Seizures as onset symptoms and rapid course in preschool children with subacute sclerosing panencephalitis

BACKGROUND: The clinical features and outcomes of subacute sclerosing panencephalitis (SSPE) in younger children are different from those of adults, leading easily to misdiagnosis during the early stage. So far, there are limited data related to SSPE in preschool children. METHODS: In order to summarize the clinical data and evolution of SSPE in preschool children and to expand the phenotypes of SSPE, the medical charts of preschool patients diagnosed with SSPE were retrospectively reviewed and analyzed; the clinical outcomes of the enrolled cases were evaluated and followed up. RESULTS: Overall, we included three cases in the study. Their onset age was 5 years and 2 months, 4 years and 3 months, and 4 years and 2 months, respectively. All patients presented drop attacks or jerks as the onset symptom, and one patient had concurrent gait disturbance. Atypical periodic complexes on electroencephalography (EEG) were recorded in all patients. The brain magnetic resonance imaging (MRI) findings of two cases showed demyelinating lesions predominantly on the white matter. The neurological conditions of all cases deteriorated rapidly. Two children died at 21 months and 6 months after onset, respectively. The other case progressively developed vegetative status and akinetic mutism within 4 months. CONCLUSIONS: In younger children, the characteristic features of SSPE may be seizures and gait instability as onset manifestations, atypical periodic complexes on EEG, and rapid worsening of neurological conditions.