Image diagnosis: headache and an isolated oculomotor nerve palsy.

Donald Mebust, MD, is an Emergency Physician at the San Diego Medical Center in CA. E-mail: [email protected]. Case Study A 55-year-old woman presented to the Emergency Department with complaints of headache, diplopia, and double vision (Figure 1). Patient noted 2 weeks of an aching right-sided headache and a “droopy eyelid.” Three days before our evaluation, her symptoms worsened and she began to develop diplopia. On exam, she demonstrated right-sided ptosis, a dilated pupil with a sluggish light response, and a downward and lateral deviation of the right eye. The remainder of neurologic exam was within normal limits. The patient underwent a stat unenhanced computed tomography (CT) scan of the brain. This study was negative for bleed, mass, or acute cerebral vascular accident. Because there was high clinical suspicion for a vascular emergency, neurology was consulted and magnetic resonance angiogram imaging of the brain was ordered. This revealed a 3 mm x 7 mm posterior communicating aneurysm. Diagnostic cerebral angiogram confirmed the diagnosis and successful endovascular coiling of the aneurysm was performed (Figure 2). The patient was discharged home on postoperative day 1 with resolution of headache but persistence of her third nerve palsy. Unfortunately, the patient has since been lost to follow-up.