Altered mental status in a 66-year-old woman during the late summer months

Suraj A. Reddy, MD, William G. Schucany, MD, and Michael J. Opatowsky, MD

In the summer of 2003, a 66-year-old woman presented to the emergency department with fever, chills, and decreased oral intake. She was discharged home after intravenous hydration. Routine laboratory evaluation showed all relevant values to be within normal limits. After returning home, the patient's clinical status progressively worsened. She returned to the emergency department with continued fever and the onset of ataxia. A chest x-ray revealed a probable right lower lobe pneumonia.

The patient was admitted, blood cultures were drawn, and broad-spectrum antibiotics, including a third-generation cephalosporin and a macrolide, were administered. After 2 days of antibiotics, the patient's clinical status continued to decline and her mental status worsened. An unenhanced computed tomography scan of the brain was unremarkable. A lumbar puncture revealed an elevated white blood cell count with a predominance of lymphocytes as well as elevated protein levels with a normal glucose. Additional cerebrospinal fluid laboratory studies were ordered.

As the patient's clinical status continued to decline, she also began to develop bilateral, lower greater than upper, extremity weakness as well as multiple cranial nerve deficits. Enhanced magnetic resonance (MR) images of the brain were obtained (Figures 1-4).