Clinical Reasoning: A 73-year-old man with sarcoidosis and multifocal ischemic strokes.

SECTION 1: CLINICAL PRESENTATION A 73-year-old man was admitted for evaluation of acute ischemic strokes. His medical history was notable for pulmonary sarcoidosis treated with oral prednisone 40 mg daily, type 2 diabetes mellitus, hypertension, and hyperlipidemia. Approximately 1 month prior to admission, he underwent elective right total knee arthroplasty at an outside institution and 1 week postoperatively developed acute delirium and fluctuating fevers. No infectious cause was identified. His mental status continued to decline and head MRI was obtained (figure, A), showing small acute infarcts in multiple vascular territories. He began having episodes of forced eye deviation and behavioral arrest lasting less than 30 seconds each. He was urgently admitted to our hospital and levetiracetam was started empirically, without recurrence of presumed seizures. He complained only of mild headache and right knee pain. On examination, he was hemodynamically stable and afebrile. He was encephalopathic and had mild right leg weakness, but the rest of the neurologic examination was nonfocal. There was no meningismus. EEG showed mild diffuse slowing but no epileptogenic activity. Complete blood counts, electrolytes, lactate, and sedimentation rate were within normal limits. Chest CT showed stable findings consistent with his diagnosis of pulmonary sarcoidosis, but no acute pathology or evidence of active infection.