CHARLES BONNET SYNDROME

Course overview

CHARLES BONNET SYNDROME (CBS) IS A PHENOMENON CHARACTERIZED BY COMPLEX VISUAL HALLUCINATIONS IN VISUALLY CHALLENGED PATIENTS BUT OTHERWISE PSYCHOLOGICALLY NORMAL. THE PHENOMENON WAS FIRST DESCRIBED IN 1760 BY SWISS PHILOSOPHER CHARLES BONNET WHO OBSERVED THIS PHENOMENON IN HIS GRANDFATHER, WHO WAS VISUALLY IMPAIRED DUE TO CATARACTS. IN THIS PHENOMENON, THE HALLUCINATIONS HAVE BEEN DESCRIBED AS FORMED, VIVID, OF REALISTIC OBJECTS OR PEOPLE, AND THEY TEND TO RECUR. IN CBS, THE PATIENT IS AWARE THAT THE IMAGE IS NOT REAL AND MAY SEE THESE IMAGES AS DISTURBING. HOWEVER, HALLUCINATIONS CAN ALSO FIT IN THE VISUAL PHENOMENON AND MAY BE INDISCERNIBLE FROM REAL OBJECTS. HALLUCINATIONS ARE DESCRIBED AS THE PERCEPTION OF UNREALISTIC IMAGES, SOUNDS, OR SMELLS IN THE ABSENCE OF ANY EXTERNAL STIMULUS. HALLUCINATIONS IN OLDER PEOPLE ARE USUALLY MARKERS OF UNDERLYING NEUROLOGICAL DISORDERS LIKE ALZHEIMER DISEASE, PARKINSONISM, DELIRIUM, SENSORY DEPRIVATION, INSOMNIA, OR PSYCHOSIS. THE OTHER TYPE OF HALLUCINATION IS RELEASE HALLUCINATION WHICH USUALLY ORIGINATES FROM THE EXTERNAL WORLD BUT IS EXPERIENCED WHEN THERE IS AN INADEQUATE STIMULUS TO THE SENSORY SYSTEM. THE HALLUCINATIONS IN CBS ARE VISUAL AND COMPLEX BUT ARE NOT DISTURBING. CBS CAN ALSO BE A MARKER OF DEMENTIA IN ELDERLY PATIENTS. CBS CAN MANIFEST WHEN THERE IS A LESION AT ANY LEVEL OF THE VISUAL SYSTEM, AND TYPICALLY PATIENTS MANIFEST WITH A LOSS OF CENTRAL VISUAL ACUITY. CBS IS ALSO ASSOCIATED WITH ARMD WITH A SECONDARY DECLINE IN VISUAL ACUITY. THIS ACTIVITY DEALS WITH THE ETIOLOGY, EPIDEMIOLOGY, AND PATHOPHYSIOLOGY OF CBS AND HIGHLIGHTS THE ROLE OF THE INTERPROFESSIONAL TEAM IN THE INVESTIGATION AND TREATMENT OF CBS.