Measles meningoencephalitis occurs in approximately 0.1% of cases of measles.1 The prognosis is poor, with a 10% to 30% mortality and 20% to 50% morbidity.2 With its variable course, an accurate diagnosis is extremely important. Isolation of the measles virus from the CSF is most difficult, and has been successful only on postmortem specimens.3,4 As a result, the diagnosis of measles meningoencephalitis is based on clinical and serological data.
Most commonly, measles meningoencephalitis, as with other forms of aseptic meningitis, is associated with a CSF lymphocytosis. The patient described herein is unusual because of the initial and prolonged CSF polymorphonuclear leukocyte response.
Report of a Case.—A 10-year-old girl was admitted to The Hospital for Sick Children, Toronto. Two weeks prior to admission, she had been in contact with a neighbor with the clinical diagnosis of measles. Ten days prior to admission, cough, coryza, and a low-grade