Abstracts

The vagal nerve stimulator (VNS) is used as adjunctive therapy in refractory epilepsy. Multiple studies show improved seizure control ranging from 20 [ndash] 40% at 3 [ndash] 24 months post device placement in children 3 [ndash] 18 years of age. However, no studies have assessed health related quality of life (HRQOL) after VNS implantation using standard, validated instruments.
All patients with VNS implantation between 8/99 and 11/02 (at least 6 months prior to this abstract[rsquo]s submission) were mailed four instruments to assess HRQOL. These included Impact of Pediatric Epilepsy Scale (IPES), Quality of Life in Childhood Epilepsy Questionnaire: Parent form (QOLCE), National Hospital Seizure Severity Scale (NHSSS), and Background Information (BI).
Of the 30 families who were sent these questionnaires, 13 responded. Of these 13, one family with 2 patients declined to participate. Data was analyzed from the remaining 11 patients.
Mean patient age was 10.7 years, range 5 [ndash] 19.2 years. Four were males and seven females. All participants reported experiencing seizures on the NHSSS scale. The total seizure burden ranged from 5 [ndash] 54, mean 22.7 (SD 18.2). The possible score ranges from 1 to 81, with higher scores indicating greater seizure burden.
The mean QOLCE total score was 45.7 (SD 15), range 28 [ndash] 81. This score, mean of 16 composite scale scores, ranges from 0 [ndash] 100 with the higher scores indicating better quality of life.
The mean IPES total score was 20.7 (SD 9.9), range 4 [ndash] 33. The possible score ranges from 0 [ndash] 33, with higher scores indicating greater impact of epilepsy on the family.
Total seizure burden and QOLCE total score showed a significant negative correlation (r = -.646, p [lt] 0.5). Total seizure burden and IPES total score showed a positive correlation (r = .636, p [lt] .05).
At least 6 months post VNS placement, seizure burden continued to have significant adverse impact on HRQOL as measured by QOLCE, and psychological impact on the family as assessed by IPES.
Our data is contradictory to the anecdotal reports of improved quality of life with VNS. This may in part be due to a heavier baseline seizure burden in our cohort. It is also possible that the instruments used are not sensitive enough to detect subtle improvements in the quality of life in this subset of refractory epilepsy patients. In addition, our retrospective data is limited due to lack of assessment of seizure burden and its impact pre and post VNS placement. To further address this issue, prospective pre and post VNS placement data collection is in progress.