Idiopathic Generalized Tonic-Clonic Seizures: Cognitive Status And Brain Structures

Objective:To explore the volumes of brain structures (Whole cerebrum, whole cerebral gray matter, whole cerebral white matter, parahippocampus), cognitive status, and the relations between them in patients who had idiopathic generalized epilepsy with with generalized tonic-clonic seizures only (IGE-GTCS) compared with healthy controls.Method:The subjects included 30 patients with IGE-GTCS and 32 healthy controls matched for age, gender, and education. Cognitive function was assessed using Wechsler Adult Intelligence Scale—Revised in China (WAIS-RC) by the same psychologist. Structural images were acquired on a GE 1.5 T scanner and processed with the software package Dr View 5.0.The boundaries of whole cerebrum and para hippocampus were manually traced. The whole cerebral gray matter and whole cerebral white matter, were segmented semiautomatically by the soft ware. We used the x2 test to analyze differences in proportions and Student t test to analyze mean differences between groups. Differences in the regions of interest were analyzed using repeated measures multivariate analysis of covariance (MANCOVA). Pearson's correlation coefficients were calculated to examine the relationships between the volumes of brain structures and the cognitive scores. The level of significance selected was p<0.05.Result:1.In patients, the mean volume of the whole cerebrum was 1122.49(21.93) cm3, the whole cerebral gray matte was 727.21 (15.32) cm3, the mean volume of the whole cerebral white matter was 395.28 (10.55) cm3, the parahippocampus was 13.83 (0.14) cm3. In controls, the mean volume of there was no significant main effect of diagnosis. For the whole cerebrum, the whole cerebral gray matter and the whole cerebral white matter, there was no significant main effect of diagnosis or gender, but significant main effects of hemisphere for these three measurements were detected. The volumes of the cerebral hemisphere (f=5.50,df=58,p=0.02) and the whole cerebral white matter were significantly larger on the left than on the right(f=162.87,df=56,p=0.004), whereas the volume of the whole cerebral gray matter was significantly larger on right hemisphere than on left hemisphere.2.The scores of all the subsets were lower than that of the controls.3.In patients, the volume of the whole cerebrum was significantly positively correlated with arithmetic (r=0.36,p<0.05), picture completion (r=0.53,p<0.01), block design (r=0.43,,p<0.05), object assembly (r=0.47,p<0.01), freedom from distractibility (r=0.39,p<0.05), perceptual organization (r=0.45,p<0.05), performance intelligence quotient (r=0.48, p<0.01), and full scale intelligence quotient (FSIQ). (r=0.40, p<0.05); The volume of the whole cerebral gray matter was significantly positively correlated with arithmetic (r=0.48,p<0.01), similarities (r=0.43,p<0.05), digit symbol(r=0.43,p<0.05), picture completion (r=0.48,p<0.01), block design (r=0.49,p<0.01), object assembly (r=0.46,p<0.05), freedom from distractibility (r=0.52,p<0.01), perceptual organization (r=0.47,p<0.01), verbal intelligence quotient (VIQ) (r=0.44,p<0.05), performance intelligence quotient (PIQ) (r=0.52,p<0.01), and FSIQ (r=0.50,p<0.01); The volume of the whole cerebral white matter was significantly positively correlated with picture completion (r=0.40,p<0.05); The volume of the right parahippocampus was significantly positively correlated with block design (r=0.42,p<0.05). In controls, the volume of the whole cerebrum was significantly positively correlated with arithmetic (r=0.37,p<0.05) and block design (r=0.61,p<0.01); The volume of the whole cerebral gray matter was significantly positively correlated with block design (r=0.53,p<0.01) only. The volume of the left parahippocampus was significantly positively correlated with object assembly (r=0.43,p<0.05).Conclusion:1.IGE-GTCS patients with total IQ (FIQ), verbal IQ (VIQ), performance IQ (PIQ) were significantly reduced, which reduce the more obvious verbal IQ.2. IGE-GTCS patients with whole brain, whole brain gray matter, total volume of white matter and parahippocampal gyrus compared with normal controls no significant change; 3. IGE-GTCS patients with whole brain, whole brain gray matter volume significantly correlated with a number of cognitive function; the right parahippocampal gyrus and the spatial memory and visual recognition...