RESUMO
BACKGROUND: There have been difficulties in achieving a uniform terminology in the literature regarding issues of classification with respect to focal cortical dysplasias (FCDs) associated with epilepsy. OBJECTIVE: S: To review and refine the current terminology and classification issues of potential clinical relevance to epileptologists, neuroradiologists, and neuropathologists dealing with FCD. METHODS: A panel discussion of epileptologists, neuropathologists, and neuroradiologists with special expertise in FCD was held. RESULTS: The panel proposed 1) a specific terminology for the different types of abnormal cells encountered in the cerebral cortex of patients with FCD; 2) a reappraisal of the different histopathologic abnormalities usually subsumed under the term "microdysgenesis," and suggested that this terminology be abandoned; and 3) a more detailed yet straightforward classification of the various histopathologic features that usually are included under the heterogeneous term of "focal cortical dysplasia." CONCLUSION: The panel hopes that these proposals will stimulate the debate toward more specific clinical, imaging, histopathologic, and prognostic correlations in patients with FCD associated with epilepsy.
Assuntos
Encefalopatias/classificação , Córtex Cerebral/anormalidades , Córtex Cerebral/patologia , Malformações do Sistema Nervoso/classificação , Terminologia como Assunto , Encefalopatias/complicações , Encefalopatias/patologia , Epilepsia/complicações , Humanos , Malformações do Sistema Nervoso/complicações , Malformações do Sistema Nervoso/patologia , Neurônios/patologiaRESUMO
BACKGROUND: Patients with hypothalamic hamartomas (HH) often have severe refractory epilepsy, incapacitating behavioral abnormalities, and cognitive decline. Attempts to control the seizure disorder by resection of apparently epileptogenic mesial temporal or other cortical structures have failed consistently. OBJECTIVE: To report a series of 13 patients in whom the hamartoma itself was resected. METHODS: All patients underwent preoperative evaluation between ages 2 and 33 years and had subtotal or complete resection of the hamartoma. Follow-up ranged from 1 to 5.5 years (mean: 2.8 y). RESULTS: Preoperatively, all patients had variable combinations of gelastic, complex partial, and generalized seizures. Eight had drop attacks. In addition, all had marked behavior abnormalities and cognitive impairment. Postoperatively, two patients are completely seizure-free and 11 are either seizure-free or have achieved a greater than 90% reduction of drop attacks and generalized tonic-clonic seizures. However, minor gelastic, complex partial, and atypical absence seizures have persisted in 11 patients, although at significantly reduced rates. In addition, there has been a dramatic improvement in behavior and cognition. Three patients had an anterior thalamic and one a capsular infarct, which left only minimal long-term deficits. Exact location of the lesion in relation to the interpeduncular fossa and the walls of the third ventricle correlated with extent of excision, seizure control, and complication rate. CONCLUSION: Resection can alleviate both the seizures and the behavioral and cognitive abnormalities of hypothalamic hamartomas, but complications are frequent.
Assuntos
Epilepsia/etiologia , Hamartoma/complicações , Hamartoma/cirurgia , Neoplasias Hipotalâmicas/complicações , Neoplasias Hipotalâmicas/cirurgia , Adolescente , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Encéfalo/cirurgia , Criança , Pré-Escolar , Transtornos Cognitivos/etiologia , Eletroencefalografia , Epilepsia/terapia , Feminino , Seguimentos , Hamartoma/diagnóstico , Humanos , Neoplasias Hipotalâmicas/diagnóstico , Lamotrigina , Imageamento por Ressonância Magnética , Masculino , Procedimentos Neurocirúrgicos/efeitos adversos , Paresia/etiologia , Recuperação de Função Fisiológica , Indução de Remissão , Tomografia Computadorizada de Emissão , Resultado do Tratamento , Triazinas/uso terapêuticoRESUMO
It is only a decade since the realization (facilitated by magnetic resonance imaging) in early 1990s that disorders of cortical development occupy an important place in the aetiologic categorization of epilepsy. Since then research has demonstrated the intrinsic epileptogenicity of disorders of cortical development, their genetic bases and their functional properties. Some of the key points of this most exciting medical and scientific enterprise are reviewed here, with an emphasis in the advances seen within the past 2 years.
Assuntos
Córtex Cerebral/anormalidades , Epilepsia/etiologia , Animais , Córtex Cerebral/cirurgia , Anormalidades Congênitas/diagnóstico , Anormalidades Congênitas/genética , Anormalidades Congênitas/cirurgia , Modelos Animais de Doenças , Eletrofisiologia/métodos , Humanos , Imageamento por Ressonância Magnética , SíndromeRESUMO
Epilepsy is a major health problem, and there is hope that current international initiatives--epitomized in the "Epilepsy: Out of the Shadows" campaign--will increase the commitment of the general public and health officials to the care of patients. Particularly in developing countries, there is great need for alleviation of the extremely difficult situation of people with epilepsy and their families. Doctors can play their part by adhering to specific medical and surgical strategies aimed at the improvement of epilepsy care in these countries. Included in the former are joining efforts to guarantee a regular distribution of conventional antiepileptic drugs (AEDs), make optimal use of the more easily available AEDs, and improve communication with patients and families at all levels. It is also important to support the creation of local and regional specialized epilepsy centers with the capability to perform presurgical evaluation and epilepsy surgery in many patients with medically refractory seizures. The establishment of such centers in developing countries will face several challenges, including a critical view of technological advances and the need to support well-trained, creative people who can evaluate and operate on patients with relatively limited resources. This article proposes that the success of such an approach depends on the progressive build-up of a "critical mass" of specialized people who are trained locally to select or reject epilepsy patients for surgery using the available resources. A stepwise approach to the increasing levels of complexity involved in the evaluation and surgical treatment is proposed, with the expectation that each center will find its level and adhere to its capability.
Assuntos
Anticonvulsivantes/uso terapêutico , Córtex Cerebral/cirurgia , Países em Desenvolvimento/estatística & dados numéricos , Epilepsia/tratamento farmacológico , Epilepsia/cirurgia , Necessidades e Demandas de Serviços de Saúde , Humanos , Seleção de Pacientes , Lobo Temporal/cirurgiaRESUMO
We report histopathological findings in 300 consecutive surgical specimens from epilepsy surgery during 6 years. Our material was mainly from temporal lobe epilepsy (70.33%). In 44% the diagnosis was hippocampal sclerosis. There were tumors in 15% of cases and neuronal migration disorders in 10%. The most common tumors were gangliogliomas (42.22%) and dysembryoplastic neuroepithelial tumors (20%). We review the more frequent diagnosis in epilepsy surgery based on this series and comparing with literature.
Assuntos
Epilepsias Parciais/patologia , Córtex Cerebral/patologia , Epilepsias Parciais/cirurgia , Hipocampo/patologia , Humanos , EscleroseRESUMO
PURPOSE: To evaluate the accuracy, feasibility and clinical value of both ictal and interictal 99mTc-ethyl cysteinate dimer (ECD) single photon emission computed tomography (SPECT) in patients with medically refractory epilepsy. METHODS: The study included 75 consecutive patients, 48 with temporal lobe epilepsy (TLE group), and 27 with extratemporal epilepsy (ExT group). The accuracy of SPECT was analyzed considering the final diagnosis reached by convergence of clinical, electrophysiologic, structural, pathologic and outcome data. RESULTS: Ictal SPECT correctly identified the epileptogenic zone in 21 (91.3%) of 23 patients, whereas interictal SPECTs could correctly identify the epileptogenic zone in only 41 (62.1%) of 66 patients (chi2 = 5.56, df = 1, p < 0.05). Results were similar when the two study groups were analyzed separately. Moreover, ictal studies had significantly higher specificity (91.3 vs. 60.6%) and positive predictive value (91.3 vs. 66.2%) than interictal studies for the whole series of patients. Considering all tools used in the preoperative workup of these patients, ictal SPECT significantly contributed to the final topographic diagnosis in seven of 14 patients from TLE group and in six of nine patients from the ExT group. In these patients, ictal SPECT either obviated the need for invasive EEG or helped to define where to concentrate the efforts of invasive investigation. CONCLUSIONS: These data demonstrate that ictal SPECT can be easily achieved by using 99mTc-ECD and can accurately localize the epileptogenic zone in both temporal and extratemporal epilepsies. Ictal ECD SPECT proved to be significantly more sensitive and specific than interictal ECD SPECT, and clinically useful in the definition of the epileptogenic zone.
Assuntos
Córtex Cerebral/diagnóstico por imagem , Cisteína/análogos & derivados , Epilepsia/diagnóstico por imagem , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Tomografia Computadorizada de Emissão de Fóton Único , Algoritmos , Córtex Cerebral/fisiopatologia , Árvores de Decisões , Eletroencefalografia , Epilepsia/diagnóstico , Epilepsia/fisiopatologia , Epilepsia do Lobo Temporal/diagnóstico , Epilepsia do Lobo Temporal/diagnóstico por imagem , Epilepsia do Lobo Temporal/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Tecnécio Tc 99m Exametazima , Tomografia Computadorizada de Emissão de Fóton Único/estatística & dados numéricosRESUMO
Children, 47, with various types of severe drug-resistant epilepsy were entered into a prospective, add-on, open trial with vigabatrin. Patients with West syndrome and idiopathic generalized epilepsies were excluded. Seven children had the drug withdrawn, five because of increase in seizure frequency and two because of adverse effects. Drug efficacy, measured according to seizure type, showed a 100% decrease in seizure frequency in 18.6% of partial seizures and 17.3% of the generalized seizures. There was a higher than 50% decrease in 39.5% of partial and 60.8% of generalized seizures, and less than 50% decrease or increase in seizure frequency in 41.8% and 21.8% of partial and generalized seizures, respectively. Vigabatrin mean dosage during phase 3 was 63.6 mg/kg per day (S.D. = 30.5), ranging from 19.3 to 110.5 mg/kg per day. Parametric statistical analysis (Student's t-test) of seizure frequency between phases 1 and 3 showed a significant decrease in seizure frequency for partial (P = 0.022), and generalized seizures (P < 0.0001). Drug-related adverse effects were observed in 18/47 cases (38.3%), consisting mainly of irritability, hyperactivity, dizziness, somnolence and gastrointestinal symptoms.
Assuntos
Anticonvulsivantes/uso terapêutico , Epilepsias Parciais/tratamento farmacológico , Epilepsia Generalizada/tratamento farmacológico , Ácido gama-Aminobutírico/análogos & derivados , Adolescente , Anticonvulsivantes/efeitos adversos , Brasil , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Masculino , Estudos Prospectivos , Vigabatrina , Ácido gama-Aminobutírico/efeitos adversos , Ácido gama-Aminobutírico/uso terapêuticoRESUMO
Cortical dysplastic lesions (CDyLs) are often associated with severe partial epilepsies. We describe the electrographic counterpart of this high degree of epileptogenicity, manifested by continuous or frequent rhythmic epileptogenic discharges recorded directly from CDyLs during intraoperative electrocorticography (ECoG). These ictal or continuous epileptogenic discharges (I/CEDs) assumed one of the following three patterns: (1) repetitive electrographic seizures, (2) repetitive bursting discharges, or (3) continuous or quasicontinuous rhythmic spiking. One or more of these patterns were present in 23 of 34 patients (67%) with intractable partial epilepsy associated with CDyLs, and in only 1 of 40 patients (2.5%) with intractable partial epilepsy associated with other types of structural lesions. I/CEDs were usually spatially restricted, thus contrasting with the more widespread interictal ECoG epileptic activity, and tended to colocalize with the magnetic resonance imaging-defined lesion. Completeness of excision of cortical tissue displaying I/CEDs correlated positively with surgical outcome in patients with medically intractable seizures; i.e., three-fourths of the patients in whom it was entirely excised had favorable surgical outcome; in contrast, uniformly poor outcome was observed in those patients in whom areas containing I/CEDs remained in situ. We conclude that CDyLs are highly and intrinsically epileptogenic, and that intraoperative ECoG identification of this intrinsically epileptogenic dysplastic cortical tissue is crucial to decide the extent of excision for best seizure control.
Assuntos
Córtex Cerebral/fisiopatologia , Epilepsias Parciais/fisiopatologia , Adolescente , Adulto , Córtex Cerebral/cirurgia , Criança , Pré-Escolar , Eletroencefalografia , Epilepsias Parciais/cirurgia , Feminino , Humanos , Lactente , Masculino , Resultado do TratamentoRESUMO
Cortical dysplastic lesions (CDLs) are usually identified by magnetic resonance imaging (MRI). Clinical, electrographic and histologic findings suggest that focal CDLs (FCDLs) are highly epileptogenic, often involve the rolandic cortex, and can present variable degrees of histopathologic abnormalities. An ictal or "ictal-like" bursting pattern of electrographic activity was recorded over dysplastic cortex in 65% of our patients. Resective surgery can eliminate or significantly reduce seizure frequency in many medically intractable patients, depending on lesion location, degree, and extent of histopathologic abnormalities. Best results are achieved when complete or major excision of both the MRI-visible lesion and the cortical areas displaying ictal electrographic activity can be performed. This is more likely when the degree of histopathologic abnormality is mild to moderate or when the lesion is in a temporal lobe. More severe histopathologic abnormalities and central insular or multilobar lesions usually lead to less favorable results: either major excision of the visualized lesion is impractical or the lesion is microscopically more extensive than shown by MRI. Multilobar resection or hemispherectomy for patients with infantile spasms associated with CDLs and for patients with hemimegalencephaly are often associated with dramatic improvement in seizure control. Callosotomy can be performed in selected patients with diffuse CDLs who have intractable drop attacks.
Assuntos
Córtex Cerebral/anormalidades , Córtex Cerebral/cirurgia , Epilepsia/cirurgia , Defeitos do Tubo Neural/cirurgia , Adolescente , Adulto , Córtex Cerebral/patologia , Pré-Escolar , Eletroencefalografia , Epilepsias Parciais/congênito , Epilepsias Parciais/diagnóstico , Epilepsias Parciais/cirurgia , Epilepsia/congênito , Epilepsia/patologia , Feminino , Humanos , Recém-Nascido , Imageamento por Ressonância Magnética , Defeitos do Tubo Neural/diagnóstico , Defeitos do Tubo Neural/patologiaRESUMO
Lesöes displásicas corticais (LDC) estäo frequentemente associadas a epilepsias de difícil controle. Nós descrevemos os correlatos eletrográficos deste alto grau de epileptogenicidade, caracterizado por descargas epileptógenas rítmicas, contínuas ou quase-contínuas, registradas diretamente das LDC durante eletrocorticografia trans-operatória. Esta atividade ictal ou descargas epileptogênicas contínuas (AI/DEC) manifestava-se por um de três padröes: (a) crises eletrográficas repetidas; (b) surtos de polipontas recorrentes; ou (c) espículas rítmicas contínuas ou quase-contínuas. Um ou mais destes padröes estava presente em 23 de 34 pacientes (67 por cento ) com epilepsia partial de difícil controle associada a LDC. Esta AI/DEC era geralmente mais localizada, assim contrastando com a atividade interictal ao eletrocorticograma, que era mais difusa. Nós concluimos que LDC säo altamente e intrinsicamente epileptogênicas e discutimos mecanismos possivelmente relacionados a esta epileptogenicidade intrínsica
Assuntos
Lactente , Pré-Escolar , Criança , Adolescente , Adulto , Humanos , Masculino , Feminino , Córtex Cerebral/lesões , Eletroencefalografia , Epilepsias Parciais , ConvulsõesRESUMO
Two experiments were carried out in healthy human volunteers in order to investigate the effect of novel experiences on retrieval, and the influence of naltrexone thereupon. Naltrexone (50 mg) and placebo (50 mg of starch) were given orally using a double blind design. In Experiment 1, the subjects were asked, on two consecutive days, to recall well-known facts or events, and to recall the year in which major events took place. On Day 2, some subjects were, and others were not, exposed to a nonsense text prior to testing, which was viewed as a novel experience by the subjects. Exposure to the text was followed by enhanced scores in both memory tests. The effect was blocked by naltrexone, but not by the placebo, given 1 hr prior to the novel experience; the treatments had no effect of their own in subjects unexposed to the nonsense text. In Experiment 2, the memory tests were the recognition of famous faces, and the dates test (see above); and the novel experience was being taken for 5 min to a room where they had never been before. Again, the novel experience was followed by increased scores in both memory tests in the untreated and placebo groups, but not in the naltrexone treated subjects. These results confirm previous findings on memory enhancement by pre-test exposure to novel experiences, and suggest that endogenous opioid, or at least naltrexone-sensitive, mechanisms are involved in the effect.