Congenital destructive hemispheric lesions and epilepsy: clinical features and relevance of associated hippocampal atrophy

Abstract

-We studied the clinical, EEG and MRI findings in 19 patients with epilepsy secondary to congenital destructive hemispheric insults. Patients were divided in two groups: 10 with cystic lesions (group 1), and 9 with atrophic lesions (group 2). Seizure and EEG features, as well as developmental sequelae were similar between the two groups, except for the finding that patients of group 2 more commonly presented seizures with more than one semiological type. MRI showed hyperintense T2 signal extending beyond the lesion in almost all patients of both groups, and it was more diffuse in group 2. Associated hippocampal atrophy (HA) was observed in 70% of group 1 patients and 77.7% of group 2, and it was not correlated with duration of epilepsy or seizure frequency. There was a good concordance between HA and electroclinical localization. The high prevalence of associated HA in both groups suggests a common pathogenesis with the more obvious lesion. Our findings indicate that in some of these patients with extensive destructive lesions, there may be a more circumscribed epileptogenic area, particularly in those with cystic lesions and HA, leading to a potential rationale for effective surgical treatment.KEY WORDS: epilepsy, magnetic resonance image, hippocampal atrophy.Epilepsia secundária a lesões destrutivas hemisféricas congênitas: achados clínicos e relevância de atrofia hipocampal associada RESUMO -Analisamos os achados clínicos, de EEG e RM de 19 pacientes com epilepsia secundária a insultos destrutivos hemisféricos congênitos. Os pacientes foram divididos em dois grupos: 10 com lesões císticas (grupo 1), e 9 com lesões atróficas (grupo 2). As características das crises e achados de EEG foram similares entre os dois grupos exceto pelo fato dos pacientes do grupo 2 terem apresentado mais comumente crises com mais de um padrão semiológico. A RM mostrou sinal T2 hiperintenso estendendo-se ao redor da lesão e à distância em quase todos os pacientes de ambos os grupos, de modo mais extenso no grupo 2. Observou-se atrofia hipocampal (AH) associada em 70% dos pacientes do grupo 1 e 77,7% do grupo 2 e não houve correlação com a duração da epilepsia ou freqüência das crises. Houve boa correlação entre a AH e localização eletroclínica. A alta prevalência de AH associada em ambos os grupos sugere uma patogenia comum com a lesão mais óbvia. Estes achados indicam que alguns destes pacientes com extensas lesões destrutivas, particularmente aqueles com lesões císticas e AH, a zona epileptogênica pode ser mais circunscrita possibilitando a indicação de uma ressecção restrita para o controle das crises. PALAVRAS-CHAVE: epilepsia, ressonância magnética, atrofia hipocampal.

Epilepsy Due to a Destructive Brain Lesion Caused by a Scorpion Sting

“…Interestingly, the lateralization of the seizures, and the right hemispheric brain destruction, followed a similar pattern of patients with HHE syndrome (hemicon- vulsion, hemiplegia, and epilepsy). 10 Rasmussen syndrome is a possible differential diagnosis; however, we have not witnessed continuous epileptic activity in the patient's electrophysiological studies or evidence of progression in her disease. The recurrent nonprovoked seizures in this patient suggest the development of a stable epileptogenic region in the area that was continuously activated by the scorpion toxin.…”