Release Hallucinations

Update item information
Identifier 926-4
Title Release Hallucinations
Ocular Movements Normal
Creator Shirley H. Wray, M.D., Ph.D., FRCP, Professor of Neurology Harvard Medical School, Director, Unit for Neurovisual Disorders, Massachusetts General Hospital
Contributor Primary Shirley H. Wray, MD, PhD, FRCP, Professor of Neurology, Harvard Medical School; Director, Unit for Neurovisual Disorders, Massachusetts General Hospital
Subject Occipital Lobe; Visual Hallucinations; Release Hallucinations; Charles Bonnet Syndrome
Supplementary Materials PowerPoint Presentation: Charles Bonnet Syndrome: Shirley H. Wray, M.D., Ph.D., FRCP, Harvard Medical School
Presenting Symptom Visual Hallucinations
History The patient is a 79 year old woman with a chief complaint of visual hallucinations. She carries a diagnosis of glaucoma and cataracts. The patient was in good health until two weeks prior to admission when she noted a black cloud in her visual field in the top central area. The cloud gradually changed into images of vivid flowers which she described as lilac colored, sometimes looking like roses. The images were intermittent lasting approximately 1 minute and occurring as many as 50 times per day. The patient realized the images were not real. She consulted her ophthalmologist and was referred to a neurologist at the Lahey Clinic. Brain CT showed no abnormality. The patient continued to have daily visual hallucinations always superimposed over the central area of her visual field. The images gradually became more varied, first flowers then images of baskets and on the day of admission she noted several full length images of woman in caps, images of girls dressed in ruffled skirts and an image of a big, plump gentleman, approximately 50 to 60 years old dressed in a jumpsuit. The images were very detailed and in color. No therapy was recommended. Past History: Significant for occasional generalized headaches, tinnitus and mild hearing loss. She had a 40 year history of hypertension treated with Dyazide. In 1950 she was hospitalized for three days following concussion. In 1958 she received electroconvulsive therapy for depression. She had a history of ethanol abuse which she stopped many years ago. Social History: Patient is widowed with no children and lives alone. Her sister is handicapped following a stroke. She graduated from high school level and she took business classes to become a secretary. Medications: Nifedapine (Procardia XL) 30 mg. p.o., q.d. (calcium channel blocker) Betoptic 0.5% 1 gtt OU b.i.d. On examination she was cheerful, attentive, and oriented to time, place and person. Cranial nerve examination showed: • Decreased visual acuity OD 20/100 OS 20/60 with arcuate nerve fiber bundle defects in the superior altitudinal fields OU. • Ishihara color testing: impaired color vision with 2/14 OD color plates correct 5/14 OS. • Pupils equal, sluggishly to light and near, • Eye movements full with no nystagmus. • Fundus exam mild optic atrophy with slight optic disc cupping (glaucoma). The remainder of the cranial nerves were intact. Limbs: normal motor strength with no drift and normal rapid fine dexterous movements of the fingers. Her gait was narrow-based and steady. She was able to tandem walk and heel and toe walk. Romberg negative. Sensory examination showed decreased pin prick sensation bilaterally in a stocking-like distribution - 2/3rds up the calf plus, decreased joint position and vibration sense in the toes and absent ankle jerk consistent with a mild motor-sensory peripheral neuropathy. Cognitive tests ruled out dementia. She did well on her memory tests and tests of executive function (i.e. frontal lobe functions), which included planning and carrying out intentional behavior. She remembered 3/3 objects and could recall 5-digits forwards and backwards. One difficulty she had was with serial 7's. She had good repetition and no abnormality of her speech. On the Boston Naming Test she was able to successfully identify 54 of 60 common objects (e.g. broom, camel, escalator), placing her performance at the mean of her age. She had no left-right confusion, finger agnosia or dyscalculia. She had no apraxia. She was able to copy a picture of a clock and draw a 3 dimensional house. The one defect detected was a specific difficulty with visuo-motor processing and encoding and retention of visual information. But, given her bilateral visual field loss, glaucoma and cataracts, it was difficult to determine to what extent these visual defects were interfering with visuomotor functions. The differential diagnosis of recurrent complex visual hallucinations in an awake person includes: 1. Medication(s) 2. Metabolic status 3. Psychiatric etiology including mania, depression, substance dependence and schizophrenia 4. Neurodegenerative diseases (e.g. Lewy Body Dementia, Alzheimer's and Parkinson's disease) 5. Release hallucinations - Charles Bonnet Syndrome An EKG showed normal sinus rhythm, axis deviation of 40 degrees and left atrial enlargement. An EEG, recorded during hallucinations, showed a question of spike activity in the parieto-occipital area. A sleep EEG was normal and ruled out epilepsy. A Brain MRI with Gadolinium showed ventricular dilation, cortical, central and cerebellar atrophy, bilateral posterior limb of internal capsule lacunes and periventricular and pontine foci of T2 hyperintensity consistent with microvascular disease. Laboratory tests showed hyponatremia with a low sodium of 121, potassium 3.2, blood urea 13, creatinine 0.9. Normal hematocrit, white blood count and coagulation factors. Liver function tests normal apart from a slightly elevated SGOT at 32. The visual hallucinations were not felt to be due to hyponatremia. They continued even when the blood sodium level was corrected to 138 with intravenous dextrose saline. A diagnosis of Release Hallucinations - The Charles Bonnet Syndrome (CBS) was made. CBS is characterized by the triad: • Complex visual hallucinations (CVH) • Ocular pathology causing visual loss and • Absence of cognitive impairment. CBS affects 12 to 15% of visually impaired patients. The hallucinations are often repetitive and stereotyped, elementary or complex, involving human figures in most cases. The patients, like the present patient, have full insight of the unrealistic character of their hallucinations. The main risk factors are old age and severe visual impairment. CVH usually involve vivid scenes of animals, flowers and people, as in this patient. They may be black and white or in color, static or dynamic and may be of normal proportions or altered in size. CVH may be episodic, periodic, or continuous and tend to be more common in the evening and at night in bed. Many individuals can stop the hallucinations by opening or closing their eyes or by deviating their gaze in another direction.
Clinical This 78 year old lady gives an excellent description of complex visual hallucinations with the following features: • The images are of normal size and shape • Very brightly colored • Fully recognized as flowers floating, women in caps, and images of men • Occasionally seen with eyes closed • Not completely obscuring her field of vision but floating The patient did not appear depressed and only became tearful when she expressed her concern that she is ill. Charles Bonnet described a case of complex hallucinations due to visual loss associated with cataracts in his cognitively intact grandfather in 1760 (11). David Cogan, in 1973, introduced the term Release Hallucinations for complex visual hallucinations occurring in the setting of visual acuity impairment or loss of visual field from eye disease or lesions in the afferent visual pathways (2). In the Charles Bonnet Syndrome (CBS), the hallucinations can be simple, (lights, colors, lines, shapes or geometric designs) complex (animals, objects, people or life-like scenes) or both. In one study of 104 patients with loss of vision from retinal or neurologic cause simple unformed hallucinations were present in 51% of patients and CVH in 21%. A visual acuity of less than 20/50 increased the likelihood of experiencing release hallucinations (7). Patients often describe CVH when they are looking at a white background such as a wall, ceiling or piece of paper, and they are typically located in the field of visual loss and therefore, they can be monocular or binocular (7). CVH may be triggered by sensory deprivation; for example, dim lighting, being alone or decreased arousal (11). However, visual hallucinations are often not reported by patients because they fear that hallucinations represent psychiatric disease or dementia. The duration of these hallucinations range from less than one minute to continuous. The frequency can be variable. The majority of patients experience hallucinations multiple times a day, weekly, or monthly. In many cases, the hallucinations wax over time and completely abate.
Neuroimaging A functional MRI (fMRI) study was carried out in 4 CBS patients while they were hallucinating (6). The patients were asked to signal the onset and offset of each hallucination over a 5-min period and to describe their visual experiences. By cross-correlating the fMRI time series with the hallucination events the investigators were able to identify the cerebral activity underlying the hallucination. They found that visual hallucinations were related to phasic increases in activity within specialized visual cortex and that the location of the increased activity defined the type of experience reported. Thus, color hallucinations accompanied increased activity in cortex specialized for color; face hallucinations, increased activity in cortex specialized for faces; object hallucinations, increased activity in the cortex specialized for objects, and so forth. In an independent set of experiments reported in the same study, the investigators found that, compared with control patients matched for age and visual impairment, patients with CBS had tonic increases in brain activity within specialized visual cortex when not hallucinating. Taken together the imaging results implied that: 1. Each specialized visual area had its own associated hallucination and 2. The pathophysiology of the hallucinations involved a localized increase in cerebral activity. Three visuopsycho-syndromes were recognized unrelated to demographic or etiological factors. The first consisted of hallucinations of extended landscape scenes and small figures in costumes with hats. The second, hallucinations of grotesque, disembodied and distorted faces with prominent eyes and teeth; and The third, visual perseveration and delayed palinopsia. The investigators hypothesized that the three visuopsycho- syndromes mirror the segregation of hierarchical visual pathway interstreams and suggest a novel theoretical framework for the pathophysiology of these visual syndromes (9).
Anatomy See Above
Pathology In man, the visual brain consists of multiple map-like cortical representations of external space, each specialized for a different visual attribute. These specialized cortical regions are interconnected forming a hierarchy, with low-level areas projecting to higher level ones. The hierarchy divides into two pathway streams, one ventral leading to the ventral temporal lobe and one dorsal leading to the parietal lobe. A third projection along the superior temporal sulcus is connected to both streams. The investigators found that pathological increases in activity within the anterior temporal portion of the ventral pathway underlie the first visuopsycho-syndrome (Fig 1, red). The second visuopsycho-syndrome relates to pathological increases in activity within the superior temporal sulcus. (Fig 1, green). The third visuopsycho-syndrome relates to pathological increases in activity in the parietal projection of the dorsal pathway. (Fig 1, yellow). The hypothesis that the third visuopsycho-syndrome relates to the parietal projection of the dorsal stream is supported by Critchley's observations in 1951, that delayed palinopsia and visual perseveration are associated with lesions in the parietal lobe (5).
Etiology Several theories are proposed regarding the pathophysiology of release hallucinations (1,2,4,8,10). The most commonly accepted theory is that they occur because visual cortical association areas are disinhibited in the setting of visual sensory deprivation.
Disease/Diagnosis Charles Bonnet Syndrome - Release Hallucinations
Treatment Therapy with Olanzapine (Zyprexa), an antipsychotic medication, 5 mg. per day is reported to lead to progressive clearance of visual hallucinations in 7 days. This effect may be medicated through a combination of dopamine and serotonin antagonism (3). Anticonvulsant drugs, such as Carbamazepine, Valproate and Gabapentin have also been tried with variable success. Reassurance of the patient that the hallucinations are associated with sensory deprivation usually results in lowering their anxiety and helping the patient to adjust to them. Increasing sensory stimulation by having a sleep radio play in the bedroom at night can be extremely helpful, and making sure the patient is not on any medication that can provoke the syndrome. Clinical trials of anti-psychotic and other medications, as well as low-vision rehabilitation, are necessary to establish valid treatments for this disorder.
References 1. Burke W. The neural basis of Charles Bonnet hallucinations: a hypothesis. J Neurol Neurosurg Psychiatry 2002;73:535-541. 2. Cogan DG. Visual hallucinations as release phenomena. Albrecht Von Graefes. Arch Klin Exp Ophthalmol 1973;188:139-150. 3. Coletti Moja M, Milano E, Gasverde S, Gianelli M. Giordana MT. Olanzapine therapy in hallucinatory visions related to Bonnet syndrome. Neurol Sci 2005, 26(3):168-170. 4. Collerton D, Perry E, McKeith I. Why people see things that are not there: a novel Perception and Attention Deficit model for recurrent complex visual hallucinations. Behav Brain Sci, 2005 Dec;28(6):737-57; discussion 757-94. 5. Critchley M. Types of visual perseveration: ‘palinopsia' and ‘illusory visual spread'. Brain 1951, 74:267-299. 6. Ffytche DH, Howard RJ, Brammer MJ, David A, Woodruff P., Williams S. The anatomy of conscious vision: an fMRI study of visual hallucinations. Nat Neurosci 1998; 1:738-742. 7. Lepore FE. Spontaneous visual phenomena with visual loss: 104 patients with lesions of retinal and neural afferent pathways. Neurology 1990;40:444-447. 8. Norton JW, Corbett JJ. Visual perceptual abnormalities: hallucinations and illusions. Semin Neurol 2000;20:111-121. 9. Santhouse AM, Howard RJ, Ffytche DH. Visual hallucinatory syndromes and the anatomy of the visual brain. Brain 2000 Oct;123 (Pt 10):2055-2064. 10. Schultz G, Melzack R. The Charles Bonnet syndrome phantom visual images. Perception 1991;20:809-825. 11. Teunisse RJ, Cruysberg JR, Hoefnagels WH, Verbeek AL, Zitman FG. Visual hallucinations in psychologically normal people: Charles Bonnet's syndrome. Lancet 1996; 347;794-797. 12. Charles Bonnet. Who Named it. Accessed 4-27-09.
Relation is Part of 10-1, 932-5, 939-4, 947-1
Contributor Secondary Steve Smith, Videographer; Ray Balhorn, Digital Video Compressionist
Reviewer D. H. ffytche, BSc MBBS MRCP. Institute of Psychiatry, London
Publisher Spencer S. Eccles Health Sciences Library, University of Utah
Date 1992
Type Image/MovingImage
Format video/mp4
Source 3/4" Umatic master videotape
Rights Management Copyright 2002. For further information regarding the rights to this collection, please visit:
Holding Institution Spencer S. Eccles Health Sciences Library, University of Utah, 10 N 1900 E, SLC, UT 84112-5890
Collection Neuro-ophthalmology Virtual Education Library: NOVEL
Language eng
ARK ark:/87278/s6t46qnt
Setname ehsl_novel_shw
Date Created 2005-08-22
Date Modified 2017-11-22
ID 188547
Reference URL
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