A 52-year-old man with a history of alcohol, cocaine, and amyl nitrate use presented with acute encephalopathy, acute kidney injury, and rhabdomyolysis. Although encephalopathy improved with treatment of these systemic disorders, he revealed persistent anterograde greater than retrograde amnesia. 

The distinct imaging finding of diffusion restricting bilateral hippocampal lesions carries a broad differential including ischemic, ictal, and various toxic-metabolic causes. This patient was favored to have had a seizure due to toxic-metabolic insult from cocaine and amyl nitrate use. Cocaine induced vasculopathy resulting in bilateral hippocampal infarcts has been reported rarely in literature, but rapid resolution of hippocampal lesions in this patient suggests this was unlikely, although may explain the corona radiata stroke. Limbic encephalitis may cause bilateral hippocampal edema, but less likely to cause diffusion restriction. A detailed history and work-up for potential toxic exposures is critical for those who do not have an alternative explanation and present with such imaging findings.