Clinical features and surgical outcome of patients with indolent brain tumors and epilepsy

INTRODUCTION: In this study the authors review the outcomes of 22 patients with medically refractory epilepsy and slow growth brain tumors. OBJECTIVES: Evaluate the clinical, electrophysiological, operative, and histopathological features. PATIENTS AND RESULTS: The majority of the tumors were located in the temporal lobe (n = 20) and involved the cortical gray matter. The most frequent tumors were gangliogliomas (n = 9), astrocytomas grade I and II (n = 6), dysembryoplastic neuroepithelial tumors (n = 5) and ganglioneuroma (n = 2). The biological behavior of the tumors was strikingly indolent, as indicated by a long preoperative history of chronic seizures (mean, 14 years). Mean follow-up time after resection was 27 months, and according to EngelÆs classification, 85 percent were seizure-free, 10 percent showed a reduction of seizure frequency of at least 90 percent, and 5 percent had reduction in seizure frequency at least 75 percent. CONCLUSION: The data indicate that neoplasms associated with pharmacoresistent epilepsy constitute a distinct clinicopathological group of tumors that arise in young patients, involve the cortex, and exhibit indolent biological behavior for many years. Complete surgical removal of these tumors, including the epileptogenic area, can achieve excellent seizure control.

INTRODUÇÃO: Neste estudo os autores avaliaram retrospectivamente 22 pacientes tratados cirurgicamente com diagnóstico de epilepsia refratária e tumor cerebral de crescimento lento. OBJETIVOS: Avaliar os aspectos clínicos, eletrofisiológicos, cirúrgicos e histopatológicos. PACIENTES E RESULTADOS: A maioria dos tumores estava localizada no lobo temporal (n = 20) com envolvimento da substância cinzenta. Ganglioglioma foi o tumor mais frequente (n = 9), seguido do astrocitoma grau I e II OMS (n = 6), tumor neuroepitelial disembrioplástico (DNET) (n = 5) e ganglioneuroma (n = 2). O comportamento biológico dos tumores foi estritamente indolente como indicado pela longa história pré-operatória de (média, 14 anos). O tempo de acompanhamento pós-operatório médio foi de 27 meses e de acordo com a Classificacão de Engel, 85 por cento ficaram sem crises (Classe I), 10 por cento obtiveram redução maior de 90 por cento das crises (Classe II), e 5 por cento tiveram redução menor que 75 por cento (Classe III). CONCLUSÃO: Os dados indicam que neoplasias associadas à epilepsia crônica refratária constituem um grupo de tumores com características clinico-patológicas distintas que se iniciam em pacientes jovens, envolvem o córtex e apresentam comportamento biológico indolente. A ressecção cirúrgica completa destes tumores, incluindo a zona epileptogênica, levou ao controle total das crises na maior parte dos casos estudados.

Stereotactic biopsy guidance in adults with supratentorial nonenhancing gliomas: role of perfusion-weighted magnetic resonance imaging.

OBJECT: The. diagnosis of low-grade glioma (LGG) cannot be based exclusively on conventional magnetic resonance (MR) imaging studies, and target selection for stereotactic biopsy is a crucial issue given the high risk of sampling errors. The authors hypothesized that perfusion-weighted imaging could provide information on the microcirculation in presumed supratentorial LGGs. METHODS: All adult patients with suspected (nonenhancing) supratentorial LGGs on conventional MR imaging between February 2001 and February 2004 were included in this study. Preoperative MR imaging was performed using a dynamic first-pass gadopentate dimeglumine-enhanced spin echo-echo planar perfusion-weighted sequence, and the tumors' relative cerebral blood volume (rCBV) measurements were expressed in relation to the values observed in contralateral white matter. In patients with heterogeneous tumors a stereotactic biopsy was performed in the higher perfusion areas before resection. Among 21 patients (16 men and five women with a mean age of 36 years, range 23-60 years), 10 had diffuse astrocytomas (World Health Organization Grade II) and 11 had other LGGs and anaplastic gliomas. On perfusion-weighted images demonstrating heterogeneous tumors, areas of higher rCBV focus were found to be oligodendrogliomas or anaplastic astrocytomas on stereotactic biopsy; during tumor resection, however, specimens were characterized predominantly as astrocytomas. Diffuse astrocytomas were associated with significantly lower mean rCBV values compared with those in the other two lesion groups (p < 0.01). The rCBV ratio cutoff value that permitted better discrimination between diffuse astrocytomas and the other lesion groups was 1.2 (80% sensitivity and 100% specificity). CONCLUSIONS: Perfusion-weighted imaging is a feasible method of reducing the sampling error in the histopathological diagnosis of a presumed LGG, particularly by improving the selection of targets for stereotactic biopsy.