We report a 27 years old man who was admitted to our hospital with progressive dementia that had begun two years ago. In his past medical history, his family reported a transient period of frequent falling and drop attacks of the head without any change of conscious, started when he was at age 18 and continued over three years; then he had a symptom-free period between the ages of 21-25 years. He had neither myoclonus nor periodic sharp and slow-wave discharges on electroencephalography (EEG) during the second phase of the disease that we saw him at age 27. Cerebrospinal fluid investigation disclosed high anti-measles IgG antibodies titer (1/640) and the patient was diagnosed with subacute sclerosing panencephalitis (SSPE). To our knowledge, this is the first case who had biphasic course without typical EEG findings of SSPE in the later phase of the disease.
Keywords: subacute sclerosing panencephalitis, electroencephalography
