Abstracts

Rationale: Congenital bilateral perisylvian syndrome (CBPS) presents wide clinical diversity. The main features are pseudobulbar palsy, developmental language disorder, variable cognitive deficits, epilepsy, and perisylvian abnormalities on imaging studies. The most frequent underlying lesion is polymicrogyria. Objective: The objective of this study was to investigate the relationship between seizures and extent of gray matter and white matter abnormalities in patients with CBPS using voxel-based morphometry (VBM) of brain magnetic resonance imaging (MRI); and to verify if the presence of seizures in patients with CBPS may be associated with the extent of structure abnormalities. Methods: We evaluated 18 patients with CBPS (MRI showed diffuse polymicrogyria around the Sylvian fissure) and divided them into two groups: with (n=7) and without seizures (n=11). Fifty-one healthy controls were compared with the two groups. The images were acquired in DICOM format and transformed to ANALYSE by MRIcro (www.mricro.com). We used SPM2 software (www.fil.ion.ucl.ac.uk) on MATLAB 7.0 to obtain the statistical maps of gray matter, by applying an optimized VBM protocol. The normalized, segmented, modulated and smoothed data were analyzed with statistical non-parametric mapping (SNPM http://www.sph.sc.edu/comd/rorden/workshop/npm/) with Brunner Munzel test. We only considered significant results those with p<0.05. We used the SYSTAT 12 (Systat Software Inc. SSI) software with non parametric Mann-Whitney U-test for continuous variables and Chi-square test to analyse frequency distributions. Results: Both CBPS and control groups were homogeneous concerning gender (p=0.3; X2 test) and age (p=0.15; Mann-Whitney u-test). Patients with CBPS and epilepsy, in addition to the perysilvian polymicrogyria, exhibited a significant reduction of the gray matter and white matter concentration in a widespread pattern, including bilateral thalamus, temporal lobes, frontal, parietal and occipital lobes. In contrast, we did not identify areas with GM and WM reduction in CPBS patients without epilepsy. Conclusions: The extent of cortical and sub-cortical GM and WM abnormalities found in patients with CBPS and epilepsy is significantly higher than in patients without seizures. Our results suggest that patients with CBPS and epilepsy appear to have a widespread neuronal damage that goes beyond the areas with polymicrogyria.