Testing an Adapted Auditory Verbal Learning Test Paradigm for fMRI to Lateralize Verbal Memory in Patients with Epilepsy.

BACKGROUND AND PURPOSE: fMRI is a noninvasive tool for predicting postsurgical deficits in candidates with pharmacoresistant temporal lobe epilepsy. We aimed to test an adapted paradigm of the Rey Auditory Verbal Learning Test to evaluate differences in memory laterality indexes between patients and healthy controls and its association with neuropsychological scores. MATERIALS AND METHODS: We performed a prospective study of 50 patients with temporal lobe epilepsy and 22 healthy controls. Participants underwent a block design language and memory fMRI. Laterality indexes and the hippocampal anterior-posterior index were calculated. Language and memory lateralization was organized into typical and atypical on the basis of laterality indexes. A neuropsychological assessment was performed with a median time from fMRI of 8 months and was compared with fMRI performance. RESULTS: We studied 40 patients with left temporal lobe epilepsy and 10 with right temporal lobe epilepsy. Typical language occurred in 65.3% of patients and 90.9% of healthy controls (P = .04). The memory fMRI laterality index was obtained in all healthy controls and 92% of patients. The verbal memory laterality index was bilateral (24.3%) more frequently than the language laterality index (7.69%) in patients with left temporal lobe epilepsy. Atypical verbal memory was greater in patients with left temporal lobe epilepsy (56.8%) than in healthy controls (36.4%), and the proportion of bilateral laterality indexes (53.3%) was larger than right laterality indexes (46.7%). Atypical verbal memory might be associated with higher cognitive scores in patients. No relevant differences were seen in the hippocampal anterior-posterior index according to memory impairment. CONCLUSIONS: The adapted Rey Auditory Verbal Learning Test paradigm fMRI might support verbal memory lateralization. Temporal lobe epilepsy laterality influences hippocampal memory laterality indexes. Left temporal lobe epilepsy has shown a higher proportion of atypical verbal memory compared with language, potentially to memory functional reorganization.

Gliomatosis cerebri and Rasmussen's encephalitis: Two different entities causing refractory epilepsy. Comparison through two clinical cases.

BACKGROUND AND IMPORTANCE: Rasmussen's Encephalitis (RE) is a chronic and progressive childhood disease caused by an inflammatory disorder that affects a cerebral hemisphere. On the other hand, Gliomatosis Cerebri (GC) is a rare primary neoplastic glial process with a diffuse and infiltrative growth. CLINICAL PRESENTATION: We present two clinical cases with a history of continuous focal epilepsy refractory to antiepileptic drugs. They share similar clinical and radiologic features, but a different histopathological diagnosis. A brain biopsy was needed to distinguish GC from a RE. CONCLUSION: The debut of a drug-resistant epilepsy with focal seizures and an ipsilateral progressive hemiparesis suggests the diagnosis of RE. However, there are other entities such as GC, which, despite its rarity, should be considered in the differential diagnosis. So, in some cases, histological diagnosis is needed.

VNS and pregnancy: A multicentric experience of four cases.

BACKGROUND: Vagus nerve stimulation system (VNS) has been employed worldwide as adjunctive therapy in drug-resistant epileptic patients. Only nine previous pregnancies with six-positive outcomes have been reported in women with epilepsy treated with VNS since 1998. AIMS OF THE STUDY: To communicate the experience of pregnancies in women treated with VNS in our country. METHODS: Clinical data of four female patients treated with VNS during pregnancy and delivery in five gestations is described. RESULTS: Four pregnancy outcomes were positive and one ended in spontaneous abortion, probably more related to the use antiepileptic drugs than VNS itself. Two births were vaginal and the other two with cesarean section. None of the complications during delivery were attributed to VNS. No teratogenicity was documented. CONCLUSIONS: Based on our experience VNS constitutes a safe therapy for the treatment of drug-resistant epilepsy in women of childbearing potential and during pregnancy and delivery. Larger series will be useful to confirm this finding.

[Results of vagal nerve stimulation in patients with pharmacoresistant epilepsy in a national epilepsy referral centre]. / Resultados de la estimulacion del nervio vago en pacientes con epilepsia farmacorresistente en un centro de referencia nacional de epilepsia.

AIM: To describe clinical results and complications derived from vagal nerve stimulation therapy in drug resistant epileptic patients unsuitable for other surgical treatments, since the first implant in an epilepsy national referral centre. PATIENTS AND METHODS: A retrospective analysis of the patients implanted in our centre was held. Data related to baseline characteristics of their epilepsy and therapy complications was collected. RESULTS: 32 new implants in 31 patients are included, mean age of 34 years, 29.3 years of disease evolution, three anti-epileptic drugs at surgery and a postoperative follow-up of 4.03 years. Complex partial seizures types (71.9%) and cryptogenic aetiology (59.4%) were the most frequent. 75% of patients hadn't history of previous epilepsy surgery. 43.8% of patients had a seizure frequency improvement above 50%, with a better response in patients with complex partial seizures (p = 0.22) and cryptogenic aetiology. None statistical significance was found between antiepileptic drugs and seizure frequency. Dysphonia, hoarseness and dysphagia, mostly transient, were the side effects registered. There was an asystole during surgery, completely recovered. One device was replaced due to hardware rupture after a seizure related trauma, one had to be adjusted due to a previous vocal cord paresis, and one dysfunctioning device was removed. In 84.4% the tolerance was excellent. CONCLUSIONS: Vagal nerve stimulation is an effective treatment for significant seizure frequency improvement of resistant patients untreatable with other medical or surgical treatments. Further studies are needed to predict the individual response of each patient to therapy and optimizing indications, therefore contributing to cost/benefit optimization.

TITLE: Resultados de la estimulacion del nervio vago en pacientes con epilepsia farmacorresistente en un centro de referencia nacional de epilepsia.Objetivos. Describir los resultados clinicos y complicaciones derivados de la estimulacion vagal en pacientes con epilepsia farmacorresistente no tributaria de otras modalidades de tratamiento quirurgico, desde el primer implante en un centro de referencia nacional. Pacientes y metodos. Se realizo un analisis retrospectivo de los pacientes implantados en nuestro centro y se extrajeron datos relativos a las caracteristicas basales de su epilepsia y complicaciones derivadas. Resultados. Se incluyeron 32 nuevos implantes en 31 pacientes, con una edad media de 34 años, evolucion de enfermedad de 29,3 años, tres farmacos antiepilepticos prequirurgicos y 4,03 años de seguimiento. Las crisis parciales complejas (71,9%) y criptogenicas (59,4%) fueron el tipo y la etiologia de crisis mas frecuentes. El 75% no tenia antecedentes quirurgicos de epilepsia. Un 43,8% presento mejoria igual o superior al 50%, mayor en las epilepsias parciales complejas (p = 0,22) y la etiologia criptogenica. No se hallo asociacion estadistica entre ajustes de medicacion y frecuencia de las crisis. Los efectos secundarios encontrados fueron disfonia, ronquera y disfagia transitorias, y una asistolia intraoperatoria recuperada. Se realizo un recambio por ruptura de hardware postraumatica. Un paciente con paresia preexistente de cuerda vocal presento estridor laringeo que requirio ajuste de intensidad, y se produjo una retirada del sistema por disfuncion. En el 84,4%, la tolerancia fue excelente. Conclusiones. Constituye un tratamiento efectivo para mejorar significativamente la frecuencia de crisis de los pacientes farmacorresistentes y con contraindicacion para otras modalidades de tratamiento quirurgico. Se precisan futuros estudios para predecir la respuesta individual de cada paciente, optimizar las indicaciones y mejorar la relacion coste/beneficio.

PET/MRI and PET/MRI/SISCOM coregistration in the presurgical evaluation of refractory focal epilepsy.

We aimed to investigate the usefulness of coregistration of positron emission tomography (PET) and magnetic resonance imaging (MRI) findings (PET/MRI) and of coregistration of PET/MRI with subtraction ictal single-photon emission computed tomography (SPECT) coregistered to MRI (SISCOM) (PET/MRI/SISCOM) in localizing the potential epileptogenic zone in patients with drug-resistant epilepsy. We prospectively included 35 consecutive patients with refractory focal epilepsy whose presurgical evaluation included a PET study. Separately acquired PET and structural MRI images were coregistered for each patient. When possible, ictal SPECT and SISCOM were obtained and coregistered with PET/MRI. The potential location of the epileptogenic zone determined by neuroimaging was compared with the seizure onset zone determined by long-term video-EEG monitoring and with invasive EEG studies in patients who were implanted. Structural MRI showed no lesions in 15 patients. In these patients, PET/MRI coregistration showed a hypometabolic area in 12 (80%) patients that was concordant with seizure onset zone on EEG in 9. In 7 patients without MRI lesions, PET/MRI detected a hypometabolism that was undetected on PET alone. SISCOM, obtained in 25 patients, showed an area of hyperperfusion concordant with the seizure onset zone on EEG in 7 (58%) of the 12 of these patients who had normal MRI findings. SISCOM hyperperfusion was less extensive than PET hypometabolism. A total of 19 patients underwent surgery; 11 of these underwent invasive-EEG monitoring and the seizure onset zone was concordant with PET/MRI in all cases. PET/MRI/SISCOM coregistration, performed in 4 of these patients, was concordant in 3 (75%). After epilepsy surgery, 13 (68%) patients are seizure-free after a mean follow-up of 4.5 years. PET/MRI and PET/MRI/SISCOM coregistration are useful for determining the potential epileptogenic zone and thus for planning invasive EEG studies and surgery more precisely, especially in patients without lesions on MRI.

Simple fMRI postprocessing suffices for normal clinical practice.

BACKGROUND AND PURPOSE: Whereas fMRI postprocessing tools used in research are accurate but unwieldy, those used for clinical practice are user-friendly but are less accurate. We aimed to determine whether commercial software for fMRI postprocessing is accurate enough for clinical practice. METHODS: Ten volunteers underwent fMRI while performing motor and language tasks (hand, foot, and orolingual movements; verbal fluency; semantic judgment; and oral comprehension). We compared visual concordance, image quality (noise), voxel size, and radiologist preference for the activation maps obtained by using Neuro3D software (provided with our MR imaging scanner) and by using the SPM program commonly used in research. RESULTS: Maps obtained with the 2 methods were classified as "partially overlapping" for 70% for motor and 72% for language paradigm experiments and as "overlapping" in 30% of motor and in 15% of language paradigm experiments. CONCLUSIONS: fMRI is a helpful and robust tool in clinical practice for planning neurosurgery. Widely available commercial fMRI software can provide reliable information for therapeutic management, so sophisticated, less widely available software is unnecessary in most cases.

Successful outcome of episodes of status epilepticus after vagus nerve stimulation: a multicenter study.

BACKGROUND AND PURPOSE: Vagus nerve stimulation (VNS) has been reported to be a safe and effective treatment for drug-resistant epilepsy. The aim of this study is to describe the effect of VNS in patients with a history of repeated episodes of status epilepticus (SE) before implantation. METHODS: From a total of 83 adult patients with drug-resistant epilepsy who had VNS implanted in four tertiary centers in Spain between 2000 and 2010, eight had a previous history of repeated episodes of SE. We performed a retrospective observational study analyzing the outcome of seizures and episodes of SE after implantation. Stimulation was started at the usual settings, and intensity increased according to clinical response and tolerability. RESULTS: Regarding the eight patients with a history of SE, the mean age at time of VNS implantation was 25.1 [14-40] years. Duration of epilepsy until the implantation was 21.7 [7-39.5] years, and they had been treated with a mean of 12 antiepileptic drugs [10-16]. Mean follow-up since implantation was 4.15 [2-7.5] years. Average seizure frequency decreased from 46 to 8.2 per month. Interestingly, four of the eight patients remained free of new episodes of SE after implantation, and in two additional patients, the frequency decreased by >75%. Adverse effects were mild or moderate in intensity and included mainly coughing and dysphonia. CONCLUSION: In those patients with refractory epilepsy and history of SE who are not surgical candidates, VNS is a safe and effective method to reduce seizure frequency and episodes of SE.

Efficacy and safety of pallidal stimulation in primary dystonia: results of the Spanish multicentric study.

BACKGROUND: Dystonia is a complex clinical syndrome originated by a wide range of aetiologies. The diagnosis of dystonia is made after the evaluation of aetiological, phenomenological and genetic factors. Medications, except in patients with dopa-responsive dystonia, are of limited efficacy. Botulinum toxin injections are not applicable to patients with generalised dystonia, since many muscular groups contribute to disability. Clinical studies in children and adults with primary generalised dystonia (PGD) have reported beneficial effects of bilateral GPi deep brain stimulation (DBS) in both motor symptoms and disability produced by dystonia as well as a favourable impact of DBS in the health-related quality of life (HRQoL). Some clinical aspects of GPi stimulation in primary dystonia still remain controversial such as the influence of disease duration or age at onset in determining the postoperative clinical outcome. RESULTS: The authors report the results of a multicentric study designed to assess the tolerability and clinical effects of bilateral pallidal DBS on motor impairment, functional disability, quality of life, pain and mood in patients with medically refractory primary generalised or segmental dystonia.

[Anesthesia considerations for deep-brain stimulation in a patient with type-2 pantothenate kinase deficiency (Hallervorden-Spatz disease)]. / Consideraciones anestésicas en una paciente con déficit de pantotenato cinasa tipo 2 (enfermedad de Hallervorden-Spatz) para estimulación cerebral profunda.

Neurodegeneration associated with pantothenate kinase deficiency is an autosomal recessive condition caused by mutations in the pantothenate kinase 2 gene (PANK2). Clinical characteristics include progressive motor impairment and dementia. Medical treatment is limited and the dystonia tends to be refractory, making stereotactic surgery with placement of deep-brain electrodes an option that is being adopted with greater frequency in these patients. We report the case of a 32-year-old woman with severe dystonia associated with PANK2 protein deficiency. The patient was scheduled for stereotactic bilateral placement of electrodes in the medial globus pallidus, guided by computed tomography and under general anesthesia, to treat the debilitating dystonia and generalized stiffness associated with her condition. Anesthesia was maintained with propofol, rocuronium and remifentanil in perfusion during the intervention, which was uneventful. After the procedure, the patient was transferred to the intensive care unit and sedation was provided with remifentanil to allow slow, gradual emergence from anesthesia. The patient was discharged from hospital after placement of the implanted pulse generator, and subsequent follow-up showed improvement of the dystonia.

[Successful functional hemispherectomy in adult patients with refractory epilepsy]. / La hemisferectomía funcional también es eficaz en pacientes adultos con epilepsia catastrófica.

INTRODUCTION: Functional hemispherectomy is a surgical technique used to treat refractory epilepsies in the setting of extensive unilateral hemispheric lesions. Most series of hemispherectomies include mainly pediatric patients. METHODS: We report our series of four adult patients that have undergone functional hemispherectomy for their refractory epilepsy. Each one had a complete presurgical evaluation including video EEG, neuropsychological testing and anatomical and functional neuroimaging. In three of them, the epilepsy was secondary to a middle cerebral artery infarction. One patient had Rasmussen encephalitis. RESULTS: After surgery, three patents have become completely seizure free (follow up 13-26 months). The fourth patient has had more than 75% reduction in seizure frequency. All of them have had significant improvement in their quality of life. Early complications included an isolated tonic-clonic generalized seizure (one patient), and status epilepticus in another patients related to infection and use of meropenem. Only one patient has presented hemianopia as a permanent neurological deficit after surgery. CONCLUSIONS: Functional hemispherectomy is a good surgical option in the setting of large unilateral hemispheric lesions causing hemiparesis and intractable seizures, even in adult patients.

Parry Romberg syndrome and linear scleroderma in coup de sabre mimicking Rasmussen encephalitis.

We present one patient with Parry Romberg syndrome and another with linear scleroderma in coup de sabre, with focal neurologic deficits and intractable seizures arising from the hemisphere ipsilateral to the cutaneous lesion. Brain MRI showed progressive hemispheric atrophy. Pathology after functional hemispherectomy showed chronic inflammatory features suggestive of Rasmussen encephalitis.

[Neuronal migration disorders: a cause of curable medication resistant epilepsy]. / Alteraciones de la migración neuronal: una causa de epilepsia farmacorresistente curable.

INTRODUCTION: Focal cortical dysplasia is a neuronal migration disorder that appears with bouts of epileptic seizures that are usually medication resistant. The improvements introduced into neuroimaging techniques in recent years have made it possible to diagnose and offer surgical treatment to certain patients who have been under polytherapy for many years with poor control over their seizures. CASE REPORT: We report the case of a 22-year-old male with epileptic fits since the age of 18 months, who was refractory to multiple combinations of oral antiepileptic drugs (AEDs) with electroencephalograms that displayed frontal, fast spike-wave discharges, with greater expression on the left side and findings from neuroimaging techniques that were repeatedly normal. After being readmitted to hospital because his seizures had got worse, the neuroimaging study was repeated and left frontal focal cortical dysplasia was observed, which led us to start considering neurosurgery. At present, six months after the intervention, the patient has had no further convulsive fits and therapy with oral AEDs is being reduced. CONCLUSIONS: Neuroimaging studies must be repeated in patients that have already been examined because in this way it may be possible to save a group of patients (who would otherwise have to resign to poor control over their seizures as well as the side effects of many AEDs) from becoming medication resistant.

[The utility of interictal SPECT in temporal lobe epilepsy]. / ¿Es útil la SPECT interictal en la epilepsia del lóbulo temporal?

INTRODUCTION: Interictal brain single photon emission computed tomography (SPECT) is used in the presurgical evaluation of patients with complex partial epilepsy. The aim of the present study was to compare interictal SPECT, MRI and video-electroencephalography (EEG) for seizure focus localization in patients with temporal lobe epilepsy, one year after temporal lobectomy, in order to determine the utility of interictal brain SPECT. PATIENTS AND METHODS: Thirty four consecutive patients with refractory temporal epilepsy were evaluated with video-EEG, MRI and interictal SPECT for seizure focus localization before surgery. Seizure focus was confirmed with the clinical follow-up one year after temporal lobectomy in all patients. MRI and SPECT analysis was performed visually. RESULTS: 31/34 patients were seizure free one year after surgery and the remaining 3 patients remain with seizures occasionally. Video-EEG results coincided with postsurgical seizure focus localization in 31 (91%) patients. MRI localized seizure focus correctly in 30 (88%) patients and was normal in 3 cases. Interictal brain SPECT was normal in 10 patients and showed temporal hypoperfusion consistent with postsurgical seizure focus in 23 (68%) patients. In all patients with abnormalities in the interictal SPECT, seizure focus was identified with video-EEG or MRI. CONCLUSIONS: When MRI and video-EEG localize seizure focus in the same temporal lobe, interictal brain SPECT does not offer any additional information for surgical decision making.

Cortical laminar necrosis related to prolonged focal status epilepticus.

Cortical laminar necrosis (CLN) is radiologically defined as high intensity cortical lesions on T1 weighted MRI images following a gyral distribution. Histopathologically, CLN is characterised by pannecrosis of the cortex involving neurones, glial cells, and blood vessels. It has been reported to be associated with hypoxia, metabolic disturbances, drugs, and infections. We present two patients who developed CLN and permanent neurological deficits after prolonged and repeated focal status epilepticus. The possible mechanisms leading to CLN in these patients are discussed, together with the implications of prompt and aggressive treatment in similar cases.

Complex motor behaviors in temporal lobe epilepsy.

Complex motor behaviors differing from typical automatisms were found in 12 of 502 patients with temporal lobe epilepsy. Movements involved proximal limb segments (6) or body axis (6) and were often preceded by auras and followed by automatisms. Seven of 12 patients are seizure free after surgery. The other 5 patients declined surgery.

[Preoperative adverse events during stereotactic microelectrode-guided deep brain surgery in Parkinson's disease]. / Incidencias peroperatorias durante la cirugía estereotáctica con utilización de microelectrodos intracerebrales profundos en la enfermedad de Parkinson.

OBJECTIVES: To evaluate the prevalence of adverse events and complications during surgery using deep brain electrodes, mainly in the treatment of Parkinsonism. To describe the adjustment of propofol to meet the needs of neurophysiological monitoring. PATIENTS AND METHODS: A prospective study of patients undergoing stereotactic microelectrode-guided deep brain surgery (stereotactic pallidotomy, implantation of electrodes in the thalamic or subthalamic neurons of the globus pallidus). After placement of a stereotactic frame and completion of a computed tomography scan of the head, the patients were transferred to the operating room. Monitoring included electrocardiography, pulse oximetry, arterial pressure (invasive), endtidal carbon dioxide pressure, and diuresis. Anesthesia was maintained by intermittent infusion of propofol. Variables recorded were age, sex, disease and time elapsed since diagnosis, surgical complications and their treatment, total dose of propofol, duration of surgery, and place of transfer for recovery. RESULTS: One hundred twenty-eight patients (50 women, 78 men) with a mean (+/- SD) age of 59.6 +/- 10.2 years underwent the procedure from 1996 through 2003. The mean time elapsed since diagnosis of the disease was 14 +/- 6.2 years. The propofol dose was 890.6 +/- 571.4 mg and duration of surgery was 8.3 +/- 2.4 hours. Adverse events were observed for 101 patients (78.9%). The most common complications involved hemodynamics: arterial hypertension (59.4%), bradycardia (18.0%), arterial hypotension (7.9%), and tachycardia (6.2%). Other more serious complications were pneumocephalus with clinical repercussions (3 cases), globus pallidus hematoma (2), air embolism (2), epileptic seizure (3), anisocoria (1), and dyspnea and/or airway obstruction (7). CONCLUSIONS: Deep brain stimulation requires surgery of long duration. Because of frequent episodes of arterial hypertension, which increases the risk of brain hemorrhage, and other less common but potentially dangerous complications, careful clinical monitoring is necessary during the procedure. The intermittent use of propofol does not interfere with neurophysiological monitoring.

Can the Wada test evaluate mesial temporal function? A SPECT study.

OBJECTIVE: To assess the value of SPECT during intracarotid amobarbital procedure (IAP) to discriminate which patients performed the test with the hippocampus inactivated and correlate it with the risk of amnesia after anterior temporal lobectomy (ATL). METHODS: The authors studied 40 consecutive patients undergoing ATL for refractory epilepsy. SPECT was performed after IV injection of 99mTc-HMPAO during the IAP (IAP-SPECT). Interictal SPECT and IAP-SPECT were realigned to obtain the perfusion change percentage (PCP), allowing a quantitative measurement. Wechsler Memory Scale Revised (WMS-R) before and during the first year of follow-up was used to assess memory impairment after surgery. RESULTS: A decrease between 10 and 12% of the mean PCP values was observed in the frontal, parietal, and lateral temporal lobes of the injected side and in the contralateral cerebellum. However, no significant PCP changes were observed in the occipital or mesial temporal lobes. Thirty-eight passed the memory evaluation of the IAP and in 6 of those 38 patients a decline in memory was demonstrated 1 year after ATL. However, high preoperative neuropsychological score (in two patients) and IAP asymmetry scores (in other three patients) predicted postoperative memory risk in five of these six patients. Fourteen of the 38 patients (40%) had hypoperfusion of the hippocampus during the IAP-SPECT (i.e., the hippocampus was inactivated) and only 1 of these 14 patients (2.5%) developed memory impairment after temporal lobectomy. On the other hand, 5 of the 24 patients (13%) who had a functional hippocampus on IAP-SPECT developed memory impairment. CONCLUSIONS: The results suggest that the combination of SPECT, intracarotid amobarbital procedure, and neuropsychological testing predicted risk for all patients who had postoperative memory decline, indicating that risk prediction should be based on multiple factors. IAP-SPECT results demonstrated that the hippocampus is not inactivated in over 60% of patients and that the lack of accuracy of the IAP alone in predicting the risk of amnesia is probably related to an insufficient inactivation of the ipsilateral hippocampus during the test.

[Complications during epilepsy surgery. Experience after 102 interventions between 1997 and 2001]. / Complicaciones en la cirugía de la epilepsia. Experiencia tras 102 intervenciones entre 1997 y 2001.

OBJECTIVES: To describe perioperative complications in different approaches to surgery for epilepsy. PATIENTS AND METHODS: All patients undergoing surgery related to epilepsy between January 1997 and December 2001 were studied. We gathered information on patient characteristics, diagnosis, anticonvulsant treatment, surgical procedure, type of anesthesia and perioperative complications. RESULTS: Ninety-eighty patients underwent 90 procedures under general anesthesia and 12 procedures with local anesthesia and sedation. Surgery was for anteromedial temporal resection in 74 patients, electrode implantation through the foramen ovale in 10 patients, extratemporal excisions in 7 patients, callosotomy in 3 patients, functional hemispherectomy in 3 patients, implantation of electrode grids in 2 patients, and craniotomy with an awake patient in 3 cases. Complications related to the surgical procedure were intraoperative bradycardia (5 cases), dural tension at the start of surgery (3), bleeding (2) and seizure (1). Complications related to anesthesia were bronchospasm (2 cases), histamine-releasing reaction upon administration of the muscle relaxant (1), and difficult intubation (1). During recovery we saw 1 case of postoperative aphasia, 1 of polyuria, 1 of pulmonary condensation, and 1 of factor VII deficit requiring plasma transfusion. CONCLUSIONS: The rate of perioperative complications in surgery for drug-resistant epilepsy is low, the most common complication being self-limiting bradycardia related to surgical maneuvers.

[Epilepsy surgery in a reference centre]. / Cirugía de la epilepsia en un centro de referencia.

INTRODUCTION: Patients with drug resistant epilepsy are potential candidates for surgery. The pre surgical study of these patients involves a multidisciplinary approach. PATIENTS AND METHODS: We included patients who had been submitted to EEG video monitoring in our centre (a tertiary university hospital) between April 1995 and May 2000. The evaluation protocol included magnetic resonance (MR) brain scan (according to a specific protocol), neuropsychological and psychiatric evaluation, and ictal/interictal SPECT, when possible. Patients who underwent surgery were followed up at regular intervals until at least two years after surgery. RESULTS: Of the 299 patients with EEG video monitoring, 87 had been submitted to surgery up to June 2000. Nine of these patients required invasive subdural studies or studies of the foramen ovale using electrodes. Of the patients who underwent surgery, 44.8% had sclerosis of the hippocampus in the MR and in 10% it was found to be normal. The results of pathological anatomy revealed: 49.3% with sclerosis of the hippocampus, 15.1% with benign tumours, 13.7% with gliosis, 4.1% heterotopias and 4.1% cavernomas. Just one patient has been submitted to surgery again because of badly controlled seizures. Eight patients have presented post surgical complications (four with permanent morbidity). Of the 73 patients who were followed up for at least a year, 83.6% are in Engel class I, 9.6% in class II, 2.7% in class III and 4.1% in class IV. Among patients who underwent a temporal resection, 88.7% were in class I and 0% in class IV. CONCLUSIONS: Epilepsy surgery, in selected patients, has a very low morbidity/mortality rate and the chances that seizures will disappear or greatly improve are high.