A case of subacute sclerosing panencephalitis developing 8 years after immunosuppressive treatment for acute lymphocytic leukemia

: A 13-year-old girl developed subacute sclerosing panencephalitis (SSPE) with atypical absence attacks as an initial symptom. Eight years earlier she had been treated for acute lymphocytic leukemia with cytotoxic treatment and radiotherapy, which had resulted in complete remission. She was first treated with an anticonvulsant because the atypical absence attacks and the presence of epileptic discharges on an EEG suggested epilepsy. However, with this mode of treatment the epileptic discharges did not disappear, but periodic high-voltage slow-wave complex discharges were revealed on subsequent EEGs. The antibody titer for measles virus in the cerebrospinal fluid and serum was elevated, confirming the diagnosis of SSPE. SSPE may arise, though rarely, in an individual in an immunosuppressive state due to congenital immunodeficiency or various kinds of malignancies, and also may arise several years after the contraction of measles infection. Our patient, however, lacked a past history of measles infection or immunization, suggesting the possibility that she had contracted measles during or shortly after the course of treatment for ALL.