Major reviewComplex Visual Hallucinations in the Visually Impaired: The Charles Bonnet Syndrome
Section snippets
History
The eponym was coined by de Morsier,33, 34 recognizing the renowned Genoese naturalist, philosopher, and biologist Charles Bonnet (1720–1793), who in 1769 described the hallucinatory experiences of his grandfather Charles Lullin,18 in probably the first scientific documentation of a hallucinatory experience.32 Lullin, an intelligent and articulate 89-year-old magistrate, described subjective perception of silent visions of men, women, birds, carriages, and buildings, varying in size, shape, and
Definitions
Perception is the intuitive recognition of stimuli presented through the sense organs, while imagery is an experience within the mind, usually without the sense of reality that characterizes perception. Imagery so intense as to accord a photographic quality is referred to as eidetic. Eidetic imagery may persist, especially when looking at poorly structured backgrounds. This phenomenon, characterized by the simultaneous existence of real and unreal images (the subject being aware of the
Epidemiology
CBS occurs predominantly in elderly, visually impaired people.116, 144
Clinical Features
One of the earliest descriptions of the clinical features of CBS is that of Ernest Naville,103 who described his own visual hallucinations as intriguing, non-deceptive, non-distressing, exclusively visual experiences (without auditory accompaniment), occurring during clear consciousness and normal perception. He was unable to consciously control the appearance and disappearance of his visions; they vanished on closing his eyes.
Diagnostic Criteria
There is lack of consensus regarding the diagnostic significance of ocular pathology, neurological disease, and the cognitive state in the context of CBS.
Damas Mora et al described CBS as a condition in which “persistent or recurrent visual pseudo-hallucinatory phenomena of a pleasant or neutral nature occur in a clear state of consciousness. Despite vividness, clarity and impelling character, they are recognized as unreal. The condition tends to occur in the elderly with clinically preserved
Associated Conditions
Charles Bonnet hallucinations have been documented in association with a wide spectrum of pathology of the eyes and visual pathway, including age-related macular degeneration,50, 55, 70, 99, 101, 132, 156 cataract,12, 91 choroideremia,156 corneal opacities,31 glaucoma,31 retinal detachment,31, 132 enucleation,38, 88 multiple sclerosis with optic neuritis,25 retinitis pigmentosa,48 occipital infarction with both homonymous hemianopia37, 82 and bilateral loss of vision,135 venous congestion of
The Neuroanatomic Basis of Complex Visual Hallucinations
Foerster,47 studying the effects of faradic stimulation of various areas of the cerebral cortex, noted that stimulation of area 17 (the area striata) and area 18 resulted in subjective perception of elementary visual sensations/flashing lights, whereas that of area 19 (the visual association area) resulted in the subjective perception of complex formed visual sensations including figures, people, and animals. It has subsequently been suggested that complex hallucinations originate from activity
Theories of Pathogenesis
Bonnet himself suggested that these hallucinations have their origin in the part of the brain subserving visual function.18 In 1932 Jackson, conceptualizing the nervous system as a hierarchy of three levels, higher (cortical), middle (sub-cortical), and lower (brain-stem), postulated that higher centers exert a controlling influence on sub-cortical centers, loss of which allows the release of activity in disinhibited sub-cortical centers, resulting in hallucinations.138
Differential Diagnosis
The visually impaired are not immune to hallucinations secondary to other neuropsychiatric conditions or emotional disturbances;104 it is therefore important to exclude other possible causes of complex visual hallucinations, such as peduncular hallucinosis, Alzheimer's disease, delirium, Parkinsonism and levodopa-induced hallucinations, Lewy Body dementia, (recovery from) migraine coma, schizophrenia, medication, epilepsy, and hallucinations experienced during sleep–wake transitions.94, 136
Up
Management
Physician awareness and compassion are the mainstays of management for CBS. Though there is no universally effective therapy, treatment may not always be necessary, especially in cognitively intact patients,149 since visual hallucinations often cease spontaneously, in response to either improvement or further deterioration of visual function.150 Moreover, many patients with CBS are not distressed by the content of their hallucinations, as much as by anxiety about the significance of their
Discussion
There has been much controversy and disagreement about inclusion and exclusion criteria for CBS. Such criteria are arguably of limited relevance since they do not alter management in any way. In the pursuit of strict, well-defined criteria we perhaps overlook the clinical significance of this phenomenon—visual hallucinations can and do occur in patients with visual impairment. Such patients are often elderly and may be considerably distressed by their visions, the nature of which they do not
Conclusion
Eponymous labels are of limited value; however the term Charles Bonnet Syndrome may serve the essential function of reminding ophthalmologists that visual hallucinations can occur in the context of visual loss.29
Visual impairment is increasingly common in the elderly. Age-related macular degeneration, the leading cause of new irreversible blindness in the elderly,102 has been estimated to occur in 1 in 5 people over the age of 65 years.81 It is important that we recognize the occurrence of
Method of Literature Search
We undertook a Medline search using the following keywords: Charles Bonnet, visual hallucinations, pseudohallucinations and phantom visions. Relevant citations from the reference lists of selected articles were also reviewed. Inclusion or exclusion of any article in the text was based on relevance and the necessity to avoid redundancy.
Outline
I. History
II. Definitions
III. Epidemiology
A. Prevalence
B. Age distribution
C. Gender distribution
D. Under-recognition
IV. Clinical features
A. Content
B. Movement
C. Stereotypy
D. Triggering and relieving factors
E. Course
F. Hallucinations of other modalities
G. Patients' reaction to their hallucinations
H. Insight
I. The mental state
J. Fear of insanity
K. Visual function
L. Quality of life in visually impaired patients
M. Neurological features
N. Other risk factors
V. Diagnostic criteria
VI. Associated
Acknowledgements
The authors reported no proprietary or commercial interest in any product mentioned or concept discussed in this article. The authors wish to thank Volker Schloenvoigt, Vladimir Thaller, Jack Kanski, Astrid Moreno-Chamorro, and Alison Alexander for kind help with translation of French, German, and Polish articles. They also wish to express their gratitude to the library staff at the Derriford Hospital, Plymouth: Jeremy Smith, Samantha Brown, Abbie Cooper, Sarah Cohen, Sue Morris, Marilyn
References (159)
- et al.
Transient formed visual hallucinations following macular translocation for subfoveal choroidal neovascularization secondary to age-related macular degeneration
Am J Ophthalmol
(2001) - et al.
Visual hallucinations in a blind elderly womanCharles Bonnet syndrome, an underrecognized clinical condition
Gen Hosp Psychiatry
(1996) - et al.
Estrogen and visual hallucinations in a patient with Charles Bonnet syndrome
Am J Ophthalmol
(2000) - et al.
Central disorders of vision in humans
Surv Ophthalmol
(2001) - et al.
Isolated visual hallucinations and the Charles Bonnet syndromea review of the literature and presentation of six cases
Compr Psychiatry
(1989) - et al.
A study of visual hallucinations in Alzheimers disease
Am J Geriatr Psych
(1995) - et al.
Alzheimers diseasea review for the ophthalmologist
Surv Ophthalmol
(2001) - et al.
Cortical response to exogenous visual stimulation during visual hallucinations
Lancet
(1995) Phantom limbs and the concept of a neuromatrix
Trends Neurosci
(1990)Charles Bonnet syndrome in leprosy; prevalence and clinical characteristics
Acta Psychiatr Scand
(1996)
Hyperperfusion in the lateral temporal cortex, the striatum and the thalamus during complex visual hallucinationssingle photon emission computed tomography findings in patients with Charles Bonnet syndrome
Psychiatry Clin Neurosci
The Charles Bonnet syndrome and grief reaction
Am J Psychiatry
Visual hallucinations. The Charles Bonnet syndrome and bereavement
Med J Aust
Hallucinations following occipital lobe damagethe pathological activation of visual representations
J Clin Exp Neuropsychol
Charles Bonnet syndrome
Br J Psychiatry
Hallucinationstheoretical and clinical overview
Am J Psychiatry
Charles Bonnet syndrome
Br J Psychiatry
Visual hallucinations
J R Coll Physicians Lond
A case of organised visual hallucinations in an old man with cataract, and their relationship to the phenomena of the phantom limb
Brain
Therapeutic options in Charles Bonnet syndrome
Acta Psychiatr Scand
The illusion of realitya review and integration of psychological research on hallucinations
Psychol Bull
Visual hallucinations and sensory delusions in the elderly
Br J Psychiatry
The Charles Bonnet syndrome and the problem of visual perceptual disorders in the elderly
Age Ageing
Charles Bonnet syndrome
Br J Psychiatry
Hallucinations
Percept Mot Skills
Visual symptoms associated with choroidal neovascularization. Photopsias and the Charles Bonnet syndrome
Arch Ophthalmol
Association among visual hallucinations, visual acuity, and specific eye pathologies in Alzheimers diseasetreatment implications
Am J Psychiatry
Cortical blindness and visual imagery
Neurology
Charles Bonnet syndromean example of cortical dissociation syndrome affecting vision
J Neurol Neurosurg Psychiatry
Charles Bonnet syndrome and multiple sclerosis
Am J Psychiatry
Visual hallucinations as release phenomena
Albrecht Von Graefes Arch Klin Exp Ophthalmol
Phantom vision
Arch Neurol
Charles Bonnet Syndrome an example of cortical dissociation syndrome affecting vision?
J Neurol Neurosurg Psychiatry
Charles Bonnet hallucinationsa case series
Can J Psychiatry
The Charles Bonnet syndrome in perspective
Psychol Med
Le Syndrome de Charles Bonnethallucinations visuelles des viellards sans deficience mentale
Ann Med Psychol
Les Hallucinations
Rev Otoneuroophtalmol
Les automatismes visuels. Hallucinations rétrochiasmatiques
Schweiz Med Wochenschr
Visual hallucinations associated with Charles Bonnet Syndrome—an ever increasing diagnosis
Ir Med J
Disorders of perceptionvisual hallucinations
A neurophysiologic theory of hallucinations
Hallucinose musicale7 cas
Rev Neurol (Paris)
The Charles Bonnet syndromea review
J Nerv Ment Dis
The anatomy of conscious visionan fMRI study of visual hallucinations
Nat Neurosci
Visual phenomenology in recently blind adults
Am J Psychiatry
Cited by (319)
Charles Bonnet Syndrome Adversely Affects Vision-Related Quality of Life in Patients with Glaucoma
2024, Ophthalmology GlaucomaVisual hallucinations in elderly people – a challenging diagnosis: Charles Bonnet syndrome
2023, NPG Neurologie - Psychiatrie - GeriatrieChloropsia in the Charles Bonnet syndrome
2022, American Journal of Ophthalmology Case ReportsCitation Excerpt :A case series on patients with CBS-induced hallucinations secondary to glaucoma, much like the one described in this report, described multiple individuals with visual acuities between 20/20 and 20/40.11 Similar findings have prompted some controversy over whether visual impairment is required for CBS diagnosis.1,11 Thus, our patient's presentation of CBS with relatively preserved visual acuity, while somewhat uncommon, is not unprecedented.
Severity of visual hallucinations worsened with lisinopril despite receiving sedative hypnotic therapy or antipsychotic therapy: First case report
2022, Research in Social and Administrative PharmacyCharles Bonnet Syndrome in Patients with Open-Angle Glaucoma: Prevalence and Correlation to Visual Field Loss
2022, Ophthalmology Glaucoma