Summary:Purpose: To determine the long-term efficacy of vagus nerve stimulation (VNS) for refractory seizures. VNS is a new treatment for refractory epilepsy. Two short-term double-blind trials have demonstrated its safety and efficacy, and one long-term study in 114 patients has demonstrated a cumulative improvement in efficacy at 1 year. We report the largest prospective long-term study of VNS to date.Methods: Patients with six or more complex partial or generalized tonic-clonic seizures enrolled in the pivotal E05 study were prospectively evaluated for 12 months. The primary outcome variable was the percentage reduction in total seizure frequency at 3 and 12 months after completion of the acute E05 trial, compared with the preimplantation baseline. Subjects originally randomized to low stimulation (active-control group) were crossed over to therapeutic stimulation settings for the first time. Subjects initially randomized to high settings were maintained on high settings throughout the 12-month study.Results: The median reduction at 12 months after completion of the initial double-blind study was 45%. At 12 months, 35% of 195 subjects had a >50% reduction in seizures, and 20% of 195 had a >75% reduction in seizures.Conclusions: The efficacy of VNS improves during 12 months, and many subjects sustain >75% reductions in seizures. Key Words: Vagus nerve stimulation-Intractable epilepsy.Vagus nerve stimulation (VNS) has emerged as an effective treatment for medically intractable epilepsy ( 1-3). VNS uses an implantable, programmable pulse generator powered by a lithium battery, which is connected to a helical bipolar lead. The lead is attached to the midcervical portion of the left vagus nerve and delivers

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In patients experiencing migraine without aura, CBF and CBV are reduced during the headache phase. Cerebral oxygen metabolism and oxygen extraction are not significantly affected.

Summary: Purpose:To compare the frequency of seizures and status epilepticus and their response to first-line drugs in patients with idiopathic generalized epilepsies receiving carbamazepine or phenytoin to those receiving other drugs or no treatment.Methods: We performed a retrospective chart review of all cases of idiopathic generalized epilepsies treated by the authors between 1985 and 1994. We compared seizure frequency and mean intravenous benzodiazepine dose required to control absence status epilepticus, intraindividually in subjects on carbamazepine or phenytoin before and after discontinuation of these compounds, and interindividually to subjects without treatment or receiving other drugs.Results: Bouts of absence or tonic-clonic status epilepticus and seizures in subjects treated with phenytoin or carbamazepine at therapeutic concentrations were considerably more frequent and proved intractable to treatment with valproic acid or benzodiazepines, compared with a cohort of subjects also with idiopathic generalized epilepsies, but naive to, or receiving subtherapeutic or therapeutic doses of other agents.Conclusions: Our observations strongly suggest that therapeutic concentrations of phenytoin and carbamazepine exacerbate idiopathic generalized epilepsies. Subjects in whom absence is one of the seizure types seem at a particularly high risk for responding paradoxically. These findings underscore the value of accurate classification of seizures and particularly the syndromic approach to diagnosis and point to the potential for iatrogenic complications with indiscriminate use of antiseizure drugs. Key Words: Idiopathic generalized epilepsiesAbsence status epilepticus-Refractoriness-Paradoxical effects-Phenytoin-Carbamazepine.Convulsive status epilepticus refractory to appropriate treatment is well recognized and comprises a sizable percentage of all cases of status (1,2). In contrast, idiopathic generalized absence status epilepticus (IGASE), refractory to appropriate drugs, is rate (3-6). A survey of the literature revealed that complete control was attained in 93% of cases from 10 different studies (7).Paradoxical increases in seizure frequency is a recognized, but difficult-to-document, adverse effect of antiepileptic agents (8-10). The main limitation evident in the existing body of literature is a lack of systematic observations over reasonably long periods of time to minimize the confounding effect of the inherently high variability in seizure frequency, a phenomenon known as "regression of seizure frequency to the median" (9, I 1 ).In addition, the majority of reported cases have been patients with symptomatic epilepsy. We report eight carefully studied cases (Group 1) with idiopathic generalized epilepsy (ICE) on phenytoin (PHT) and carbamazepine (CBZ) with very frequent, seemingly intractable absence (AS) and tonic-clonic seizures who presented in absence status epilepticus (ASE) that proved refractory to intravenous high-dose benzodiazepines (BZDs). The lack of response in these cases was in star...