(Kiosk 4) Visual Recovery of Charles Bonnet Syndrome Following Hypoxic Brain Injury: A Case Report

Case Diagnosis: 36 year-old man with Charles Bonnet Syndrome secondary to hypoxic ischemic brain injury.

Case Description or Program Description: The patient sustained a hypoxic ischemic brain injury secondary to cardiac arrest in the field. Return of spontaneous circulation was obtained after an estimated 25 minutes. CT head was negative for acute pathology. MRI revealed signs of hypoxic injury with posterior/occipital enhancement and 2 small acute cerebellar infarcts. After extubation in the intensive care unit, he showed symptoms of cortical blindness, confabulation, hypophonia, and ataxia. He was discharged to inpatient rehabilitation 5 weeks after his cardiac arrest.

Setting: Acute Inpatient Rehabilitation Hospital

Assessment/Results: Upon arrival to inpatient rehabilitation, he did not respond to visual cues. He participated in therapies with scanning tasks using brightly colored objects, and his vision improved, reading small print and tracking people walking by his room. He then reported seeing things like his workplace, despite knowing he was in a hospital. Optometry evaluation showed visual acuity at 20/40 OD and 20/50 OS. Ocular motor function was impaired with choppy smooth pursuits and slow saccades. Post-discharge, he continued to experience visual symptoms, such as the walls shifting colors or seeing the inside of others’ homes. Follow-up optometry evaluation demonstrated left homonymous hemianopsia and right homonymous lower quadrantanopia with macular sparing and visual acuity 20/25 OD and OS within his remaining visual field.

Discussion (relevance): Charles Bonnet Syndrome (CBS) is characterized by visual hallucinations with good insight after significant vision impairment or visual field loss. Usually observed in the aging population with ocular pathology, CBS is more rarely encountered following hypoxic ischemic brain injury. This case highlights the importance of detailed visual assessments in patients with cortical visual impairments to optimize their rehabilitation.

Conclusions: CBS is a rare complication of hypoxic ischemic brain injury, the recovery of which during inpatient rehabilitation requires further investigation.