Selective cognitive patterns resulting from bilateral hippocampal ischemia

A 54-year-old diabetic, hypertensive man with poorly controlled moderate-severe sleep apnea presented with acute onset of severe anterograde amnesia and well preserved remote memory without additional cognitive impairment. Investigations, including a lumbar puncture, electroencephalogram (EEG) and serology testing ruled out infectious, neoplastic and epilleptogenic causes. MRI taken 10 days after symptom onset, was suggestive of sequential ischemic damage to both hippocampal formations. Neuropyschological evaluation suggested a focal and dense amnestic syndrome with little improvement over time. The bilateral nature of hippocampal ischemia though has been reported, is rare.