Multimodal MRI Study Of Brain Structure And Function In Children With Congenital Sensorineural Hearing Loss

Section I Voxel-based morphometry to study the volume changes of gray matter in children with congenital sensorineural hearing lossObjectives To study the changes of gray matter volume in children with congenital sensorineural hearing loss(CSNHL),and to explore the brain structural characteristics of CSNHL patients.Materials and Methods In this prospective study,42 children aged 3.5-18 years old with profound CSNHL were selected and 29 age-and gender-matched normal controls were included in the study.Using 3.0T MR,the head of subjects was scanned by 3D T1 sequence and the volume of whole brain gray matter was measured by voxel-based morphometry(VBM).The volume changes of whole brain gray matter were studied by double-sample t-test,and the changes of CSNHL gray matter were quantitatively evaluated.Results The study cohort consisted of 42 children with profound CSNHL,22 boys and 20 girls,with an average age of 5.93 ± 2.47(Mean age ± SD)years,ranging from 3.5 to 13 years.The normal control group consisted of 29 children matched by gender and age,17 boys and 12 girls,with an average age of 10.34 ±3.97(Mean age ± SD)years,ranging from 3.5 to 16 years.Compared with the control group,the volume of bilateral putamen(p = 0.000,corrected P < 0.001),left paracentral lobule(p = 0.001,corrected P < 0.001)and right middle occipital gyrus(p = 0.000,corrected P < 0.001)increased significantly in the profound CSNHL group.No significant reduction of gray matter was found in children with profound CSNHL.(corrected P > 0.001).Conclusions In this study,VBM technology based on 3D T1 sequence was used to investigate the changes of whole brain gray matter volume in children with profound CSNHL.It can be concluded that:(1)The gray matter volume changes in the important auditory conduction pathway,visual cortex and motor cortex in children with profound CSNHL may be due to compensation and reconstruction of brain structure;(2)VBM can non-invasively quantify brain structure changes in children with CSNHL.It is a valuable method for CSNHL and is suitable for promotion in clinical work.Section II Cerebral white matter microstructural changes in children with congenital sensorineural hearing loss: a tract-based spatial statistics studyObjectives To investigate the structural characteristics of white matter in children with congenital sensorineural hearing loss(CSNHL).Materials and Methods Children(> 3.5 years old)with profound CSNHL and age-matched healthy controls with normal hearing were enrolled in this prospective study and underwent brain MRI scans with diffusion tensor imaging(DTI)using tract-based spatial statistics to evaluate white matter microstructural characteristics.DTI parameters including fractional anisotropy,mean diffusivity,axial diffusivity and radial diffusivity were compared between the CSNHL group and control group.Voxel-wise correlative analysis of the DTI parameters and the ages of the study participants was performed for both groups.Results The study cohort consisted of 36 children with CSHNL(18 boys and 18 girls;mean age ± SD: 6.66±2.82 years;range: 3.5–13.5 years)and 18 children in the control group(12 boys and 6 girls;mean age ± SD: 10.47±3.85 years;range: 3.5–15.3 years).We found no significant differences in fractional anisotropy or mean diffusivity between the two groups.However,the axial diffusivity values were significantly greater in the left anterior thalamic radiation,right corticospinal tract,and cingulate gyrus in the CSHNL group than in the control group.Significantly increased radial diffusivity values in the left anterior thalamic radiation and left inferior fronto-occipital fasciculus were also noted in the CSHNL group as compared to the controls.There was no significant correlation between the DTI parameters and age.Conclusions Our study showed higher axial and radial diffusivities in the children affected by CNHNL as compared to the children with normal hearing.Our study findings suggest that abnormalities of myelination and axonal structure may occur in the auditory pathway of the children with CSHNL.This information may help to design and track hearing rehabilitation in the children with CSNHL.Section III Resting-state functional magnetic resonance imaging study of regional homogeneity changes in children with congenital sensorineural hearing lossObjectives To study the changes of regional homogeneity(Reho)in resting state children with congenital sensorineural hearing loss(CSNHL)and to explore the characteristics of brain function in CSNHL children.Materials and Methods Data of 45 children aged 0-18 with severe CSNHL and 20 age-and gender-matched normal controls were collected in the study.The subjects' heads were scanned with 3.0T MR using 3D T1 and resting BOLD sequences.The data were analyzed by KCC-Reho and Cohoe-Reho methods.SPSS 13.0 was used for inter-group double-sample t test and alphasim correction.Age,gender and mean framewise displacement were removed as control variables by regression.Pearson correlation analysis was performed between average Reho value and age,and alphasim correction was used.Results The study cohort included 45 children with severe CSNHL,including 25 boys and 20 girls,with an average age of 4.82 ± 2.64 years,age range of 1.5-13 years,and mean framewise displacement of 0.15 ± 0.07.The normal control group consisted of 20 children matched by gender and age,13 boys and 7 girls,with an average age of 5.66 ± 3.36,age range of 0.5±16 years,and mean framewise displacement of 0.19 ± 0.10.The spatial distribution of KCC-Reho in profound CSNHL group and normal control group was significantly increased,(1)KCC-Reho values in left calcarine,left cuneus,left precentral and right superior parietal lobule were significantly increased,(2)KCC-Reho values in left ventrolateral prefrontal cortex and right dorsolateral prefrontal cortex were significantly decreased.Cohe-Reho spatial distribution in the brain,(1)Cohe-Reho values in left calcarine increased significantly,(2)Cohe-Reho values in bilateral ventrolateral prefrontal cortex and right dorsolateral prefrontal cortex decreased significantly.Reho value was correlated with age in profound CSNHL group,but not with age in normal control group.The results of KCC-Reho and Cohe-Reho in CSNHL group were consistent.The related brain areas were prefrontal cortex,posterior cingulate gyrus/precuneus,bilateral fusiform/parahippocampal and precentral gyrus.The prefrontal cortex,posterior cingulate gyrus/precuneus were positively correlated with age and the strongest point was in the left ventrolateral prefrontal cortexe.The fusiform/ parahippocampal and precentral gyrus were negatively correlated with age,and the strongest point was in the right fusiform.Conclusions By using KCC-Reho and Cohe-Reho methods,we studied the changes of resting state brain function in children with profound CSNHL.We can draw the following conclusions:(1)abnormal functional changes of auditory,visual and motor cortex in children with profound CSNHL may be caused by perceptual compensation and nerve remodeling;(2)With the increase of age or the prolongation of deafness time in children with profound CSNHL,the information integration ability of relevant brain regions or the ability to process different information differently increased;(3)KCC-Reho and Cohoe-Reho methods have high stability and repeatability,which are suitable for the study of brain function in CSNHL patients.