Abstracts

Subacute sclerosing panencephalitis (SSPE) is a rare but devastating late neurological complication of measles infection characterized by a progressive encephalopathy, myoclonus, and focal neurologic deficits occuring 7-10 years after initial infection. Survival from onset is typically 1-3 years. There is no proven effective therapy. We report a 15-year old girl with SSPE who had marked improvement in atonic seizures and neurocognitive status with zonisamide and interferon-beta 1a., Case report., A 15-year-old girl presented to our epilepsy center with seizures and cognitive decline. At 19 months, a febrile exanthem illness diagnosed as Kawasaki disease was treated with intravenous immunoglobulins. At age 13 she developed nocturnal frontal lobe complex partial seizures, successfully controlled with lamotrigine. Eighteen months later, her family noticed personality changes and inattentiveness. Cognitive decline continued over the next 8 months; full scale IQ decreased from 101 to 77. At age 15, she began to have atonic seizures and falls. Video EEG monitoring showed frequent atonic episodes, brief behavioral arrests with slow eye blinks, and myoclonic jerks, concurrent with periodic generalized high-voltage slow wave complexes occurring once every 5 - 6 seconds. Laboratory data included markedly elevated IgG, IgG index, and IgG synthesis rate with positive CSF oligoclonal bands. Serum and CSF measles IgG were significantly elevated. MRI of the brain revealed subtle bilateral occipital white matter T2 hyperintensities. Functional MRI synchronized to the abnormal blinks showed increased BOLD signal and perfusion in bilateral putamina and cingulate cortex. Zonisamide 250mg daily was added to her regimen. Atonic episodes remitted completely, and EEG 1 month later showed no periodic slow wave complexes. On isoprinosine 3000mg/day, neurologic status remained stable for 6 months. Cognitive status then declined again (FSIQ 40, modified mini-mental status exam (MMSE) 20/57) and new MRI T2 hyperintense lesions appeared in bilateral basal ganglia. She was started on interferon-beta 1a 44mcg subcutaneously three times weekly. Her Neurologic Disability Index declined from 24% to 6%, and MMSE improved to 36/57. She continues to improve 1 year after subcutaneous interferon was initiated., Myoclonic and atonic seizures, hallmarks of SSPE, are usually refractory to standard antiepileptic drugs. Our case demonstrates a rapid and complete response to zonisamide which was sustained over nearly two years, suggesting a new avenue for therapy of these refractory seizures. In addition, our patient showed sustained improvement in neurocognitive function with subcutaneous interferon beta 1a. This therapy should be considered in SSPE patients who have the failed the current standards of care.,