Case of subacute sclerosing panencephalitis with atypical absences and myoclonic-atonic seizures as a first symptom.

The 2-year history of a 10-year-old boy with subacute sclerosing panencephalitis is presented. After 6 months of epilepsy manifested by atypical absences and myoclonic-atonic seizures with an electroencephalographic (EEG) correlation of generalized spike-and polyspike-wave discharges, the child developed chorioretinitis and demonstrated a dramatic intellectual decline during corticosteroid treatment. Neuroimaging investigations did not demonstrate any pathologic changes, including at the time of fully developed disease, with neurologic deficits, periodic spasms, polymorphic epileptic seizures, and dementia. The typical generalized periodic complexes and general slowing replaced the epileptic abnormalities in the EEG. The initial anticonvulsant treatment was temporarily effective, and the purposeful isoprinosine therapy had no significant beneficial effect. The subacute sclerosing panencephalitis rapidly developed to stages III to IV, and only during the vegetative state did computed tomography show marked brain atrophy. This case is among the few described in the literature with atypical absences and myoclonic-atonic seizures as the first manifestation of subacute sclerosing panencephalitis.