Charles Bonnet syndrome: an early marker for dementia?

Vision loss and hallucinations: perspectives from neurology and ophthalmology

PURPOSE OF REVIEW

The aim of this article is to summarize the evidence for visual impairment as a risk factor for visual hallucinations in neurologic disease and recent advances in our understanding of the central visual pathways that mediate this association.

RECENT FINDINGS

Recent studies have described the prevalence Charles Bonnet syndrome and questioned its lack of association with cognitive impairment, used advanced neuroimaging to show that disinhibition of the occipital lobe is involved in the pathogenesis of visual hallucinations in Parkinson's disease, and demonstrated that visual impairment because of eye disease is a consistent risk factor for visual hallucinations across a number of different neurodegenerative disease populations.

SUMMARY

Through connections between the primary visual cortex and other brain structures, visual function is closely tied to visual hallucinations. Given that the vast majority of vision loss is caused by ophthalmic disease, much of which is preventable or treatable, the detection and treatment of vision loss in at-risk populations may reduce the burden and consequences of visual hallucinations in older adults.

An overview of psychological and social factors in Charles Bonnet syndrome

Charles Bonnet syndrome (CBS) is a condition where cognitively normal individuals with sight impairment experience simple and/or complex visual hallucinations. The exact pathogenesis of CBS is unknown; however, deafferentation is often recognised as a causal mechanism. Studies have provided insight into the multifaceted impact of CBS on wellbeing. Onset of CBS may cause distress among those believing visual hallucinations are indicative of a neurological condition. Hallucinatory content is often congruent with the emotional response. For example, hallucinations of a macabre nature typically result in a fearful response. Visual hallucinations may be highly disruptive, causing everyday tasks to become challenging. Clinical management relies on forewarning and pre-emptive questioning. Yet, knowledge and awareness of CBS is typically low. In this review, we provide a summary of the social and psychological implications of CBS and explore recent developments aimed at raising awareness and improving patient management.

Benefit of psychiatric evaluation on anxiety in patients with Charles Bonnet syndrome

Objective

Charles Bonnet syndrome (CBS) is defined as an occurrence of visual hallucinations (VHs) in the absence of any psychiatric/neurological disorder. Significantly reduced vision due to age-related macular degeneration (AMD), cataract or glaucoma is the most common cause for CBS. Aim of this randomized controlled study was to assess whether additional treatment by a psychiatrist is beneficial for patients with CBS.

Methods and Analysis

Patients with visual acuity of 0.5 LogMAR or worse in the better eye were screened. Instruments used were an interview asking about details of the VH, a mental test and a questionnaire on quality of life. Patients with CBS were randomised into two groups: in group 1, a patient-doctor consultation was performed by an ophthalmologist, and in group 2 a consultation and, if needed, additional medical assessment and treatment was given by a psychiatrist.

Results

4900 patients were screened. 390 patients met the inclusion criteria and among these a CBS prevalence of 34 patients (8.7%) was found. The female-to-male ratio was 4:1 and the average age was 79.3 ± 9.7 years. Four different types of VH were observed: 41% humans (n=14), 32% geometrical shapes/patterns (n=11), 15% plants (n=5) and 12% animals (n=4). The change in quality of life in patients with CBS was not significantly different in both groups (p=0.727, ophthalmologist: n=18, psychiatrist: n=16).

Conclusion

It is essential for medical staff involved with patients suffering from severe vision loss to be aware of CBS. This will help to better identify and interpret symptoms and could also lead to a more adequate treatment for affected patients.

Discussion

It is essential for medical staff involved with patients suffering from severe vision loss to be aware of CBS. This will help to better identify and interpret symptoms and could also lead to a more adequate treatment for affected patients.

Frightening Complex Visual Hallucinations in an Elderly Patient with Ophthalmological Pathology and Vascular Dementia

A lady in her 90s was referred to the Later Life Team (LLT) in a rural area of the United Kingdom with complex visual hallucinations (VH). She had significant ophthalmological pathology, including cataracts, a branch retinal vein occlusion, and vitreous haemorrhage. The hallucinations included seeing monkeys ripping the heads off of her cats and lions prowling the garden. The patient was distressed by the hallucinations and believed them to be real events. Her management involved low dose olanzapine and requesting that her ophthalmological surgery be expedited. The surgery resulted in a significant reduction in VH. A diagnosis of vascular dementia went on to be made following cognitive testing and imaging. The cognitive impairment may have contributed to the patient's inability to identify her experiences as hallucinations and thus render her without insight. A review of the computed tomography (CT) scans performed prior to the patient's presentation to our service confirmed significant vascular pathology including small vessel disease and lacunar infarcts. Cognitive testing confirmed a cognitive impairment which had gone unnoticed by her family. This case leads to an interesting discussion regarding diagnosis in complex VH in cases of significant ophthalmological pathology but a lack of insight. Various authors have proposed theories to explain VH; cortical release and the Perception and Attention Deficit (PAD) model are explored as possible explanations for the experiences of this patient.

Evaluation of the Clinical Features, Management, and Prognoses of Patients With Charles Bonnet Syndrome

Charles Bonnet syndrome (CBS) is characterized by visual hallucinations with preservation of cognitive abilities. The hallucinations consist mostly of vivid (realistic) objects and tend to reoccur. Here, we evaluate the etiologies, symptoms, treatments, and prognoses of 13 CBS cases. All patients had visual hallucinations but were normal on cognitive and psychiatric assessments. Patient demographic and clinical characteristics, treatment options, and 3-month follow-up data were retrospectively reviewed. The possible causes of CBS and what the patients perceived during their hallucinations were recorded. Antipsychotic agents, such as risperidone and quetiapine, and anticonvulsants, such as levetiracetam, may be effective in some cases.

The elephant in the room: understanding the pathogenesis of Charles Bonnet syndrome

PURPOSE

Charles Bonnet syndrome (CBS) is a syndrome characterised by complex visual hallucinations in individuals who are cognitively normal, though often elderly and visually impaired. Although first described over 250 years ago, the condition remains poorly understood and difficult to treat.

RECENT FINDINGS

Our understanding of CBS pathogenesis has advanced little since it was first described, and much of the recent literature consists of case studies strikingly similar to the first published account of CBS. However, imaging studies have provided some indication as to the cortical areas implicated in the genesis of complex visual hallucinations, and the existence of similar hallucinatory syndromes in other sensory modalities suggests a common underlying mechanism.

SUMMARY

This review begins by describing what is currently known about CBS, focusing on epidemiology, clinical presentation and diagnosis. It then explores potential starting points for better understanding the pathogenesis of CBS, namely the existence of similar conditions in other sensory modalities and the reproduction of complex visual hallucinations in sensory deprivation scenarios. Finally, it discusses how CBS should be approached in clinical practice.

Charles Bonnet Syndrome: A Review of the Literature

Charles Bonnet syndrome (CBS) commonly occurs in older adults with visual impairments, particularly those with age-related macular degeneration. It is characterized by complex visual hallucinations in individuals without mental disorders. The authors explore diagnostic criteria, demographic characteristics, clinical features, theories of pathogenesis, and management options for people who are diagnosed with CBS.

The utility and application of electrophysiological methods in the study of visual hallucinations

Visual hallucinations (VH) are a common symptom in multiple clinical and non-clinical populations. Although structural and functional neuroimaging has informed the understanding of VH, temporal resolution is limited. Electrophysiological techniques provide a complementary perspective on dynamic and temporal aspects of neural functioning, offering greater insight into the mechanisms underlying their formation. In this review we examine and critically evaluate the emerging evidence base utilising electrophysiological approaches in the study of VH. Overall, increased visual system excitability, dysfunctional visual processing and network connectivity, and cholinergic dysfunction have been consistently observed in VH-prone pathologies. However, a major limitation is in the lack of robust experimental studies and the reliance on single case reports. We conclude that electrophysiology provides tentative evidence for the contribution of bottom-up, top-down, and network dysfunction in the aetiology of VH, supporting several existing VH models. Furthermore, we discuss how electrophysiology has been directly utilised in specific clinical interventions for VH. Further exploration utilising electrophysiology in combination with, for example, neuroimaging will help better understand VH aetiology while aiding in the development of novel therapeutic interventions for this difficult to treat symptom.

Cognitive impairment and Charles Bonnet syndrome: a prospective study

OBJECTIVES

Charles Bonnet syndrome (CBS) is a common cause of visual hallucinations in older people. The relationship between CBS and cognitive impairment is unclear, but anecdotal reports exist of dementia emerging in patients diagnosed with CBS. This work set out to determine if there is an increased incidence of dementia, and increased severity of cognitive impairment, in people with CBS compared to controls from the same clinical setting.

METHOD

People over 65 attending low-vision and glaucoma clinics, and a cohort of age-matched controls, underwent a psychiatric assessment. The cohorts were followed up after one year.

RESULTS

Mild cognitive impairment was present in 2/12 CBS participants and 2/10 controls. Partial insight was seen in nine CBS participants. Two participants with CBS, and no controls, developed dementia at follow-up. No significant differences in performance on the ACE-R were found between the groups. Both participants who developed dementia had partial insight and hallucinations of familiar figures at diagnosis of CBS, and one had mild cognitive impairment.

CONCLUSIONS

Reassurance that CBS is universally benign may be misplaced. Some people given this diagnosis go on to develop dementia. Cognitive testing at the point of diagnosis was unable to identify those at risk of this outcome. Partial insight, the presence of Mild Cognitive Impairment, and hallucinations of familiar figures at diagnosis of CBS may confer an increased risk of subsequent dementia diagnosis. Copyright © 2017 John Wiley & Sons, Ltd.

Hallucinations Experienced by Visually Impaired: Charles Bonnet Syndrome

Supplemental digital content is available in the text.

Charles Bonnet Syndrome is a condition where visual hallucinations occur as a result of damage along the visual pathway. Patients with Charles Bonnet Syndrome maintain partial or full insight that the hallucinations are not real, absence of psychological conditions, and absence of hallucinations affecting other sensory modalities, while maintaining intact intellectual functioning. Charles Bonnet Syndrome has been well documented in neurologic, geriatric medicine, and psychiatric literature, but there is lack of information in optometric and ophthalmologic literature. Therefore, increased awareness of signs and symptoms associated with Charles Bonnet Syndrome is required among practicing clinicians. This review of the literature will also identify other etiologies of visual hallucinations, pathophysiology of Charles Bonnet Syndrome, and effective management strategies.

Hallucinations in Healthy Older Adults: An Overview of the Literature and Perspectives for Future Research

KEY POINTS

➢ Studies suggest a substantial minority of healthy older adults have hallucinatory experiences, in line with existing evidence on hallucinations in other age groups, though it is still unclear if hallucination prevalence increases or declines with age in older cohorts.

➢ Stigma attached to both hallucinations and ageing leads to considerable under-reporting of these experiences in healthy older adults and may negatively bias how professionals, family members, and the public respond.

➢ Why and when hallucinations in healthy older adults remit, persist, or progress to other clinical disorders remains poorly understood.

➢ Current evidence points to a range of factors associated with hallucinations in older adults including decline in sensory or cognitive functioning, poor sleep, and psychosocial stressors (e.g., social isolation, loneliness, and bereavement), highlighting the need for accurate assessment and tailored interventions.

Hallucinations, though common in youth and younger adults, are not the preserve of these age groups. Accumulating evidence shows that hallucinatory experiences are also present at surprisingly high rates in healthy older adults in the general community. Furthermore, stigma and misunderstanding of hallucinations, together with ageism, may lead to under-reporting of these experiences by older adults, and misdiagnosis or mismanagement by health and mental health practitioners. Consequently, improved public and professional knowledge is needed about the nature and significance of hallucinations with advancing age. The purpose of this review is to provide a comprehensive overview, and critical analysis, of research on the prevalence, psychosocial, and neurobiological factors associated with hallucinations in people aged 60 years and over. To the best of our knowledge, this is the first review of its kind in the literature. The evidence supports a dynamic conceptualization of hallucinations, in which the emergence of hallucinations is viewed as a balance between the sensory, cognitive, or social impairments accompanying advancing age and the degree to which compensatory processes elicited by these impairments are successful. We briefly summarize the implications of the literature for aged care services and interventions, and stress that far more studies are needed in this important field of research.

Visual Hallucination in Craniometaphyseal Dysplasia Successfully Treated with Olanzapine

Objective:

To report the successful treatment of visual hallucinations in a patient with craniometaphyseal dysplasia (CMD) with olanzapine.

Case Summary:

A 15-year-old girl with CMD presenting with transient episodes of total blindness and complex visual hallucinations was successfully treated with olanzapine.

Discussion:

The co-occurrence of visual hallucination and blindness in this patient suggests a variety of the Charles Bonnet syndrome, a diagnosis made almost exclusively in the older population. Compared with traditional antipsychotics, the reduced propensity of olanzapine to produce extrapyramidal side effects may make it more favorable in specific situations.

Conclusions:

More experience with olanzapine in treating visual hallucinations is needed to determine whether it is more effective than typical antipsychotics in treating visual hallucinations associated with CMD or Charles Bonnet syndrome.

Seeing the unseen: Charles Bonnet syndrome revisited

Charles Bonnet syndrome (CBS) is a rare condition that encompasses three clinical features: complex visual hallucinations, ocular pathology causing visual deterioration, and preserved cognitive status. Common associated ocular pathologies include age-related macular degeneration, glaucoma, and cataracts. Several theories have been proposed to try to explain the visual hallucinations. However, the pathophysiology remains poorly understood, and treatment is largely based on anecdotal data. The lack of awareness of CBS among medical professionals often leads to inappropriate diagnosis and medication. In a country like India, where awareness of mental health is not widespread, cultural myths and stigma prevent patients from seeking professional help. Here we describe two cases of CBS and revisit different ocular morbidities that have been reported to occur in conjunction with CBS. Psychiatrists and ophthalmologists alike must be sensitive to this clinical condition to ensure prompt diagnosis and treatment.

Charles Bonnet syndrome and cognitive impairment: a systematic review

ABSTRACT Background: Charles Bonnet syndrome (CBS) is defined as complex persistent visual hallucinations in the absence of mental disorder. It is common in conditions causing significant visual impairment. Many authors advise reassurance, considering the condition benign. However, others have suggested that CBS may in some patients represent the early stages of dementia. This review seeks to systematically examine the evidence for any link between CBS and cognitive impairment. Methods: Literature search using OVID Medline, PsychINFO, and Embase. Results: Three studies where cognitive functioning was the primary focus of the research were found. All were small, did not properly apply diagnostic criteria, and reported conflicting results. Eight other studies commented on cognitive functioning, but none used tests sufficiently sensitive to detect changes seen in early dementia. One hundred and thirty four case reports were scrutinized, and reports found of 16 patients with CBS where dementia emerged. High rates of partial insight at diagnosis of CBS were seen in these patients. Conclusions: There have been no adequately powered studies, using accepted diagnostic criteria, where changes in cognitive functioning were the primary outcome. Existing studies are of limited methodological quality and allow no conclusion regarding a relationship between cognitive impairment and CBS to be reached. Numerous case reports of dementia developing in patients with CBS and partial insight raise the possibility of a link between these conditions. There is a clear need for properly constructed studies to investigate this.

Considering the senses in the diagnosis and management of dementia

Associations between dementia and impairments in hearing, vision, olfaction and (to a lesser degree) taste have been identified. Hearing impairment has been shown to precede cognitive decline, but it is not clear if the hearing loss is an early marker of dementia or a modifiable risk factor. Olfactory impairment is seen in many neurodegenerative conditions, but it has been shown that those with dementia have particular difficulties with the recognition and identification of odours rather than the detection, suggesting a link to impairment of higher cognitive function. Olfactory impairment has been shown to be predictive of conversion from mild cognitive impairment to Alzheimer's disease with 85.2% sensitivity. As cognitive function deteriorates, the world is experienced at a sensory level, with reduced ability to integrate the sensory experiences to understand the context. Thus, people with dementia are very sensitive to sensory experiences and their environment needs to be managed carefully to make it understandable, comfortable, and (if possible) therapeutic. Light can be used to stabilise the circadian rhythm, which may be disturbed in dementia. Music therapy, aromatherapy, massage and multisensory stimulation are recommended by NICE for the management of behavioural and psychological symptoms of dementia (BPSD), although the mechanisms behind such interventions are poorly understood and evidence is limited. Sensory considerations are likely to play a greater role in dementia care in the future, with the development of purpose-built dementia care facilities and the focus on non-pharmacological management strategies for BPSD.

Olfactory Hallucinations without Clinical Motor Activity: A Comparison of Unirhinal with Birhinal Phantosmia

Olfactory hallucinations without subsequent myoclonic activity have not been well characterized or understood. Herein we describe, in a retrospective study, two major forms of olfactory hallucinations labeled phantosmias: one, unirhinal, the other, birhinal. To describe these disorders we performed several procedures to elucidate similarities and differences between these processes. From 1272, patients evaluated for taste and smell dysfunction at The Taste and Smell Clinic, Washington, DC with clinical history, neurological and otolaryngological examinations, evaluations of taste and smell function, EEG and neuroradiological studies 40 exhibited cyclic unirhinal phantosmia (CUP) usually without hyposmia whereas 88 exhibited non-cyclic birhinal phantosmia with associated symptomology (BPAS) with hyposmia. Patients with CUP developed phantosmia spontaneously or after laughing, coughing or shouting initially with spontaneous inhibition and subsequently with Valsalva maneuvers, sleep or nasal water inhalation; they had frequent EEG changes usually ipsilateral sharp waves. Patients with BPAS developed phantosmia secondary to several clinical events usually after hyposmia onset with few EEG changes; their phantosmia could not be initiated or inhibited by any physiological maneuver. CUP is uncommonly encountered and represents a newly defined clinical syndrome. BPAS is commonly encountered, has been observed previously but has not been clearly defined. Mechanisms responsible for phantosmia in each group were related to decreased gamma-aminobutyric acid (GABA) activity in specific brain regions. Treatment which activated brain GABA inhibited phantosmia in both groups.

Clinical phenomenology and mortality in Charles Bonnet syndrome

BACKGROUND/AIM

Despite existing diagnostic criteria for Charles Bonnet syndrome (CBS), clinical manifestations vary greatly. We examined the clinical course and mortality of patients diagnosed with CBS.

METHODS

We conducted a retrospective chart review of patients with CBS. We collected demographic and clinical information and medical burden scores. Kaplan-Meier mortality curves were compared using log-rank test. Cox proportional hazard model was used for multivariate analysis and hazard ratio (HR). Mortality was compared to expected mortality from Minnesota population.

RESULTS

Seventy-seven patients with CBS had a mean age of 79.5 (standard deviation ± 13.0) and were predominantly Caucasian (97%) and female (73%). In all, 20 (26%) subsequently developed a dementia syndrome, most often Lewy body. A total of 46 (60%) deaths occurred with an average follow-up time of 33.0 months. Characteristics associated with mortality included older age (75-84 [HR 3.34, P = .029], >85 [HR 4.58, P = .007]) and renal disease (HR 3.39 with 95% confidence interval 1.31-8.80, P = .012). Medical burden scores were not associated with overall mortality. Mortality was high compared to Minnesota population (P < .0001).

CONCLUSIONS

A large proportion of patients with CBS developed dementia, and there was a high mortality rate associated with older age and renal disease. Medical burden was not associated with mortality.

Analysis of caregiver perceptions of "hallucinations" in people with dementia in institutional settings

This study investigated the meanings and etiologies of hallucinations in persons with dementia. Participants were 74 nursing home residents aged ≥ 65 diagnosed with dementia. Most of the reported visual and auditory hallucinations involved talking to persons who are not present, a phenomenon described as either a visual or auditory hallucination, or both. All participants who were reported to experience a hallucination had poor vision. Current results suggest that hallucination was a term staff caregivers used for the phenomena they could not easily explain, demonstrating their lack of understanding of the resident and/or the phenomena they termed hallucination. The classification of hallucinations into subtypes may not be meaningful, and most visual and auditory hallucinations were not associated with negative affect. Some hallucinations occurred out of boredom, which exacerbated the sensory deprivation experienced by these persons, thereby increasing the likelihood of hallucinations.

Yi-gan san for treatment of charles bonnet syndrome (visual hallucination due to vision loss): an open-label study

BACKGROUND

Recent studies indicate that the traditional Japanese herbal medicine yi-gan san (YGS, yokukan-san in Japanese) may be safe and useful for treating behavioral and psychological symptoms in dementia, borderline personality disorder, neuroleptic-induced tardive dyskinesia, and treatment-resistant schizophrenia. Visual hallucinations are common and often distressing consequences of vision loss, particularly in age-related macular degeneration. Charles Bonnet syndrome (CBS) is defined by the triad of complex visual hallucinations, ocular pathology causing visual deterioration, and preserved cognitive status. We aimed at evaluating both the efficacy and safety of YGS in patients with CBS.

METHODS

Twenty patients diagnosed with CBS were investigated, according to the diagnostic criteria established by Gold and Rabins and Teunisse. Participants were treated in a 4-week open-label study with YGS at an average daily dose of 5.8 ± 2.6 g (2.5-7.5 g). Psychometric instruments used to assess efficacy included the Neuropsychiatric Inventory, hallucination subscale of the Positive and Negative Syndrome Scale, and Clinical Global Impression. No cases of serious adverse events were attributed to the study's drug therapy.

RESULTS

A significant decrease in visual hallucination was observed at 2 and 4 weeks in the Neuropsychiatric Inventory, hallucination subscale of the Positive and Negative Syndrome Scale, and Clinical Global Impression scores.

CONCLUSIONS

Yi-gan san may be an effective and safe therapy to control visual hallucination in patients with CBS and should be further tested in double-blind, placebo-controlled trials. Given the design characteristics of this trial, the present findings should be taken cautiously.

Charles Bonnet syndrome: a review

PURPOSE OF REVIEW

The aging of the population and the resultant increase in the number of patients with low vision due to age-related macular degeneration and other ocular diseases necessitate an increase in awareness of the Charles Bonnet syndrome among ophthalmic care providers.

RECENT FINDINGS

The clinical features of Charles Bonnet syndrome have been described by several different authors as formed visual hallucinations due to disturbances of the visual system in patients who are otherwise mentally normal. Theories regarding the causes underlying the Charles Bonnet syndrome are multifaceted and offer insight into the function of the visual system. The incidence of the Charles Bonnet syndrome varies among different population groups, but is underdiagnosed in most settings. Recent case reports of treatment options involve varied pharmacologic interventions, but visual improvement and patient reassurance remain the mainstays of treatment.

SUMMARY

As Charles Bonnet syndrome becomes more prevalent as the population ages, all physicians who care for low vision or elderly patients should be aware of its clinical characteristics and treatment options. Understanding of this syndrome by caregivers will lead to decreased anxiety among the patients who experience it. Further exploration of treatment options will be necessary in the future.

Charles Bonnet Syndrome: Case series

Since its first description in 1760, Charles Bonnet syndrome (CBS) has been reported in many studies. The main characteristics are visual hallucinations, preserved awareness of unreal visions, and absence of psychotic symptoms. CBS can occur with lesions located anywhere along the central visual pathway, from the eye to the calcarine fissure.

Objective

To describe patients with CBS and carry out a review of the literature.

Methods

Six patients with visual hallucinations were evaluated in an outpatient memory clinic between 2001 and 2008, and their clinical characteristics recorded.

Results

Four patients were female, and the mean age was 74.5±16.9 years. Three patients had visual loss secondary to eye disease and three due to cerebral lesions. The visions consisted of animals, persons, moving objects, bizarre creatures or colored forms, and were considered disturbing by five patients. Five patients received treatment, and only three reported partial benefit from the therapy. Complete recovery was not seen in any of the subjects.

Conclusions

CBS is relatively rare and its recognition is important to avoid misdiagnoses with psychiatric or dementing illnesses.

Charles Bonnet syndrome in age-related macular degeneration: the nature and frequency of images in subjects with end-stage disease

INTRODUCTION

The term Charles Bonnet syndrome (CBS) is used to describe visual hallucinations resulting from ocular pathology. As part of a larger case-control study we assessed factors which may predispose to this phenomenon in Age-related macular degeneration (AMD).

METHODS

Three-hundred and sixty cases of late AMD underwent a detailed questionnaire about visual symptoms experienced. Potential ocular and environmental risk factors were compared in two groups; those experiencing symptoms of CBS (n = 97) and those not experiencing CBS symptoms (n = 263).

RESULTS

Twenty-seven percent experienced CBS. Poor visual acuity was the only factor associated with the development of these images in AMD with an odds ratio of 3.50 (95% CI 1.64-7.48, p = 0.001) for those with best binocular visual acuity worse than 6/36. In those who experienced CBS, the images tended to be straight ahead (84.5%), colored (72.2%), have moving parts (62.9%), and occur on average once per day (34%). The most common visual image was of people (19.6%) followed by geometric patterns (15.8%). The majority (71.1%) felt the experience to be neither pleasant nor unpleasant. In 41% images were present throughout the course of their disease. There was no association between visual acuity and complexity of images.

CONCLUSION

The prevalence of CBS in late AMD is high, the main risk factor being poor better eye visual acuity. The most commonly experienced hallucinations were of people. Although most patients were unperturbed by the images, reassurance of their benign nature was welcomed. Practitioners should be aware that resolution of symptoms over time does not always occur.

Dementia with lewy bodies and charles bonnet syndrome

BACKGROUND

Ophthalmologists may be the first to hear about formed visual hallucinations in the setting of visual loss. Although such hallucinations are likely benign and occur in association with the Charles Bonnet syndrome, it is important to be aware of the strong association of hallucinations with dementia with Lewy bodies because the latter diagnosis is associated with significant prognostic and therapeutic implications for the patient.

METHODS

Single case report.

RESULTS

A patient with macular disease was presumed to have formed hallucinations due to the Charles Bonnet syndrome and was subsequently diagnosed with dementia with Lewy bodies after being admitted to a psychiatric facility.

CONCLUSION

Both patients with the Charles Bonnet syndrome and patients with dementia with Lewy bodies can present with formed visual hallucinations. Ophthalmologists and retina specialists, in particular, should be familiar with the features of dementia with Lewy bodies because the diagnosis of this condition can allow appropriate intervention and help prevent drug-related side effects. If there is any suspicion of early dementia in such patients, they may benefit from neuropsychiatric evaluation.

Charles Bonnet Syndrome: successful treatment of visual hallucinations due to vision loss with selective serotonin reuptake inhibitors

Visual hallucinations are a common and often distressing consequence of vision loss, particularly in age-related macular degeneration. Charles Bonnet Syndrome (CBS) is defined by the triad of complex visual hallucinations, ocular pathology causing visual deterioration and preserved cognitive status. So far, although this condition is frequent, no established treatment for CBS has been stated. We report here the case of a 78-year-old woman, who came in our hospital because of a 4-week long mild depressive symptomatology. For 1 year she experienced daily sudden, unexpected, vivid and elaborate hallucinations. Insight was completely present, so the patient stated that the hallucinations were unreal and that the faces, geometrical figures and animals she saw every day were possibly due to her vision loss. The Mini Mental State Examination, digit span and verbal fluency were administered and no cognitive impairment was reported. The visual acuity was hand motion. After 4 days of treatment with venlafaxine the hallucinations completely disappeared. This is the first case to show that selective serotonin (and noradrenalin) reuptake inhibitors may be an effective and well-tolerated treatment for visual hallucinations associated with vision loss, and it adds to evidence implicating serotonergic pathways in the pathogenesis of visual hallucinations.

The Charles Bonnet syndrome: a review of recent research

PURPOSE OF REVIEW

The Charles Bonnet syndrome is a disorder of visual hallucinations typically occurring in older persons with vision impairment or deafferentation of the visual cortex. This review cites recent studies on Charles Bonnet syndrome and discusses treatment options. The numbers of affected persons will increase with aging of the population, making recognition and treatment important components of ophthalmologic care.

RECENT FINDINGS

The etiology of the Charles Bonnet syndrome is varied; most often it involves direct damage to the visual system (e.g. age-related macular degeneration, glaucoma) but it may also result from cerebral pathology interrupting connections between the eye and the occipital cortex. Case reports of different management approaches demonstrate the range of treatment options.

SUMMARY

This review suggests that the Charles Bonnet syndrome will affect an increasingly large number of older persons as the population ages and the occurrence of vision and cerebral disorders increases. Clinical trials of antipsychotic and other medications, as well as low-vision rehabilitation, are necessary to establish valid treatments for this disorder.

Treatment of typical Charles Bonnet syndrome with donepezil

Charles Bonnet syndrome (CBS) is characterized by the presence of complex visual hallucinations in psychologically normal people. Although visual hallucinations in the elderly are often associated with dementia with Lewy body (DLB), Alzheimer's disease and delirium, they are excluded from the diagnosis of typical CBS, as are cognitive or psychiatric disturbances, sleep disorders and focal neurological lesions. Here, we describe a patient with typical CBS, who responded to donepezil, a cholinesterase inhibitor, and has not shown any symptoms suggestive of Alzheimer's disease or DLB for approximately the past 40 months. However, follow-up examination of her clinical symptoms is necessary for a definite exclusion of Alzheimer's disease and DLB. The effectiveness of donepezil indicates that the patient's visual hallucinations might be related to dysfunction of cholinergic neurones, although she did not exhibit any cognitive decline, or morphological and physiological brain pathology. Because donepezil has fewer adverse effects than anticonvulsants and neuroleptic drugs, it may be a safer option for the treatment of CBS in the elderly.

The rarity of Charles Bonnet syndrome

Charles Bonnet syndrome (CBS) is characterized by complex visual hallucinations in otherwise psychologically normal people. Estimates of the prevalence of CBS in different samples vary from a small percentage (around 1%), to a relatively large percentage (about 10%). The purpose of the present study is to determine whether CBS is rare or not. One-thousand ophthalmologic and optometric outpatients at a university hospital were consecutively screened by a questionnaire to identify patients possibly experiencing visual hallucinations. The mean corrected visual acuity in the best eye was 1.1. Those who positively responded to the questionnaire were further investigated to determine whether their symptoms were consistent with CBS. As a result, the prevalence of CBS was 0.5% (5/1000). In subclass analyses, the prevalence was 3 of 372 (0.8%) in the low vision group, 2 of 346 (0.6%) in the elderly, and 1 of 120 (0.8%) in both conditions. These were not significantly different from each other or from the overall prevalence (0.5%). This low prevalence of CBS in our subjects may be due to their relatively good visual acuity because previous studies with high prevalence of CBS investigated patients with a visual acuity of less than 0.3. The prevalence of CBS may be low in patients with these particular characteristics, and this syndrome seems to be rare in even ophthalmologic and optometric patients if they do not have seriously low vision. Further studies are needed to investigate the prevalence of CBS in general population.

Aging and visual hallucinations in elderly psychiatric outpatients

Estimates of the reported prevalence of visual hallucinations in the elderly vary from study to study. The aim of the present investigation was to re-evaluate the prevalence of visual hallucinations in elderly psychiatric outpatients and to examine pertinent risk factors. One hundred and twenty-two elderly (> or =60 years old) consecutive outpatients at our university hospital were investigated with a questionnaire regarding visual hallucinations and the Mini-Mental State Examination. Twelve of 122 (10%) patients suffered from visual hallucinations. Although advanced age, lower MMSE scores and dementia were significantly associated with the presence of visual hallucinations, logistic regression analysis revealed that only advanced age showed a tendency to predict the presence of visual hallucinations. In 53 patients with dementia examined separately, only advanced age was significantly associated with visual hallucinations. The present findings suggest that the prevalence of visual hallucinations in the elderly is about 10% and that aging is an important risk factor in the development of visual hallucinations in dementia. Further studies are required in order to investigate the contribution of age-related factors such as lowering visual acuity, bereavement and loneliness to the presence of visual hallucinations.

Charles Bonnet syndrome: visual hallucination and multiple sclerosis

Multiple sclerosis (MS) is a fairly common condition that affects approximately 350,000 people in the United States. It is associated with various neuropsychiatric symptoms including cognitive and behavioral symptoms. However, visual hallucinations are rare in multiple sclerosis without the presence of cognitive deficits. We are describing the case of a 40-year-old married white female with isolated complex visual hallucinations compatible with the Charles Bonnet syndrome (CBS). The patient was successfully treated with the atypical antipsychotic olanzapine.

Nonpharmacologic interventions for psychotic symptoms in dementia

This article proposes an initial nomenclature and systematic approach for the nonpharmacologic understanding and treatment of psychotic symptoms in dementia. An analysis of delusions and hallucinations must examine alternative etiologies, including misdiagnosis and misunderstanding, the misinterpretation of reality because of cognitive losses, sensory deprivation and vision loss, ambiguous sensations, and delirium and medical causes. Nonpharmacologic treatments frequently follow directly from etiology, such as improving sensory function via hearing aids or eyeglasses, providing stimulation, changing antecedents prone to misinterpretation (eg, reflections in windows), or circumventing misinterpretations (eg, ensuring that an equivalent object is available so there is no sense of loss or theft). Given the differences between psychotic symptoms in Alzheimer's disease and those in other diseases, the term psychosis should be abandoned for most dementia patients, and assessments of etiology should be developed. Future research should clarify what proportion of symptoms currently identified as psychotic are attributable to related etiologies.

Visual hallucinations and Charles Bonnet syndrome after photodynamic therapy for age related macular degeneration

AIMS

To report on visual hallucinations and Charles Bonnet syndrome (CBS) that may occur in patients with age related macular degeneration (AMD) treated by photodynamic therapy (PDT) with verteporfin for choroidal neovascularisation (CNV).

METHODS

100 consecutive patients were asked to respond to an orally administered questionnaire on visual hallucinations following PDT. Three groups of patients, respectively without visual hallucinations, with unstructured visual hallucinations, and with structured hallucinations-that is, CBS, were compared by ANOVA, Scheffe's test, or the chi(2) test, to establish whether age, sex, or visual acuity, as scored on ETDRS charts, are risk factors for the occurrence of visual hallucinations.

RESULTS

Five patients (5%) described transient structured visual hallucinations, including known or unknown faces and geometric patterns. Fifteen patients (15%) reported photopsias and flashing lights of various colours. These symptoms usually occurred a few days after PDT. There was no significant difference between the group of patients with structured visual hallucinations and the two other groups, with regard to age (p =0.435), sex (p =0.406), or visual acuity (p =0.835).

CONCLUSIONS

Visual hallucinations and CBS appear to be a possible, although unrecognised, side effect of PDT for CNV, which occur just after treatment. These results suggest the need to include the possibility of visual hallucinations in the information given to patients before PDT.

Complex visual hallucinations in the visually impaired: the Charles Bonnet Syndrome

Visually impaired patients may experience complex visual hallucinations, a condition known as the Charles Bonnet Syndrome. Patients usually possess insight into the unreality of their visual experiences, which are commonly pleasant but may sometimes cause distress. The hallucinations consist of well-defined, organized, and clear images over which the subject has little control. It is believed that they represent release phenomena due to de-afferentation of the visual association areas of the cerebral cortex, leading to a form of phantom vision. Cognitive defects, social isolation, and sensory deprivation have also been implicated in the etiology of this condition. This condition, which is most common in the elderly, frequently goes unrecognized in clinical practice, due to both lack of awareness among doctors and patients' reluctance to admit to hallucinatory experiences, for fear of being labeled mentally unstable. Furthermore, patients who comprehend the unreality of their hallucinations may be distressed by the real fear of imminent insanity. Sensitive and sympathetic history taking is essential to ascertain the existence of hallucinations. Reassurance and explanation that the visions are benign and do not signify mental illness have a powerful therapeutic effect. Hallucinatory activity may terminate spontaneously, on improving visual function or on addressing social isolation. There is no universally effective drug treatment but anticonvulsants may play a limited role in aborting the hallucinations. Physician awareness and empathy are the cornerstones of management.

Charles Bonnet syndrome in glaucoma patients with low vision

PURPOSE

To characterize the nature and frequency of Charles Bonnet syndrome in glaucoma patients with low vision.

PATIENTS AND METHODS

All patients attending the glaucoma clinic during a period of 10 months who had visual acuity of 20/80 or less in both eyes were included in this study. Each patient was questioned about the occurrence of visual hallucinations. Those who responded positively had a thorough interview relating to the characteristics of the hallucinations. Medical history and social history were taken, followed by a complete ocular examination.

RESULTS

Eighty-nine patients met the inclusion criteria. Eleven patients (12.3%), eight men and three women, admitted to having experienced visual hallucinations. Except for one case, the patients did not disclose this experience previously. Eight patients had one repeatable hallucination, and three patients experienced more than one sight. The visions were usually sharp, and the figures were occasionally incomplete. Most hallucinations were chromatic. Frequency of hallucinations varied between daily and weekly, and duration was mostly a few minutes. In addition to glaucoma, nine of the eleven patients had other ocular findings that could have contributed to the reduction of vision.

CONCLUSION

Visual hallucinations are not rare in glaucoma patients with low vision. Patients tend to conceal their experience of visual hallucinations, but a discussion of these phenomena with the patient and assurance of their harmless nature will reduce his or her anxiety and concerns.