Potentially life-threatening ictal bradycardia in intractable epilepsy.

BACKGROUND: Recently a high prevalence of asystole was found in individuals with refractory epilepsy. OBJECTIVE: To measure the prevalence and characterize the pattern of ictal bradycardia (IB) in our cohort. METHOD: We analyzed ictal heart rate (HR) and seizure localization in 69 consecutive individuals with intractable epilepsy. Ictal bradycardia was defined by HR less than 60 beat per min (bpm) and a fall of more than 30 bpm. RESULTS: Ictal bradycardia was observed in 1.9% of seizures and in five individuals (7.2%), who presented IB in 5.7% of their seizures. Four of them had also relative IB (a decrease of HR of more than l0 bpm) in the majority of their seizures. Four additional individuals showed relative IB. CONCLUSION: Ictal bradycardia occurs more frequently than previously thought in individuals with refractory epilepsy. Recognition of individuals with small to moderate ictal HR decrease may help to identify those at greatest risk for asystole.

Microsurgery of epileptic foci in the insular region.

OBJECT: The insular region has long been neglected in the investigation and treatment of refractory epilepsy. Surgery in the insular region is rarely performed because of the risk of injury to the opercula, the arteries transiting on the surface of the insula, and the deep structures such as the basal ganglia and the internal capsule. This study was undertaken to report the results of insular surgery using modern microsurgical techniques in patients with epilepsy. METHODS: The authors performed a retrospective study of cases involving patients who underwent surgery for insular lesions associated with epilepsy over the last 10 years. In the majority of patients, intracranial electrodes were implanted with neuronavigation guidance to confirm the localization of the epileptic foci. RESULTS: Nine patients underwent insular surgery: 7 for refractory epilepsy with no tumor and 2 for tumors associated with seizures. Four of the resections were performed in the left hemisphere. After an average follow-up of 54 months (range 14-122 months), Engel Class IA outcome had been achieved in 6 of 7 cases in the Epilepsy Surgery Group. The remaining patient had an Engel Class III outcome after partial insular resection but later became seizurefree (Engel Class IA) following insular Gamma Knife surgery. Postoperatively, the majority of patients suffered from minor reversible hemipareses that disappeared completely within a few months. There was no surgical mortality. CONCLUSIONS: Insular surgery is both safe and beneficial when it is well planned and performed with modern microsurgical techniques and good anatomical knowledge. Insulectomy is associated with little permanent morbidity and a high rate of seizure control. To the authors' knowledge, this is the first series of insulectomies predominantly performed for refractory epilepsy since those performed by Penfield.

Revisiting the role of the insula in refractory partial epilepsy.

PURPOSE: Recent evidence suggesting that some epilepsy surgery failures could be related to unrecognized insular epilepsy have led us to lower our threshold to sample the insula with intracerebral electrodes. In this study, we report our experience resulting from this change in strategy. METHODS: During the period extending from October 2004 to June 2007, 18 patients had an intracranial study including 10 with insular coverage. The decision to sample the insula with intracerebral electrodes was made in the context of (1) nonlesional parietal lobe-like epilepsy; (2) nonlesional frontal lobe-like epilepsy; (3) nonlesional temporal lobe-like epilepsy; and (4) atypical temporal lobe-like epilepsy. RESULTS: Intracerebral recordings confirmed the presence of insular lobe seizures in four patients. Cortical stimulation performed in 9 of 10 patients with insular electrodes elicited, in decreasing order of frequency, somatosensory, viscerosensory, motor, auditory, vestibular, and speech symptoms. DISCUSSION: Our results suggest that insular cortex epilepsy may mimic temporal, frontal, and parietal lobe epilepsies and that a nonnegligeable proportion of surgical candidates with drug-resistant epilepsy have an epileptogenic zone that involves the insula.