A serial ¹⁸FDG-PET study of a patient with SSPE who had good prognosis by combination therapy with interferon alpha and ribavirin.

We describe a 15-year-old girl with subacute sclerosing panencephalitis (SSPE) in stage II who was treated with isoprinosine, intraventricular interferon alpha (IFN-α), and ribavirin for 3 years. She is alive at three years from onset and studies at school with the assistance of a special educational teacher. To assess residual brain function, serial (18)FDG-positron emission tomography (PET) was performed three times to measure cortical metabolism: at onset, a year later, and three years later. At onset, PET study revealed preserved glucose metabolism of the cerebral cortex. In serial PET study, glucose metabolism of the cerebral cortex was also preserved even after three years. Although SSPE is a progressive disease of the neuronal system, and typically leads to death in approximately 2-3 years, the neurological prognosis of our case was good. We consider that combination therapy in the very early stage without hypometabolism in the cerebral cortex may be effective for SSPE.