Abstracts

Rationale: Children with various neurological disorders can develop Infantile Spasms (IS) and the treatment outcome of IS appears to be affected by the primary underlying etiology/pathology. Children with Down syndrome frequently develop IS; however, variable seizure outcome has been reported and not much is known about the clinical-electrophysiological factors affecting these outcome. We evaluated the clinical, neuroimaging and electrophysiological data in our DS with IS patient cohort, with a relatively long follow-up duration, to address some of these issues.Methods: We reviewed the clinical, neuroimaging, electrophysiological and outcome data in 15 children (F:M=7:8) with IS and DS with a follow-up duration of 10-197 months.Results: The median age at onset of spasms was 7 (2-16) months. Electroencephalogram showed hypsarrhythmia in 10 infants, and patterns of diffusely disorganised background with multifocal independent spike-wave activity in 5. Brain MRI (n=8) revealed no abnormality in 3, microcephaly in 2, delayed myelination in one, and minimal volume changes in 2. PET scans (n=5) showed diffuse glucose hypometabolism in 3, focal hypo- or hypermetabolism in 1 and 2 patients, respectively, and increased or decreased basal-ganglia metabolism in one each. Spasms disappeared in 8 patients (53.3%; six off medication). Seven of the 8 responders had shown hypsarrhythmia. Cessation of spasms was achieved by ACTH alone (n=1) or in combination with vigabatrin or zonisamide (n=1, each), and monotherapy with zonisamide (n=2), topiramate (n=1), prednisone (n=1), and ketogenic diet (n=1). Two patients showed evolution into complex partial epilepsy or Lennox-Gastaut syndrome. One child had dystonic cerebral palsy associated with perinatal asphyxia.Conclusions: Spasms develop relatively later in patients with IS and DS, compared to cryptogenic IS patients, and shows only modest treatment response. Presence of hypsarrhythmia may signal a better treatment response.