Abstracts

The objective of this study was to examine the thalamic volume in a large group of patients with juvenile myoclonic epilepsy (JME) using high resolution magnetic resonance imaging (MRI) and compare the results with a control group of healthy normal subjects. All patients had JME diagnosis supported by clinical and EEG features according to ILAE recommendations. MRI images were acquired in a 2.0T scanner and a 3D T1 gradient echo sequence with 1 mm isotropic voxels was used for volumetry. Images were previously processed for field non-homogeneity correction and linear stereotaxic transformation into a standard space to reduce interindividual variation. Volumetry was performed with manual segmentation of the right and left thalamus using the software Display (BIC, Montreal Neurological Institute) which permits simultaneous visualization of the images in three different planes facilitating the identification of anatomic boundaries. Right and left thalamic volumes achieved of each patient were compared with ipsilateral volumes of 35 normal control subjects using Student[rsquo]s [italic]t[/italic]-test. The relation between thalamic volumes with patients[rsquo] age and duration of epilepsy was assessed using Pearson correlation test. We performed volumetry of 64 patients with JME. Thalamic volumes of patients with JME (mean [italic]z[/italic]-score [plusmn] SD, right thalamus 0.83 [plusmn] 1.16 and left thalamus 0.83 [plusmn] 1.19) were larger in comparison with controls ([italic]p[lt][/italic]0.001[italic])[/italic]. There was no correlation between thalamic volumes with patients[rsquo] age and duration of epilepsy. Our study shows, for the first time, an increased thalamic volume in a large group of patients with JME in comparison with normal controls. This finding supports the importance of this structure in the physiopathology of JME. (Supported by CAPES, FAPESP)