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Visual release hallucinations

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Visual release hallucinations
SpecialtyPsychiatry, ophthalmology Edit this on Wikidata

Charles Bonnet syndrome (CBS) is a condition that causes patients with visual loss to have complex visual hallucinations, first described by Charles Bonnet in 1760[1][2] and first introduced into English-speaking Psychiatry in 1982.[3]

Characteristics

Sufferers, who are mentally healthy people with often significant visual loss, have vivid, complex recurrent visual hallucinations (fictive visual percepts). One characteristic of these hallucinations is that they usually are "lilliput hallucinations" (hallucinations in which the characters or objects are smaller than normal). Sufferers understand that the hallucinations are not real and the hallucinations are only visual, that is, they do not occur in any other senses, eg: hearing, smell or taste[4][5]. The prevalence of Charles Bonnet Syndrome has been reported to be between 10% and 40%; a recent Australian study has found the prevalence to be 17.5% [2]. Two Asian studies, however, report a much lower prevalence [6].[7]. The high incidence of non-reporting of this disorder is the greatest hindrance to determining the exact prevalence; non-reporting is thought to be as a result of sufferers being afraid to discuss the symptoms out of fear that they will be labelled insane[5]. Other symptoms include sufferers, who are predominently female, complaining of electrical sensations in their perineum.[citation needed]

People suffering from CBS may experience a wide variety of hallucinations. Images of complex coloured patterns and images of people are most common, followed by animals, plants or trees and inanimate objects. The hallucinations also often fit into the person's surroundings[2].

Causes

CBS predominantly affects people with visual impairments due to old age or damage to the eyes or optic pathways. In particular, central vision loss due to a condition such as macular degeneration combined with peripheral vision loss from glaucoma may predispose to CBS, although most people with such deficits do not develop the syndrome. The syndrome can also develop after bilateral optic nerve damage due to methyl alcohol poisoning.[8]

Prognosis

There is no treatment of proven effectiveness for CBS. It usually disappears within a year or 18 months, but this can vary greatly from person to person. Some people experience CBS for anywhere from a few days up to many years, and these hallucinations can last only a few seconds or continue for most of the day. For those experiencing CBS, knowing that they are suffering from this syndrome and not a mental illness seems to be the best treatment so far, as it improves their ability to cope with the hallucinations. Most people with CBS meet their hallucinations with indifference, but they can still be disturbing because they may interfere with daily life. It seems that there are a few activities that can make the hallucinations stop although many people are not aware of these. Interrupting vision for a short time by closing the eyes or blinking is sometimes helpful.[2]

Treatment

Because there is no prescribed treatment, the physician will consider on a case by case basis whether to treat any depression or other problems that may be related to CBS. A recent case report suggests selective serotonin reuptake inhibitors may be helpful.[9]

History

Charles Bonnet, first to describe the syndrome.

The disease is named after the Swiss naturalist Charles Bonnet, who described the condition in 1769. He first documented it in his 89-year-old grandfather[citation needed], who was nearly blind from cataracts in both eyes but perceived men, women, birds, carriages, buildings, tapestries, and scaffolding patterns.[10]

Society and culture

This syndrome is well portrayed in Vilayanur S. Ramachandran's book Phantoms in the Brain and in Vikram Chandra's book Sacred Games.

See also

References

  1. ^ de Morsier G (1967)"Le syndrome de Charles Bonnet: hallucinations visuelles des vieillards sans deficience mentale" (in French). Ann Med Psychol 125:677-701.
  2. ^ a b c d Vukicevic M, Fitzmaurice K (2008) "Butterflies and black lacy patterns: the prevalence and characteristics of Charles Bonnet hallucinations in an Australian population". Clinical and Experimental Ophthalmology. 36:659-65
  3. ^ Berrios G E and Brook P (1982) The Charles Bonnet Syndrome and the Problems of Visual Perceptual Disorder in the Elderly. Age and Ageing 11: 17-23
  4. ^ Schultz G, Melzack R (1991) "The Charles Bonnet Syndrome: phantom visual images". Perception. 20:809-25
  5. ^ a b Mogk LG, Riddering A, Dahl D, Bruce C, Brafford S (2000) "Charles Bonnet Syndrome in adults with visual impairments from age-related macular degeneration. In Stuen C et al. Vision Rehabilitation: Assessment, Intervention and Outcomes.117-119
  6. ^ Tan C, Lim V, Ho D, Yeo E, Ng B, Au Eong K. (2005)"Charles Bonnet syndrome in Asian patients in a tertiary ophthalmic centre". British Journal of Ophthalmology.88(10):1325-9
  7. ^ Abbott E, Connor G, Artes P, Abadi R. "Visual Loss and Visual Hallucinations in Patients with Age-Related Macular Degeneration (Charles Bonnet Syndrome)". Investigative Ophthalmology and Visual Science.48:1416-23.
  8. ^ Olbrich HM, Lodemann E, Engelmeier MP (1987). "Optical hallucinations in the aged with diseases of the eye" (in German). Z Gerontol. 20 (4): 227–9. PMID 3660920
  9. ^ Lang et al. (2007)J. Psychopharmacology 2007; 21:553.
  10. ^ http://www.whonamedit.com/synd.cfm/2874.html
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