Surface-based Morphometry Analysis Study Of Brain In Benign Childhood Epilepsy With Centrotemporal Spikes

Objective:To investigate brain cortical morphology changes（cortical thickness,gyrification,sulcal depth and fractal dimension）of drug-naive benign childhood epilepsy with centrotemporal spikes（BECTS）,analyze the correlation between morphology changes and age of onset and intelligence quotient（IQ）,and explore the possible influence of morphological changes on cognition,thus providing imaging evidence of cognitive dysfunction in BECTS.Methods:Twenty-five drug-naive BECTS patients took part in this study from Affiliated Hospital of Zunyi Medical University between April 2014 and April 2019.These patients with BECTS were diagnosed by intermediate grade pediatricians or higher,according to the 2010 version epilepsy classification criteria of the International League Against Epilepsy（ILAE）.Meanwhile,twenty healthy volunteers were enrolled as the control group.All participants were dextromanuality,and underwent MRI examinations（3.0T HDxt,GE）including T₂-FLAIR and 3D-T₁ acquisition.The neuropsychological assessment based on the Chinese Wechsler Intelligence Scale for Children was conducted by a specialist on the same day of MRI scan.3D-T₁WI data analysis was performed with the CAT12 toolkit.Two-sample t tests were carried out to compare the differences in cortical thickness,gyrification,sulcal depth and fractal dimension of brain regions between the patient and control groups with age and sex as covariates.Spearman correlation analyses were used to demonstrate the relationships between morphological characteristics in abnormal brain regions and age of onset and IQ which included verbal intelligence quotient（VIQ）,performance intelligence quotient（PIQ）and full scale intelligence quotient（FIQ）.In this study,p<0.05 was considered statistically significant.Results:（1）There were no significant differences in age,gender composition,or years in education between the BECTS patients and control group（p>0.05）.（2）Compared with control group,the BECTS patients showed extensive cortical thinning predominantly in bilateral frontal,temporal regions and limbic system,which including superior frontal gyrus,middle frontal gyrus,inferior frontal gyrus,medial orbitofrontal gyrus,precentral gyrus,fusiform gyrus,middle temporal gyrus and cingulate gyrus in bilateral hemisphere,parahippocampal gyrus,temporal pole,lateral occipital gyrus and insula in the left hemisphere,superior temporal gyrus,paracentral lobule,inferior parietal gyrus and inferior temporal gyrus in the right hemisphere（p<0.05,FWE corrected,cluster size>30）.The BECTS patients showed significantly increased cortical gyrification predominantly in the left hemisphere and partial right hemisphere,including superior frontal gyrus,frontal pole,lingual gyrus,lateral occipital gyrus,cingulate gyrus,postcentral gyrus,inferior parietal gyrus,supramarginal gyrus and inferior frontal gyrus in the left hemisphere,inferior temporal gyrus,middle temporal gyrus,inferior frontal gyrus,superior frontal gyrus in the right hemisphere（p<0.05,FWE corrected,cluster size>30）.The decreased cortical gyrification was only in the left hemisphere,including insula,inferior frontal gyrus,inferior temporal gyrus,lateral occipital gyrus,superior temporal gyrus,middle temporal gyrus and precental gyrus（p<0.05,FWE corrected,cluster size>30）.The increased sulcal depth was left fusiform gyrus（p<0.05,FWE corrected,cluster size>30）.There was no statistically significant in fractal dimension（p>0.05,FWE corrected,cluster size>30）.（3）Correlation analysis revealed the negative correlation between age of onset and cortical thickness in the right precentral gyrus（r_s=-0.495,p=0.011）,age of onset and cortical gyrification in the left inferior parietal gyrus（r_s=-0.523,p=0.007）,VIQ and cortical gyrification in the left supramarginal gyrus of BECTS patients（r_s=-0.455,p=0.022）.Conclusion:This study reveals aberrant cortical thickness,cortical gyrification and sulcal depth of BECTS in areas relate to cognitive functions such as language,attention and memory,and the correlation between some brain regions and VIQ and age of onset,which providing new imaging evidence for study of cognitive function in BECTS.