Effects of Vagal Nerve Stimulation in Alternating Hemiplegia of Childhood (I15.001)

Abstract

OBJECTIVE: To assess the efficacy of vagal nerve stimulation (VNS) to modulate epilepsy and other paroxysmal spells of Alternating Hemiplegia of Childhood (AHC). BACKGROUND: AHC is characterized by episodic hemiplegia and dystonia with symptom onset prior to 18 months. Up to 50[percnt] develop epilepsy that is often refractory to antiepileptic medication. Although use of VNS as adjunctive therapy for refractory epilepsy has shown favorable outcomes in children, it is not known how VNS would impact seizures and other disease manifestations in AHC. METHODS: Data was obtained through retrospective and prospective review of medical records and parent-reported accounts of seizures and AHC spells of four patients with AHC implanted with VNS for refractory seizures. Initial response to VNS was determined after 8 weeks of therapy without change in medication. Patients were followed for responses for at least 12 mos up to 3 yrs. RESULTS: VNS side effects including hoarseness and cough were mild and resolved with adjustment of settings. Polysomnography in one patient pre- and post-VNS showed a subtle increase in apnea hypopnea index from 2.3 to 3.5 events/hr; whereas, sleep efficiency improved from 88.7[percnt] to 94.4[percnt] with normalization of REM sleep. In the four cases studied, VNS decreased the frequency of seizures by 87.5[percnt], 98.9[percnt], 87.5[percnt] and 92[percnt]. Frequency of hemiplegic spells was also reduced by 66.7[percnt], 90[percnt], 71.7[percnt], and 60[percnt]; and dystonic spells reduced by 70[percnt], 90[percnt], 30.8[percnt], and 60[percnt]. Magnet activation shortened the duration of seizures by 86.7[percnt], 90[percnt], 85[percnt] and 66.7[percnt]; hemiplegia by 94.2[percnt], 87.5[percnt], 95[percnt], and 50[percnt]; and dystonia by 88.9[percnt], 97.8[percnt], 96.7[percnt], and 50[percnt] respectively. CONCLUSIONS: Our preliminary experience with VNS suggests that it is well tolerated and has shown promising results in the control of seizures as well as hemiplegia and dystonia spells associated with AHC.Study supported by the Cure AHC Foundation

Disclosure: Dr. Helseth has nothing to disclose. Dr. Prange has nothing to disclose. Dr. Kansagra has nothing to disclose. Dr. Muh has nothing to disclose. Dr. Mikati has nothing to disclose.