ABSTRACT
The authors studied human vagus nerve electrophysiology intraoperatively on 21 patients (age range: 4 to 31 years) during implantation of a vagus nerve stimulator for seizure control. The study was performed with direct electrical stimulation of the vagus nerve with various stimulation parameters resembling those employed by the Cyberonics NeuroCybernetic Prosthesis System (Houston, TX), which is used clinically for vagus nerve stimulation for treatment of seizures. Recordings were made directly from the rostral end of the vagus nerve. The response of the vagus nerve to various stimulus parameters in patients of different ages was studied. Based on the vagus nerve characteristics, age-related adjustments for stimulus parameters were recommended.
Subject(s)
Electric Stimulation Therapy/instrumentation , Epilepsy/therapy , Guidelines as Topic , Vagus Nerve/physiology , Adult , Age Factors , Child , Child, Preschool , Electrodes, Implanted , Female , Humans , MaleABSTRACT
PURPOSE: Patients with symptomatic generalized epilepsy (SGE) may have antiepileptic drug (AED)-resistant mixed generalized seizures. Vagus nerve stimulation (VNS) reduces partial seizures and may help SGE. METHODS: We added VNS to stable AED therapy in five SGE patients. Nine-month postoperative VNS treatment seizure rates were compared to a 1-month preoperative baseline. RESULTS: All patients had mixed generalized seizures, EEG generalized slow spike-and-wave and behavioral abnormalities. Median number of previous AEDs taken was 6 (range 5-12). Median baseline seizure rate was 75/month (range 29-110). VNS produced a median seizure rate production of -41% (range -40% - -85%). Adverse events reported in one patient each were: incisional infection, choking sensation and voice change; and coughing (noted by two patients). One patient discontinued VNS due to coughing. CONCLUSIONS: We conclude that VNS may be useful add-on therapy for SGE. A larger, controlled, and blinded trial may be warranted.
Subject(s)
Electric Stimulation Therapy/methods , Epilepsy, Generalized/therapy , Vagus Nerve/physiology , Adult , Anticonvulsants/therapeutic use , Combined Modality Therapy , Electric Stimulation , Electric Stimulation Therapy/adverse effects , Electroencephalography , Epilepsy, Generalized/drug therapy , Female , Humans , Male , Pilot Projects , Treatment OutcomeABSTRACT
PURPOSE: To determine rates of all-cause mortality and of sudden, unexpected, unexplained deaths in epilepsy (SUDEP) in a cohort of individuals treated with the Neuro Cybernetic Prosthesis (NCP) System for intractable epilepsy, and; to contrast the NCP experience with other epilepsy cohorts. METHODS: A cohort of 791 individuals were followed for 1,335 person-years from implantation. Of the total cohort, 120 individuals had their NCP System devices deactivated. The 15 deaths which occurred during NCP System activation were reviewed for SUDEP by a panel. There were three additional deaths and 242.5 person-years of monitoring after deactivation. RESULTS: The standardized mortality ratios for NCP System were 5.3, 95% confidence interval (CI) 3.0-8.7; and for the time period after device deactivation, 4.4, 95% CI 0.9-12.8. Six of the deaths during stimulation were considered definite or probable SUDEP and two as possible SUDEP. Seven were not considered to be SUDEP. The incidence of definite/probable SUDEP was 4.5 per 1,000 person-years and 6.0 per 1,000 person-years for definite/probable/possible SUDEP. CONCLUSIONS: The mortality rates and standardized mortality ratios are comparable with studies of young adults with intractable epilepsy who were not treated with NCP System. These SUDEP rates are not significantly different from those reported in the recent studies of lamotrigine (LTG), gabapentin (GBP), and tiagabine (TGB). The higher rates of SUDEP in the NCP System cohort, as compared with recent drug trials, presumably is explained by the selection of relatively higher-risk patients for the NCP System device.
