Visual release hallucinations (Charles Bonnet syndrome)
- Victoria S Pelak, MD
Victoria S Pelak, MD
- Associate Professor of Neurology and Ophthalmology
- Director, Neurology Residency Program
- University of Colorado Denver, School of Medicine, Department of Neurology
The Charles Bonnet syndrome refers to symptoms of visual hallucinations that occur in patients with visual acuity loss or visual field loss. These are often called release hallucinations, reflecting the most widely accepted theory of their pathogenesis.
Underlying conditions of vision loss associated with the Charles Bonnet syndrome affect the eye, optic nerve, or brain and include a diverse set of pathologies, such as macular degeneration and stroke. While often not functionally disabling, the hallucinations can be distressing to patients and negatively impact quality of life . Published case reports suggest that the syndrome is not well recognized by clinicians and may often be misdiagnosed as psychosis or early dementia [2,3].
The pathophysiology, causes, clinical features, diagnosis, and treatment of the Charles Bonnet syndrome will be reviewed here. Other causes and the overall approach to visual hallucinations are discussed separately. (See "Approach to the patient with visual hallucinations".)
The Charles Bonnet syndrome (CBS) may be more common than is generally appreciated. Visual hallucinations are often unreported by patients because they fear that they represent psychiatric disease [1,4,5]. When this symptom is specifically solicited in older patients with impaired vision, 11 to 15 percent admit to having visual hallucinations [1,5-11]. The reported prevalence was even higher, 39 percent, in one survey of patients diagnosed with macular disease . These surveys also reveal that most patients had failed to report these symptoms to their physician or to family members. One study found that only 12 percent of patients attending a retinal clinic were aware of the condition .
Release hallucinations have been reported in all age groups, including children [8,14]. However, most patients with CBS are elderly; in large case series, the mean age is between 70 and 85 years [4,8,15,16]. This probably reflects the mean age at which the most common underlying conditions causing vision loss are seen. Some investigators, but not others, have found that advanced age is a risk factor for release hallucinations within their study population [6,11,17].
- Scott IU, Schein OD, Feuer WJ, Folstein MF. Visual hallucinations in patients with retinal disease. Am J Ophthalmol 2001; 131:590.
- Jacob A, Prasad S, Boggild M, Chandratre S. Charles Bonnet syndrome--elderly people and visual hallucinations. BMJ 2004; 328:1552.
- Siatkowski RM, Zimmer B, Rosenberg PR. The Charles Bonnet syndrome. Visual perceptive dysfunction in sensory deprivation. J Clin Neuroophthalmol 1990; 10:215.
- Teunisse RJ, Cruysberg JR, Hoefnagels WH, et al. Visual hallucinations in psychologically normal people: Charles Bonnet's syndrome. Lancet 1996; 347:794.
- Nesher R, Nesher G, Epstein E, Assia E. Charles Bonnet syndrome in glaucoma patients with low vision. J Glaucoma 2001; 10:396.
- Teunisse RJ, Cruysberg JR, Verbeek A, Zitman FG. The Charles Bonnet syndrome: a large prospective study in The Netherlands. A study of the prevalence of the Charles Bonnet syndrome and associated factors in 500 patients attending the University Department of Ophthalmology at Nijmegen. Br J Psychiatry 1995; 166:254.
- Holroyd S, Rabins PV, Finkelstein D, et al. Visual hallucinations in patients with macular degeneration. Am J Psychiatry 1992; 149:1701.
- Menon GJ, Rahman I, Menon SJ, Dutton GN. Complex visual hallucinations in the visually impaired: the Charles Bonnet Syndrome. Surv Ophthalmol 2003; 48:58.
- Freiman TM, Surges R, Vougioukas VI, et al. Complex visual hallucinations (Charles Bonnet syndrome) in visual field defects following cerebral surgery. Report of four cases. J Neurosurg 2004; 101:846.
- Brown GC, Murphy RP. Visual symptoms associated with choroidal neovascularization. Photopsias and the Charles Bonnet syndrome. Arch Ophthalmol 1992; 110:1251.
- Abbott EJ, Connor GB, Artes PH, Abadi RV. Visual loss and visual hallucinations in patients with age-related macular degeneration (Charles Bonnet syndrome). Invest Ophthalmol Vis Sci 2007; 48:1416.
- Cox TM, ffytche DH. Negative outcome Charles Bonnet syndrome. Br J Ophthalmol 2014; 98:1236.
- Singh A, Subhi Y, Sørensen TL. Low awareness of the Charles Bonnet syndrome in patients attending a retinal clinic. Dan Med J 2014; 61:A4770.
- Schwartz TL, Vahgei L. Charles Bonnet syndrome in children. J AAPOS 1998; 2:310.
- Schultz G, Melzack R. The Charles Bonnet syndrome: 'phantom visual images'. Perception 1991; 20:809.
- Teunisse RJ, Cruysberg JR, Hoefnagels WH, et al. Risk indicators for the Charles Bonnet syndrome. J Nerv Ment Dis 1998; 186:190.
- Lepore FE. Spontaneous visual phenomena with visual loss: 104 patients with lesions of retinal and neural afferent pathways. Neurology 1990; 40:444.
- Adachi N, Watanabe T, Matsuda H, Onuma T. Hyperperfusion in the lateral temporal cortex, the striatum and the thalamus during complex visual hallucinations: single photon emission computed tomography findings in patients with Charles Bonnet syndrome. Psychiatry Clin Neurosci 2000; 54:157.
- Teunisse RJ, Cruysberg JR, Hoefnagels WH, et al. Social and psychological characteristics of elderly visually handicapped patients with the Charles Bonnet Syndrome. Compr Psychiatry 1999; 40:315.
- Russell G, Burns A. Charles Bonnet syndrome and cognitive impairment: a systematic review. Int Psychogeriatr 2014; :1.
- Vaphiades MS, Celesia GG, Brigell MG. Positive spontaneous visual phenomena limited to the hemianopic field in lesions of central visual pathways. Neurology 1996; 47:408.
- Cogan DG. Visual hallucinations as release phenomena. Albrecht Von Graefes Arch Klin Exp Ophthalmol 1973; 188:139.
- Burke W. The neural basis of Charles Bonnet hallucinations: a hypothesis. J Neurol Neurosurg Psychiatry 2002; 73:535.
- Berrios GE, Brook P. The Charles Bonnet syndrome and the problem of visual perceptual disorders in the elderly. Age Ageing 1982; 11:17.
- Ffytche DH, Howard RJ, Brammer MJ, et al. The anatomy of conscious vision: an fMRI study of visual hallucinations. Nat Neurosci 1998; 1:738.
- Baier B, de Haan B, Mueller N, et al. Anatomical correlate of positive spontaneous visual phenomena: a voxelwise lesion study. Neurology 2010; 74:218.
- Kölmel HW. Complex visual hallucinations in the hemianopic field. J Neurol Neurosurg Psychiatry 1985; 48:29.
- Flint AC, Loh JP, Brust JC. Vivid visual hallucinations from occipital lobe infarction. Neurology 2005; 65:756.
- Lance JW. Simple formed hallucinations confined to the area of a specific visual field defect. Brain 1976; 99:719.
- Lang UE, Stogowski D, Schulze D, et al. Charles Bonnet Syndrome: successful treatment of visual hallucinations due to vision loss with selective serotonin reuptake inhibitors. J Psychopharmacol 2007; 21:553.
- Alao AO, Hanrahan B. Charles Bonnet syndrome: visual hallucination and multiple sclerosis. Int J Psychiatry Med 2003; 33:195.
- Choi EJ, Lee JK, Kang JK, Lee SA. Complex visual hallucinations after occipital cortical resection in a patient with epilepsy due to cortical dysplasia. Arch Neurol 2005; 62:481.
- Chen CS, Lin SF, Chong MY. Charles Bonnet syndrome and multiple sclerosis. Am J Psychiatry 2001; 158:1158.
- Komeima K, Kameyama T, Miyake Y. Charles Bonnet syndrome associated with a first attack of multiple sclerosis. Jpn J Ophthalmol 2005; 49:533.
- Benson MT, Rennie IG. Formed hallucination in the hemianopic field. Postgrad Med J 1989; 65:756.
- Fernandez A, Lichtshein G, Vieweg WV. The Charles Bonnet syndrome: a review. J Nerv Ment Dis 1997; 185:195.
- Levine AM. Visual hallucinations and cataracts. Ophthalmic Surg 1980; 11:95.
- Sonnenblick M, Nesher R, Rozenman Y, Nesher G. Charles Bonnet syndrome in temporal arteritis. J Rheumatol 1995; 22:1596.
- Holroyd S, Rabins PV. A three-year follow-up study of visual hallucinations in patients with macular degeneration. J Nerv Ment Dis 1996; 184:188.
- Issa BA, Yussuf AD. Charles bonnet syndrome, management with simple behavioral technique. J Neurosci Rural Pract 2013; 4:63.
- Eperjesi F, Akbarali N. Rehabilitation in Charles Bonnet syndrome: a review of treatment options. Clin Exp Optom 2004; 87:149.
- Plummer C, Kleinitz A, Vroomen P, Watts R. Of Roman chariots and goats in overcoats: the syndrome of Charles Bonnet. J Clin Neurosci 2007; 14:709.
- Tueth MJ, Cheong JA, Samander J. The Charles Bonnet syndrome: a type of organic visual hallucinosis. J Geriatr Psychiatry Neurol 1995; 8:1.
- Coletti Moja M, Milano E, Gasverde S, et al. Olanzapine therapy in hallucinatory visions related to Bonnet syndrome. Neurol Sci 2005; 26:168.
- Ukai S, Yamamoto M, Tanaka M, Takeda M. Treatment of typical Charles Bonnet syndrome with donepezil. Int Clin Psychopharmacol 2004; 19:355.
- Hori H, Terao T, Shiraishi Y, Nakamura J. Treatment of Charles Bonnet syndrome with valproate. Int Clin Psychopharmacol 2000; 15:117.
- Paulig M, Mentrup H. Charles Bonnet's syndrome: complete remission of complex visual hallucinations treated by gabapentin. J Neurol Neurosurg Psychiatry 2001; 70:813.
- Chaudhuri A. Charles Bonnet syndrome: an example of cortical dissociation syndrome affecting vision. J Neurol Neurosurg Psychiatry 2000; 69:704.
- Görgens K, Liedtke M. [Charles Bonnet syndrome]. Psychiatr Prax 1998; 25:85.
- Hosty G. Charles Bonnet syndrome: a description of two cases. Acta Psychiatr Scand 1990; 82:316.
- Ranen NG, Pasternak RE, Rovner BW. Cisapride in the treatment of visual hallucinations caused by vision loss: the Charles Bonnet syndrome. Am J Geriatr Psychiatry 1999; 7:264.
- Bergman Y, Barak Y. Escitalopram for antipsychotic nonresponsive visual hallucinosis: eight patients suffering from Charles Bonnet syndrome. Int Psychogeriatr 2013; 25:1433.