Acute Disseminated Encephalomyelitis.

Introduction: Acute Disseminated Encephalomyelitis (ADEM) is a rare autoimmune demyelinating disorder of the central nervous system. Clinical manifestations include encephalopathy, motor deficits, ataxia, and meningeal signs. In most cases, ADEM is preceded by either vaccination or viral illness. Here, we present a case with neither of the two predisposing elements. Discussion: A 28-year-old Hispanic female presenting with substance use and suicidal ideation was placed on an involuntary psychiatric hold, started on olanzapine and scheduled for a psychiatric facility transfer. The following day, she was noted to have neurological deficits when ambulating. Computed tomography of the brain showed a right frontal lesion. Magnetic resonance imaging of the brain was notable for multiple peripherally enhancing white matter lesions. Multiple sclerosis and other etiologies were ruled out through supporting tests and lumbar puncture. ADEM was suspected, and the patient was treated with both a five-day course of intravenous methylprednisolone as well as immune globulins. She continued to have mild expressive aphasia after treatment; however, the majority of her symptoms improved. Conclusions: Diagnosis of ADEM versus multiple sclerosis can be difficult given there are no current diagnostic criteria for it in the adult population. In this case, we explain how we reached a diagnosis of ADEM and provide further discussion regarding the disease course and treatment.