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Figure 1.
Structured history taking.

Structured history taking.

Table 1. 
Causes of Visual Impairment
Causes of Visual Impairment
Table 2. 
Control Group*
Control Group*
1.
de Morsier  G Les automatismes visuels: hallucinations rétrochiasmatiques. Schweiz Med Wochenschr 1936;66700- 708
2.
de Morsier  G Les hallucinations. Rev Otoneurophthalmol 1938;16244- 352
3.
Bonnet  C Essai Analytique sur les Facultes de l’Ame. 2nd ed. Geneva, Switzerland Philibert1769;176- 178
4.
de Morsier  G The Charles Bonnet syndrome: visual hallucinations in the aged without mental deficiency [in French]. Ann Med Psychol (Paris) 1967;2678- 702
5.
Damas-Mora  JSkelton-Robinson  MJenner  FA The Charles Bonnet syndrome in perspective. Psychol Med 1982;12251- 261
PubMedArticle
6.
Fernandez  ALichtshein  GVieweg  AWR The Charles Bonnet syndrome: a review. J Nerv Ment Dis 1997;185195- 200
PubMedArticle
7.
Levêque de Pouilly  JS Eloge de Charles Bonnet.  Lausanne, Switzerland Henbach1794;120- 121
8.
American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition.  Washington, DC American Psychiatric Association1994;767
9.
Borruat  FX Visual hallucinations and illusions, symptoms frequently misdiagnosed by the practitioner [in French]. Klin Monatsbl Augenheilkd 1999;214324- 327
PubMedArticle
10.
Johnson  FCSmith  LD Cognition. Thompson  LMathias  PLyttle’s Mental Health and Disorder 2nd ed. London, England Bailliere Tindall1994;175- 240
11.
Kolmel  HW Visual illusions and hallucinations. Baillieres Clin Neurol 1993;2243- 264
12.
Sedman  G A comparative study of pseudohallucinations, imagery, and true hallucinations. Br J Psychiatry 1966;1129- 17
PubMedArticle
13.
Sims  AMundt  CBerner  PBarocka  A Descriptive phenomenology. Gelder  MGLopez-Ibor  JJAndreasen  NCNew Oxford Textbook of Psychiatry Oxford, England Oxford Medical Publications2000;55- 70
14.
Taylor  FK On pseudohallucinations. Psychol Med 1981;11265- 271
PubMedArticle
15.
Duke-Elder  SScott  GI Disorders of perception: visual hallucinations. Duke-Elder  SSystem of Ophthalmology Vol 12 London, England Henry Kimpton1971;562- 569
16.
Manford  MAndermann  F Complex visual hallucinations: clinical and neurobiological insights. Brain 1998;1211819- 1840
PubMedArticle
17.
Cogan  DG Visual hallucinations as release phenomena. Albrecht Von Graefes Arch Klin Exp Ophthalmol 1973;188139- 150Article
18.
Kolmel  HW Complex visual hallucinations in the hemianopic field. J Neurol Neurosurg Psychiatry 1985;4829- 38
PubMedArticle
19.
Lepore  FE Spontaneous visual phenomena with visual loss. Neurology 1990;40444- 447
PubMedArticle
20.
Olbrich  HMEngelmeier  MPPauleckhoff  DWaubke  T Visual hallucinations in ophthalmology. Graefes Arch Clin Exp Ophthalmol 1987;225217- 220
PubMedArticle
21.
Özsancak  CAuzou  P Palinopsia in Charles Bonnet syndrome [letter in French]. Presse Med 1998;27359
PubMed
22.
Schultz  GMelzack  R The Charles Bonnet syndrome: “phantom visual images.” Perception 1991;20809- 825
PubMedArticle
23.
Siatkowski  RMZimmer  BRosenberg  PR The Charles Bonnet syndrome: visual perceptive dysfunction in sensory deprivation. J Clin Neuroophthalmol 1990;10215- 218
PubMed
24.
Tueth  MJChong  JASamander  J The Charles Bonnet syndrome: a type of organic visual hallucinosis. J Geriatr Psychiatry Neurol 1995;81- 3
PubMedArticle
25.
Berrios  GEBrook  P The Charles Bonnet syndrome and the problem of visual perceptual disorders in the elderly. Age Ageing 1982;1117- 23Article
26.
Bartlett  JE A case of organized visual hallucinations in an old man with cataract, and their relationship to the phenomena of the phantom limb. Brain 1951;74363- 373
PubMedArticle
27.
Needham  WTaylor  RE Benign visual hallucinations, or phantom vision in vis-ually impaired and blind persons. J Vis Impairment Blindness 1992;86245- 248
28.
Foerster  O The cerebral cortex in man. Lancet 1931;2309- 312
29.
Lance  JW Simple formed hallucinations confined to the area of specific visual field. Brain 1976;99719- 734
PubMedArticle
30.
Price  JWhitlock  FAHall  RT The psychiatry of vertebro-basilar insufficiency with the report of a case. Psychiatr Clin (Basel) 1983;1626- 44
31.
Adachi  NWatanabe  TMatsuda  HOnuma  T Hyperperfusion in the lateral temporal cortex, the striatum and the thalamus during complex visual hallucinations: single photon emission computed tomography findings in patients with Charles Bonnet syndrome. Psychiatry Clin Neurosci 2000;54157- 162Article
32.
Anderson  SWRizzo  M Hallucinations following occipital lobe damage: the pathological activation of visual representations. J Clin Exp Neuropsychol 1994;16651- 663
PubMedArticle
33.
Ffytche  DHHoward  RJBrammer  MJDavid  AWoodruff  PWilliams  S The anatomy of conscious vision: an fMRI study of visual hallucinations. Nat Neurosci 1998;1738- 742Article
34.
Holroyd  SRabins  PV A three-year follow-up study of visual hallucinations in patients with macular degeneration. J Nerv Ment Dis 1996;184188- 189
PubMedArticle
35.
Rousseaux  MDebrock  DCabaret  MSteinling  M Visual hallucinations with written words in a case of left parietotemporal lesion. J Neurol Neurosurg Psychiatry 1994;571268- 1271
PubMedArticle
36.
Santhouse  AMHoward  RJFfytche  DH Visual hallucination syndromes and the anatomy of the visual brain. Brain 2000;1232055- 2064
PubMedArticle
37.
Rosenbaum  FHarati  YRRolak  L Visual hallucinations in sane people: the Charles Bonnet syndrome. J Am Geriatr Soc 1987;3566- 68
PubMed
38.
Hécaen  HAlbert  ML Disorders of visual perception. Human Neuropsychology New York, NY John Wiley & Sons1978;144- 167
39.
Podoll  KOsterheider  MNoth  J The Charles Bonnet syndrome [in German]. Fortschr Neurol Psychiatr 1989;5743- 60Article
40.
Teunisse  RJZitman  FGRaes  DCM Clinical evaluation of 14 patients with Charles Bonnet syndrome (isolated visual hallucinations). Compr Psychiatry 1994;3570- 75
PubMedArticle
41.
Berrios  GEBrook  P Visual hallucinations and sensory delusions in the elderly. Br J Psychiatry 1984;144662- 664
PubMedArticle
42.
Girkin  CAMiller  NR Central disorders of vision in humans. Surv Ophthalmol 2001;45379- 405
PubMedArticle
43.
Gold  KRabins  PV Isolated visual hallucinations and the Charles Bonnet syndrome: a review of the literature and presentation of six cases. Compr Psychiatry 1989;3090- 98
PubMedArticle
44.
Hécaen  HBadarocco  JG Les hallucinations visuelles au cours des ophthalmopathies et des lesions des nerfs et du chiasma optiques. Evol Psychiatr (Paris) 1956;21157- 179
45.
Holroyd  SRabins  PVFinkelstein  D  et al.  Visual hallucinations in patients with macular degeneration. Am J Psychiatry 1992;1491701- 1706
PubMed
46.
Norton-Willson  LMunir  M Visual perceptual disorders resembling the Charles Bonnet syndrome: a study of 434 consecutive patients referred to a psychoger-iatric unit. Fam Pract 1987;427- 35
PubMedArticle
47.
Teunisse  RJCruysberg  JRVerbeek  AZitman  FG The Charles Bonnet syndrome: a large prospective study in the Netherlands: a study of the prevalence of the Charles Bonnet syndrome and associated factors in 500 patients attending the University Department of Ophthalmology at Nijmegen. Br J Psychiatry 1995;166254- 257
PubMedArticle
48.
White  NJ Complex hallucinations in partial blindness due to eye disease. Br J Psychiatry 1980;136284- 286
PubMedArticle
49.
Dodd  JHeffeman  ABlake  J Visual hallucinations associated with Charles Bonnet syndrome: an ever increasing diagnosis. Ir Med J 1999;92344- 345
PubMed
50.
Fernandes  LHScassellati-Sforzolini  BSpaide  RF Estrogen and visual hallucinations in a patient with Charles Bonnet syndrome [case report]. Am J Ophthalmol 2000;129407
PubMedArticle
51.
Kurata  AMiyasaka  YYoshida  TKunii  MYada  KKan  S Venous ischemia caused by dural arteriovenous malformation: case report. J Neurosurg 1994;80552- 555
PubMedArticle
52.
McNamara  MEHeros  RCBollor  F Visual hallucinations in blindness: the Charles Bonnet syndrome. Int J Neurosci 1982;1713- 15
PubMedArticle
53.
Ormond  AW Visual hallucinations in sane people. BMJ 1925;2376- 377
54.
Brown  GCMurphy  RP Visual symptoms associated with choroidal neovascularization: photopsias and the Charles Bonnet syndrome. Arch Ophthalmol 1992;1101251- 1256
PubMedArticle
55.
Levine  AM Visual hallucinations and cataracts. Ophthalmic Surg 1980;1195- 98
56.
Holroyd  SRabins  PVFinkelstein  DLavrisha  M Visual hallucinations in patients from an ophthalmology clinic and medical clinic population. J Nerv Ment Dis 1994;182273- 276
PubMedArticle
57.
Pliskin  NHKiolbasa  TATowle  VL  et al.  Charles Bonnet syndrome: an early marker for dementia? J Am Geriatr Soc 1996;441055- 1061
PubMed
58.
O’Reilly  RChamberlaine  C Charles Bonnet syndrome: incidence and demographic and clinical features. Can J Psychiatry 1996;41259- 260
PubMed
59.
Teunisse  RJCruysberg  JRHoefnagels  WHvan’t Hof  MAVerbeek  ALZitman  FG Risk factors for the Charles Bonnet syndrome. J Nerv Ment Dis 1998;186190- 192Article
60.
Fuchs  TLauter  H Charles Bonnet syndrome and musical hallucinations in the elderly. Katona  CLevy  RDelusions and Hallucinations in Old Age London, England Gaskell, Royal College of Psychiatrists1992;187- 198
61.
Teunisse  RJCruysberg  JRHoefnagels  WHVerbeek  ALZitman  FG Visual hallucinations in psychologically normal people: Charles Bonnet’s syndrome. Lancet 1996;347794- 797
PubMedArticle
62.
Hart  CT Formed visual hallucinations: a symptom of cranial arteritis. BMJ 1967;3643- 644Article
63.
Fitzgerald  RG Visual phenomenology in recently blind adults. Am J Psychiatry 1971;1271533- 1539
PubMed
64.
Adair  DKKeshavan  MS The Charles Bonnet syndrome and grief reaction [letter]. Am J Psychiatry 1988;145895- 896
PubMed
65.
Dlugon  U Charles Bonnet syndrome. Psychiatr Pol 2000;34307- 316
PubMed
66.
Bhatia  MSKhastgir  UMalik  SC Charles Bonnet syndrome. Br J Psychiatry 1992;161409- 410
PubMedArticle
67.
Chaudhuri  A Charles Bonnet syndrome: an example of cortical dissociation syndrome affecting vision? J Neurol Neurosurg Psychiatry 2000;69704- 705
PubMedArticle
68.
Chen  CSLin  SFChong  MY Charles Bonnet syndrome and multiple sclerosis [letter]. Am J Psychiatry 2001;1581158- 1159
PubMedArticle
69.
Görgens  KLiedtke  M Charles Bonnet syndrome [in German]. Psychiatr Prax 1998;2585- 86
70.
Hosty  G Charles Bonnet syndrome: a description of two cases. Acta Psychiatr Scand 1990;82316- 317
PubMedArticle
71.
Terao  T Effect of carbamazepine and clonazepam combination on Charles Bonnet syndrome: a case report. Hum Psychopharmacol Clin Exp 1998;13451- 453Article
72.
Hori  HTerao  TShiraishi  YNakamura  J Treatment of Charles Bonnet syndrome with valproate. Int Clin Psychopharmacol 2000;15117- 119Article
73.
Paulig  MMentrup  H Charles Bonnet’s syndrome: complete remission of complex visual hallucinations treated by gabapentin. J Neurol Neurosurg Psychiatry 2001;70813- 814
PubMedArticle
74.
Nevins  M Charles Bonnet syndrome. J Am Geriatr Soc 1997;45894- 895
PubMed
75.
Ranen  NGPasternak  RERovner  BW Cisapride in the treatment of visual hallucinations caused by vision loss: the Charles Bonnet syndrome. Am J Geriatr Psychiatry 1999;7264- 266
PubMedArticle
76.
Thorpe  L The treatment of psychotic disorders in late life. Can J Psychiatry 1997;42 ((suppl 1)) 19S- 27S
PubMed
77.
Hartmann  PMKosko  DACohn  JA The Charles Bonnet syndrome (pseudohallucinations) in an AIDS patient with cytomegalovirus retinitis. J Nerv Ment Dis 1995;183549- 550
PubMedArticle
78.
Chen  JGomez  MViet  SO’Dowd  MA Visual hallucinations in a blind elderly woman: Charles Bonnet syndrome, an underrecognized clinical condition. Gen Hosp Psychiatry 1996;18453- 455
PubMedArticle
79.
Howard  RMeehan  OPowell  RMellers  J Successful treatment of Charles Bonnet syndrome type visual hallucinosis with low-dose risperidone. Int J Geriatr Psychiatry 1994;9677- 678
80.
Batra  ABartels  MWormstall  H Therapeutic options in Charles Bonnet syndrome. Acta Psychiatr Scand 1997;96129- 133
PubMedArticle
81.
Asaad  GShapiro  B Hallucinations: theoretical and clinical overview. Am J Psychiatry 1986;1431088- 1097
PubMed
Clinical Sciences
March 01, 2005

Complex Visual Hallucinations in the Visually ImpairedA Structured History-Taking Approach

Author Affiliations

Author Affiliation: Royal Eye Infirmary, Plymouth, England.

Arch Ophthalmol. 2005;123(3):349-355. doi:10.1001/archopht.123.3.349
Abstract

Objective  To study complex visual hallucinations in visually impaired individuals.

Methods  A prospective comparative study involving structured history taking and cognitive assessment in 48 consecutive visually impaired individuals with best-corrected visual acuity of 20/200 or worse and an age-matched cohort of 48 consecutive patients with visual acuity of 20/40 or better in at least 1 eye.

Results  Thirty visually impaired subjects (63%) experienced hallucinations, unrelated to specific ocular pathology. None volunteered the symptom; 2 admitted hallucinations on nonleading questioning and 28 on direct questioning. All displayed insight into the unreality of their hallucinations, although 18 (60%) achieved this after initial deception. Seventeen (57%) expressed concern; 7 (23%) experienced disturbing images. Nineteen (63%) feared being labeled as insane were they to admit to hallucinations, while 10 (33%) were fearful of impending insanity. Sixteen (94%) of 17 concerned patients derived comfort from sympathetic reassurance that their hallucinations did not represent sinister pathology. In contrast, none of the individuals with normal vision experienced any hallucinations (P<.001). Cognition was intact in all groups.

Conclusions  Complex visual hallucinations with insight commonly occur in visually impaired, cognitively intact individuals due to acquired visual impairment and are unrelated to chronological age. Hallucinatory experiences are almost invariably admitted to only on direct questioning, due to fears of being considered insane. Although generally pleasant, hallucinations may cause distress, because of content or implications of the hallucinatory activity. Sympathetic explanation affords significant emotional relief.

Charles Bonnet syndrome (CBS) was so named by de Morsier,1,2 recognizing the renowned Genoese philosopher Charles Bonnet (1720-1793), who in 1769 described the visual hallucinatory experiences of his intelligent, articulate, cognitively intact, and visually impaired grandfather Charles Lullin,3 in the first scientific documentation of a hallucinatory experience.4 Lullin, an 89-year-old magistrate, described subjective silent visions of men, women, birds, carriages, and buildings, which he fully realized were “fictions” of his brain.5,6 Ironically, Bonnet later underwent visual deterioration and experienced hallucinations typical of the syndrome to which he lent his name.4,7

A hallucination is a subjective sensory experience, occurring without external stimulation of the relevant sensory organ.810 The term pseudohallucination signifies a similar phenomenon, in which the subject possesses insight into the unreality of the sensory experience.1014 Visual hallucinations may be elementary or complex. The former are characterized by colored or colorless bright lights such as flashes or sparks. Complex visual hallucinations, on the other hand, consist of formed images of objects or persons.11,15,16

The visual hallucinations in CBS are widely considered to represent a “release phenomenon”6,1624 secondary to deafferentation of the visual association areas of the cerebral cortex,25 analogous to that seen in the phantom limb syndrome.22,2527 Complex visual hallucinations are believed to originate in the visual association areas of the cerebral cortex,2830 notably the lateral temporal cortex, corpus striatum, and thalamus.31 Neuroimaging studies3236 suggest that activation of different areas of visual association cortex may result in different specific hallucinatory images.

There is, however, no consensus on the role of visual impairment in the development of CBS. de Morsier2,4 considered visual impairment etiologically irrelevant to the genesis of visual hallucinations and therefore not obligatory for diagnosis, despite the frequent incidence of ocular pathology in such subjects. Others22,37 suggest that impaired vision is almost invariable in CBS, some38 considering it mandatory to the diagnosis of CBS. Others39,40 concur with de Morsier that visual impairment, although common, is not essential for diagnosis.

Many investigators, however, recognize a strong relationship between CBS and visual impairment,5,6,11,19,20,22,31,3948 age-related macular degeneration representing the most commonly associated ocular pathology,16 although CBS has been reported in the context of visual impairment secondary to pathology anywhere along the visual pathway, from eye to calcarine cortex.18,30,4952 Such visual hallucinations occur only in the context of acquired visual loss and never in those who are congenitally blind.53

The emergence of hallucinations may relate more to the degree of visual impairment than to any specific underlying ocular pathology.47 Charles Bonnet syndrome has been reported to occur more commonly in higher degrees of visual impairment19,42,45,47 and in bilateral rather than unilateral ocular pathology.45,47,54 It is also well recognized that improvement of visual function,18,39,52,55 whether spontaneously or by interventional means (such as cataract surgery), often results in cessation of hallucinatory phenomena. Some authors, however, counter that hallucinatory activity bears no relationship to the degree of visual impairment,27,56,57 a theory supported by the paradoxical cessation of hallucinatory activity on further visual deterioration.24

Conflicting figures exist with regard to the sex distribution of CBS. de Morsier4 originally reported a male preponderance. Other studies22,40,43,46,56,58,59 suggest a clear preponderance of women, yet others6,39,47,60 recognize no sex bias. It is, however, widely agreed that CBS is underrecognized,19,54,61 a phenomenon attributed to patients’ natural reluctance to admit to their hallucinatory experiences, for fear of being deemed mentally unstable,11,23,26,39 and to unfamiliarity of medical personnel with CBS, with a resultant tendency to misdiagnose mental illness.19,46,54,62

Previous studies18,20,45,54,59,61,63 have estimated that the prevalence of complex visual hallucinations among patients with visual impairment is between 11% and 15%. Most information pertaining to this condition is, however, in the psychiatric rather than the ophthalmic literature. This study, therefore, set out to determine the prevalence and characteristics of visual hallucinatory phenomena among visually impaired individuals and to identify any relationship between hallucinations, cognitive function, and relative degree of visual impairment.

METHODS

This prospective cohort study, commenced with approval from the South and West Devon Research Ethics Committee, United Kingdom, involved structured history taking and cognitive assessment in visually impaired subjects, consecutively encountered during normal clinical duties at the Royal Eye Infirmary, from May 1, 2001, to April 30, 2002. An arbitrary cut-off visual acuity of 20/200 was used; individuals with best-corrected visual acuity of 20/200 or worse in the better eye were included in the study.

Forty-eight such visually impaired individuals (22 men and 26 women) were encountered during the study, in outpatient clinics, pre-theater examinations, accident and emergency clinics, and ophthalmic wards. Structured, sensitive, and sympathetic history taking was commenced with nonleading questions about unusual visual symptoms or experiences apart from blurred vision. If a history of hallucinations was not forthcoming, patients were advised that some visually impaired individuals experience visual hallucinations, a well-recognized physiological consequence of visual impairment. Following this, specific and direct inquiry with regard to any complex visual hallucinatory experiences was made. If hallucinations were then admitted to, systematic inquiry was then directed toward elucidating the characteristics of the hallucinatory phenomena, namely, image content, movement, triggering and relieving factors, and any associated hallucinations of other sensory modalities. History taking was continued regarding whether the subject had confided in anyone about his or her hallucinations, harbored any concerns, or had experienced any distress because of the hallucinations (Figure 1). Sympathetic explanation with regard to the benign nature of hallucinations in the context of visual impairment was then offered and the patients’ reactions recorded. Finally, cognitive function was assessed in all subjects, irrespective of a history or otherwise of hallucinations, with a Mini-Mental State Examination, modified in that 2 of the prescribed tasks that require visual function were omitted. The cognitive score was thus calculated out of a maximum of 28.

The mean ± SD age of the visually impaired cohort was 79.1 ± 10.9 years (age range, 43-96 years). An equal number of consecutive patients older than 65 years, without visual impairment, arbitrarily defined as a visual acuity of 20/40 or better in at least 1 eye along with a full visual field, was then recruited as a control group and subjected to history taking and cognitive assessment along identical lines.

RESULTS

In the visually impaired cohort, no one volunteered a history of hallucinations. Two individuals (who were previously aware of CBS) admitted to hallucinations on nonleading questioning and a further 28 on being directly questioned about any hallucinatory experiences. Thirty subjects (63%) therefore admitted to having experienced complex visual hallucinations. In contrast, none of the subjects in the control group experienced any visual hallucinations. The prevalence of visual hallucinations among the visually impaired cohort was thus significantly greater than that among the non–visually impaired cohort (χ2 = 40.8, P<.001).

The prevalence of hallucinatory activity appeared unrelated to specific underlying ocular pathology (Table 1). Of the 48 patients, only 1 had a neurological diagnosis, a 76-year-old woman with long-standing optic atrophy secondary to multiple sclerosis. Even in this case, visual impairment was secondary to optic atrophy rather than cerebral disease, and neuroimaging was not performed. In effect, therefore, all patients exhibited visual impairment secondary to ocular pathology. Three individuals underwent cataract surgery, with varying degrees of visual improvement; none experienced any further hallucinations.

The mean ± SD age of the visually impaired cohort was 79.1 ± 10.9 years (age range, 43-96 years), while that of the control group (Table 2) was 75.0 ± 5.9 years (age range, 66-90 years). There was thus no significant age difference between the 2 cohorts (t = 2.27, P = .03; 2-tailed t test). The mean age of the hallucinators was 79.5 years, and that of the nonhallucinators was 78.3 years. An independent samples t test found no statistically significant age difference between the hallucinating and nonhallucinating groups within the visually impaired cohort (t = 0.37, P = .71).

With regard to sex distribution, the 30 hallucinators comprised 19 women and 11 men. Among the visually impaired cohort, 19 (73%) of 26 women had experienced hallucinations, compared with 11 (50%) of 22 men. This difference between men and women, however, fell short of statistical significance (χ2 = 1.8, P = .18).

Hallucinatory content was variable, the most commonly observed image being that of a person (adult [14 subjects] or child [6 subjects]). Visions of faces (4 subjects) often with grotesque features, animals (6 subjects) such as cats and dogs, and inanimate objects (12 subjects) were also experienced. Patients also reported that their visions appeared brilliantly clear and detailed, in sharp contrast to their usual blurred images of the real world. The images remained motionless in 6 subjects and manifested en bloc movement (movement of the whole image, without relative movement of its constituent parts) in 5, intrinsic movement (internal movement of the various parts of an image, eg, the hands and feet of a man) in 17, and intrinsic and en bloc movement in 1, while the remaining 1 patient could not remember.

The hallucinatory images were largely independent of volition; triggering and relieving factors were uncommon. Four patients (13%) reported that their hallucinations were sometimes triggered by dim illumination. Six (20%) possessed the ability to voluntarily terminate their hallucinations, 4 by shutting their eyes, 1 by looking directly at the images, and 1 by executing ocular saccades. The hallucinations were invariably silent, unaccompanied by hallucinations of other sensory modalities.

All patients manifested insight into the unreality of their hallucinations. However, 18 (60%) attained such insight only after an initial phase of deception, especially if the hallucinations were realistic and appeared consistent with the surroundings.

Seventeen subjects (57%) expressed concern about their hallucinations; 7 (23%) had experienced disturbing or frightening images. Nineteen (63%) feared being labeled as insane were they to admit to their hallucinations, while 10 (33%) were fearful that they were becoming insane or senile. Ten subjects (33%) had previously admitted the existence of their hallucinations, 7 to family members. Three of these were already aware of CBS, while 4 had been experiencing disturbing images.

Sixteen (94%) of 17 concerned patients admitted to deriving emotional and psychological comfort from sympathetic explanation that their hallucinations represented a release phenomenon in the context of visual impairment, analogous to that of the phantom limb syndrome, and represented neither sinister pathology nor imminent insanity. The remaining 1 patient, although concerned, was not unduly bothered by hallucinations, although the hallucinatory images were frightening.

The cognitive scores of 2 patients, 1 each in the hallucinating and nonhallucinating categories, were excluded, one being dyslexic and the other illiterate. Both individuals, however, appeared well oriented, giving no reason to suspect any cognitive deficit. The mean ± SD cognitive score was higher among hallucinating subjects (mean, 27.2 ± 1.0 [range, 25-28]) than among nonhallucinating subjects (mean, 26.8 ± 1.4 [range, 24-28]). This difference, although not statistically significant (P = .18), demonstrates intact cognition among patients with CBS. The control group also demonstrated intact cognition, with a mean ± SD cognitive score of 26.4 ± 1.3 (range, 24-28).

COMMENT

The results of this study demonstrate that acquired visual impairment is responsible for the development of complex visual hallucinations and that the emergence of such hallucinations is independent of age. Moreover, such hallucinations are more common than hitherto believed. The hallucinatory phenomenology is exclusively visual, without noise or hallucinations of other senses. This study also highlights the fact that such patients almost invariably do not admit to their hallucinatory experiences unless specifically asked and draws attention to the need for sensitive and sympathetic history taking, with direct inquiry about visual hallucinations in such subjects. The 2 individuals who admitted to their hallucinations on nonleading questioning were already aware of CBS.

These individuals manifest no cognitive deficits and display accurate insight into the unreality of their hallucinatory experiences, although not always immediately, especially if the perceived images appear real and appropriate to the surroundings. The observed difference between men and women, although falling short of statistical significance, suggests that the condition is commoner in women and merits further study to ascertain whether this is indeed the case.

Hallucinatory experiences also appear to be not as “enjoyable” for patients as described in the literature.5,22,26,39,43,64 The images can be frightening or otherwise disturbing, and patients often experience anxiety with regard to their mental health.

Perhaps most importantly, this study demonstrates the benefits that accrue from providing reassuring and sympathetic explanation of the etiology of visual hallucinations. Apart from improving visual function, which may not always be possible, it is well recognized that sympathetic explanation of the benign nature of such hallucinatory experiences is a source of considerable emotional and psychological relief.27,65 In this cohort, no patient required any therapy beyond such reassurance. Moreover, the fact that a formal test of cognitive function had been performed afforded patients objective evidence that they were cognitively normal, thus lending credibility to any reassurance that they were not becoming senile or insane.

However, hallucinations that are frequent, nonresolving, distressing, or impairing quality of life may necessitate effective therapy. Unfortunately, a universally effective remedy is still elusive; psychological techniques, including hypnosis and cognitive restructuring, such as that used in therapy for phantom limb pain, have been proposed to minimize the unpleasant effects of persistent, intrusive, and troublesome visual hallucinations.27

Pharmacotherapy is disappointing,11,39 as evidenced by the diverse range of therapeutic agents advocated in this condition, including carbamazepine,6670 clonazepam,71 and valproate sodium,72 individually and in combination. Other drugs used with some measure of success include low-dose gabapentin,73 cisapride (a potent 5-hydroxytryptamine-3 antagonist),74,75 and antipsychotic drugs (neuroleptics),76 such as thioridazine hydrochloride,77 haloperidol decanoate,78 and the atypical neuroleptics risperidone79 and melperone.80 A trial of pharmacotherapy may, however, be justified, under the guidance of an expert physician or psychiatrist in the context of persistent disturbing hallucinations in a subject refractory to reassurance.

I suggest that all visually impaired patients should be directly questioned regarding any hallucinatory experiences. In this context, it would appear sensible to advise all visually impaired individuals, even those who do not admit to hallucinatory experiences, of the possible future occurrence of hallucinations, to render them better prepared to deal with such an experience, should it arise.

Because hallucinations may occur in other states, such as psychiatric disease, drug ingestion, sleep-wake transitional states, metabolic and endocrine disorders, epilepsy, cerebral ischemia, and other forms of neurological disease,16,22,46,81 it would appear prudent to perform a brief but formal assessment of cognitive function, if a history of hallucinations is identified. Further referral is perhaps indicated only in the case of a demonstrable cognitive deficit or suspicion of other neurological or psychiatric pathology. If, as in most cases, cognition is intact, no further measures are indicated save for sensitive and sympathetic explanation and reassurance. In this context, a good performance by a patient on a formal cognitive test lends credibility to any reassurance provided by the ophthalmologist, because patients frequently harbor fears of impending insanity.

Three major groups of investigators, Damas-Mora et al,5 Podoll et al,39 and Gold and Rabins,43 have suggested diagnostic criteria for CBS. All stipulate the occurrence of formed visual hallucinations with insight. However, although the first 2 acknowledge an association with ocular pathology, none specify visual impairment as causative to the emergence of such hallucinations. I therefore suggest the following diagnostic criteria for CBS: (1) acquired visual impairment; (2) complex visual hallucinations that are (a) persistent or recurrent, (b) vivid and clear, (c) pleasant or unpleasant, and (d) stereotyped or variable; (3) no hallucinations of other modalities; (4) insight into the unreality of the hallucinations, which may be delayed; (5) intact cognition; (6) preserved intellectual function; and (7) no neurological or psychiatric disease.

In conclusion, this study demonstrates that visually impaired patients commonly experience hallucinations. It is relevant that Charles Lullin, the first reported case, and later Charles Bonnet, after whom the syndrome was named, were visually impaired. Moreover, ophthalmologists seldom encounter hallucinating patients without pathology of the eyes or visual pathway. I therefore submit that the term Charles Bonnet syndrome should be reserved for visual hallucinations in the visually impaired and moreover that visual impairment, prerequisite to the emergence of hallucinatory activity, be therefore considered an essential diagnostic criterion for CBS.

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Article Information

Correspondence: G. Jayakrishna Menon, FRCS, FRCOphth, Royal Eye Infirmary, Apsley Road, Plymouth PL4 6PL, England (jay.menon@doctors.org.uk).

Submitted for Publication: September 18, 2002; final revision received March 29, 2004; accepted June 29, 2004.

Acknowledgment: I am deeply indebted to Gordon Dutton, MD, FRCOphth, David Barr, FRCS, FRCOphth, and Stephen Shaw, PhD, for valuable advice about the study and assistance with statistical analysis.

Financial Disclosure: None.

References
1.
de Morsier  G Les automatismes visuels: hallucinations rétrochiasmatiques. Schweiz Med Wochenschr 1936;66700- 708
2.
de Morsier  G Les hallucinations. Rev Otoneurophthalmol 1938;16244- 352
3.
Bonnet  C Essai Analytique sur les Facultes de l’Ame. 2nd ed. Geneva, Switzerland Philibert1769;176- 178
4.
de Morsier  G The Charles Bonnet syndrome: visual hallucinations in the aged without mental deficiency [in French]. Ann Med Psychol (Paris) 1967;2678- 702
5.
Damas-Mora  JSkelton-Robinson  MJenner  FA The Charles Bonnet syndrome in perspective. Psychol Med 1982;12251- 261
PubMedArticle
6.
Fernandez  ALichtshein  GVieweg  AWR The Charles Bonnet syndrome: a review. J Nerv Ment Dis 1997;185195- 200
PubMedArticle
7.
Levêque de Pouilly  JS Eloge de Charles Bonnet.  Lausanne, Switzerland Henbach1794;120- 121
8.
American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition.  Washington, DC American Psychiatric Association1994;767
9.
Borruat  FX Visual hallucinations and illusions, symptoms frequently misdiagnosed by the practitioner [in French]. Klin Monatsbl Augenheilkd 1999;214324- 327
PubMedArticle
10.
Johnson  FCSmith  LD Cognition. Thompson  LMathias  PLyttle’s Mental Health and Disorder 2nd ed. London, England Bailliere Tindall1994;175- 240
11.
Kolmel  HW Visual illusions and hallucinations. Baillieres Clin Neurol 1993;2243- 264
12.
Sedman  G A comparative study of pseudohallucinations, imagery, and true hallucinations. Br J Psychiatry 1966;1129- 17
PubMedArticle
13.
Sims  AMundt  CBerner  PBarocka  A Descriptive phenomenology. Gelder  MGLopez-Ibor  JJAndreasen  NCNew Oxford Textbook of Psychiatry Oxford, England Oxford Medical Publications2000;55- 70
14.
Taylor  FK On pseudohallucinations. Psychol Med 1981;11265- 271
PubMedArticle
15.
Duke-Elder  SScott  GI Disorders of perception: visual hallucinations. Duke-Elder  SSystem of Ophthalmology Vol 12 London, England Henry Kimpton1971;562- 569
16.
Manford  MAndermann  F Complex visual hallucinations: clinical and neurobiological insights. Brain 1998;1211819- 1840
PubMedArticle
17.
Cogan  DG Visual hallucinations as release phenomena. Albrecht Von Graefes Arch Klin Exp Ophthalmol 1973;188139- 150Article
18.
Kolmel  HW Complex visual hallucinations in the hemianopic field. J Neurol Neurosurg Psychiatry 1985;4829- 38
PubMedArticle
19.
Lepore  FE Spontaneous visual phenomena with visual loss. Neurology 1990;40444- 447
PubMedArticle
20.
Olbrich  HMEngelmeier  MPPauleckhoff  DWaubke  T Visual hallucinations in ophthalmology. Graefes Arch Clin Exp Ophthalmol 1987;225217- 220
PubMedArticle
21.
Özsancak  CAuzou  P Palinopsia in Charles Bonnet syndrome [letter in French]. Presse Med 1998;27359
PubMed
22.
Schultz  GMelzack  R The Charles Bonnet syndrome: “phantom visual images.” Perception 1991;20809- 825
PubMedArticle
23.
Siatkowski  RMZimmer  BRosenberg  PR The Charles Bonnet syndrome: visual perceptive dysfunction in sensory deprivation. J Clin Neuroophthalmol 1990;10215- 218
PubMed
24.
Tueth  MJChong  JASamander  J The Charles Bonnet syndrome: a type of organic visual hallucinosis. J Geriatr Psychiatry Neurol 1995;81- 3
PubMedArticle
25.
Berrios  GEBrook  P The Charles Bonnet syndrome and the problem of visual perceptual disorders in the elderly. Age Ageing 1982;1117- 23Article
26.
Bartlett  JE A case of organized visual hallucinations in an old man with cataract, and their relationship to the phenomena of the phantom limb. Brain 1951;74363- 373
PubMedArticle
27.
Needham  WTaylor  RE Benign visual hallucinations, or phantom vision in vis-ually impaired and blind persons. J Vis Impairment Blindness 1992;86245- 248
28.
Foerster  O The cerebral cortex in man. Lancet 1931;2309- 312
29.
Lance  JW Simple formed hallucinations confined to the area of specific visual field. Brain 1976;99719- 734
PubMedArticle
30.
Price  JWhitlock  FAHall  RT The psychiatry of vertebro-basilar insufficiency with the report of a case. Psychiatr Clin (Basel) 1983;1626- 44
31.
Adachi  NWatanabe  TMatsuda  HOnuma  T Hyperperfusion in the lateral temporal cortex, the striatum and the thalamus during complex visual hallucinations: single photon emission computed tomography findings in patients with Charles Bonnet syndrome. Psychiatry Clin Neurosci 2000;54157- 162Article
32.
Anderson  SWRizzo  M Hallucinations following occipital lobe damage: the pathological activation of visual representations. J Clin Exp Neuropsychol 1994;16651- 663
PubMedArticle
33.
Ffytche  DHHoward  RJBrammer  MJDavid  AWoodruff  PWilliams  S The anatomy of conscious vision: an fMRI study of visual hallucinations. Nat Neurosci 1998;1738- 742Article
34.
Holroyd  SRabins  PV A three-year follow-up study of visual hallucinations in patients with macular degeneration. J Nerv Ment Dis 1996;184188- 189
PubMedArticle
35.
Rousseaux  MDebrock  DCabaret  MSteinling  M Visual hallucinations with written words in a case of left parietotemporal lesion. J Neurol Neurosurg Psychiatry 1994;571268- 1271
PubMedArticle
36.
Santhouse  AMHoward  RJFfytche  DH Visual hallucination syndromes and the anatomy of the visual brain. Brain 2000;1232055- 2064
PubMedArticle
37.
Rosenbaum  FHarati  YRRolak  L Visual hallucinations in sane people: the Charles Bonnet syndrome. J Am Geriatr Soc 1987;3566- 68
PubMed
38.
Hécaen  HAlbert  ML Disorders of visual perception. Human Neuropsychology New York, NY John Wiley & Sons1978;144- 167
39.
Podoll  KOsterheider  MNoth  J The Charles Bonnet syndrome [in German]. Fortschr Neurol Psychiatr 1989;5743- 60Article
40.
Teunisse  RJZitman  FGRaes  DCM Clinical evaluation of 14 patients with Charles Bonnet syndrome (isolated visual hallucinations). Compr Psychiatry 1994;3570- 75
PubMedArticle
41.
Berrios  GEBrook  P Visual hallucinations and sensory delusions in the elderly. Br J Psychiatry 1984;144662- 664
PubMedArticle
42.
Girkin  CAMiller  NR Central disorders of vision in humans. Surv Ophthalmol 2001;45379- 405
PubMedArticle
43.
Gold  KRabins  PV Isolated visual hallucinations and the Charles Bonnet syndrome: a review of the literature and presentation of six cases. Compr Psychiatry 1989;3090- 98
PubMedArticle
44.
Hécaen  HBadarocco  JG Les hallucinations visuelles au cours des ophthalmopathies et des lesions des nerfs et du chiasma optiques. Evol Psychiatr (Paris) 1956;21157- 179
45.
Holroyd  SRabins  PVFinkelstein  D  et al.  Visual hallucinations in patients with macular degeneration. Am J Psychiatry 1992;1491701- 1706
PubMed
46.
Norton-Willson  LMunir  M Visual perceptual disorders resembling the Charles Bonnet syndrome: a study of 434 consecutive patients referred to a psychoger-iatric unit. Fam Pract 1987;427- 35
PubMedArticle
47.
Teunisse  RJCruysberg  JRVerbeek  AZitman  FG The Charles Bonnet syndrome: a large prospective study in the Netherlands: a study of the prevalence of the Charles Bonnet syndrome and associated factors in 500 patients attending the University Department of Ophthalmology at Nijmegen. Br J Psychiatry 1995;166254- 257
PubMedArticle
48.
White  NJ Complex hallucinations in partial blindness due to eye disease. Br J Psychiatry 1980;136284- 286
PubMedArticle
49.
Dodd  JHeffeman  ABlake  J Visual hallucinations associated with Charles Bonnet syndrome: an ever increasing diagnosis. Ir Med J 1999;92344- 345
PubMed
50.
Fernandes  LHScassellati-Sforzolini  BSpaide  RF Estrogen and visual hallucinations in a patient with Charles Bonnet syndrome [case report]. Am J Ophthalmol 2000;129407
PubMedArticle
51.
Kurata  AMiyasaka  YYoshida  TKunii  MYada  KKan  S Venous ischemia caused by dural arteriovenous malformation: case report. J Neurosurg 1994;80552- 555
PubMedArticle
52.
McNamara  MEHeros  RCBollor  F Visual hallucinations in blindness: the Charles Bonnet syndrome. Int J Neurosci 1982;1713- 15
PubMedArticle
53.
Ormond  AW Visual hallucinations in sane people. BMJ 1925;2376- 377
54.
Brown  GCMurphy  RP Visual symptoms associated with choroidal neovascularization: photopsias and the Charles Bonnet syndrome. Arch Ophthalmol 1992;1101251- 1256
PubMedArticle
55.
Levine  AM Visual hallucinations and cataracts. Ophthalmic Surg 1980;1195- 98
56.
Holroyd  SRabins  PVFinkelstein  DLavrisha  M Visual hallucinations in patients from an ophthalmology clinic and medical clinic population. J Nerv Ment Dis 1994;182273- 276
PubMedArticle
57.
Pliskin  NHKiolbasa  TATowle  VL  et al.  Charles Bonnet syndrome: an early marker for dementia? J Am Geriatr Soc 1996;441055- 1061
PubMed
58.
O’Reilly  RChamberlaine  C Charles Bonnet syndrome: incidence and demographic and clinical features. Can J Psychiatry 1996;41259- 260
PubMed
59.
Teunisse  RJCruysberg  JRHoefnagels  WHvan’t Hof  MAVerbeek  ALZitman  FG Risk factors for the Charles Bonnet syndrome. J Nerv Ment Dis 1998;186190- 192Article
60.
Fuchs  TLauter  H Charles Bonnet syndrome and musical hallucinations in the elderly. Katona  CLevy  RDelusions and Hallucinations in Old Age London, England Gaskell, Royal College of Psychiatrists1992;187- 198
61.
Teunisse  RJCruysberg  JRHoefnagels  WHVerbeek  ALZitman  FG Visual hallucinations in psychologically normal people: Charles Bonnet’s syndrome. Lancet 1996;347794- 797
PubMedArticle
62.
Hart  CT Formed visual hallucinations: a symptom of cranial arteritis. BMJ 1967;3643- 644Article
63.
Fitzgerald  RG Visual phenomenology in recently blind adults. Am J Psychiatry 1971;1271533- 1539
PubMed
64.
Adair  DKKeshavan  MS The Charles Bonnet syndrome and grief reaction [letter]. Am J Psychiatry 1988;145895- 896
PubMed
65.
Dlugon  U Charles Bonnet syndrome. Psychiatr Pol 2000;34307- 316
PubMed
66.
Bhatia  MSKhastgir  UMalik  SC Charles Bonnet syndrome. Br J Psychiatry 1992;161409- 410
PubMedArticle
67.
Chaudhuri  A Charles Bonnet syndrome: an example of cortical dissociation syndrome affecting vision? J Neurol Neurosurg Psychiatry 2000;69704- 705
PubMedArticle
68.
Chen  CSLin  SFChong  MY Charles Bonnet syndrome and multiple sclerosis [letter]. Am J Psychiatry 2001;1581158- 1159
PubMedArticle
69.
Görgens  KLiedtke  M Charles Bonnet syndrome [in German]. Psychiatr Prax 1998;2585- 86
70.
Hosty  G Charles Bonnet syndrome: a description of two cases. Acta Psychiatr Scand 1990;82316- 317
PubMedArticle
71.
Terao  T Effect of carbamazepine and clonazepam combination on Charles Bonnet syndrome: a case report. Hum Psychopharmacol Clin Exp 1998;13451- 453Article
72.
Hori  HTerao  TShiraishi  YNakamura  J Treatment of Charles Bonnet syndrome with valproate. Int Clin Psychopharmacol 2000;15117- 119Article
73.
Paulig  MMentrup  H Charles Bonnet’s syndrome: complete remission of complex visual hallucinations treated by gabapentin. J Neurol Neurosurg Psychiatry 2001;70813- 814
PubMedArticle
74.
Nevins  M Charles Bonnet syndrome. J Am Geriatr Soc 1997;45894- 895
PubMed
75.
Ranen  NGPasternak  RERovner  BW Cisapride in the treatment of visual hallucinations caused by vision loss: the Charles Bonnet syndrome. Am J Geriatr Psychiatry 1999;7264- 266
PubMedArticle
76.
Thorpe  L The treatment of psychotic disorders in late life. Can J Psychiatry 1997;42 ((suppl 1)) 19S- 27S
PubMed
77.
Hartmann  PMKosko  DACohn  JA The Charles Bonnet syndrome (pseudohallucinations) in an AIDS patient with cytomegalovirus retinitis. J Nerv Ment Dis 1995;183549- 550
PubMedArticle
78.
Chen  JGomez  MViet  SO’Dowd  MA Visual hallucinations in a blind elderly woman: Charles Bonnet syndrome, an underrecognized clinical condition. Gen Hosp Psychiatry 1996;18453- 455
PubMedArticle
79.
Howard  RMeehan  OPowell  RMellers  J Successful treatment of Charles Bonnet syndrome type visual hallucinosis with low-dose risperidone. Int J Geriatr Psychiatry 1994;9677- 678
80.
Batra  ABartels  MWormstall  H Therapeutic options in Charles Bonnet syndrome. Acta Psychiatr Scand 1997;96129- 133
PubMedArticle
81.
Asaad  GShapiro  B Hallucinations: theoretical and clinical overview. Am J Psychiatry 1986;1431088- 1097
PubMed
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