Subacute sclerosing panencephalitis (SSPE) is a progressive, fatal disease of the central nervous system caused by a persistent measles virus. It is clinically characterized by insidious onset of intellectual deterioration and behavioral changes followed by myoclonias and eventually complete neurologic deterioration. The diagnosis is based on characteristic clinical features, periodic electroencephalography (EEG) complexes of high slow waves and increased antibody titer against measles in cerebrospinal fluid. Here, we report four SSPE cases, two of whom manifested with hemiparesis; in the third and fourth cases, cerebellar ataxia and acute encephalopathy with focal seizures were the presenting symptoms at the onset of disease, respectively. The typical periodic EEG complexes in our patients led to the diagnosis of SSPE. Our findings show that SSPE should be considered in the differential diagnosis of hemiparesis, cerebellar ataxia and acute encephalopathy, and highlight the diagnostic significance of EEG in unidentified cases.