Bonnet Syndrome Research Articles

The cover photo shows different neovascularization types from the paper by Smid et al.

The cover photo shows different neovascularization types from the paper by Smid et al.

Atypical presentation of Charles Bonnet Syndrome: frightening hallucinations coinciding with hypertensive urgency

Atypical presentation of Charles Bonnet Syndrome: frightening hallucinations coinciding with hypertensive urgency

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

ObjectiveCharles 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...

Exacerbation of visual hallucinations in Charles Bonnet syndrome due to the social implications of COVID-19

ObjectiveCharles Bonnet syndrome (CBS) occurs secondary to sight loss, characterised by spontaneous visual hallucinations. Symptom manifestation can be influenced by social isolation. This research aims to evaluate the effect of...

Charles Bonnet Syndrome as Another Cause of Visual Hallucinations

Charles Bonnet syndrome (CBS) presents as gradual vision loss and associated visual hallucinations in a patient who is otherwise neurologically and psychiatrically intact. This syndrome presents primarily as ophthalmologic disease, however, may be secondary to an ischemic stroke or tumor in the occipital lobe. Patients present with a complaint of vivid visual hallucinations ranging from spots and geometric shapes to seeing people, distorted figures and landscapes.First noted in the 1760s, CBS did not reach the western scientific community until the early 1980s.Our patient reported seeing her dog and deceased mother only when looking left. She was having an experience of phantom images in addition to a visual field impairment but was otherwise of sound mind with no gross neurological deficits. Computer topography of the brain revealed a subacute infarct in the right posterior occipital lobe. The patient was ultimately diagnosed with CBS following magnetic resonance imaging and ophthalmology consultation at tertiary center.Diagnosis may be delayed by lack of symptom reporting as patients do not want to carry a stigma as ‘crazy.’ Further, physician awareness of this etiology is low and a better understanding of the disease will prevent missed diagnosis as well as lack of appropriate consultation and follow-up. Treatment includes close outpatient ophthalmology care, maximizing existing vision and lifestyle changes including adjustments in lighting, decreasing stress and increasing socialization. Trials of prescription treatment (i.e., antipsychotics, serotonin reuptake inhibitors, antiepileptics) have shown only anecdotal evidence at efficacy. CBS is an uncommon presentation of cerebral vascular disease that warrants the attention of emergency department physicians.

Charles bonnet syndrome

Charles Bonnet Syndrome (CBS) or visual release hallucinations are a type of psychophysical visual disturbance and the experience of complex visual hallucinations (VHs) in a person with partial or severe blindness. We present a case of 73-year-old blind male, who lost his vision due to glaucoma, presented with a history of complex VHs. The investigations for alternative pathological causes of VHs were negative and therefore, the etiology of hallucinations was attributed to CBS. Excellent response to low-dose olanzapine was seen, with complete remission by the end of 5th week after starting olanzapine.

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.

Investigation of Structural Brain Changes in Charles Bonnet Syndrome

Investigation of Structural Brain Changes in Charles Bonnet Syndrome

Vision loss and psychopathology

Purpose: By examining associations between vision loss and various types of psychopathology within the literature, this manuscript will provide ophthalmologists, psychiatrists, and psychologists insight into the relationships between vision and psychopathology to foster cross-professional relations. Design: Retrospective narrative literature review. Methods: A narrative literature review was conducted using PubMed, Google Scholar, and Scopus searches. Study types included reviews, case studies, survey analyses, population-based studies, and twin studies, among others. Topics explored include mental health consequences of vision loss, functional neurological disorders and deception syndromes, eye specific personality changes, Charles Bonnet syndrome, and vision disorders associated with psychosis. Results: Visual impairment correlates with depression and worsened overall quality of life and mental health. Visual health clinicians should improve competencies in basic suicide risk assessments in collaboration with primary care providers and mental health colleagues. When patients with functional neurological disorders or deception syndromes present, understanding their symptoms and motivations is crucial for proper management. Patients with myopia and keratoconus are anecdotally alleged to have unique personalities; however, research shows openness is the only trait correlated with myopia, while a proposed “keratoconus personality” is unfounded. The unique vivid hallucinations of Charles Bonnet syndrome typically do not bother patients and physician reassurance is usually enough to ease the anxious patient. Finally, Usher syndrome involves congenital deafness and progressive blindness in young children with links to psychosis and schizophrenia. Conclusions: The bidirectional psychosomatic ophthalmological landscape highlights a need to improve screening, recognition, and integrated treatment coordination between visual health providers and mental health providers.

Musical hallucinations in cerebrovascular disease.

Musical hallucinations (MH) are a subset of complex auditory hallucinations in which individuals perceive music in the absence of an external auditory stimulus. It is a rare phenomenon, first described by Ballinger in 1846, with diverse presentations from familiar childhood melodies to a simple pitch which evolved into the harmonies Robert Schumann incorporated in his sole Violin Concerto. This uncommon phenomenon has diverse etiologies, including psychiatric and neurological backgrounds, which guide its classification and methods of treatment. The pathophysiological basis of MH remains understood incompletely, potentially resulting from lesions anywhere along the auditory pathway, from the external auditory canal to the auditory cortex. The strong association between MH and hearing impairment has led researchers to hypothesize that MH represent a "release phenomenon," in which sensory deprivation, eliminating the afferent input to the auditory sensory network, instigates spontaneous activity within a system - comparable to the Charles Bonnet syndrome, in which visual impairment precipitates the development of visual hallucinations (so called auditory Charles Bonnet syndrome), and phantom limb syndrome, in which amputees experience sensations in a limb that is not no longer there. In this paper, we report on six cases of MH in patients with cerebrovascular disease, who presented to the neurology department at the Poznan University of Medical Sciences from 2015 to 2018. We discuss the findings of computed tomography and magnetic resonance imaging of six cases of MH in patients with cerebrovascular disease, and the treatment leading to its resolution. We briefly review the literature on MH in patients with cerebrovascular diseases, discussing their suggested pathophysiology, clinical presentations and response to medical treatment.

Chapter 17 - Illusions, hallucinations, and visual snow

Illusions and hallucinations are commonly encountered in both daily life and clinical practice. In this chapter, we review definitions and possible underlying mechanisms of these phenomena and then review what is known about specific conditions that are associated with them, including ophthalmic causes, migraine, epilepsy, Parkinson's disease, and schizophrenia. We then discuss specific syndromes including the Charles Bonnet syndrome, visual snow syndrome, Alice in Wonderland syndrome, and peduncular hallucinosis. The scientific study of illusions and hallucinations has contributed significantly to our understanding of how eye and brain process vision and contribute to perception. Important concepts are the distinction between topologic and hodologic mechanisms underlying hallucinations and the involvement of attentional networks. This chapter examines the various ways in which pathological illusions and hallucinations might arise in relation to the phenomenology and known pathology of the various conditions associated with them.

How do the blind 'see'? The role of spontaneous brain activity in self-generated perception.

Spontaneous activity of the human brain has been well documented, but little is known about the functional role of this ubiquitous neural phenomenon. It has previously been hypothesized that spontaneous brain activity underlies unprompted (internally generated) behaviour. We tested whether spontaneous brain activity might underlie internally-generated vision by studying the cortical visual system of five blind/visually-impaired individuals who experience vivid visual hallucinations (Charles Bonnet syndrome). Neural populations in the visual system of these individuals are deprived of external input, which may lead to their hyper-sensitization to spontaneous activity fluctuations. To test whether these spontaneous fluctuations can subserve visual hallucinations, the functional MRI brain activity of participants with Charles Bonnet syndrome obtained while they reported their hallucinations (spontaneous internally-generated vision) was compared to the: (i) brain activity evoked by veridical vision (externally-triggered vision) in sighted controls who were presented with a visual simulation of the hallucinatory streams; and (ii) brain activity of non-hallucinating blind controls during visual imagery (cued internally-generated vision). All conditions showed activity spanning large portions of the visual system. However, only the hallucination condition in the Charles Bonnet syndrome participants demonstrated unique temporal dynamics, characterized by a slow build-up of neural activity prior to the reported onset of hallucinations. This build-up was most pronounced in early visual cortex and then decayed along the visual hierarchy. These results suggest that, in the absence of external visual input, a build-up of spontaneous fluctuations in early visual cortex may activate the visual hierarchy, thereby triggering the experience of vision.

Cerebellar correlates of visual hallucinations in Parkinson's disease and Charles Bonnet Syndrome

Hallucinations, percepts in the absence of external stimuli, are a shared feature of eye-disease (Charles Bonnet Syndrome, CBS) and Parkinson's disease (PD) thought to arise through pathophysiologically distinct mechanisms: deafferentation and attentional network dysfunction respectively. Recent studies have found an association between visual hallucinations and structural changes in the cerebellum without obvious link to either mechanism.Here, we employed Voxel Based Morphometry (VBM), optimised for the cerebellum using the Spatially Unbiased Infratentorial Template (SUIT), to characterise similarities and differences in cerebellar structure associated with visual hallucinations in PD and CBS. Grey and white matter volume (GMV & WMV) from patients with eye-disease (n = 12 hallucinators; n = 9 non-hallucinators) and PD (n = 7 hallucinators; n = 9 non-hallucinators) was examined in a 2-way ANOVA controlling for age, sex, and intracranial volume.Comparing hallucinators to controls across both groups, lower GMV was found bilaterally within cerebellar lobule VIII extending to IX/VII. GMV reductions were also found in Crus 1, greater in PD than eye-disease. Predominantly within PD, hallucination-related lower WMV was found in the medulla. No regions of increased GMV or WMV were found. A correlation was observed between brainstem WMV and lobule VIIIb GMV suggesting a functional association.Lobule VIII comprises a functional node within the Dorsal Attention Network (DAN), linking these findings to current attentional theories of hallucinations, while Crus 1 is linked to cortical visual processing. These findings provide preliminary evidence of a cerebellar contribution to hallucinations that transcends clinical conditions.

Successful treatment of Charles Bonnet Syndrome with sodium valproate and sertraline: A case report

The Sri Lanka Journal of Psychiatry (SLJP) is a peer-reviewed, open access journal published bi annually by the Sri Lanka College of Psychiatrists.The Journal publishes original papers, brief reports including case reports and commentaries relevant to psychiatry and allied sciences. The Sri Lanka Journal of Psychiatry is committed to maintaining and conforming to the editorial and ethical standards recommended by the International Committee of Medical Journal Editors.Cover“Perseverance”. These tenacious fishermen in Mannar continue their livelihood despite numerous difficulties. L. N. P. Samarasinghe, Acting Consultant Psychiatrist, Base Hospital Nikaweratiya, Sri Lanka.

Vision loss and hallucinations: perspectives from neurology and ophthalmology.

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 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. 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.

Visual hallucinations and sight loss in children and young adults: a retrospective case series of Charles Bonnet syndrome

Background/AimsCharles Bonnet syndrome (CBS) is a complication of sight loss affecting all ages; yet, few childhood cases have been reported. Our aim is to raise awareness of this under-reported association...

Atypický Charles Bonnetov syndróm a psychóza pri Parkinsonovej chorobe: dvaja hráči u jednej pacientky

Psychoza pri Parkinsonovej chorobe sa manifestuje najcastejsie zrakovými halucinaciami a bludmi u pacientov s Parkinsonovou chorobou. Výskyt iných typov halucinacii je omnoho nižsi a može poukazovať na inu diagnozu. Zriedkavo sa u pacientov možu vyskytnuť bimodalne halucinacie. V nasej kazuistike prezentujeme pripad pacientky s Parkinsonovou chorobou, u ktorej sa popri zrakových halucinaciach vyskytovali sucasne aj sluchove halucinacie, ktorých pricinou je vzacny atypický Charles Bonnetov syndrom vznikajuci pri dlhodobej a zavažnej poruche sluchu.

Visual hallucinations in psychiatric, neurologic, and ophthalmologic disease.

Recent studies have increased our understanding of the biochemical and structural bases of visual hallucinations in patients with a variety of underlying causes. Visual hallucinations may be related to disruption of functional connectivity networks, with underlying biochemical dysfunction such as decreased in cholinergic activity. Structural abnormalities in primary and higher order visual processing areas also have been found in patients with visual hallucinations. The occurrence of visual hallucinations after vision loss, the Charles Bonnet syndrome, may have more functional similarity to psychiatric and neurodegenerative causes than previously suspected despite retained insight into the unreal nature of the phenomena. Visual hallucinations are common, and patients may not report them if specific inquiries are not made. Presence or absence of hallucinations may be of diagnostic and therapeutic importance, especially in patients with neurodegenerative conditions that have overlapping features. Treatment of visual hallucinations remains challenging and must be tailored to each patient based on the underlying cause and comorbid conditions.

Charles Bonnet syndrome: low awareness among patients with glaucoma

Charles Bonnet syndrome: low awareness among patients with glaucoma

Prevalence of Charles Bonnet syndrome in patients with glaucoma: a systematic review with meta-analyses.

Glaucoma is a widespread sight-threatening condition often only recognized when very pronounced. It is initially characterized by peripheral visual field losses, while advanced stages also affect the central vision. Some of these patients may experience visual hallucinations, the Charles Bonnet syndrome (CBS). In this systematic review and meta-analysis, we provide an overview of the literature dealing with the prevalence of CBS in patients with glaucoma. We searched the databases PubMed/MEDLINE, Embase, Web of Science, the Cochrane Central and PsycInfo on 22 March 2020. Eight studies (n=827 patients) were identified and included for a qualitative and quantitative analysis. No studies included a representative sample of patients with only glaucoma. In patients with glaucoma in different stages and with ocular comorbidities, prevalence of CBS was 2.8% (CI95%: 0.7-6.1%). Among patients with glaucoma where all had bilateral low visual acuity, prevalence of CBS was 13.5% (CI95%: 8.4-19.6%). In patients with glaucoma who visited vision rehabilitation clinics, presumably due to an extensive vision impairment, prevalence of CBS was 20.1% (CI95%: 16.8-23.6%). Risk factors of CBS besides low vision were high age, female gender, reduced contrast sensitivity and not living alone. Taken together, we find that CBS may not be rare in patients with advanced glaucoma with and without ocular comorbidities. However, limitations of the current literature should be highlighted and careful approach towards conclusions is important. More studies are needed to better understand the prevalence and risk factors among different populations of patients with glaucoma.