Atypical imaging and clinical presentation of fulminant subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE) is a late progressive fatal central nervous system sequelae of measles infection. The diagnosis is made based on clinical and electroencephalography (EEG) findings and confirmed by elevated titers of anti-measles antibodies in cerebrospinal fluid. The usual clinical presentation is in the form of progressive behavioral change, cognitive decline, and myoclonic jerks with some cases presenting in an atypical manner in the form of ataxia, epilepsy, and stroke. EEG is quiet characteristic in the form of periodic discharges of slow wave complex. Magnetic resonance imaging (MRI) early in the disease is usually normal with abnormal scans showing focal leukodystrophy, predominantly in the posterior cerebral white matter, and development of cortical atrophy with disease progression. Cord involvement is not common in SSPE. We report a child with SSPE who had initial presentation with cerebellar ataxia, acute progression of encephalitis, and atypical EEG findings. MRI brain on the initial presentation showed very subtle and focal abnormality which later progressed to have disseminated brain lesions and dorsal cord myelitis and further in the disease course showed cerebral venous sinus thrombosis. This case report emphasizes that SSPE can have very atypical presentation with rapid deterioration and can mimic as acute encephalitis or demyelinating disease.