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.