Malformações do desenvolvimento cortical : contribuição dos fatores geneticos e ambientais para sua etiologia, aspectos clinicos e de neuroimagem

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

Rationale - Malformations of cortical deve10pment (MCD) can be associated with hippocampal abnormalities. Our objective was to assess whether different hippocampal abnormalities are associated with a particular class ofMCD. Methods - We evaluated 83 consecutive patients with MRI diagnosis ofMCD (37 men, ages ranging ttom 2 to 58 years; mean=18.5). High resolution:MRI was performed in a 2.0T scanner. Volumetric measurements were performed manually on 3mm thick TI-IR corona! slices, perpendicular to the long axis ofthe hippocampus. Hippocampal volumes were corrected for intracranial volumes and compared to the values of a normal control group of20 healthy volunteers. Values below or above 2 SD ttom the mean ofthe control group were considered abnormal. Results - Twenty-five patients had focal cortical dysplasia, four hemimegalencephaly, five unilateral nodular heterotopia, four bilateral periventricular nodular heterotopia, one transmantle heterotopia, four subcorticallaminar heterotopia, five lissencephaly (agyria- pachigyria), five schizencephaly and 30 polymicrogyria. Enlarged hippocampus was present in 44% ofpatients with MCD due to diffuse migration disorders (2/5 lissencephaly and 2/4 subcorticallaminar heterotopia). Conversely, hippocampal atrophy was present in 14% ofpatients with focal MCD (2/25 focal cortical dysplasia, 3/30 polymicrogyria, 3/5 schizencephaly, 2/5 unilateral nodular heterotopia, and in none with periventricular nodular heterotopia or transmantle heterotopia). Patients with hemimegalencephaly presented both atrophy (n=I/4) or enlargement (n=2/4) ofthe hippocampus. The hippocampal abnormality was always ipsilateral to the lesion. Two patients with hippocampal atrophy never presented seizures. Conclusion - We found hippocampal volume abnormalities in 17 (20%) patients with MCD. The pattern ofhippocampal abnormality varied according to the type ofMCD: enlarged hippocampi in diffuse migration disorders and hippocampal atrophy in focal MCD. Two patients with hippocampal atrophy never presented seizures and the hippocampal abnormality was always ipsilateral to the dysp1astic lesion suggesting a common physiopathology for the hippocampallesion and MCD

ASSUNTO(S)

ressonancia epilepsia nas crianças infancia epilepsia

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