Subacute sclerosing panencephalitis: a cause of acute vision loss

A 4-year-old male presented with only acute vision loss. His neurologic examination, funduscopic examination, and pupils were normal. Cranial magnetic resonance imaging revealed abnormal hyperintense, bilaterally symmetric lesions (on T(2)-weighted and fluid-attenuated inversion recovery, images) in bilateral optic radiations, pulvinar region in the thalami, crus posterior of internal capsules, periventricular white matter, and unilaterally left anterior pons. Elevated measles antibody titers in the cerebrospinal fluid confirmed the diagnosis of subacute sclerosing panencephalitis. Vision loss improved and cranial magnetic resonance imaging findings regressed,but myoclonic jerks and deterioration began 7 months later. The diagnosis of subacute sclerosing panencephalitis should be considered in cases with acute vision loss resulting from cortical blindness even when classical findings of the central nervous system do not exist.