Visual Hallucinations: Charles Bonnet Syndrome
An 86-year-old woman presented to the ED with a chief complaint of visual hallucinations. She had been having these “visions” for a week, occurring mainly in the evening. The hallucinations were episodic, binocular and lasted for hours. She was unable to identify any specific factors that would trigger their arrival or resolution.\nThe hallucinations were clear and vivid, representing either various objects around the house moving, such as a clock and a planter, or people and faces on the ceiling or corner of her room. She had become so frightened thinking she was “going crazy” that she decided to come to the ED. While experiencing these hallucinations, the patient had no change in mental status and maintained full insight and awareness. She denied any other visual disturbances, such as diplopia, scotomata, tunnel vision or loss of vision. She further denied auditory or other sensory hallucinations as well as headaches, fever, or trauma. There was no history of drug or alcohol abuse.\nHer past medical history included open-angle glaucoma, macular degeneration, cataracts, hypothyroidism, hyperlipidemia and gastric reflux. Her surgical history was relevant for bilateral cataract surgeries with her right eye requiring 2 surgeries, as well as a corneal transplant. She denied any psychiatric history.\nOn physical examination she appeared well and in no acute distress. She was oriented to person, place and time. Her vital signs were: blood pressure 213/98 mmHg, pulse rate 66 beats/minute and regular, respirations 20 breaths/minute, temperature of 36.8°C and oxygen saturation of 97% on room air. There were no complaints of any hallucinations at the time of the exam. She had bilateral iridectomies and her corrected visual acuities were 20/50 OD and 20/100 OS. The visual fields were full, and her fundoscopic exam revealed no gross abnormalities. Neurologic examination showed no focal findings. A mental status examination did not reveal mood disturbance or cognitive deficits, and she scored 30/30 points on her Mini Mental Status Exam (MMSE). The remainder of her physical examination was normal.\nLaboratory studies demonstrated a serum sodium level of 128 mEq/L and a serum chloride of 92 mEq/L. Glucose and renal function were normal. White blood cell count was 8.3 × 109/L. A urinalysis was positive for nitrites, 2+ leukocyte esterase and 50–100 white blood cells/HPF. Computed tomography (CT) of the head without contrast showed no acute intracranial hemorrhage, stable moderate to marked chronic microvascular ischemic changes in the supratentorial white matter, and a stable small chronic infarct in the right basal ganglia.\nBased on clinical history and exam, a diagnosis of Charles Bonnet syndrome was made by the ED attending physician. She was seen 2 days later by her ophthalmologist who concurred with the ED diagnosis based on similar presentation of many previous patients in his practice. At the time of her follow up, the hallucinations had resolved and her eye exam was unremarkable.