Abstracts

Rationale: The SSQ has been used in large clinical trials to assess the severity of seizures and as such should differentiate between seizure types. This analysis evaluated the responsiveness of individual items to clinical response according to seizure type as further validation of the instrument. Methods: Data from open-label extensions (OLEs) of two phase III trials of lacosamide in focal epilepsy (SP756, SP774) were pooled. Patients completed the SSQ at double-blind baseline and every 24 weeks during OL treatment. The SSQ is a 22-item questionnaire (addressing Aura/Warning, Ictal, and Post-Ictal events) that is scored as 3 composite scores and a total score, and includes questions for frequency and helpfulness of warning signs as well as severity and/or bothersomeness of ictal movement and loss of consciousness. Also included are 9 items measuring the frequency, severity, and bothersomeness of post-ictal cognitive, emotional, and physical effects. Item scores range from 1-7, with higher scores indicating greater severity, except the warning item. Mean change from baseline to week 48 of the OLE was calculated for each item by seizure type response for those with only complex partial seizures (CPS) or only secondarily generalized partial seizures (SGPS) at baseline. Responders were defined as subjects with a ≥50% reduction in seizure frequency in the 24 weeks before week 48, compared to baseline. Differences between responders and non-responders were compared between seizure-type groups. Results: SSQ data were available for 166 CPS responders and 127 non-responders; and for 26 SGPS responders and 24 non-responders. The warning item showed little difference between responders and non-responders in both seizure type groups. On the ictal movement and consciousness items, responders showed large improvements with larger differences observed in the SGPS group: >1.5 points compared with 0.71 to 0.96 points among CPS responders. Scores for non-responders remained stable in both groups of patients. On post-ictal recovery questions for cognitive, emotional or physical effects, the SGPS group showed much larger responder to non-responder differences than the CPS group for each of the 3 bothersomeness items, with less differentiation for the frequency and severity items. SGPS responders showed mean improvements of more than 2 points on frequency, severity, and bothersomeness items for after-seizure physical effects. Conclusions: SSQ items showed excellent differentiation between seizure type responders related to ictal movement and consciousness, and related to bothersomeness of post-ictal effects. The frequency, severity, and bothersomeness of post-ictal physical effects were markedly improved for SGPS responders. These data support the usefulness of the SSQ in describing treatment effects. Sponsored by UCB.