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.

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.

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.

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.

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.

[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.

[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.

[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.

Levodopa withdrawal after bilateral subthalamic nucleus stimulation in advanced Parkinson disease.

CONTEXT: Subthalamic nucleus (STN) stimulation may be effective in ameliorating parkinsonian symptoms even to the extent to permit levodopa withdrawal. OBJECTIVES: To analyze the efficacy of STN stimulation in patients with Parkinson disease (PD) and to determine if levodopa may be withdrawn after surgery. DESIGN: Before-after trial. SETTING: Referral center, hospitalized care. PATIENTS: Fifteen patients with advanced PD. INTERVENTIONS: Microelectrode-guided bilateral STN high-frequency stimulation. OUTCOME MEASURES: Before surgery patients were evaluated in off-medication and on-medication conditions. Dopaminergic drug dosages were reduced after surgery, aiming for complete withdrawal. Six months after surgery, patients were reeavaluated in off- and on-medication conditions, with the stimulation turned on and off. RESULTS: Total Unified Parkinson's Disease Rating Scale (UPDRS) motor score in the off-medication condition improved by 65.9%; and axial symptoms, bradykinesia, rigidity, and tremor improved by 65.8%, 60.4%, 66.1%, and 81.1%, respectively. UPDRS part II scores were reduced by 71.8% and Schwab and England scores improved by 45.3%. Levodopa was withdrawn in 8 patients and the overall levodopa dose was reduced 80.4%. "Off" time was reduced 89.7% and the severity of dyskinesias decreased 80.6% after surgery. All results reached significance (P<.001). Stimulation of the STN achieved antiparkinsonian effect similar to that of treatment with levodopa. No life-threatening adverse effects occurred. CONCLUSIONS: Bilateral STN stimulation safely improves all parkinsonian symptoms, decreases or eliminates the need for levodopa, and ameliorates motor fluctuations and dyskinesias. Complete withdrawal of levodopa is feasible with this technique and the overall motor effect of STN stimulation is quantitatively comparable to that obtained with levodopa.

Effects of bilateral subthalamic stimulation on cognitive function in Parkinson disease.

BACKGROUND: Chronic bilateral subthalamic deep brain stimulation (STN-DBS) is known to improve motor function in patients with Parkinson disease (PD). However, the possible effects of STN-DBS on neuropsychological functions have been studied less. OBJECTIVE: To investigate the effects of STN-DBS on neuropsychological functions in PD. DESIGN: Before-after trial. PATIENTS AND METHODS: Fifteen consecutive patients were assessed before and 3 months after implantation of stimulators for STN-DBS (postsurgical assessment with the stimulators switched on). Both assessments were performed with patients in a drug-free condition. The neuropsychological battery consisted of tests measuring memory and visuospatial and frontal functions. RESULTS: The comparison between presurgical and postsurgical performance showed a moderate deterioration in verbal memory and prefrontal and visuospatial functions, and a moderate improvement in a prefrontal task and obsessive-compulsive traits. The motor state improved in all patients. CONCLUSION: Therapy with STN-DBS improves motor symptoms in PD without any clinically relevant neuropsychological deterioration.

Effects of unilateral posteroventral pallidotomy on 'on-off' cognitive fluctuations in Parkinson's disease.

In Parkinson's disease, cognitive performance can vary according to levodopa levels (on-off states). Both positive and negative effects of dopaminergic stimulation have been reported. Pallidotomy is also able to change cognitive performance, in addition to levodopa pharmacokinetics. The aim of this investigation was to study the effects of pallidotomy on cognitive on-off fluctuations in Parkinson's disease. A brief neuropsychological battery was administered to 15 PD patients during on and off states before and after surgery. Before pallidotomy, patients performed better in the on condition on Trail Making test B; after pallidotomy levodopa no longer improved performance, and the interaction between surgery and state was significant. In relation to the difference between preoperative and postoperative performance in Trail Making B test, there was a significant postsurgical improvement only in off state. Verbal fluency decreased after pallidotomy in both on and off conditions. Our results suggest that pallidotomy can change the effects of levodopa on neuropsychological functions.

Zinc-rich synaptic boutons in human temporal cortex biopsies.

The distribution of zinc-rich synaptic boutons in biopsies of the temporal cortex from epileptic patients who had undergone surgery is described. Unfixed cryostat sections were exposed to H(2)S vapour to precipitate endogenous zinc, which was subsequently shown by silver enhancement. In the temporal cortex, the stain for zinc was arranged in bands: stain was heavy in layers II and VI, moderate-to-heavy in layers I, III and V, and low in layer IV. The white matter was virtually devoid of staining. At the electron microscope level, labelling was found in synaptic boutons that made asymmetric synaptic contacts. Immunohistochemical staining for glutamate receptor subunits GluR2/3 was observed in cell bodies in layers II, III, V and VI, coincident with the layers that showed heavy staining for zinc. Immunostaining for glutamate receptor subunit GluR1 was prominent in non-pyramidal neurons in deep cortical layers. These results support findings in other mammals and indicate that the human neocortex may contain an extensive system of zinc-rich cortico-cortical connections. This system may be altered in pathological conditions.

Reliability and clinical usefulness of the short-forms of the Wechsler memory scale (revised) in patients with epilepsy.

PURPOSE: The Wechsler Memory Scale-R (WMS-R) is often used for the evaluation of patients with epilepsy, but is time consuming. Two shortened forms of the WMS-R have been published in an effort to reduce the time involved in the test. The purpose of this study is to cross-validate these abbreviated forms in patients with epilepsy. METHODS: We assessed 103 consecutive patients with drug-resistant partial epilepsy being treated in our epilepsy unit. The WMS-R was administered to all patients. The reliability of two shortened versions of the WMS-R were evaluated. The appraisal was performed taking into account the side of the epileptogenic region. The statistical analyses were carried out with the Pearson's correlation and with the intraclass correlation coefficient. RESULTS: Both shortened formulas showed good reliability coefficients for predicting the General Memory and Delayed Recall Indices. In the overall accuracy of the predictions by both short forms no significant differences were found among the three study. groups (right, left or bilateral). However, when considering the predictive error only the three-subtest formulas comprising logical memory, verbal paired associates and visual reproduction efficiently predicted performance, regardless of the side of the epileptogenic region. Of the predicted scores in the overall sample, 92 and 97% fell below the standard error of measurement for general and delayed memory index, respectively. Both short forms correctly classified 89-94% of the performances at the average or impaired level. CONCLUSIONS: The short form of the M-MS-R using three subtests (logical memory, verbal paired associates and visual reproduction) is reliable and time-efficient for estimating the General and Delayed Recall Memory indexes in patients with drug-resistant partial epilepsy.

[Efficacy and safety of posteroventral pallidotomy for the treatment of advanced Parkinson's disease]. / Efectividad y seguridad de la palidotomía posteroventral en el tratamiento de la enfermedad de Parkinson avanzada.

OBJECTIVES: To analyze the results, efficacy and safety of unilateral microelectrode guided pallidotomy for the treatment of advanced Parkinson's disease, three months and one year after surgery. PATIENTS AND METHODS: 23 patients with advanced Parkinson's disease (mean age 58.9 years and mean disease duration 14.4 years) were submitted to pallidotomy. Neurological evaluation, three months (n = 23) and one year (n = 16) after surgery, was performed during the morning in overnight "off" condition and after receiving 100-150% of their usual l-dopa dose. Parkinsonian symptoms were evaluated in each follow up visit through motor scales, activities of daily living scales, a dyskinesia rating scale and motor timed tests. RESULTS: Contralateral dyskinesias improved 92% three months after surgery and 89% at one year. Parkinsonian motor scores were reduced by 36.5% after three months and by 26.7% one year after surgery. In the one year follow up visit, contralateral tremor improved 48%, rigidity 36.2% and bradykinesia 37.4%. All these changes were statistically significant (p < 0.01). Adverse effects were minor or transient. Antiparkinsonian medication dosage did not significantly change during the study period. CONCLUSION: Microelectrode guided unilateral pallidotomy is an effective and safe procedure to improve contralateral motor symptoms in Parkinson's disease, being specially useful for the treatment of l-dopa induced dyskinesias.

[Thalamic neuro inhibition in the treatment of post traumatic tremor]. / Neuroinhibición tal mica para el tratamiento del temblor postraumático.

INTRODUCTION: Severe head trauma could be followed by a wide range of movement disorders. Usually, they appear as a moderate or severe intention tremor that causes great patient disability. Those movement disorders use to be refractary to medical treatment, although sometimes they would be spontaneusly controlled by a year. CLINICAL CASE: 14 year old boy who suffered severe head trauma at age of 8. One year after the injury he developed an action tremor and choreiform dyskinesia with hemibalistic features evocated by the movement. Medical treatment was ineffective. Due to the great patients disability, we chose the surgical treatment based on the placement of an stimulation electrode in thalamic Vop/Vim complex, obtaining a tremor abolition with an improvement in the scales of tremor and quality of life. DISCUSSION: Surgical treatment of postraumatic tremors tryes to improve in terms of function and activities of daily living, more than suppresion of a symptom. The aim of this treatment is cut the palidal thalamic cortical pathways. Anyway, target is defined by the tremor related cells and, it is more a functional target than an anatomical one. We prefer stimulation more than lesion, due to the lack of brain definitive injury because its reversibility and adjustability features.

[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.

[Cerebral SPECT in partial epilepsy]. / SPECT cerebral en la epilepsia parcial.

UNLABELLED: Effective surgical treatment of patients with medically intractable complex partial seizures depends on accurate preoperative localization of the seizure focus. 99mTc-HMPAO brain SPECT could assist us in localizing the epileptic foci showing focal hypoperfusion on interictal SPECT and hyperperfusion on ictal SPECT. METHODS: Video-EEG monitoring, MRI, as well as interictal and peri-ictal brain SPECT were performed on 37 patients with refractory epilepsy. Ictal brain SPECT was performed on 14 patients and in the remaining 23 patients a postictal SPECT was obtained. Video-EEG was used as the gold standard procedure for localizing the seizure focus and was compared to the interictal and peri-ictal brain SPECT results. Twenty-four patients suffered from temporal lobe epilepsy and 13 had extratemporal seizures. RESULTS: Interictal brain SPECT correctly localized the seizure focus in 43% of the patients (58.3% of the patients with temporal lobe seizures and 15.4% of the patients with extratemporal seizures). Ictal SPECT correctly identified the seizure focus in the 93% of cases (100% of the patients with temporal lobe seizures and 75% of the patients with extratemporal seizures). Finally, 52% of the patients were correctly identified with postictal SPECT (71.4% of the patients with temporal lobe seizures and 22.2% of the patients with extratemporal seizures). CONCLUSION: Our findings suggest that interictal brain SPECT could assist in the localization of temporal lobe seizures. Tracer injection during seizure or immediately after it (peri-ictal SPECT) is the method of choice for SPECT imaging aimed at the non-invasive localization of seizure focus.

[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.

[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.