of connection between thoughts, memories, feelings, surroundings, behavior, and identity. […] Dissociative amnesia, along with other dissociative disorder symptoms, is caused by profound psychological distress (usually in response to past trauma) rather than structural damage to the brain or excessive substance use. […] The stress response triggered by trauma can impact the hippocampus, an important part of the brain for forming and recalling memories, affecting its ability to accurately store and remember memories.

• #50 Kevin William Grant—Registered Psychotherapist – When Memories Vanish: The Phenomenon of Dissociative Amnesia

  https://www.kevinwgrant.com/blog/item/phenomenon-of-dissociative-amnesia

  Dissociative Amnesia is a complex psychological condition primarily characterized by the inability to recall crucial autobiographical information, most often of a traumatic or stressful nature (American Psychiatric Association [APA], 2013). Such memory loss is more extensive than ordinary forgetfulness and is inconsistent with any known neurological or medical conditions (Staniloiu Markowitsch, 2014). […] While the mechanism remains a topic of study, some research suggests that amnesia may act as a defense mechanism, offering temporary relief from distressing memories, leading to emotional numbness or reduced responsiveness to the external environment (Dorahy et al., 2014). […] One of the prominent theories is that neurobiological alterations in the hippocampus and amygdala, brain regions implicated in memory and emotional processing, are observed in individuals with DA (Vermetten et al., 2006). These changes might reflect the brain’s attempt to modulate traumatic memories.

• #51 Kevin William Grant—Registered Psychotherapist – When Memories Vanish: The Phenomenon of Dissociative Amnesia

  https://www.kevinwgrant.com/blog/item/phenomenon-of-dissociative-amnesia

  Dissociative Amnesia is a complex psychological condition primarily characterized by the inability to recall crucial autobiographical information, most often of a traumatic or stressful nature (American Psychiatric Association [APA], 2013). Such memory loss is more extensive than ordinary forgetfulness and is inconsistent with any known neurological or medical conditions (Staniloiu Markowitsch, 2014). […] While the mechanism remains a topic of study, some research suggests that amnesia may act as a defense mechanism, offering temporary relief from distressing memories, leading to emotional numbness or reduced responsiveness to the external environment (Dorahy et al., 2014). […] One of the prominent theories is that neurobiological alterations in the hippocampus and amygdala, brain regions implicated in memory and emotional processing, are observed in individuals with DA (Vermetten et al., 2006). These changes might reflect the brain’s attempt to modulate traumatic memories.

• #52 Kevin William Grant—Registered Psychotherapist – When Memories Vanish: The Phenomenon of Dissociative Amnesia

  https://www.kevinwgrant.com/blog/item/phenomenon-of-dissociative-amnesia

  The etiology of Dissociative Amnesia (DA) is a combination of psychological, environmental, and neurobiological factors contributing to its onset. A prominent theory postulates that DA is a psychological response to traumatic or intensely stressful events (Brand, Vissia, Chalavi, Nijenhuis, Webermann, Draijer, Reinders, 2016). […] Neurobiological factors involved in memory processing and emotional regulation, primarily the hippocampus and amygdala, have been implicated in DA. Changes in these areas might reflect the brain’s attempt to modulate traumatic memories, potentially leading to amnesia (Vermetten et al., 2006). […] Recent research on Dissociative Amnesia (DA) has delved into various aspects, from neurobiological underpinnings to treatment approaches. In neurobiology, studies have highlighted changes in the brain’s memory and emotional centers in individuals with DA. For instance, alterations in the structure and functioning of the hippocampus and amygdala have been observed in individuals with dissociative disorders, suggesting a potential neural basis for memory disruptions (Vermetten et al., 2016).

• #53 The neurocognitive mechanisms underlying dissociative amnesia

  https://www.repository.cam.ac.uk/items/76dd0e18-06ff-48f1-a964-7cb96d889734

  Dissociative amnesia refers to the loss of autobiographical memory with a presumed psychological cause. This can involve memory loss for traumatic experiences, such as in PTSD. It can also involve more extensive amnesia for several years, or, in its most extreme form, a fugue state involving total loss of memory and sense of identity. […] These latter, generalised forms of dissociative amnesia are rare, and the mechanisms underlying the memory loss are poorly understood. It has been theorised that the amnesia results from a prefrontally-mediated inhibition of memory systems, which is presumed to occur sub or semi-consciously (Kopelman, 2000, 2002). A parallel body of experimental work has defined a prefrontally-mediated memory control’ network, which can be engaged to inhibit memory retrieval voluntarily. These findings offer a candidate neurobiological mechanism for the inhibition of retrieval in dissociative amnesia, and provide a set of specific, testable predictions regarding the putative role of this mechanism in the memory loss.

• #54 Amnesia: What It Is, Causes, Symptoms, Treatment & Types

  https://my.clevelandclinic.org/health/diseases/21455-amnesia

  Amnesia is when you have significant memory loss. There are many possible causes of it. Sometimes its a symptom of other conditions, but it can also happen on its own. It can involve past memories, or you can have trouble making and storing new memories. Treating the underlying cause may reverse it, but some causes are permanent. […] Amnesia can happen for many reasons. The causes fall broadly into two main categories: neurological causes and psychological causes. […] Neurological causes of amnesia all involve damage to your brain or disruptions in brain activity. The possible causes include (but arent limited to) the following: Alcohol intoxication (this can temporarily block the formation of new memories, causing a blackout). Alzheimers disease. Brain aneurysms. Brain tumors (including cancerous and noncancerous growths). Cerebral hypoxia (brain damage from lack of oxygen). Drugs and medications (especially certain sedatives and anesthesia medications), including nonmedical drug use. Epilepsy and seizures (especially temporal lobe epilepsy). Frontotemporal dementia. Head injuries like concussions or traumatic brain injuries (TBIs). Infections (especially ones that cause encephalitis like herpes simplex virus). Other degenerative brain diseases, like Parkinsons disease or multiple sclerosis (MS). Stroke. Toxins and poisons like carbon monoxide poisoning or heavy metal poisoning. Transient global amnesia. Wernicke-Korsakoff syndrome (this is a severe vitamin B1 deficiency that happens with long-term alcohol use disorder).

• #55 Amnesia: What It Is, Causes, Symptoms, Treatment & Types

  https://my.clevelandclinic.org/health/diseases/21455-amnesia

  Amnesia is when you have significant memory loss. There are many possible causes of it. Sometimes its a symptom of other conditions, but it can also happen on its own. It can involve past memories, or you can have trouble making and storing new memories. Treating the underlying cause may reverse it, but some causes are permanent. […] Amnesia can happen for many reasons. The causes fall broadly into two main categories: neurological causes and psychological causes. […] Neurological causes of amnesia all involve damage to your brain or disruptions in brain activity. The possible causes include (but arent limited to) the following: Alcohol intoxication (this can temporarily block the formation of new memories, causing a blackout). Alzheimers disease. Brain aneurysms. Brain tumors (including cancerous and noncancerous growths). Cerebral hypoxia (brain damage from lack of oxygen). Drugs and medications (especially certain sedatives and anesthesia medications), including nonmedical drug use. Epilepsy and seizures (especially temporal lobe epilepsy). Frontotemporal dementia. Head injuries like concussions or traumatic brain injuries (TBIs). Infections (especially ones that cause encephalitis like herpes simplex virus). Other degenerative brain diseases, like Parkinsons disease or multiple sclerosis (MS). Stroke. Toxins and poisons like carbon monoxide poisoning or heavy metal poisoning. Transient global amnesia. Wernicke-Korsakoff syndrome (this is a severe vitamin B1 deficiency that happens with long-term alcohol use disorder).

• #56 Amnesia – Symptoms and causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/amnesia/symptoms-causes/syc-20353360

  Amnesia can be caused by damage to areas of the brain that are vital for memory processing. […] Amnesia can result from damage to brain structures that form the limbic system, which controls emotions and memories. […] Amnesia caused by brain injury or damage is known as neurological amnesia. […] Possible causes of neurological amnesia include: Stroke. […] Brain inflammation, which may be due to an infection with a virus such as herpes simplex virus. […] Long-term alcohol misuse that leads to too little vitamin B-1, known as thiamin, in the body. […] Alzheimer’s disease and other diseases that involve the degeneration of nerve tissue. […] Head injuries that cause a concussion, whether from a car accident or sports, can lead to confusion and problems remembering new information. […] Another rare type of amnesia, called dissociative amnesia, stems from emotional shock or trauma.

• #57 What is Amnesia? Understanding Memory Loss

  https://lonestarneurology.net/blog/what-is-amnesia/

  Because the hippocampus is especially sensitive to hypoxia and ischemia, its damage is observed in violation of blood circulation, suffocation, and carbon monoxide intoxication. With a gradually increasing memory loss, it can arise from a tumor, mental illness, degenerative changes in the brain. […] Anterograde amnesia is caused by trauma or previous illness. The patient cannot reconstruct recent events and display their sequence but accurately and distinctly remember past events. […] The causes of the disease can be craniocerebral trauma, surgical interventions. Moreover, to physical impact, mental disorders (dementia, mental retardation, epilepsy) and psychogenic factors (stress, psychological trauma) can lead to illness. […] The first stage of treatment for loss of memory is carried out in a hospital. It is required to eliminate the symptoms of the underlying disease that led to a loss of memory. Nootropics, drugs to improve cholinergic conduction, are prescribed. Neuropsychological correction is being carried out. In some cases, the brain is exposed to a low-intensity current. With atrophic and degenerative changes in the brain, memory damage can be irreversible.

• #58 Amnesia: What It Is, Causes, Symptoms, Treatment & Types

  https://my.clevelandclinic.org/health/diseases/21455-amnesia

  Memory loss can also happen in connection with mental health issues. Examples include dissociative disorders, especially dissociative amnesia, and post-traumatic stress disorder (especially complex PTSD). These cases usually involve a traumatic event, or severe mental or emotional distress. Experts dont fully understand why it happens, but they suspect its your brains way of trying to limit or protect you from psychological harm. […] Theres no direct treatment or medication that can cure amnesia. When it happens because of a treatable condition, treating that condition is the best way to reverse it. Because many conditions can cause amnesia, the treatments can vary widely, too. Many times, your brain can recover on its own, and youll regain your memory as it does.

• #59 Dissociative Amnesia: What It Is, Symptoms & Treatment

  https://my.clevelandclinic.org/health/diseases/9789-dissociative-amnesia

  Dissociative amnesia is when dissociation causes memory loss (amnesia). […] Dissociative amnesia often happens because of very traumatic experiences, including abuse, war and natural disasters. […] To understand dissociative amnesia, it helps to know a little bit about how memory works. […] There are two main ways that dissociative amnesia can work: Retrograde and Anterograde. […] Dissociative amnesia can happen in connection with one-time, isolated events or long-term stress or trauma. […] Experts think that multiple factors can increase the risk of developing dissociative amnesia. […] The severity of dissociative amnesia often corresponds to the severity of the underlying cause(s) or contributing factor(s). […] The more severe the trauma that causes the amnesia, the more severe the amnesia and its effects will be.

• #60 Trauma & Memory Loss Explained | Harbor Psychiatry & Mental Health

  https://harbormentalhealth.com/2023/02/17/does-trauma-cause-memory-loss/

  Traumatic experiences can have a profound effect on memory function, often leading to memory loss as a coping mechanism. […] This impairment can stem from physical or emotional trauma, with memory loss serving as the brains way of processing and managing the experience. […] Research underscores the connection between emotional, psychological, or physical trauma and memory disturbances. […] While some memory loss may be temporary and aid in coping with trauma, severe brain injury or distressing psychological trauma can lead to permanent memory loss. […] Following a traumatic event, these memories may remain inaccessible until the individual confronts the trauma again. […] In essence, memory loss can act as a defense mechanism to shield individuals from recalling and reliving traumatic experiences.

• #61 Trauma & Memory Loss Explained | Harbor Psychiatry & Mental Health

  https://harbormentalhealth.com/2023/02/17/does-trauma-cause-memory-loss/

  Individuals with PTSD may encounter dissociative amnesia, leading to memory loss related to their trauma. […] Dissociative amnesia occurs independently of brain injury or cognitive decline, typically triggered by severe stressors such as accidents, warfare, abuse, or natural disasters. […] Direct physical trauma or medical conditions, like strokes, can directly impact memory function, particularly if they affect brain regions crucial for memory processing. […] Traumatic brain injuries (TBI) can result in short-term memory decline, challenges in remembering tasks, or memory loss regarding the injury incident. […] Psychological and emotional trauma can trigger memory loss as a protective mechanism against reliving distressing emotions associated with trauma. […] Chronic exposure to traumatic situations, such as abuse or domestic violence, can lead to emotional memory suppression as a survival strategy.

• #62 What is Amnesia? Understanding Memory Loss

  https://lonestarneurology.net/blog/what-is-amnesia/

  Amnesia is a disorder of a persons memory, manifested in the form of a pathological loss of memories of the circumstances of life. Amnestic syndrome remains a common complication of neurological diseases, mental disorders, chronic intoxication, or acute poisoning. […] The main clinical manifestation is the loss of a persons memories of significant events in the past or the circumstances of recent actions. Amnestic syndrome remains a common manifestation of neurological and psychiatric disorders. […] Experts say that one of the reasons for loss of memory is the presence of mental and neurological diseases. It is in these patients that memory problems are quite often observed. Among the pathologies that can provoke the onset of amnesia, one can distinguish epilepsy, dissociative disorder or multiple personality disorder, hysteria, schizophrenia, and Alzheimers disease.

• #63 Trauma & Memory Loss Explained | Harbor Psychiatry & Mental Health

  https://harbormentalhealth.com/2023/02/17/does-trauma-cause-memory-loss/

  Individuals with PTSD may encounter dissociative amnesia, leading to memory loss related to their trauma. […] Dissociative amnesia occurs independently of brain injury or cognitive decline, typically triggered by severe stressors such as accidents, warfare, abuse, or natural disasters. […] Direct physical trauma or medical conditions, like strokes, can directly impact memory function, particularly if they affect brain regions crucial for memory processing. […] Traumatic brain injuries (TBI) can result in short-term memory decline, challenges in remembering tasks, or memory loss regarding the injury incident. […] Psychological and emotional trauma can trigger memory loss as a protective mechanism against reliving distressing emotions associated with trauma. […] Chronic exposure to traumatic situations, such as abuse or domestic violence, can lead to emotional memory suppression as a survival strategy.

• #64 Amnesia for Violent Offenses: Factors Underlying Memory Loss and Recovery | Journal of the American Academy of Psychiatry and the Law

  https://jaapl.org/content/42/2/202

  The most important factor associated with amnesia was peritraumatic dissociation (PTD), preceding and following the time of the offense. This result was indicated by dissociative symptoms such as depersonalization, derealization, and identity disturbance around the time of the violent act. […] A second important factor associated with amnesia was its occurrence in the context of a crime of passion. This finding is consistent with observations in previous (less systematic) studies. By definition, such crimes are generally associated with intense emotional arousal. It is likely that this degree of emotion makes the offender vulnerable to amnesia because either the intense emotional arousal results in a complete or partial failure in encoding, or the traumatic memories are stored as isolated fragments of sensory perceptions and affective states, rather than as a clear and distinct declarative memory.

• #65 The Amnesia Gene | Scientific American

  https://www.scientificamerican.com/article/the-amnesia-gene/

  Human memory is highly influenced by emotion. […] In some individuals, extremely stressful or traumatic events can induce amnesia, so that they lose the ability to remember what happened. […] Amnesia induced by negative emotions is considered a psychological defense mechanism that protects the organism from the consequences of extreme trauma and catastrophic fear. […] Understanding how negative emotions induce amnesia, and why only some people who are exposed to traumatic events develop emotion induced amnesia, may have clinical and preventive implications. […] The data suggest that the contribution of 5-HTTLPR to disturbances in emotional memory may be specific to emotion-induced retrograde amnesia, which occurs when subjects are unable to remember what happened before the traumatic event.

• #66 The Amnesia Gene | Scientific American

  https://www.scientificamerican.com/article/the-amnesia-gene/

  The hyperactive amygdala in these individuals may, at least in part, explain why they are more susceptible to emotion-induced memory loss. […] This paper showing a link between 5-HTTLPR short variant genotype and emotion induced memory loss marks an important advancement in understanding the genetic basis of stress induced psychiatric disorders and sets the stage for personalized mental health care based on risk factors for mental illness.

• #67 How Dissociative Amnesia Affects Daily Life and Ways You Can Help – BrightQuest Treatment Centers

  https://www.brightquest.com/blog/how-dissociative-amnesia-affects-daily-life-and-ways-you-can-help/

  Dissociative amnesia is any significant loss of identity or memories that is not consistent with normal forgetting. We all forget some details of our past, but amnesia is more serious. It can persist for months or years, or memories may be recovered within hours or days. […] There are different types of amnesia based on the type of forgetting. Localized amnesia is the loss of memories associated with a specific period of time or event. Selective amnesia is when a person forgets something specific, like one person or their own identity. Generalized amnesia occurs when someone forgets everything about their past and identity. This is very rare. […] Dissociative amnesia is a serious mental health issue. Having family and friends to provide support during the journey to recovered memories is so important for overall wellness and healing from trauma.

• #68 Amnestic disorders. Pathophysiology and patterns of memory dysfunction.

  https://pmc.ncbi.nlm.nih.gov/articles/PMC1002292/

  A wide variety of conditions seen in medical practice can produce memory impairment (amnesia). […] Systemic illnesses can impair memory by injuring vulnerable limbic regions sensitive to hypoxia or hypoglycemia. […] Recent studies suggest that immediate, recent, and remote memory functions have different neuroanatomic substrates, as do the processes of registration, retention, and retrieval. […] The neuropharmacology of memory now includes several peptides in addition to cholinergic and noradrenergic pathways. […] Critical limbic regions have been discovered that mediate memory consolidation, and neuronal mechanisms such as long-term potentiation are being implicated in the unique capacity of these areas to permit new learning to take place.

• #69 Amnestic disorders. Pathophysiology and patterns of memory dysfunction.

  https://pmc.ncbi.nlm.nih.gov/articles/PMC1002292/

  A wide variety of conditions seen in medical practice can produce memory impairment (amnesia). […] Systemic illnesses can impair memory by injuring vulnerable limbic regions sensitive to hypoxia or hypoglycemia. […] Recent studies suggest that immediate, recent, and remote memory functions have different neuroanatomic substrates, as do the processes of registration, retention, and retrieval. […] The neuropharmacology of memory now includes several peptides in addition to cholinergic and noradrenergic pathways. […] Critical limbic regions have been discovered that mediate memory consolidation, and neuronal mechanisms such as long-term potentiation are being implicated in the unique capacity of these areas to permit new learning to take place.

• #70 Amnestic disorders. Pathophysiology and patterns of memory dysfunction.

  https://pmc.ncbi.nlm.nih.gov/articles/PMC1002292/

  A wide variety of conditions seen in medical practice can produce memory impairment (amnesia). […] Systemic illnesses can impair memory by injuring vulnerable limbic regions sensitive to hypoxia or hypoglycemia. […] Recent studies suggest that immediate, recent, and remote memory functions have different neuroanatomic substrates, as do the processes of registration, retention, and retrieval. […] The neuropharmacology of memory now includes several peptides in addition to cholinergic and noradrenergic pathways. […] Critical limbic regions have been discovered that mediate memory consolidation, and neuronal mechanisms such as long-term potentiation are being implicated in the unique capacity of these areas to permit new learning to take place.

• #71 Amnesia – Wikipedia

  https://en.wikipedia.org/wiki/Amnesia

  Amnesia is a deficit in memory caused by brain damage or brain diseases, but it can also be temporarily caused by the use of various sedative and hypnotic drugs. The memory can be either wholly or partially lost due to the extent of damage that is caused. […] Case studies also show that amnesia is typically associated with damage to the medial temporal lobe. In addition, specific areas of the hippocampus (the CA1 region) are involved with memory. Research has also shown that when areas of the diencephalon are damaged, amnesia can occur. Recent studies have shown a correlation between deficiency of RbAp48 protein and memory loss. […] Individuals with amnesia also retain substantial intellectual, linguistic, and social skills despite profound impairments in the ability to recall specific information encountered in prior learning episodes.

• #72 Amnesia pathophysiology – wikidoc

  https://www.wikidoc.org/index.php/Amnesia_pathophysiology

  Memory is the stored information in the hippocampal region of the brain. According to Richard Semon (1904), experiences cause some structural and functional changes in the neurons and these changes are referred to as engram and they form memory of that experience. Reactivation of these neurons occur when patient tries to recall those memories. […] Pathogenesis: Dissociative Amnesia Psychological origin. Transient global amnesia Precipitated by brain ischemia, migraine, epileptic seizure, venous congestion, psychological trauma. Post-traumatic Amnesia Amnesia that follows head trauma could be temporary or permanent. Infantile Amnesia Influenced by cultural norms and sexual repression. Drug-Induced Amnesia Benzodiazepine are the most common group of drugs that can cause drug-induced amnesia, especially if used with alcohol. Neurologically Derived Amnesia Brain regions involved are the hippocampus and the medial temporal lobes. Amnesia in Korsakoffs Syndrome Caused by thiamine deficiency due to prolonged alcohol use or severe malnutrition. Deficiency of thiamine damages medial thalamus, mammillary bodies and causes cerebral atrophy due to lack of pyruvate decarboxylation. […] Deficiency of RbAp48 protein encoded by RBBP4 gene have been co-related to memory loss.

• #73 Amnestic disorders. Pathophysiology and patterns of memory dysfunction.

  https://pmc.ncbi.nlm.nih.gov/articles/PMC1002292/

  A wide variety of conditions seen in medical practice can produce memory impairment (amnesia). […] Systemic illnesses can impair memory by injuring vulnerable limbic regions sensitive to hypoxia or hypoglycemia. […] Recent studies suggest that immediate, recent, and remote memory functions have different neuroanatomic substrates, as do the processes of registration, retention, and retrieval. […] The neuropharmacology of memory now includes several peptides in addition to cholinergic and noradrenergic pathways. […] Critical limbic regions have been discovered that mediate memory consolidation, and neuronal mechanisms such as long-term potentiation are being implicated in the unique capacity of these areas to permit new learning to take place.

• #74 Amnesia after Repeated Head Impact Is Caused by Impaired Synaptic Plasticity in the Memory Engram | Journal of Neuroscience

  https://www.jneurosci.org/content/44/8/e1560232024

  The memory engram refers to the collection of changes that happen in the brain that hold the substrate for a specific memory. […] We report that HFHI does not alter the number of dentate gyrus neurons in the memory engram, but it does interfere with the ability of memory engram neurons to physiologically distinguish themselves from nonengram dentate gyrus neurons. […] HFHI prevents reactivation of the engram without affecting engram size. […] HFHI does not cause retrograde amnesia by interfering with memory consolidation, as we found that five head impacts delivered 15min after training (which is the same day 1 protocol for HFHI) does not cause a significant reduction in memory recall at 24h post-head impact. […] Rather, there was impaired reactivation of the engram in HFHI mice, as revealed by a reduction in the number of engram cells that were positive for c-Fos protein following presentation of natural recall cues.

• #75 Amnesia Vs Dementia (Differences & Similarities In Memory Loss)

  https://optoceutics.com/amnesia-vs-dementia-memory-loss-differences/?srsltid=AfmBOor3NRfyloQJIMeToImeRRKNOWBvzCXzAbfjQeHszrcCMt_bc1u0

  As for amnesia, it frequently results from an infection, illness, or head injury and is a sudden loss of memory. […] The causes of Alzheimer’s Disease are still unknown, but it is linked to a mixture of genetic, lifestyle, and environmental factors. […] However, some research has pointed out that it may be due to the buildup of beta-amyloid plaques and tau tangles that are discovered in the brain. […] As for amnesia, it is believed to be caused by infections such as meningitis or encephalitis, head injury, stroke, neurodegenerative disease, reactions to medication and substances, sleep deprivation, and even vitamin and nutritional deficiencies.

• #76 9.5: Brain Mechanisms of Memory Disorders – Social Sci LibreTexts

  https://socialsci.libretexts.org/Courses/Sacramento_City_College/Psyc_310%3A_Biological_Psychology_(Keys)/09%3A_Learning_and_Memory/9.05%3A_Brain_Mechanisms_of_Memory_Disorders

  According to this theory, an amnesiac patient like H. M. could remember events from his remote past because those memories were fully consolidated and no longer depended on the hippocampus, but instead had been transferred to other brain areas, primarily to particular areas of the cerebral cortex. […] Korsakoffs syndrome is similar to global amnesic syndrome, except that people with Korsakoffs are more prone to confabulation to cover up gaps in their memories of their own past. […] In Alzheimers disease, beta-amyloid, an insoluble toxic substance, forms clumps known as senile plaques around the neurons. […] The memory circuits that depend on them, especially those in the hippocampus, are thus permanently damaged. […] Certain encephalopathies due to anoxias, ischemias, hypoglycemias, carbon monoxide poisoning, or prolonged epileptic attacks can cause the loss of large numbers of neurons in both hippocampi.

• #77 Amnesia – Wikipedia

  https://en.wikipedia.org/wiki/Amnesia

  Many forms of amnesia fix themselves without being treated. However, there are a few ways to cope with memory loss if treatment is needed. Since there are a variety of causes that form different amnesia, there are different methods that response better with the certain type of amnesia. Emotional support and love as well as medication and psychological therapy have been proven effective. […] Although improvements occur when patients receive certain treatments, there is still no actual cure remedy for amnesia so far. To what extent the patient recovers and how long the amnesia will continue depends on the type and severity of the lesion.

• #78 Amnesia for Violent Offenses: Factors Underlying Memory Loss and Recovery | Journal of the American Academy of Psychiatry and the Law

  https://jaapl.org/content/42/2/202

  The present investigation also found that the experience of shame did not occur more commonly in amnesic than nonamnesic offenders, despite suggestions that amnesic offenders may experience higher levels of shame related to an inability to disclose or consciously confront their actions. […] The length of the memory gap in the amnesic offenders, according to their self-reports, varied from only a few seconds in many of them to 10 hours or more; the median was 15 minutes. Offenders with longer amnesic gaps had significantly higher peritraumatic dissociation scores for the period of the offense. […] In our previous investigation, we found that amnesia was reported by 29 percent of life-sentence inmates. In reports prepared for the Parole Board at three years after conviction, 33 percent of the sample were described as having experienced complete return of memory, 26 percent a partial return, and 41 percent no change. In the present study, we interviewed a subsample of 31 amnesic offenders, finding that 16 (52%) had some recovery of memory. Of these, 6 (37.5%) experienced complete return of memory, and 10 (62.5%) a partial return. […] It seems plausible that this brief amnesic gap results from a common underlying mechanism, reflecting the extreme emotional arousal during the offense and possibly a brief period of impaired or absent encoding, as in crimes of passion.

• #79 Amnesia: Types, causes, symptoms, diagnosis, and treatment

  https://www.medicalnewstoday.com/articles/9673

  Wernicke-Korsakoff syndrome, a condition caused by extended alcohol misuse or thiamin (vitamin B1) deficiency, can lead to progressive memory loss that worsens over time. […] Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM5) lists amnesia as a type of dissociative disorder. […] Psychological stressors are more likely to disrupt personal, historical memories rather than interfere with forming new memories. […] In many cases, amnesia resolves without treatment. […] However, if an underlying physical or mental disorder is present, treatment for that condition may be necessary. […] There are currently no drugs available for restoring memory lost due to amnesia. However, there are treatments for the underlying causes. […] Amnesia often resolves on its own without treatment. […] A person should speak with a doctor to determine the reason for their memory loss.

• #80 Amnesia – Wikipedia

  https://en.wikipedia.org/wiki/Amnesia

  Many forms of amnesia fix themselves without being treated. However, there are a few ways to cope with memory loss if treatment is needed. Since there are a variety of causes that form different amnesia, there are different methods that response better with the certain type of amnesia. Emotional support and love as well as medication and psychological therapy have been proven effective. […] Although improvements occur when patients receive certain treatments, there is still no actual cure remedy for amnesia so far. To what extent the patient recovers and how long the amnesia will continue depends on the type and severity of the lesion.

• #81 Amnesias – Neurologic Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/neurologic-disorders/function-and-dysfunction-of-the-cerebral-lobes/amnesias

  Clinical findings usually suggest causes and any necessary tests. […] Treatment directed at the cause. Any underlying disorder or psychologic cause of amnesia must be treated. […] Certain disorders that cause amnesia (eg, Alzheimer disease, Korsakoff psychosis, herpes encephalitis) can be treated; however, treatment of the underlying disorder may or may not lessen the amnesia. […] Amnesias have various causes, including traumatic brain injury, degenerative dementias, metabolic disorders, seizures, and psychologic trauma or stress.

• #82 Amnesia after Repeated Head Impact Is Caused by Impaired Synaptic Plasticity in the Memory Engram | Journal of Neuroscience

  https://www.jneurosci.org/content/44/8/e1560232024

  Subconcussive head impacts are associated with the development of acute and chronic cognitive deficits. […] To better understand the mechanisms underlying HFHI-induced memory decline, we used TRAP2/Ai32 transgenic mice to enable visualization and manipulation of memory engrams. […] This lack of plasticity coincided with impaired activation of the engram network, leading to retrograde amnesia in HFHI mice. […] Our work shows that chronic cognitive impairment after HFHI is a result of deficiencies in synaptic plasticity instead of a loss in neuronal infrastructure, and we can reinstate a forgotten memory in the amnestic brain by stimulating the memory engram. […] Targeting synaptic plasticity may have therapeutic potential for treating memory impairments caused by repeated head impacts.

• #83 Amnesia after Repeated Head Impact Is Caused by Impaired Synaptic Plasticity in the Memory Engram | Journal of Neuroscience

  https://www.jneurosci.org/content/44/8/e1560232024

  It is this inability of the HFHI engram neurons to differentiate themselves from the surrounding nonengram neurons that impairs reactivation when stimulated with natural cues. […] Our study tells us several things about head impact-induced amnesia. […] Interventions targeting synaptic plasticity may have therapeutic potential for treating memory impairments caused by repeated head impact exposure.

• #84 Dissociative Amnesia | Charlie Health

  https://www.charliehealth.com/post/dissociative-amnesia-2

  The amount of memory loss that someone experiences with dissociative amnesia varies. […] Dissociative amnesia is a response to trauma, research shows it often co-occurs with other trauma-related mental health conditions, such as post-traumatic stress disorder (PTSD), and personality disorders. […] If you are experiencing memory loss that is creating difficulties in your daily life, it is important that you reach out to a medical professional who can conduct a thorough assessment and provide an accurate diagnosis. […] If you’re diagnosed with dissociative amnesia, treatment typically targets the underlying cause—in most cases, trauma. […] Different forms of psychotherapy (talk therapy) have been shown to help with the recovery of past memories related to trauma.

• #85 Trauma & Memory Loss Explained | Harbor Psychiatry & Mental Health

  https://harbormentalhealth.com/2023/02/17/does-trauma-cause-memory-loss/

  Individuals may forget traumatic events despite acknowledging their occurrence. […] Alternatively, they may experience sudden recall of traumatic memories (recovered memories) or develop false memories influenced by external factors. […] Therapeutic interventions like Trauma-Focused Therapy (TFT), Eye Movement Desensitization and Reprocessing (EMDR), Cognitive Processing Therapy (CPT), Cognitive Behavioral Therapy (CBT), and Dialectical Behavior Therapy (DBT) can assist individuals in processing trauma and improving memory function. […] Understanding the intricate interplay between trauma and memory loss is pivotal in navigating recovery. […] Memory loss, often a defense mechanism against trauma-related distress, underscores the need for compassionate and specialized therapeutic interventions.

• #86 Amnesias – Neurologic Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/neurologic-disorders/function-and-dysfunction-of-the-cerebral-lobes/amnesias

  Clinical findings usually suggest causes and any necessary tests. […] Treatment directed at the cause. Any underlying disorder or psychologic cause of amnesia must be treated. […] Certain disorders that cause amnesia (eg, Alzheimer disease, Korsakoff psychosis, herpes encephalitis) can be treated; however, treatment of the underlying disorder may or may not lessen the amnesia. […] Amnesias have various causes, including traumatic brain injury, degenerative dementias, metabolic disorders, seizures, and psychologic trauma or stress.

• #87 Memory Loss Mechanism On Amnesia | International Journal of Scientific Development and Research

  https://www.ijsdr.org/viewpaperforall.php?paper=IJSDR2411002

  Neurological amnesia has been the focus of a lot of research because scientists want to better understand how memory works and how the brain is involved. […] There is now a general agreement that damage to the hippocampus (a part of the brain) or areas around it leads to problems with episodic memory, which is the ability to remember personal experiences, as well as issues with recalling things after some time and remembering details of events. […] However, there is still ongoing debate about how other types of memory, like general knowledge (semantic memory), recognizing things after a delay, short-term memory (working memory), and the ability to imagine, are affected by amnesia. […] This review highlights some recent advances in these discussions and what they tell us about amnesia and how the hippocampus works.

• #88 A human memory circuit derived from brain lesions causing amnesia | Nature Communications

  https://www.nature.com/articles/s41467-019-11353-z

  Human memory is thought to depend on a circuit of connected brain regions, but this hypothesis has not been directly tested. […] This circuit is reproducible across discovery (n=27) and replication (n=26) cohorts and specific to lesions causing amnesia. […] Connectivity with this single location defines a human brain circuit that incorporates 95% of lesions causing amnesia. […] This network aligns with neuroimaging correlates of episodic memory, abnormalities in Alzheimer’s disease, and brain stimulation sites reported to enhance memory in humans. […] The exact location of this circuit has taken on new importance with the increased prevalence of memory disorders such as Alzheimer’s disease and efforts to identify new therapies. […] The hypothesis that human brain lesions that disrupt memory localize to a single connected brain circuit has never been formally tested.

• #89 Memory Loss Mechanism On Amnesia | International Journal of Scientific Development and Research

  https://www.ijsdr.org/viewpaperforall.php?paper=IJSDR2411002

  Neurological amnesia has been the focus of a lot of research because scientists want to better understand how memory works and how the brain is involved. […] There is now a general agreement that damage to the hippocampus (a part of the brain) or areas around it leads to problems with episodic memory, which is the ability to remember personal experiences, as well as issues with recalling things after some time and remembering details of events. […] However, there is still ongoing debate about how other types of memory, like general knowledge (semantic memory), recognizing things after a delay, short-term memory (working memory), and the ability to imagine, are affected by amnesia. […] This review highlights some recent advances in these discussions and what they tell us about amnesia and how the hippocampus works.

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