Subacute sclerosing panencephalitis: A clinical appraisal

Introduction: Subacute sclerosing panencephalitis (SSPE) is a rare chronic, progressive encephalitis affecting primarily children and young adults, caused by a persistent infection of immune resistant measles virus. The aim of the present study is to describe the clinical profile and natural history of patients with SSPE. Methods: We collected data of patients with SSPE during 2004-2010 who fulfilled Dyken's criteria. We analyzed demographical, clinical, electrophysiological, and imaging features. Results: Study included 34 patients, 26 (76.5%) males with age of onset from 3 to 31 years. Twenty one patients were below 15 years of age formed childhood SSPE and 13 above 15 years of age constituted adult onset group. 85.3% had low-socioeconomic status. Eleven received measles vaccination and seven were unvaccinated. 59.9% patients had measles history. Most common presenting symptom was scholastic backwardness (52.5%) followed by seizures (23.5%). Three patients each had cortical blindness, macular degeneration, decreased visual acuity, and optic atrophy. Electroencephalographic (EEG) showed long interval periodic complexes and cerebrospinal fluid anti-measles antibody was positive in all. Magnetic resonance imaging was done in 70.5% with was abnormal in 52.5%. Mean incubation period of SSPE after measles was 9.6 years. The follow-up duration was 1-10 years, (average of 2 years). Only one patient died from available data of follow-up, 9 were stable and 10 deteriorated in the form of progression of staging. Conclusion: SSPE is common in low-socioeconomic status. The profile of adult onset did not differ from childhood onset SSPE, except for a longer interval between measles infection and presence of the ophthalmic symptom as presenting feature in adult onset group.