Morphometry Study Of Conventional MRI-negative Epilepsy At3.0T High Field Magnetic Resonance Scaner

Objective To study cerebral gray matter structure change in conventional MRI-negative epilepsy patients by Voxel-based morphometry technique, and analyze volume change of common abnonnal area in epilepsy using region of interest (ROI) method.To investigate the correlation between abnormal brain region and illness duration of epilepsy, and provide new available evidence for diagnosis and treatment of conventional MRI-negative epilepsy.Methods Forty-six patients from Affiliated Hospital of Zunyi Medical College took part in current study. The patients were diagnosed by experienced doctor of Neurology and pediatrics, according to the diagnostic criteria of the International League Against Epilepsy and Electroencephalogram examination. Conventional MRI and3D-T1WI sequence were performed for all patients. Excluding the intracranial organic disease and the head movement more than1mm,32cases were finally analyzed. The control group was32healthy volunteers matching for age, gender, handness and education level with Patient group. According to the EEG, patient group was divided into the left side (6cases), right side (4cases) and bilateral sides group (11cases). According to seizure type, divided into generalized seizures (23cases) and partial seizures group(9cases). ROIEditor software was used for Regions of interest (ROI) analysis. The defined ROIs include bilateral head of hippocampus, hippocampus, amygdala, thalamus, head of caudate nucleus and lenticular nucleus, Statistical analysis were performed by independent samples T test. The differences of p<0.05would be considered as statistical significance. VBM analysis were performed using voxel-wise analysis approaches as implemented in statistical parametric mapping (SPM8) software, including display, segment, create templates, normalization and smoothing. Patient group and subgroups were compared with the normal group. Comparison of subgroups were analyzed between the left group and the bilateral group, generalized seizures and partial seizures group.Statistical analysis were made using two sample-test, The differences of p<0.05would be considered as statistical significance. Pearson correlation analysis was used for ROI correlation analysis, Multiple regression analysis in SPM8software for VBM. The differences of-p<0.05would be considered as statistical significance.Results Sex,Age and handedness between patient group and control group were no statistically difference(P=0.8、0.431、0.8), All the patients and volunteers were right-handed. ROI Analysis:Compared with control group, patient group showed reduced volume in bilateral head of hippocampus and the right amygdala. VBM analysis, compared with the control group, Gray matter atrophy in patient group were found in left middle temporal gyrus, the left precuneus, the left lingual gyrus (BA18) volume reduction, the left side group in left inferior frontal gyrus (BA45)and left precuneus, the bilateral group in left inferior occipital gyrus (BA19), the left middle temporal gyrus (BA38), right middle temporal gyrus and right inferior parietal lobe (BA40), the generalized seizures group in the right inferior parietal lobe(BA40), right posterior cerebellum lobe, right precentral gyrus (BA4), right middle temporal gyrus, the right superior temporal gyrus (BA22), left occipital lingual gyrus, the left cerebellum posterior lobe, left thalamus and left midbrain, partial seizures group in left superior temporal gyrus (BA38). Compared with the left side group, bilateral group reduced volume in the left middle occipital gyrus, left inferior temporal gyrus (BA20), left superior temporal gyrus and the right corpus callosum. Compared with partial seizures group, generalized seizures group decreased volume in right parietal post-central gyrus (BA2), left superior temporal gyrus (BA38), left inferior frontal gyrus (BA47), left parietal post-central gyrus (BA4) and left inferior occipital gyrus. The correlation analysis of ROI found that right lenticular nuclear volume was positively correlated with the illness duration and bilateral group, VBM showed that right middle temporal gyrus, right anterior cingulate gyrus (BA32), right medial prefrontal gyrus, right superior temporal gyrus (BA38) and left inferior temporal gyrus (BA20), right inferior parietal lobe (BA40) volume was negative correlated with the illness duration.Conclusions Conventional MR-negative epilepsy patients have brain morphological changes,3.0T high-resolution3D-T1WI sequences can detect such abnormalities, VBM analysis could found more abnormal brain regions, and part of the brain volume change are negative correlated with the duration, providing a theoretical basis for clinical diagnosis and treatment of conventional MRI-negative epilepsy.