Radionuclide imaging in subacute sclerosing panencephalitis.

Three patients with subacute sclerosing panencephalitis (SSPE)--two with acute disease and one with an exacerbation--had abnormal radionuclide brain scans during periods of rapid neurologic deterioration. In two of the three patients radionuclide brain scan showed lesions of both cortex and deeper structures, indicating the panencephalic nature of the disease. There was no contrast enhancement on computerized tomography (CT) in the areas of radiopharmaceutical accumulation in the two patients studied. We feel that delayed radionuclide scanning is more sensitive in detecting acute SSPE than routine contrast-enhanced CT, because more time is allowed for tracer accumulation in lesions and for background activity to decrease.