Materiały źródłowe

• #1 Charles Bonnet Syndrome – Patients – The American Society of Retina Specialists

  https://www.asrs.org/patients/retinal-diseases/38/charles-bonnet-syndrome

  CBS is named after the 18th century Swiss scientist, Charles Bonnet, who described this condition experienced by his grandfather, and who later developed it himself. […] The exact cause of visual hallucinations is not known. Most researchers believe they are due to deafferentation: a loss of signals from the eye to the brain. There is some evidence from special MRI studies indicating that these signals normally inhibit nerve activity in the brain; when the signals are absent, there is more spontaneous nerve activity that is perceived as hallucinations.

• #2 What is Charles Bonnet syndrome, the eye condition that causes hallucinations?

  https://theconversation.com/what-is-charles-bonnet-syndrome-the-eye-condition-that-causes-hallucinations-122322

  Visual hallucinations, or seeing things that aren’t really there, can be frightening and distressing. […] But a lesser known cause is Charles Bonnet syndrome (pronounced bo-nay), named after the Swiss scientist who first described the condition in 1760. […] Charles Bonnet syndrome (also called visual release hallucinations) refers to visual hallucinations in patients with severe vision loss due to eye, optic nerve or brain disease. […] We don’t know the exact cause of Charles Bonnet syndrome. But the most commonly accepted theory is the loss of visual sensory signals to the brain (for example, when a person becomes blind) means the brain cannot put the brakes on excessive and unwanted brain activity. […] The causes of blindness that lead to Charles Bonnet syndrome are usually macular degeneration, glaucoma, diabetes, stroke and injury – but any disease that leads to blindness may cause Charles Bonnet syndrome. […] The syndrome does not occur in congenital blindness (people born blind from birth). […] Unfortunately though, generally the causes of vision loss that lead to Charles Bonnet syndrome can’t be treated.

• #3 Charles Bonnet Syndrome – EyeWiki

  https://eyewiki.org/Charles_Bonnet_Syndrome

  Several risk factors for CBS have been noted with some degree of inconsistency. The most commonly accepted risk factors include worsening visual acuity and older age. […] There is a lack of consensus on how severe vision loss must be — visual acuity worse than 20/50 has been associated with CBS, but it occurs in those with better visual acuity as well. […] Other proposed risk factors include social isolation, cortical atrophy, and cognitive impairment. […] CBS is believed to be underrepresented due to under-reporting of visual hallucinations out of fear of being considered mentally unstable, as these patients realize that their hallucinations are not real. […] The most commonly accepted theory is deafferentation. In this context, deafferentation refers to the loss of afferent neurons responsible for vision transduction.

• #4 Charles Bonnet Syndrome – Patients – The American Society of Retina Specialists

  https://www.asrs.org/patients/retinal-diseases/38/charles-bonnet-syndrome

  CBS is named after the 18th century Swiss scientist, Charles Bonnet, who described this condition experienced by his grandfather, and who later developed it himself. […] The exact cause of visual hallucinations is not known. Most researchers believe they are due to deafferentation: a loss of signals from the eye to the brain. There is some evidence from special MRI studies indicating that these signals normally inhibit nerve activity in the brain; when the signals are absent, there is more spontaneous nerve activity that is perceived as hallucinations.

• #5 Charles Bonnet Syndrome – EyeWiki

  https://eyewiki.org/Charles_Bonnet_Syndrome

  The loss of the afferent fibers results in aberrant hyperexcitability in the visual cortex and can be attributed to a host of factors, including an increase in presynaptic release of neurotransmitters, an increase in the number of postsynaptic receptors, and a decrease in inhibitory neurotransmitter release; these changes give rise to visual hallucinations.

• #6 Visual Hallucinations: Charles Bonnet Syndrome – PMC Lock

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3555593/

  The following is a case of Charles Bonnet syndrome in an 86-year-old woman who presented with visual hallucinations. The differential diagnosis of visual hallucinations is broad and emergency physicians should be knowledgeable of the possible etiologies. […] Charles Bonnet syndrome is an uncommon condition causing visual hallucinations in patients without mental illness. […] The neurophysiology explaining the visual hallucinations in Charles Bonnet syndrome is not clearly elucidated. The currently accepted theory suggests that vision loss leads to visual sensory de-afferentation, causing disinhibition, and later spontaneous firing, of the visual cortical regions. […] Patients with Charles Bonnet syndrome are also likely to have a history of diminished visual acuity or visual field loss. Both this and elderly age were found to be the primary factors correlated with Charles Bonnet syndrome.

• #7 Charles Bonnet Syndrome – StatPearls – NCBI BookshelfTwitterFacebookLinkedInGitHubNCBI Insights BlogTwitterFacebookYoutube

  https://www.ncbi.nlm.nih.gov/books/NBK585133/

  The proposed theory for CBS is the phantom limb pain theory. Phantom limb pain theory explains a feeling of pain even when the limb has been removed. The patient feels pain even though the limb has been removed. Similarly, patients with CBS may have visual sensations despite being unable to see them.

• #8 Charles Bonnet Syndrome: Symptoms, Causes, and TreatmentHealthline

  https://www.healthline.com/health/charles-bonnet-syndrome

  Charles Bonnet syndrome (CBS) is a condition that causes vivid hallucinations in people who suddenly lose all or part of their vision. […] CBS occurs after losing your eyesight or having visual impairment due to surgery complications or an underlying condition, such as: macular degeneration, cataracts, severe myopia, retinitis pigmentosa, glaucoma, diabetic retinopathy, optic neuritis, retinal vein occlusion, central retinal artery occlusion, occipital stroke, temporal arteritis. […] Researchers aren’t sure about why this happens, but there are several theories. One of the main ones suggests that CBS works similarly to phantom limb pain. Phantom limb pain refers to still feeling pain in a limb that’s been removed. Instead of feeling pain in a limb that’s no longer there, people with CBS may still have visual sensations despite not being able to see.

• #9 Eyes – Charles Bonnet syndrome | Better Health ChannelExternal LinkExternal LinkExternal LinkExternal LinkExternal LinkExternal LinkExternal LinkExternal LinkExternal Link

  https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/eyes-charles-bonnet-syndrome

  Charles Bonnet syndrome refers to the visual hallucinations caused by the brain’s adjustment to significant vision loss. […] The underlying mechanism of Charles Bonnet syndrome is not understood. Doctors know that vision loss triggers the visual hallucinations. It is not clear how the brain stores visual information, but we know that visual information from the eyes stops the brain from creating its own images. Perhaps the loss of visual information from the eyes allows the brain to ‘play’ with its stored picture library.

• #10 Charles Bonnet syndrome – NHS

  https://www.nhs.uk/conditions/charles-bonnet-syndrome/

  Charles Bonnet syndrome is linked to vision loss. […] When you lose your sight, your brain gets less information from your eyes than it’s used to. Your brain sometimes makes up for this by creating hallucinations. […] Not everyone who loses their sight will get Charles Bonnet syndrome. You’re more likely to get it if: your sight suddenly gets worse; you lose sight in both eyes. […] It’s common in people who have eye conditions such as age-related macular degeneration or cataracts. […] Charles Bonnet syndrome is not caused by a mental health problem or dementia.

• #11 Charles Bonnet syndrome (CBS) – Macular Society

  https://www.macularsociety.org/macular-disease/macular-conditions/charles-bonnet-syndrome/

  When hallucinations happen as a result of sight loss, they are known as Charles Bonnet syndrome (CBS), after the 18th century Swiss scientist and philosopher who first described the condition. […] What causes it in people with sight loss? […] With our eyes open, the visual brain expects to receive and process a flood of complex electrical signals. In people with eye disease or a break in the visual pathways, what was once a flood becomes a trickle. This leaves the visual areas of the brain with little to do. […] The idle visual brain cells, waiting for an appropriate trigger, begin to fire spontaneously. […] This explains why, for many people, the hallucinations gradually reduce over time. […] More research into Charles Bonnet syndrome is needed. For example, we do not know why only some people with sight loss have hallucinations. […] However bizarre, frightening or funny their content, Charles Bonnet hallucinations are no more than a normal brain’s response to reduced visual input.

• #12 The Ophthalmologist’s Map to Charles Bonnet Syndrome

  https://eyesoneyecare.com/resources/ophthalmologists-map-to-charles-bonnet-syndrome/

  Charles Bonnet syndrome (CBS) is a phenomenon in which an individual with poor vision begins to see images that do not exist—visual hallucinations. […] While CBS cannot be explained as resulting from a mental illness, other theories try to explain this phenomenon. […] Phantom-Vision Theory (deafferentation theory) suggests that a lack of sensory input due to severe vision loss causes spontaneous visual cortex activity, resulting in visual hallucinations. […] Release Theory claims that sensory deprivation, in this case, vision loss, may lead to a release of subconscious perceptions. […] Irritative Theory claims that spontaneous electrical discharges from the brain’s visual cortex cause hallucinations; however, there has not been much research or results in neuroimaging that can validate this theory.

• #13 Frightening visual hallucinations: atypical presentation of Charles Bonnet syndrome triggered by the Black Saturday bushfires | The Medical Journal of Australiafacebookblueskylinkedinemailfacebookblueskylinkedinemailama-logo

  https://www.mja.com.au/journal/2010/193/3/frightening-visual-hallucinations-atypical-presentation-charles-bonnet-syndrome

  Charles Bonnet syndrome (CBS) is a disorder in which psychologically normal people, often with vision impairment, experience complex visual hallucinations. […] The occurrence of complex visual hallucinations, as reported in this case, was first described by Swiss philosopher, naturalist and lawyer Charles Bonnet in 1760, after whom the disorder was later named. CBS is characterised by vivid, elaborate and recurrent visual hallucinations in psychologically normal people, who have full insight into the unreal nature of the hallucinations. […] Two theories have been proposed to explain CBS: the “release” and “sensory deprivation” theories. The release theory postulates that a lesion at any level of the visual pathway leads to the release of defective electrochemical impulses, thereby causing visual hallucinations. The sensory deprivation theory proposes a similar mechanism, except that it is reduced sensory input to the brain as a result of an ocular lesion that causes spontaneous discharge of neurones at the level of the retina or cortex.

• #14 Charles Bonnet Syndrome – StatPearls – NCBI BookshelfTwitterFacebookLinkedInGitHubNCBI Insights BlogTwitterFacebookYoutube

  https://www.ncbi.nlm.nih.gov/books/NBK585133/

  Charles Bonnet syndrome (CBS) is a phenomenon characterized by complex visual hallucinations in visually challenged patients but otherwise psychologically normal. […] CBS can manifest when there is a lesion at any level of the visual system, and typically patients manifest with a loss of central visual acuity. […] Cognitive malfunction, social isolation, and sensory deprivation have been liked as the primary etiologies of CBS. […] Except for congenital blindness, CBS can originate from any factor affecting the visual pathway, extending from the visual cortex down to the eyes. […] Common etiologies include diabetic retinopathy, age-related macular degeneration, cerebral infarctions, glaucoma, macular degeneration, cataract, high myopia, retinitis pigmentosa, optic neuritis, retinal vein occlusion, central retinal arterial occlusion, occipital stroke, and temporal arteritis.

• #15 What is Charles Bonnet syndrome, the eye condition that causes hallucinations? – Faculty of Medicine – University of Queensland

  https://medicine.uq.edu.au/article/2020/02/what-charles-bonnet-syndrome-eye-condition-causes-hallucinations

  Visual hallucinations, or seeing things that aren’t really there, can be frightening and distressing. […] But a lesser known cause is Charles Bonnet syndrome (pronounced bo-nay), named after the Swiss scientist who first described the condition in 1760. […] We don’t know the exact cause of Charles Bonnet syndrome. But the most commonly accepted theory is the loss of visual sensory signals to the brain (for example, when a person becomes blind) means the brain cannot put the brakes on excessive and unwanted brain activity. […] The causes of blindness that lead to Charles Bonnet syndrome are usually macular degeneration, glaucoma, diabetes, stroke and injury – but any disease that leads to blindness may cause Charles Bonnet syndrome. […] The syndrome does not occur in congenital blindness (people born blind from birth). […] Unfortunately though, generally the causes of vision loss that lead to Charles Bonnet syndrome can’t be treated.

• #16 UT Health Austin | Visual Release Hallucinations (Charles Bonnet…

  https://uthealthaustin.org/conditions/charles-bonnet-syndrome

  Charles Bonnet syndrome (CBS) refers to symptoms of visual hallucinations that occur in patients with visual acuity loss or visual field loss. […] Charles Bonnet syndrome refers to visual hallucinations produced as the brain adjusts to significant vision loss. […] A decrease or total loss of this visual input is thought to result in less regulation of visual cortex activity. […] Because the condition involves an increase in cortical activity following sensory deprivation, people who are born blind do not experience visual release hallucinations. […] It’s important to note that hallucinations associated with this condition are caused by failing eyesight, not by a mental health problem or dementia. […] Visual release hallucinations occur most often among the elderly population as they are the most likely age group to have optical conditions such as macular degeneration that affect eyesight. […] Risk factors for Charles Bonnet syndrome may include: Age: Charles Bonnet syndrome is most common in individuals 70-85 years or older. […] Health history: Visual impairment or vision loss, involving either one or both eyes, can cause condition onset.

• #17 Charles Bonnet Syndrome – EyeWiki

  https://eyewiki.org/Charles_Bonnet_Syndrome

  Charles Bonnet Syndrome (CBS), named after the Swiss scientist who first described visual hallucinations in his grandfather in the 1970s, has three features: hallucinations, ocular pathology, and intact cognition. […] CBS most commonly occurs in elderly individuals who have a severe visual impairment commonly due to age-related macular degeneration. Other ocular impairments causing CBS include retinitis pigmentosa, severe myopia, glaucoma, cataract, diabetic retinopathy, and optic neuritis. […] CBS has also been found in patients with vascular associated vision loss including central retinal artery occlusion, retinal vein occlusion, temporal arteritis, and occipital infarction. […] Ocular procedures have also been noted to induce CBS, including CE/PCIOL, bilateral laser iridotomies, anti-VEGF injections, and enucleation.

• #18 Charles Bonnet Syndrome – EyeWiki

  https://eyewiki.org/Charles_Bonnet_Syndrome

  Several risk factors for CBS have been noted with some degree of inconsistency. The most commonly accepted risk factors include worsening visual acuity and older age. […] There is a lack of consensus on how severe vision loss must be — visual acuity worse than 20/50 has been associated with CBS, but it occurs in those with better visual acuity as well. […] Other proposed risk factors include social isolation, cortical atrophy, and cognitive impairment. […] CBS is believed to be underrepresented due to under-reporting of visual hallucinations out of fear of being considered mentally unstable, as these patients realize that their hallucinations are not real. […] The most commonly accepted theory is deafferentation. In this context, deafferentation refers to the loss of afferent neurons responsible for vision transduction.

• #19 EyeRounds.org: Charles Bonnet Syndrome

  http://eyerounds.org/cases/302-Charles_Bonnet.htm

  Charles Bonnet Syndrome is relatively common, with an estimated prevalence of 10-40% in visually impaired patients. […] The visual hallucinations in CBS have been described with conditions of visual loss affecting any part of the visual system, including the eye, optic nerve, and brain, and may occur in almost any acquired disorder of the visual system. […] The most common conditions among patients with CBS include age-related macular degeneration, glaucoma, diabetic retinopathy, and stroke. […] Several studies have found advanced age to be a risk factor for development of CBS, with one study noting a significant association between development of hallucinations and age over 64 years. […] Other risk factors which have been implicated in the development of CBS include visual acuity worse than 20/60, binocular disease, cognitive impairment, cerebrovascular disease, cortical atrophy, and social deprivation.

• #20 Charles Bonnet Syndrome | Low Vision of Fox ValleyOpen MenuClose Menu

  https://www.scott-eyecare.com/eye-care-services/low-vision-optometrist/low-vision-eye-diseases/charles-bonnet-syndrome/

  Charles Bonnet Syndrome is caused by the way the brain reacts to vision loss. It begins in the weeks and months following a dramatic deterioration of sight. […] The brain doesn’t receive as much information from the eyes as it used to, leading the brain to fill these gaps by creating new illusionary images. […] This condition affects up to about 40% percent of people with low vision. Research suggests that it is more likely to occur in those with visual acuity between 20/120 and 20/400.

• #21 Visual Hallucination: Charles Bonnet Syndrome

  https://www.patientcareonline.com/view/visual-hallucination-charles-bonnet-syndrome

  Charles Bonnet syndrome is an uncommon condition causing visual hallucination in patients who do not have mental illness. […] The majority of patients with CBS are elderly, with a mean age of 70 to 85 years. Most have some degree of visual impairment or deafferentation of the visual cortex. […] Although the etiology of CBS is unknown, Burk proposes a pathophysiologic model of “neuronal deafferentation.” It is hypothesized that deafferentation caused by retinal or cortical lesions renders neurons more responsive to neurotransmitter release by increasing the number and/or sensitivity of the postsynaptic receptors and creating a state of hyperexcitability. […] Visual acuity or visual field loss from any cause that affects the eye, optic nerve, optic chiasm, optic tract, optic radiations, or the visual cortex can cause visual hallucination, or CBS. […] The strongest risk factors for CBS are bilateral visual system impairment, declining visual acuity, cerebral damage, cognitive defects, social isolation, and sensory deprivation.

• #22 Charles Bonnet Syndrome: Causes, Symptoms, and Treatment

  https://patient.info/eye-care/charles-bonnet-syndrome

  CBS affects people who have experienced a sharp decline in their vision. It can occur in anyone who has experienced moderate to severe visual loss. […] CBS is much more common in older patients because visual loss is more common in older people. However, anyone of any age may develop CBS, as any condition which causes sight loss can trigger it. […] CBS has nothing whatsoever to do with dementia and is entirely due to loss of sight. […] The condition is believed to occur in 10-15% of all people with moderate visual loss and up to 60% of people with severe visual loss.

• #23 Visual release hallucinations (Charles Bonnet syndrome) – UpToDate

  https://www.uptodate.com/contents/visual-release-hallucinations-charles-bonnet-syndrome

  The Charles Bonnet syndrome (CBS) refers to symptoms of visual hallucinations that occur in patients with visual acuity loss or visual field loss. These are often called release hallucinations, reflecting the most widely accepted theory of their pathogenesis. […] Underlying conditions of vision loss associated with the CBS affect the eye, optic nerve, or brain and include a diverse set of pathologies, such as macular degeneration and stroke. […] The pathophysiology, causes, clinical features, diagnosis, and treatment of the CBS will be reviewed here. […] Patients with more significant vision loss may be more likely to experience and report visual hallucinations. In one survey of patients diagnosed with macular disease, the reported prevalence was 39 percent, and among patients with glaucoma attending a visual rehabilitation program, the prevalence was 20 percent.

• #24 Visual Hallucinations: Charles Bonnet Syndrome – PMC Lock

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3555593/

  Symptoms caused by Charles Bonnet syndrome cannot be explained by the presence of a psychiatric disorder, and patients do not have any significant metabolic derangements or impaired sensorium that would otherwise explain the symptoms. […] Currently, there is no universally accepted treatment for Charles Bonnet syndrome. Visual hallucinations often resolve once the underlying cause of vision loss is rectified. […] Charles Bonnet syndrome should be considered in all elderly patients who present with visual hallucinations. However, more serious causes of hallucinations should be considered and ruled out, as Charles Bonnet syndrome is a clinical diagnosis of exclusion.

• #25 Frightening visual hallucinations: atypical presentation of Charles Bonnet syndrome triggered by the Black Saturday bushfires | The Medical Journal of Australiafacebookblueskylinkedinemailfacebookblueskylinkedinemailama-logo

  https://www.mja.com.au/journal/2010/193/3/frightening-visual-hallucinations-atypical-presentation-charles-bonnet-syndrome

  Charles Bonnet syndrome (CBS) is a disorder in which psychologically normal people, often with vision impairment, experience complex visual hallucinations. […] The occurrence of complex visual hallucinations, as reported in this case, was first described by Swiss philosopher, naturalist and lawyer Charles Bonnet in 1760, after whom the disorder was later named. CBS is characterised by vivid, elaborate and recurrent visual hallucinations in psychologically normal people, who have full insight into the unreal nature of the hallucinations. […] Two theories have been proposed to explain CBS: the “release” and “sensory deprivation” theories. The release theory postulates that a lesion at any level of the visual pathway leads to the release of defective electrochemical impulses, thereby causing visual hallucinations. The sensory deprivation theory proposes a similar mechanism, except that it is reduced sensory input to the brain as a result of an ocular lesion that causes spontaneous discharge of neurones at the level of the retina or cortex.

• #26 Charles Bonnet syndrome stroke – Emianopsia

  https://www.emianopsia.com/en/charles-bonnet-syndrome/

  Charles Bonnet syndrome (CBS) is characterized by visual hallucinations in the absence of psychiatric pathology. […] The increase in the number of visually impaired patients in industrialized countries is mainly caused by optic-retinal diseases. […] Charles Bonnet’s syndrome involves a release phenomenon caused by the suppression of afferent nerve impulses (deafferentation) to the visual associative areas of the cerebral cortex, resulting in phantom vision. […] The brain misinterprets visual information, generating visions that can be debilitating and disturbing. […] Due to the nature of hallucinations and the most common aetiologies, Charles Bonnet syndrome often goes unrecognized and is misdiagnosed as early dementia or psychosis.

• #27 What Is Charles Bonnet Syndrome? – Glaucoma Research FoundationSearchMenu OpenMenu CloseArrow IconArrow IconArrow IconArrow IconArrow IconArrow IconArrow IconArrow IconArrow IconArrow IconArrow IconArrow IconSearchBack arrowBack to top

  https://glaucoma.org/articles/what-is-charles-bonnet-syndrome

  Charles Bonnet Syndrome (CBS) is a condition where patients with significant vision loss experience visual hallucinations in the absence of cognitive or psychological illness. […] One leading hypothesis is that loss of vision leads to decreased connections from the eye to the brain. This can lead to abnormal or rogue neuronal signaling resulting in visual disruptions and hallucinations. The irregular neuronal activation may compensate for decreased visual input from the world.

• #28 Charles Bonnet Syndrome – Fighting Blindness incorporating The National League of the Blind

  https://www.fightingblindness.ie/living-with-sight-loss/eye-conditions/charles-bonnet-syndrome/

  First noted in 1760, Charles Bonnet Syndrome (CBS, also known as phantom vision syndrome) describes the condition in which visual hallucinations are experienced by people of any age living with significant sight loss. […] The underlying mechanism by which this condition presents is unknown, although a number of theories exist. Research has suggested that a more significant loss of vision may correspond to an increased susceptibility to developing this condition. […] At present, many research groups are trying to confirm the underlying cause of this condition. In finding out more about the cause, it may reveal ways in which these hallucinations can be cured or treated.

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