INTRODUCTION: Subacute sclerosing panencephalitis (SSPE) affects primarily children and adolescents with age of onset from 5 to 15 years. Only 12.7% of cases present with symptoms after the age of 18 years. We present a case of Subacute Sclerosing Panencephalitis Jabbour Stage 11 in a 26-year old male with progressive decline in mental function and myoclonic jerks.

CLINICAL PRESENTATION: This is a case of a 26 year-old male with a one year history of decreasing cognitive function and a seven week history of progressive myoclonic jerks resulting in difficulty ambulating, frequent falls and loss of balance with decreasing verbal output. There was a history of measles infection and meningitis at 8 months.

DIAGNOSTIC WORK-UP: The EEG was abnormal showing generalized complexes of sharps, sharp-slow wave and slow delta waves that appeared with pseudo-periodicity and time-locked with the appearance of myoclonic jerks that involved mainly the trunk. There was generalized slowing of the background activity. The findings support the clinical impression of Subacute Sclerosing Panencephalitis. CSF and Serum Measles lgG antibodies showed positive results with values of 5.55 and 11.06, respectively (cutoff at 0.70 for both serum and CSF lgGAb).

TREATMENT AND FOLLOW-UP: The patient was given Valproic Acid titrated to 25 mg/kg/day, and lsoprinosine at 100 mg/kg/day. The patient's family was appraised of the patient's condition and prognosis. Regular OPD follow-up was encouraged.