We conducted a prospective study over 24 months to compare health-related quality of life in surgically and medically treated patients with intractable temporal lobe epilepsy. Seizure frequency and health-related quality of life were assessed in 81 patients before and 6, 12, and 24 months after treatment. Using the Epilepsy Surgery Inventory 55 (ESI-55), we compared (1) different seizure outcome groups and (2) temporal lobectomy with continuing medical management. Follow-up was satisfactory in 72 patients (89%), 51 treated with temporal lobectomy and 21 with no surgery. Pretreatment seizures and health-related quality of life were comparable in the two groups. Seizure outcome was significantly better at 6, 12, and 24 months after surgery. At 24 months, seizure-free patients and those with at least a 90% reduction in seizure frequency reported significant improvements in health-related quality of life (on 5 of 10 subscales and overall Epilepsy Surgery Inventory 55 scale). Deterioration in quality of life occurred with less than 90% seizure reduction. Only one Epilepsy Surgery Inventory 55 subscale at 6 months and two subscales at 12 months showed a significant difference. Patients with good seizure outcome experience improved health-related quality of life after treatment. Since temporal lobectomy results in considerably better seizure control than continued medical management, the findings support surgery as the preferred treatment, although changes in health-related quality of life may not be evident until the second postoperative year.

The effects of electrical stimulation of the vagus nerve, a proposed treatment for patients with intractable epilepsy, on focal interictal spikes produced by penicillin and EEG secondarily generalized seizures induced by pentylenetetrazol were assessed in rats. Interictal spike frequency was reduced by 33% during 20 s of stimulation (p < 0.001) and remained low for < or = 3 min. Amplitude of residual spikes was also decreased. Cardiac and respiratory rates were suppressed. Cooling the nerve proximal to the point of stimulation abolished the EEG and respiratory effects. A similar reduction in spike frequency of 39% was obtained by heating the animals' tail (p < 0.01). Vagal stimulation at onset of seizures reduced mean seizure duration from 30.2 +/- 15.7 s without stimulation to 5.0 +/- 1.8 s (p < 0.01). Only the EEG equivalent of the clonic phase of the seizure was affected. These findings suggest that vagus nerve stimulation can be a potent but nonspecific method to reduce cortical epileptiform activity, probably through an indirect effect mediated by the reticular activating system.

SUMMARYThe effect of continuous electrical stimulation of the hippocampus bilaterally on seizures and memory was assessed in two subjects with seizures from both mesial temporal lobes who were not candidates for resective epilepsy surgery. A double blind, randomized, controlled, cross-over trial design was utilized. Two electrodes with four contacts each were implanted along the axis of the hippocampus bilaterally. Simultaneous stimulation of all electrodes contacts was either on or off during each 3-month interval. Seizure frequency decreased by 33% in the two patients during stimulation and remained lower by 25% for the 3 months after stimulation was turned off before returning to baseline (p < 0.01). No consistent change in objective or subjective measures of memory occurred. No other adverse effects occurred. Seizure frequency is reduced both during and for a period after bilateral hippocampal stimulation, but the overall impact in this study is not as robust as has been previously reported. KEY WORDS: Seizure, Hippocampus, DBS, Memory, Epilepsy.A possible therapeutic role of direct electrical stimulation of the hippocampus (HS) has been suggested in recent reports as an alternative to temporal lobectomy for management of seizures in intractable temporal lobe epilepsy, particularly when seizures are multifocal in origin or there is a risk of postoperative memory impairment (Velasco et al., 2000;Vonck et al., 2002;Tellez-Zenteno et al., 2006). We performed a double blind, randomized, crossover, controlled trial of chronic bilateral simultaneous HS in two patients. Methods Patients and study designTwo adults, ages 45 and 54 years, with medically intractable focal epilepsy who were poor candidates for resective surgery on the basis of independent bitemporal originating seizures were assessed. Both had normal intelligence and provided informed consent as required by our university ethics review board. A double blind, randomized, controlled, cross-over design was used. Following a 3-month baseline period after implantation with no stimulation, the stimulator was either on or off for a randomly determined 3-month interval. Each ''on'' interval was followed by 3 months of no stimulation (washout) to look for any holdover effect. Both the treating neurologist and patient were blind to the stimulator status. StimulationEquipment from our deep brain stimulation program for movement disorders was used and the implantation technique modified to target the hippocampus. Under general anesthesia, a stereotaxic head frame was used to insert a Pisces quadripolar electrode 3 mm in length with an interelectrode distance of 6 mm (Medtronic 3487A, Minneapolis, MN, U.S.A.) along the axis of the hippocampus on each side so that the anterior contact rested in the anterior pes hippocampus (Tellez-Zenteno et al., 2006). This

Hippocampal sclerosis is the sole abnormality found in approximately 65% of all temporal lobe specimens resected for intractable temporal lobe epilepsy. Up to 27% of en bloc temporal lobectomy specimens, however, show no definitive pathological changes. The lateral amygdaloid nucleus from 8 consecutive patients who underwent temporal lobectomy in whom no definitive hippocampal pathology was present and corresponding tissue from 8 consecutive patients with hippocampal sclerosis were subjected to quantitative estimation of neuronal density and astrogliosis. As compared to amygdaloid tissue from autopsy control subjects with no history of neurological disease, both the patient group with and that without hippocampal sclerosis consistently exhibited severe neuronal loss and gliosis with no quantitative differences between the two groups. Blinded clinical review of both groups of patients revealed that the development of hippocampal sclerosis was associated with a history of early brain insult; this history was absent in patients with isolated amygdaloid sclerosis. Neuropsychological testing prior to surgery demonstrated that patients with hippocampal sclerosis displayed a greater degree of memory impairment than did those without hippocampal sclerosis. We conclude that amygdaloid sclerosis occurs in the absence of hippocampal sclerosis, and that these patients form a distinct group with no history of early brain insult and milder memory impairment than that seen in patients afflicted with hippocampal sclerosis.

Background:The assessment of thalamocortical function in comatose patients in the intensive care unit (ICU) can be difficult to determine. Since the electroencephalogram (EEG) affords such assessment, we have developed an EEG classification for comatose patients in our general ICU. Methods: One hundred EEGs were classified in a blinded fashion by two EEGers, using our method and that of Synek. Interobserver agreement was assessed using kappa score determination. Results: Kappa scores were 0.90 for our system and 0.75 for the Synek system. (The Kappa score represents the inter-rater agreement that is beyond chance; 0.90 is almost perfect agreement, while 0.75 is substantial agreement). Conclusion: Our system for classifying EEGs in comatose patients has a higher interobserver reliability than one that was previously published. This EEG classification scheme should be useful in clinical electrophysiological research involving ICU patients, allowing for internal consistency and comparisons among centres. RESUME: Une classification electroencephalographique du coma. Introduction: II peut etre difficile d'eValuer la fonction thalamocorticale chez les patients comateux a l'unite de soins intensifs (USI). Comme cette evaluation peut etre faite au moyen de l'electroencephalogramme, nous avons developpe une classification EEG pour les patients comateux a notre USI generale. Methodes: Deux electeoencephalographistes ont classify cent EEGs a l'aveugle, en utilisant notre methode et celle de Synek. La concordance interobservateur a et6 evaluee au moyen de la cote kappa. Resultats: Les cotes kappa etaient de 0.90 pour notre systeme et de 0.75 pour le systeme Synek. (La cote kappa represente la concordance interobservateur au-dela de la chance; 0.90 est une concordance presque parfaite, alors que 0.75 est une bonne concordance). Conclusion: Notre systeme de classification des EEGs chez les patients comateux a une plus grande fiabilite interobservateur qu'une autre classification deja publi6e. Cette methode de classification EEG devrait etre utile en recherche clinique electrophysiologique chez des patients de l'USI, en tenant compte de la concordance interne et de la comparaison intercentres.Can. J. Neurol. Sci. 1997; 24: 320-325 Neurological disease in the setting of the intensive care unit (ICU) has a variable prognosis from full recovery to death. More than 10% of patients in general ICUs suffer serious central nervous system complications that add to their morbidity and mortality.1 Assessment of illness severity is an important component of the management of such cases. There are a number of standardized assessment scales for measuring the severity of illness, which is related to outcome: APACHE (Acute Physiology and Chronic Health Evaluation), APACHE II or APACHE III, the Sepsis Severity Score, Simplified Acute Physiology Score II (SAPS II) and the Mortality Prediction Model (MPM) 2 "6 The APACHE scales use the Glasgow Coma Scale as part of the acute physiology evaluation while other scales incorporate clini...