| PART I AN MRI STUDY ON VOLUME REFERENCE RANGE OF THE CORPUS CALLOSUM AND ITS IN TYPICALLY DEVELOPING PRESCHOOL CHILDRENObjectives: The corpus callosum(CC)is the largest connecting fibrea that connects the two hemispheres,playing an important role in coordination between the two hemispheres.However,there is currently no standard for CC morphology in clinical work in neuroimaging,both nationally and internationally.In this paper,we recruited CC-related data from typically developing volunteers and mapped the reference ranges of CC and each subregion in children of different ages and sexs in preschool,expecting to provide some reference for clinical work in paediatric imaging and provide a reference for subsequent clinical and scientific research on neurodevelopmental disorders.Methods: typically developing volunteer children aged 2~6 years were publicly recruited in Chongqing from March 2018 to March 2019,their3DT1 sequence images of brain MR were imported,CC was automatically extracted using Free Surfer software,and CC was subdivided into five subregions,and data analysis of CC and its individual subregion volumes by sex and age was performed using SPSS 22.0 statistical software.Results:In typically developing children aged 2-6 years,the posterior corpus callosum(PCC),mid-posterior corpus callosum(PMCC),middle corpus callosum(MCC),anterior-middle corpus callosum(AMCC),and total corpus callosum(TCC)showed a positive correlation with age(r =0.250,r = 0.450,r = 0.344,r = 0.257,r = 0.373,P < 0.05),while anterior corpus callosum(ACC)volume did not show a correlation with age(r =0.155,P = 0.148).The difference in volume of the subregions of the CC between the sexes at overall age(24~72 months)was not statistically significant(P > 0.05),but a comparison of the volumes of the subregions of the CC between the sexes by age group revealed that there were statistically significant differences in the volumes of the subregions of the CC between the sexes at certain ages,with statistically significant differences in the volumes of the PCC between the sexes in children aged 24-36 months,48-60 months and60-72 months(P > 0.05).Statistically significant differences existed in the volume of ACC by gender(P < 0.05)and in the TCC of the corpus callosum by sex in children aged 24 to 36 months and 48 to 60 months(P < 0.05).A range of reference values for the total volume of the CC and the volume of each subregion was plotted for different sexes and ages(95% CI for the volume of the corresponding sex for each age group was taken).Conclusions: The ACC has completed its development at 2 years of age and is relatively constant in volume,while the volumes of the other four subregions of the corpus callosum including the PCC,PMCC,MCC and AMCC remain progressively developed with age during the 2 to 6 years stage.In the study of the volume of the corpus callosum in children aged 2to 6 years,it is necessary to analyse and refer to it according to age and sex.PART II CORPUS CALLOSUM VOLUMES IN 2~4YEAR-OLD CHILDREN WITH AUTISM SPECTRUM DISORDERS: SEX-ASSOCIATED DIFFERENCESObjectives: This study aimed to analyze the relationship between sex andcorpuscallosum(CC)volume in children with Autism Spectrum Disorders(ASD)aged 2-4 years.Methods: A prospective study of 100 children including 50 children with ASDs and 50 cases with TD,and CC size measured by MRI.Also the CC was divided into five sub-regions in a mid-sagittal slice according to the Freesurfer software.Results: MPCC,AMCC and TCC volumes in ASD group was higher(MPCC: [0.39 ± 0.07] cm3 versus [0.31 ± 0.03] cm3;AMCC: [0.48 ± 0.09]cm3versus [0.40 ± 0.07] cm3;TCC: [2.71 ± 0.28] cm3 versus [2.52 ± 0.20]cm3;P < 0.05 for all)than that in TD group.No significant differences in PCC,MCC and ACC volumes(P = 0.410,P= 0.926 and P = 0.909,respectively)were observed between ASD and TD groups.The MPCC,AMCC and TCC volumes of ASD-Females were significantly higher than that of ASD-Males and TD-Females(P < 0.05),but the difference of CC size between TD-Males and TD-Females was not statistically significant(P > 0.05).There was no statistically significant difference in ACC,MCC and PCC volumes among ASD-Female,ASD-Male,TD-Female,and TD-Male(all P > 0.05).Conclusions: There may be compensatory mechanisms due to axonal overgrowth,axonal proliferation,pruning imbalance and inadequate intracerebral connectivity in children aged 2-4 years with ASD.Females myelinate faster than males,and axonal pruning,axonal elimination and proliferation may be more active in females than males during myelin formation.PART III SEXDIFFERENCES OF LANGUAGE ABILITIES IN PRESCHOOL CHILDREN WITH AUTISM SPECTRUM DISORDERS AND THEIR ANATOMICAL CORRELATION WITH BROCA AND WERNICKE AREASObjectives: Language and social interaction deficits are core symptoms of ASD and the presence of language abilities is also considered an indicator of the prognosis of children with ASD.This study aims to explore the sex differences in language ability of children with ASD and the correlation with the anatomy of Broca and Wernicke areas.Methods: The language development quotient(DQ)scores of Gesell Developmental Scale(GDS)and the scores of language communication of Childhood Autism Rating Scale(CARS)were used to judge the language ability.Structures(including surface area,cortical thickness and volume)of the language centres(Brocaand Wernicke area)on 3DT1 sequences were extracted using Freesurfer software.Correlations were made between the language abilities of children with ASD and the anatomical structures of Broca and Wernicke areas.Results: The study initially included 44 cases of ASD,with 36 males(81.8%)and 8 females(18.2%),the age range was 24 to 72 months.Males have better language abilities than females.Specifically,Analysis of differences in language brain areas including Broca and Wernicke(cortical thickness,surface and volume)by sex showed that cortical thickness in left Broca area was reduced in females compared to males(t= 3.354,P = 0.002),but there were no sex differences in surface or volume in left Broca area;surface in right Broca area was reduced in females compared to males(t =-2.178,P = 0.035),but there were no sex differences in surface or volume in right Broca area.The surface area of right Broca area was reduced in females compared to males(t =-2.178,P = 0.035),but there were no sex differences in cortical thickness and volume of right Broca area.Both surfaceand volume of the right Wernicke area were significantly greater in females than in males(surface of the right Wernicke area: t =-2.191,P =0.034;volume of right Wernicke area: t =-2.555,P = 0.014),whereas cortical thickness of right Wernicke area and volume of left Wernicke mirror area were significantly greater in females than in males.There were no sex differences in cortical thickness,surface,or volume in the right Wernicke area or in left Wernicke area.Correlation analysis of language ability and the structure of Broca and Wernicke areas showed that GDS language DQ was positively correlated with cortical thickness in Broca area of the left side of the brain,but negatively correlated with surface in the right Broca area and surface and volume in the right Wernicke area(all P < 0.05),while GDS language DQ was correlated with.No significant correlations were found between cortical thickness,surface and volume in the Wernicke area on the left side of the brain with CARS language level 4,whose cortical thickness was lower in the Broca area on the left side of the brain than in language levels 2 and 3(5.76 ± 0.17 mm vs 6.21 ± 0.30 mm & 6.11 ±0.35 mm,all P < 0.05),and in right Broca area,whose surface was higher than the language level for levels 2 and 3(2706.80 ± 340.95mm2 vs 1947.73± 467.50mm2& 2091.18 ± 550.35mm2,both P < 0.05),while the cortical thickness in Wernicke area on the right side of the brain was also lower than the language level for levels 2 and 3(21.61 ± 1.13 mm vs 22.80 ± 1.01mm& 22.65 ± 1.10 mm,both P < 0.05).Conclusions: Female preschoolers with ASD have significantly lower language abilities than males of the same age,possibly related to reduced cortical thickness in Broca area.The presence of lateralized development in Broca’s area in children with ASD supports the theory of language lateralization;it is important to focus not only on the dominant hemisphere,but also on the non-dominant hemisphere.Differences in language ability in children with ASD are mainly in Broca area,while structural differences in Wernicke area are not significant. |
PDF Full Text Request