<p>Charles Bonnet Syndrome in a Patient with Parkinson’s Disease and Bilateral Posterior Capsule Opacification</p>

Abstract

Charles Bonnet syndrome (CBS) is a condition of visual hallucinations or disturbances occurring in patients with visual pathway pathology not due to underlying psychiatric, metabolic, or neurologic disease. A patient with Parkinson's disease experiencing visual hallucinations was evaluated by the ophthalmology service and found to have decreased vision due to bilateral reversible posterior capsular opacification. The patient's hallucinations did not improve on clozapine, a medication requiring careful monitoring due to potentially severe systemic side effects. However, the hallucinations resolved and vision improved after bilateral treatment of the posterior capsular opacification. Clozapine was then discontinued, and the patient was able to resume his previous Parkinson's disease therapy. This case highlights the importance of considering visual pathway pathology as a contributing factor to visual hallucinations, even in patients with previously diagnosed underlying psychiatric, metabolic, or neurologic disease that could additionally be the etiology of the visual disturbances.

Neurocognitive Psychiatric and Neuropsychological Alterations in Parkinson’s Disease: A Basic and Clinical Approach

“…Hallucinations of insects or small animals predominate, while other times, they are fleeting visions of people, adults or children, and static and silent images; however, hallucinations are rare. Visual hallucinations, which are frequently observed in patients with an intact state of consciousness, materialize as visions of people, animals, or inanimate objects; they can become illusions, that is, distorted perceptions of existing stimuli, and have threatening content, inducing feelings of fear such as Charles Bonnet syndrome, in which patients report false perception of threatening forms of objects when there is a decrease in ambient brightness [ 73 ].…”