Impact of epilepsy surgery on quality of life and burden of caregivers in children and adolescents.

OBJECTIVE: The objective of this study was to analyze the impact of pediatric epilepsy surgery on the quality of life (QOL), determining whether patients improve, worsen, or maintain their preoperative patterns, as it relates to the burden of caregivers, as well as evaluating potential related factors, from both the children and caregivers perspectives. MATERIAL AND METHODS: This is a retrospective study of children and adolescents who underwent epilepsy surgery and were evaluated through clinical data, videoelectroencephalogram (V-EEG), neuroimaging findings, neuropsychological testing, and aspects of QOL. These assessments were performed prior to surgery and after six months and two years of follow-up. Quality of life was assessed with epilepsy-specialized questionnaires, namely Questionnaire health-related quality of life for children with epilepsy (QVCE-50), Autoquestionnaire Qualité de Vie Enfant Image Scale (AUQUEI), Quality of life in epilepsy inventory for adolescents (QOLEI-AD-48); and burden of caregivers with Burden Interview - ZARIT scale. Postoperative changes in QVCE-50 were quantified using measures of the analysis of variance (ANOVA MR) for comparison of the difference between the three times of the scale and domains. RESULTS: Fifty patients were enrolled. Of these, 27 (54%) were male, with a mean age at surgery of 8.2 years (range: 1-18 years). Thirty-five patients (70%) were Engel I and one was Engel II (2%) at six months of follow-up, whereas 28 (56%) were Engel I and 32 (64%) were Engel I or II at two years of follow-up. Preoperatively, 21 (42%) presented with moderate or severe intellectual disability. Postoperative cognitive evaluations at the two-year follow-up showed 18 (36%) maintained similar deficits. The QVCE-50 showed postoperative improvement in the two-year follow-up period, but not at six months after surgery. Postoperative improvements were associated mainly with better seizure outcome. Autoperception evaluations were limited because of the clinical and cognitive severity of patients. The burden of caregivers was quoted as mild to moderate and remained unchanged postoperatively. CONCLUSIONS: Children and adolescents with surgically treated epilepsy reach a good seizure outcome, stabilize in intellectual and adaptive functions, and have an increase in QOL, from the caregiver's perspective. Nevertheless, their burden remains unchanged. Seizure outcome is the main factor for improvement in the QOL. The upgrading of structured questionnaires and QOL instruments specific to pediatric epilepsy can be helpful to assess patient- and caregiver-reported surgical outcomes, allowing for better planning of therapeutic approaches.

Left hemispherectomy in older children and adolescents: outcome of cognitive abilities.

PURPOSE: Hemispherectomy is an effective treatment option for pharmacoresistant epilepsy. Nevertheless, when high cortical functions are at risk during the presurgical evaluation, especially for older children, and for the left hemisphere, despite good seizure outcome, the anticipated decrease of cognitive functions may prevent a decision to perform surgery. The objective of this study is to report the cognitive outcome, based on verbal and performance intelligence skills, in a series of older children and adolescents who underwent left hemispherectomy, analyzing the risks (residual cognitive deficit) and benefits (seizure reduction) of surgery. METHODS: We retrospectively analyzed pre- and postoperative clinical and neuropsychological data from our patients who underwent left hemispherectomy, aged between 6 and 18 years. RESULTS: We included 15 patients, with a mean follow-up of 3.1 years, 12 patients (80%) were Engel I, and the other three were classified as Engel II, III, and IV. Nine patients were tested by Wechsler Scales of Intelligence; postsurgically all but one kept the same intellectual levels; verbal intelligence quotient (VIQ) remained unchanged in 13 and improved in one, whereas performance intelligence quotient (PIQ) decreased in four patients. Both Total Vineland and communication scores of Vineland Adaptive Behavior Scales were obtained in six patients: in all, scores were classified as deficient adaptive functioning pre- and postoperatively, remaining unchanged. CONCLUSION: The evaluation of the remaining intellectual abilities after left hemispherectomy in older children and adolescents is useful to discuss the risks and benefits of this surgery, enabling better and safer decisions regarding surgical indications and timing.

Potential role of a cognitive rehabilitation program following left temporal lobe epilepsy surgery.

OBJECTIVES: To assess the effects of a memory rehabilitation program in patients with left temporal lobe epilepsy following surgery. METHODS: Twenty-four patients agreed to participate and 18 completed the study; nine received memory rehabilitation while nine had no input and were designated as controls. Verbal learning efficiency, naming abilities, memory subjective ratings, ecological activity measures and a language fMRI paradigm were used as outcome measures. RESULTS: Improved verbal learning and naming test performance, increase in memory strategy use and improved self-perception were observed following the rehabilitation. Changes in fMRI activation patterns were seen in the rehabilitation group over the long term. CONCLUSION: The findings support the potential role of a cognitive rehabilitation program following left temporal lobe surgery.

Potential role of a cognitive rehabilitation program following left temporal lobe epilepsy surgery / Reabilitação neuropsicológica em pacientes com epilepsia submetidos à lobectomia temporal dominante

ABSTRACT Research into memory and epilepsy has focused on measuring problems and exploring causes with limited attention directed at the role of neuropsychological rehabilitation in alleviating post-operative memory difficulties. Objectives To assess the effects of a memory rehabilitation program in patients with left temporal lobe epilepsy following surgery. Methods Twenty-four patients agreed to participate and 18 completed the study; nine received memory rehabilitation while nine had no input and were designated as controls. Verbal learning efficiency, naming abilities, memory subjective ratings, ecological activity measures and a language fMRI paradigm were used as outcome measures. Results Improved verbal learning and naming test performance, increase in memory strategy use and improved self-perception were observed following the rehabilitation. Changes in fMRI activation patterns were seen in the rehabilitation group over the long term. Conclusion The findings support the potential role of a cognitive rehabilitation program following left temporal lobe surgery.

RESUMO As publicações na área de epilepsia e memória se focam em mensurar prejuízos e investigar causas, com poucos dados sobre reabilitação neuropsicológica em pacientes pós-cirúrgicos. Objetivos Avaliar os efeitos da reabilitação neuropsicológica em pacientes submetidos a lobectomia temporal dominante. Métodos Vinte e quatro pacientes iniciaram o estudo, apenas dezoito o concluíram, dos quais 9 foram participantes de sessões de reabilitação com enfoque em memória. Todos os participantes foram avaliados quanto a autopercepção de dificuldades de memória; ao uso de estratégias para minimizar tais dificuldades; a habilidade de nomeação e a aprendizagem verbal e foram submetidos à ressonância magnética funcional. Resultados Foi encontrado efeito significativo da reabilitação neuropsicológica na autopercepção de dificuldades de memória; no uso de estratégias compensatórias; na aprendizagem verbal e na nomeação. Alterações no padrão de ativação na RMf foram observadas no grupo submetido a reabilitação. Conclusão A reabilitação neuropsicológica pode beneficiar pacientes submetidos a lobectomia temporal antero-mesial dominante com prejuízos de memória.

Neuroimaging observations linking neurocysticercosis and mesial temporal lobe epilepsy with hippocampal sclerosis.

OBJECTIVE: To test if chronic calcificed neurocysticercosis (cNCC) and hippocampal sclerosis occur more often than by chance ipsilateral to the same brain hemisphere or brain region in mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS) plus neurocysticercosis. This proof-of-concept would provide important evidence of a direct pathogenic relationship between neurocysticercosis and MTLE-HS. METHODS: A cohort of 290 consecutive MTLE-HS surgical patients was studied. A test of proportions was used to analyze if the proportion of patients with a single cNCC lesion matching the same brain hemisphere or region of hippocampal sclerosis was significantly greater than 50%, as expected by the chance. RESULTS: Neuroimaging findings of cNCC were observed in 112 (38.6%) of 290 MTLE-HS patients and a single cNCC lesion occurred in 58 (51.8%) of them. There were no differences in main basal clinical characteristics of MTLE-HS patients with single or multiple cNCC lesions. In patients with single cNCC lesions, the lesion matched the side in which hippocampal sclerosis was observed in 43 (74.1%) patients, a proportion significantly greater than that expected to occur by chance (p=0.008). Neurocysticercosis in temporal lobe was ipsilateral to hippocampal sclerosis in 85.0% of patients and accounted mostly for this result. CONCLUSIONS: This work is a proof-of-concept that the association of neurocysticercosis and MTLE-HS cannot be explained exclusively by patients sharing common biological or socio-economic predisposing variables. Instead, our results suggest the involvement of more direct pathogenic mechanisms like regional inflammation, repetitive seizures or both. Neurocysticercosis within temporal lobes was particularly related with ipsilateral hippocampal sclerosis in MTLE-HS, a finding adding new contributions for understanding MTLE-HS plus cNCC or perhaps to other forms of dual pathology in MTLE-HS.

Hemispheric dysplasia and hemimegalencephaly: imaging definitions.

BACKGROUND AND PURPOSE: Hemispheric dysplasia (HD) and hemimegalencephaly (HME) are both brain malformations with early clinical manifestation including developmental delay and intractable epilepsy. Sometimes the differentiation of these conditions is not simple. HME is an anomaly of cortical development caused by a combination of neural proliferation and cell migration dysfunction, showing lobar or hemispheric enlargement. On the other hand, HD shows no brain hypertrophy, and even brain atrophy, eventually. PATIENTS AND METHODS: To compare both conditions, we reviewed clinical, MRI, and histopathology of 23 patients with developmental delay and refractory epilepsy treated with hemispheric surgery. RESULTS: Histologically, both groups presented polymicrogyria, focal cortical dysplasia, gray matter (GM) heterotopia, pachygyria, and agyria. The white matter (WM) showed different degrees of gliosis and myelin impairment. Even though with no specificity in histopathology, the degree of lesion was more impressive on HME. The combination of WM dysmyelination and hypertrophy leads to the so called hamartomatous appearing. Although not all HME showed brain enlargement and some HD might show no size changes or atrophy, the size of affected hemisphere and the hamartomatous appearance of the WM were the more relevant signs to differentiate both conditions. CONCLUSION: Brain MRI was the best diagnostic tolls because it allowed together high contrast resolution, whole brain coverage and spatial distribution analysis. HD and HMD showed brain asymmetry tendency, but in opposite directions. The size of affected hemisphere and the hamartomatous appearance of the WM were the more relevant signs to differentiate both conditions.

Auditory stimuli from a sensor glove model modulate cortical audiotactile integration.

The purpose of this study was to shed light on cortical audiotactile integration and sensory substitution mechanisms, thought to serve as a basis for the use of a sensor glove in the preservation of the cortical map of the hand after peripheral nerve injuries. Fourteen subjects were selected and randomly assigned either to a training group, trained to replace touch for hearing with the use of a sensor glove, or to a control group, untrained. Training group volunteers had to identify textures just by the sound. In an fMRI experiment, all subjects received three types of stimuli: tactile only, combined audiotactile stimulation, and auditory only. Results indicate that, for trained subjects, a coupling between auditory and somatosensory cortical areas is established through associative areas. Differences in signal correlation between groups point to a pairing mechanism, which, at first, connects functionally the primary auditory and sensory areas (trained subjects). Later, this connection seems to be mediated by associative areas. The training with the sensor glove influences cortical audiotactile integration mechanisms, determining BOLD signal changes in the somatosensory area during auditory stimulation.

Cognitive and surgical outcome in mesial temporal lobe epilepsy associated with hippocampal sclerosis plus neurocysticercosis: a cohort study.

BACKGROUND: Where neurocysticercosis (NCC) is endemic, chronic calcified neurocysticercosis (cNCC) can be observed in patients with mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS). Considering that both disorders cause recurrent seizures or cognitive impairment, we evaluated if temporal lobectomy is cognitively safe and effective for seizure control in MTLE-HS plus cNCC. METHODS: Retrospective cohort study of neuropsychological profile and surgical outcome of 324 MTLE-HS patients submitted to temporal lobectomy, comparing the results according to the presence or absence of cNCC. FINDINGS: cNCC occurred in 126 (38.9%) of our MTLE-HS patients, a frequency higher than expected, more frequently in women than in men (O.R. = 1.66; 95% C.I. = 1.05-2.61; p = 0.03). Left-side (but not right side) surgery caused impairment in selected neuropsychological tests, but this impairment was not accentuated by the presence of cNCC. Ninety-four (74.6%) patients with MTLE-HS plus cNCC and 153 patients (77.3%) with MTLE-HS alone were Engel class I after surgery (O.R. = 1.16; 95% C.I. = 0.69-1.95; p = 0.58). However, the chances of Engel class IA were significantly lower in MTLE-HS plus cNCC than in patients with MTLE-HS alone (31.7% versus 48.5%; O.R. = 2.02; 95% C.I. = 1.27-3.23; p = 0.003). Patients with MTLE-HS plus cNCC showed higher rates of Engel class ID (15.1% versus 6.6%; O.R. = 2.50; 95% C.I. = 1.20-5.32; p = 0.012). INTERPRETATION: cNCC can be highly prevalent among MTLE-HS patients living in areas where neurocysticercosis is endemic, suggesting a cause-effect relationship between the two diseases. cNCC does not add further risk for cognitive decline after surgery in MTLE-HS patients. The rates of Engel class I outcome were very similar for the two groups; however, MTLE-HS plus cNCC patients achieved Engel IA status less frequently, and Engel ID status more frequently. Temporal lobectomy can be safely performed in most patients with MTLE-HS plus cNCC without affecting cognitive outcome. Long-term surgical seizure control in MTLE-HS plus cNCC is still satisfactory, as long as selected patients remain under medication.

Impact of pediatric epilepsy surgery on intellectual efficiency.

INTRODUCTION: Epilepsy surgery may be a promising alternative therapy for seizure control in patients with refractory seizures, resistant to medication. Cognitive outcome is another important factor in favor of the surgical decision. AIM: To investigate the correlation between seizure outcome and cognitive outcome after epilepsy surgery in a pediatric population. PATIENTS AND METHODS: A total of 59 pediatric patients were retrospectively assessed with the WISC-III (Full Scale, Verbal Scale and Performance Scale) before and, at least, 6 months after surgery. Patients were divided into two groups according whether or not improvement of seizure control after surgery. Data collected for each child included: epileptic syndrome, etiology, age at epilepsy onset, duration of epilepsy and seizure frequency. RESULTS: Comparison using a MANOVA test revealed significant differences across pre-operative Full Scale, Verbal Scale and Performance Scale (p = 0.01) with seizure reduction group performing better than no seizure reduction group. Seizure improvement group achieved significant Performance Scale improvement (p = 0.01) and no seizure improvement group showed significant Verbal Scale worsened after surgery (p = 0.01). CONCLUSIONS: Our results suggest that the success of the epilepsy surgery in childhood when the seizure control is achieved may also provide an improvement in the Performance Scale whereas the seizure maintenance may worsen the Verbal Scale.

Image evaluation of HIV encephalopathy: a multimodal approach using quantitative MR techniques.

INTRODUCTION: A multimodal approach of the human immunodeficiency virus (HIV) encephalopathy using quantitative magnetic resonance (MR) techniques can demonstrate brain changes not detectable only with conventional magnetic resonance imaging (MRI). The aim of this study was to compare conventional MRI and MR quantitative techniques, such as magnetic resonance spectroscopy (MRS) and relaxometry and to determine whether quantitative techniques are more sensitive than conventional imaging for brain changes caused by HIV infection. METHODS: We studied prospectively nine HIV positive children (mean age 6 years, from 5 to 8 years old) and nine controls (mean age 7.3 years; from 3 to 10 years), using MRS and relaxometry. Examinations were carried on 1.5-T equipment. RESULTS: HIV-positive patients presented with only minor findings and all control patients had normal conventional MR findings. MRS findings showed an increase in choline to creatine (CHO/CRE) ratios bilaterally in both frontal gray and white matter, in the left parietal white matter, and in total CHO/CRE ratio. In contrast, N-acetylaspartate to creatine (NAA/CRE) ratios did not present with any significant difference between both groups. Relaxometry showed significant bilateral abnormalities, with lengthening of the relaxation time in HIV positive in many regions. CONCLUSION: Conventional MRI is not sensitive for early brain changes caused by HIV infection. Quantitative techniques such as MRS and relaxometry appear as valuable tools in the diagnosis of these early changes. Therefore, a multimodal quantitative study can be useful in demonstrating and understanding the physiopathology of the disease.

The Boston Naming Test as a predictor of post-surgical naming dysfunctions in temporal lobe epilepsy / O Boston Naming Test como marcador para disfunção nominativa no pós-operatório de epilepsia do lobo temporal

OBJECTIVES: Patients that undergo epilepsy surgery for temporal lobe epilepsy (TLE) in the dominant hemisphere are more susceptible to naming deficits. The aim of the present study was to perform an observational retrospective study comparing two groups of patients for naming performance, those with left and right temporal lobe resections regarding the performance in naming by Boston Naming Test (BNT). METHODS: A total of 120 right-handed patients (52 right temporal lobe and 68 left temporal lobe), aged between 18 and 59, with pharmacoresistant mesial TLE were retrospectively analyzed. All patients underwent pre and postoperative neuropsychological assessment. RESULTS AND CONCLUSIONS : The BNT was a good predictor for possible post-surgical language deficits in patients submitted to left temporal lobectomy.

OBJETIVO: Pacientes submetidos a cirurgia de epilepsia portadores de epilepsia do lobo temporal (ELT) em hemisfério dominante são mais suscetíveis a apresentarem déficits de nomeação. O objetivo do presente estudo foi realizar um estudo retrospectivo observacional comparando dois grupos de pacientes sendo um grupo submetido a lobectomia temporal dominante e outro a lobectomia temporal não dominante em relação ao desempenho na tarefa de nomeação através do Boston Naming Test (BNT). METÓDOS: Um total de 120 pacientes destros foram retrospectivamente analisados (52 temporal direito e 68 temporal esquerdo) com idade entre 18 e 59 anos, com epilepsia do lobo temporal mesial fármaco resistente. Todos os pacientes foram submetidos a avaliação neuropsicológica pré e pós-operatória utilizando o BNT para medida de nomeação. RESULTADOS E CONCLUSÕES: O BNT foi mostrou-se um bom instrumento para predizer possíveis déficits de linguagem em pacientes submetidos a lobectomia temporal esquerda.

Rasmussen Encephalitis: longterm outcome after surgery / Encefalite de Rasmussen: avaliação de resultados depois da cirurgia

BACKGROUND AND PURPOSE: Rasmussen Encephalitis (RE) is characterized by intractable epilepsy, progressive hemiparesis and unilateral hemispheric atrophy. The progression of the symptoms usually occurs within months to few years. Antiepileptic drugs are usually not effective to control disease progression and epilepsy surgery in the form of hemispheric disconnection has been considered the treatment of choice. This work describes the clinical and electrographic analyses, as well as the post-operative evolution of patients with RE. PATIENTS AND METHODS: This work includes all the patients with RE evaluated from January 1995 to January 2008 by the Ribeirão Preto Epilepsy Surgery Program (CIREP) considering demographic data, interictal and ictal electroencephalographic (EEG) findings; anatomo-pathological findings and clinical outcome. RESULTS: Twenty-five patients were evaluated, thirteen were female. Mean age of epilepsy onset was 4.4±2.0 years. There were no differences between patients with slow and fast evolution with respect to age of epilepsy onset (p=0.79), age at surgery (p=0.24), duration of epilepsy (0.06), and follow-up (p=0.40). There were no correlations between the presence of bilateral EEG abnormalities or the absence of spikes and post-operative seizure outcome (p=0.06). Twenty-three patients underwent surgery. The mean follow-up was 75.3 months. Eleven patients had total seizure control. Twelve individuals persisted with seizures consisting of mild facial jerks (6 patients), occasional hemigeneralized tonic-clonic seizures (3 patients), and frequent tonic-clonic seizures (3 patients). Mental and language impairment was observed in 15 and 12 patients, after surgery, respectively. CONCLUSIONS: This retrospective study reported the clinical and electrographic analysis, as well as the evolution of 23 patients with RE. Fourteen patients achieved satisfactory seizure control, three patients had partial response to surgery, and five patients had maintenance of the pre-operative condition. All patients with left side involvement presented with some language and cognitive disturbance.

INTRODUÇÃO E OBJETIVOS: A Encefalite de Rasmussen (ER) é caracterizada por epilepsia intratável, hemiparesia progressiva e atrofia hemisférica unilateral. A progressão dos sintomas geralmente ocorre em meses ou poucos anos. As drogas antiepilépticas são usualmente ineficazes no controle da progressão da doença e o tratamento cirúrgico, com desconexão hemisférica tem sido considerado o tratamento de escolha. Neste trabalho descreveremos os achados clínicos e eletrográficos, assim como a evolução pós-operatória de pacientes com ER. PACIENTES E MÉTODOS: foram incluídos todos os pacientes com ER avaliados no período de janeiro de 1995 a janeiro de 2008, no Centro de Cirurgia de Epilepsia de Ribeirão Preto (CIREP), sendo considerados os dados demográficos, os achados do eletrencefalograma (EEG) interictal e ictal, resultado anatomo-patológico e o seguimento clínico. RESULTADOS: Vinte e cinco pacientes foram avaliados, 13 eram do sexo feminino. A idade média de início da epilepsia foi de 4.4±2.0 anos. Não houve diferenças significativas entre os pacientes com evolução lenta ou rápida considerando-se a idade de início da epilepsia (p=0,79), idade da cirurgia (p=0,24), duração da epilepsia (p=0,06) e tempo de seguimento (p=0,40). Não houve correlação entre a presença de alterações bilaterais ou ausência de descargas ao EEG e o seguimento pós-operatório (p=0,06). Vinte e três pacientes foram submetidos à cirurgia. O tempo médio de seguimento foi de 75,3 meses. Onze pacientes evoluíram com controle total das crises. Doze pacientes permaneceram com crises que consistiram de clonias faciais sutis (6 pacientes), crises tônico-clônicas hemigeneralizadas ocasionais (3 pacientes) ou crises tônico-clônicas frequentes (3 pacientes). Alterações cognitivas e de linguagem foram observadas em 15 e 12 pacientes após a cirurgia, respectivamente. CONCLUSÕES: este estudo retrospectivo relatou os achados clínicos, eletrográficos e a evolução de 23 pacientes. Controle satisfatório das crises foi obtido em 14 pacientes. Três pacientes tiveram resposta parcial com a cirurgia e cinco pacientes mantiveram o quadro pré-operatório. Todos os pacientes com envolvimento do hemisfério cerebral esquerdo evoluíram com distúrbio de linguagem e cognitivo.

Comparative role of neuropsychological testing in the presurgical evaluation of children with medically intractable epilepsies.

PURPOSE: In the present study, we evaluated the preoperative demographic, clinical, and neuropsychological variables that could predict postoperative seizure outcome in a group of pediatric epileptic patients. MATERIALS AND METHODS: We studied 40 consecutive pediatric patients, ages ranging from 6 to 16 years, that underwent resective surgery for the treatment of medically intractable epilepsy at the Clinical Hospital of Ribeirão Preto School of Medicine. We performed ictal electroencephalography (EEG), interictal EEG, magnetic resonance imaging (MRI), and a preoperative neuropsychological assessment in the presurgical workup. RESULTS: The following factors were correlated with seizure outcome: (1) duration of epilepsy, (2) surgery localization, (3) localized Neuropsychological (NPS) Evaluation, (4) ictal EEG, (5) interictal EEG, and (6) MRI. Mental retardation, NPS tests, and the other demographic variables failed to correlate with seizure reduction. CONCLUSIONS: The identification of predictor variables of epilepsy surgery outcome could improve the epileptic prognosis and guarantee the children's full potential development.

Neurovascular coupling and functional neuroimaging in epilepsy / Acoplamento neurovascular e neuroimagem funcional em epilepsia

INTRODUCTION: The neural regulation of the microcirculation is done by the functional neurovascular unit that is composed of vascular, astroglial and neuronal cells. The neurovascular unit represents the interface between the Central Nervous System and the Vascular System. OBJECTIVE: This paper reviews the literature on functional neuroimaging with a particular focus on the mechanisms of the neurovascular coupling. CONCLUSIONS: Functional neuroimaging techniques as functional MRI, SPECT and PET distinguish metabolic and physiological processes underlying normal and abnormal events, based on neurovascular coupling. Although these techniques still have limitations in temporal and spatial resolution, they have considerably reduced the need for intracranial electrodes or invasive functional tests in the presurgical evaluation for intractable epilepsy. Recently, new techniques as optical approaches (measurement of intrinsic optical signals and near infrared spectroscopy) have increased both temporal and spatial resolutions. The use of such techniques in animal models has yielded experimental evidence for a neurovascular coupling in normal and epileptic conditions.

INTRODUÇÃO: A regulação da microcirculação cerebral é realizada pela unidade neurovascular, que é composta por vasos sangüíneos, células astrogliais e neuronais. A unidade neurovascular representa a interface funcional entre o Sistema Nervoso Central e o sistema vascular. OBJETIVO: Este trabalho revisa a literatura sobre técnicas de neuroimagem funcional com especial enfoque nos mecanismos do acoplamento neurovascular. CONCLUSÃO: Técnicas de neuroimagem como a Ressonância Magnética funcional, SPECT e PET baseiam-se no acoplamento neurovascular para explorarem os processos metabólicos e fisiológicos subjacentes a eventos cerebrais normais e anormais. Embora estas técnicas apresentem limitações de resolução temporal e espacial, sua aplicabilidade em epilepsia tem reduzido consideravelmente a necessidade de eletrodos intracranianos e de outros métodos funcionais invasivos na avaliação pré-cirúrgica de pacientes com epilepsia intratável. Recentemente, novos procedimentos ópticos (mensuração do sinal intrínseco óptico e espectroscopia por raio infravermelho) que possuem excelente resolução espacial e temporal têm fornecido evidências experimentais do acoplamento neurovascular no cérebro normal e epiléptico.

Rasmussen encephalitis: long-term outcome after surgery.

BACKGROUND AND PURPOSE: Rasmussen encephalitis (RE) is characterized by intractable epilepsy, progressive hemiparesis, and unilateral hemispheric atrophy. The progression of the symptoms to significant neurological impairment usually occurs within months to a few years. RE causes are unknown, although evidence of an autoimmune process has been extensively described in the literature. Antiepileptic drugs are usually not effective to control seizures or cerebral atrophy; despite data supporting a beneficial effect of early immunosuppressive and immunomodulatory interventions, for intractable seizures in RE patients with advanced disease, epilepsy surgery in the form of hemispheric disconnection has been considered the treatment of choice. This work describes the clinical and electrographic analyses, as well as the post-operative evolution of patients with RE. MATERIALS AND METHODS: This work includes all the patients with RE evaluated from January 1995 to January 2008 by the Ribeirão Preto Epilepsy Surgery Program (CIREP), taking variables such as gender; age at epilepsy onset; seizure semiology; seizure frequency; interictal and ictal electroencephalographic (EEG) findings; age at surgery, when done; duration of epilepsy; surgery complications; follow-up duration; anatomo-pathological findings; post-surgery seizure; language and cognitive outcome; and anti-epileptic drug treatment after surgery into account. RESULTS: Twenty-five patients were evaluated; thirteen were female. Mean age of epilepsy onset was 4.4+/-2.0 years. There were no differences between patients with slow and fast evolution with respect to age of epilepsy onset (p=0.79), age at surgery (p=0.24), duration of epilepsy (0.06), and follow-up (p=0.40). There were no correlations between the presence of bilateral EEG abnormalities or the absence of spikes and post-operative seizure outcome (p=0.06). Immunomodulatory therapy was tried in 12 patients (48%). Twenty-three patients underwent surgery. The mean follow-up was 63.3 months. Eleven patients had total seizure control. Twelve individuals persisted with seizures consisting of mild facial jerks (six patients), occasional hemigeneralized tonic-clonic seizures (three patients), and frequent tonic-clonic seizures (three patients). Mental and language impairment was observed in 15 and 12 patients, after surgery, respectively. Eight patients presented post-operative cognitive decline, while only two patients had cognitive improvement. Comparing pre- and post-operative language deficits, 66.7% of the 12 patients with language disturbance did not improve after surgery. CONCLUSIONS: This retrospective study reported the clinical and electrographic analysis, as well as the evolution of 23 patients with RE. Patients were divided into two groups: fast evolution and slow evolution to hemiparesis and epilepsia partialis continua. These groups may represent different RE substrates. Fourteen patients achieved satisfactory seizure control, three patients had partial response to surgery, and five patients had maintenance of the pre-operative condition. All patients with left-side involvement presented with some language disturbance, which did not improve after surgery in 66.6% of patients. Cognitive evaluation showed that the majority of the patients did not have any significant improvement, and 38.1% had cognitive deterioration after surgery.

Variable fMRI activation during two different language tasks in a patient with cognitive delay.

Functional MRI produces a more accurate localization of the language areas for epilepsy surgery purpose, but requires the patient's cooperation. We report a 34 year-old woman with mental retardation who underwent two different verbal fluency tasks, category and word naming. We found a strong activation of Broca's area in the most difficult task. We suggest that a multi-task fMRI study could be successful in patients with cognitive delay.

Variable fMRI activation during two different language tasks in a patient with cognitive delay

Functional MRI produces a more accurate localization of the language areas for epilepsy surgery purpose, but requires the patient cooperation. We report a 34 years-old woman with mental retardation who underwent two different verbal fluency tasks, category and word naming. We found a strong activation of the Broca’s area in the most difficult task. We suggest that a multi-task fMRI study could be successful in patients with cognitive delay.

A ressonância magnética funcional permite uma localização acurada da área da linguagem para fins de cirurgia de epilepsia, mas requer a colaboração do paciente na execução da tarefa proposta, o que pode limitar a sua utilização em pacientes com retardo mental. Nós apresentamos o caso de uma mulher com 34 anos de idade, com retardo mental, que foi submetida a duas tarefas distintas de geração silenciosa de palavras, por categoria e letras. Encontramos forte ativação da área de Broca na tarefa mais complexa. Sugerimos que um estudo com múltiplas tarefas pode ser útil em pacientes com retardo mental.

Outcome of hemispheric surgeries for refractory epilepsy in pediatric patients.

BACKGROUND: Hemispheric brain lesions are commonly associated with early onset of catastrophic epilepsies and multiple seizure types. Hemispheric surgery is indicated for patients with unilateral intractable epilepsy. Although described more than 50 years ago, several new techniques for hemispherectomy have only recently been proposed aiming to reduce operatory risks and morbidity. MATERIALS AND METHODS: We present the clinical characteristics, presurgical workup, and postoperative outcome of a series of pediatric patients who underwent hemispherectomy for medically intractable epileptic seizures. Thirty-nine patients with medically intractable epilepsy underwent surgery from 1996 to 2005. RESULTS AND DISCUSSION: We analyzed demographic data, interictal and ictal EEG findings, age at surgery, surgical technique and complications, and postsurgical seizure outcome. There were 74.4% males. Tonic and focal motor seizures occurred in 30.8 and 20.5% of the patients. Most frequent etiologies were Rasmussen encephalitis (30.8%) and malformation of cortical development (23.1%). Postsurgical outcomes were Engel classes I and II for 61.5% of the patients. In general, 89.5% of the patients exhibited at least a 90% reduction in seizure frequency. All patients had acute worsening of hemiparesis after surgery. Basically, two surgical techniques have been employed, both with similar results, although a trend has been noted toward one of the procedures which produced consistently complete disconnection. Patients with hemispheric brain lesions usually have abnormal neurological development and intractable epilepsy. When video-EEG monitoring and magnetic resonance imaging show unilateral disease, the patient may evolve with a good surgical outcome. We showed that a marked reduction in seizure frequency may be achieved, with acceptable neurological impairments.

Cognitive performance of patients with mesial temporal lobe epilepsy is not associated with human prion protein gene variant allele at codons 129 and 171.

Cognitive impairment has long been recognized in people with medically refractory epilepsies. Mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS), the most common surgically remediable epileptic syndrome, has been associated with a cellular prion protein (PrPc) gene (Prnp) variant allele at codon 171. The polymorphism consisting of a methionine-for-valine substitution at codon 129 has been associated with early cognitive deterioration in elderly people and patients with Down syndrome. The same variant allele in homozygosis (V129V) has been associated to a lower long-term memory in healthy humans. PrPc mediates several processes related to neuroplasticity, and its role in cognitive processes remains unknown. In this study, we evaluated the genetic contribution of Prnp alleles to cognitive performance in patients with MTLE-HS. Cognitive performance, measured with 19 neuropsychological tests, of patients with refractory MTLE-HS with the normal Prnp genotypes was compared with that of patients with the variant alleles at codons 129 and 171. With the effects of clinical, demographic, electrophysiological, and neuroimaging variable interactions controlled by multiple linear regression analysis and adjustment for multiple test comparisons, the presence of Prnp variant alleles was found not to be significantly associated to cognitive performance of patients with MTLE-HS. The presence of variant alleles at codons 129 and 171 is not associated to cognitive performance of patients with refractory MTLE-HS.

Language and motor FMRI activation in polymicrogyric cortex.

PURPOSE: To analyze the patterns of brain activation in polymicrogyric cortex in epilepsy patients by blood oxygenation level-dependent (BOLD) functional MRI (fMRI), during language and motor activation tasks. METHODS: Five patients with extratemporal epilepsy associated with polymicrogyria were scanned in a 1.5-T Siemens scanner with BOLD fMRI sequences, by following language and motor paradigms. Functional images were processed by using Brain Voyager software. RESULTS: Activation of polymicrogyric cortex in the brain area that corresponds to the motor strip was present in all patients. Language studies revealed activation of polymicrogyric cortex over Broca's area in three cases. CONCLUSIONS: Functionality was shown in polymicrogyric areas. Therefore if surgical resection is indicated, a careful functional planning is necessary because of functionality of the polymicrogyric cortex.