[MS1-2A-2] Efficacy of Vagus Nerve Stimulation for Core-Tonic Spasms/Brief Tonic Seizures With Electrodecremental Activity
[Objective] Vagus nerve stimulation (VNS) exerts antiepileptic effect. The efficacy of VNS for epileptic spasms and brief tonic seizures (ES/TS) has not been clarified enough. Electrodecremental activity is a ‘core’ EEG finding in ES/TS. We hypothesized that the ES/TS with electrodecremental activity (core-ES/TS) is refractory to VNS.
[Methods] We retrospectively collected the medically refractory epilepsy patients who underwent VNS implantation under 20 year-old. By the type of individual main seizure, we selected the patients of group A: core-ES/TS, and group B: partial seizures/secondary generalization (PS/SG). Core-ES/TS was confirmed with generalized electrodecremental activity (>1sec) at the onset of ictal scalp-video EEG. We used McHugh classification for outcome evaluations. We compared the clinical information and the outcomes among the two groups. For the comparison, we used Mann-Whitney U-test.
[Results] We collected 37 patients (group A: 20; group B: 17). The onset ages ranged 0-14 year-old (median 1). The ages at implantation ranged 1-19 year-old (12). The follow-up periods ranged 1.0-5.3 y (2.7 y). Twenty-four patients showed severe developmental delay (IQ/DQ: below 30). Compared with group B, the patients in group A showed earlier onset of seizure (p=0.004), and worse development (p=0.003). The seizure outcomes of group A (class I: 2; II: 2; III: 5; IV: 0; V: 11) were poorer than those of group B (I: 4; II: 6; III: 2; IV: 2; V: 3) (p=0.020).
[Conclusion] VNS is poorly effective for core-ES/TS in children with medically refractory epilepsy. VNS may be less effective for the seizures with those seizures.
[Methods] We retrospectively collected the medically refractory epilepsy patients who underwent VNS implantation under 20 year-old. By the type of individual main seizure, we selected the patients of group A: core-ES/TS, and group B: partial seizures/secondary generalization (PS/SG). Core-ES/TS was confirmed with generalized electrodecremental activity (>1sec) at the onset of ictal scalp-video EEG. We used McHugh classification for outcome evaluations. We compared the clinical information and the outcomes among the two groups. For the comparison, we used Mann-Whitney U-test.
[Results] We collected 37 patients (group A: 20; group B: 17). The onset ages ranged 0-14 year-old (median 1). The ages at implantation ranged 1-19 year-old (12). The follow-up periods ranged 1.0-5.3 y (2.7 y). Twenty-four patients showed severe developmental delay (IQ/DQ: below 30). Compared with group B, the patients in group A showed earlier onset of seizure (p=0.004), and worse development (p=0.003). The seizure outcomes of group A (class I: 2; II: 2; III: 5; IV: 0; V: 11) were poorer than those of group B (I: 4; II: 6; III: 2; IV: 2; V: 3) (p=0.020).
[Conclusion] VNS is poorly effective for core-ES/TS in children with medically refractory epilepsy. VNS may be less effective for the seizures with those seizures.