Does Etiology and Hypsarrhythmia Subtype Influence Outcome in West Syndrome? Challenges Encountered from a Referral Center Perspective.

Background: Prediction of outcome of West syndrome (WS) in relation to etiology and electrophysiology remain pertinent challenges.

Objective: This study aimed to compare electro-clinical and imaging characteristics between WS of "unknown-etiology"; "symptomatic"WS; to gauge the evolution and impact of electroencephalographic (EEG) patterns on seizure outcomes.

Materials And Methods: Electro-clinico-radiological data of 76 children with WS who were followed up for atleast 1 year was collected for reviewing clinical, therapeutic and EEG profiles (sub-typed as typical and modified hypsarrhythmia [HA]). Quantified seizure scores were assessed.

Results: Among 76 children included in this retrospective analysis, 31 (40.8%) were of unknown-etiology and 45 (59.2%) were "symptomatic" (structural cause/developmental-encephalopathy). Children with symptomatic WS (p = 0.037), specifically with gliosis on imaging (p = 0.05) and typical HA (including the multifocal subtype; P = 0.023) were more likely to have other seizure types before onset of spasms and exhibit prior delay or regression in milestones (p = 0.017). There was negative correlation between time to diagnosis and reduction in seizure scores (r = -0.32; p = 0.005).Significant reduction was noted in seizure scores with pharmacotherapy, irrespective of etiology (P < 0.001 in unknown-etiology and symptomatic subgroups). Seizure freedom rates did not differ between typical and modified HA groups (p = 0.215) with a higher proportion of children with meaningful reduction in seizure scores in the former sub-group (p = 0.030). Children who failed to achieve seizure remission were more likely to exhibit developmental impairment (p = 0.019).

Conclusions: Early diagnosis and initiation of optimal therapy is crucial towards improving outcome, irrespective of etiology (which impacts pre-spasm development) and HA subtypes.