Clinical Manifestations And MRI Profiles Of Children With Language Disorder

PART Ⅰ CLINIC MANIFESTATIONS AND GENERALMRI PROFILES OF CHILDREN WITH LANGUAGEDISORDERObjective: To explore the pathogenesis or relevant factors andclinical charecteristics of children language disorder, combining withgeneral MRI profiles to provide the bases for early diagnosis andtreatment.Methods: A total of243children who saw a doctor for languagedisorder were collected from our hospital. All children have undergoneroutine neurological examination and MRI. Every one’s Language levelwas assessed by 《Early Language Milestone Scale》, PCDI, DSM-IV-TR,and IQ by WISC or Gesell according to different ages.Results: Ages were from1.5to14years. The medical histories werenegative history（163cases）,absence of language environment （5cases）,hearing deficits（1case）,tongue movement impairment（1case）, HIE（17cases）, preterm birth（11cases）, bilirubin encephalopathy（5cases）,intrauterine infection（2cases）,hypertension of pregnancy （2cases）, epilepsy（2cases）, father having language delay （1case）, autism diagnosisedfirstly（12cases）,unknown history（21cases）.Excluding hearing deficits（1case）,tongue movement impairment（1case）, autism（8cases） andepilepsy（2cases）, the percentage ratios of different age range childrenamonge231were2.6%（1.5-2years,6case）,29.4%（2.1-3years,71case）,1.6%（3.1-4years,53cases）,17.3%（4.1-5yeas,41cases）,10%（5.1-6years,24cases）,9%（>6years,47cases）, male77.1%（178cases）, female22.9%（53cases）. Themain comorbidity are dyskinesia（78cases,33.8%）, mental retardation（45cases,18.5%）, both of them（38cases,16.5%）. The others are113cases（48.9%）without or with mental retardation（IQ≥70）,no special history andnegative neurological profiles,among them92cases（81.4%）preschoolchildren（≤6years） and21cases（18.6%）children（﹥6years）。General MRIshowed frontal and temporal lobe atrophy bilaterally（68case,29.4%）,cerebral atrophy （10cases,4.3%）,cerebellar atrophy(6cases,2.6%, corpuscallosum dysgenesis （12cases,5.2%）, abnormal white matter myelination（8cases,3.5%）,others（14cases,6.1%）, negative MRI（113,48.9%）. All datawere analyzed by SAS9.13software, stastistical significance was set atp<0.05.Conclusion:（1）The pathogenesis or relevant factors of childrenlanguage disorder presented complexity and diversity,including unknownaetiology.（2）Language disorder in preschool children was the mostcommon among the children, especially between2to4years，also the high ratio of male children reflected in every age range.（3） The maincomorbidity were dyskinesia and mental retardation, while developmentallanguage disorder also accounted for higher percentage, particularly inpreschool children.（4）General MRI revealed the abnormal structural brainfrom developmental and secondary factors in children with languagedisorder. Obvious findings were frontal and temporal atrophy bilaterally,suggesting that language disorder during the growth period was mainlyduo to language areas dysfunction. But negative MRI in most childrenwith language disorder were also observed。 PART Ⅱ A voxel-based morphometry study of brainstructure in preschool children with developmental languagedisorder（DLD）Objective: To study the difference of the brain structure between thepreschool children with DLD and the typically developing age-matchedcontrol children by VBM, and further to explore the neural bases oflanguage disorder.Methods:21preschool boys with DLD（age range2-6.2years,average4.4years） and20age-matched control boys （age range2-6.4years,average4years）participated in the study.all of them wereright-handed without neurological symptoms and signs by routine examination. A diagnosis of DLD was according to the DSM-IV-TR,and intelligence quotient≥70by WISC or Gesell，and the absence ofhearing loss, primary social or emotional problems, environmentaldeprivation, autism, or other specific neurological diagnoses.Controlchildren were typically developing children who had normal IQ（IQ≥85）and normal language scores on standardized tests. All children haveundergone routine and high-resolution3D-T1WI MRI examination. Thedata were assessed using the optimized VBM with DARTEL.The datapreprocessing was conducted with Statiscal Parametric Mapping （SPM8）software package on a Matlab R2010a platform, including normalizing,segmenting, modulating and smoothing. All these images-processed werestatistically analyzed automatically by SPM. We compared the differencesof the brain structure in gray density, gray and white matter volume ofwhole brain between2groups. Statistical parametric maps werethresholded at an FDR-corrected voxel-wise threshold of p<0.05, andonly the clusters with no less than50voxels were reported.Results: Relative to controls, The DLD group showed thoses, asfollows:（1）decreased gray matter volume in the Precuneus_L, Angular_Land Temporal_Mid_L, also density in Angular_L, Occipital_Mid_R,Precuneus_L, Hippocampus_L, Cingulum_Mid_L, Supp_Motor_Area_L,Cingulum_Ant_L, Fusiform_L, Parahippocampus_L, Amygdala_L,Fusiform_R, Precentral_R, Cerebelum_Crus1_R, Cerebelum_45L, and increased gray matter density in Frontal_Sup_R, Temporal_Mid_R,Frontal_Sup_Orb_R, Rolandic_Oper_R, Insular_L, Frontal_Inf_Oper_L,Temporal_Inf_R,Frontal_Sup_Medial_R,Frontal_Sup_L, Cerebelum_8R.（2）decreased white matter volume in Frontal_Sup_R,Frontal_Mid/Inf_L,Frontal_Sup_L, Frontal_Sup_Orb_R, and increased inTemporal_Mid_L, Angular_L,Temporal_Sup_R,Precuneus_L.Conclusion:（1） The preschool children with DLD had wide range ofbrain structural abnormality, which presented obviously decreased graymatter density and volume in the left cerebral hemisphere conforming tohemispheric language dominance in children with right-handness.（2） Theincreased gray matter density mainly in the right cerebral hemispheresuggested the right compensatory function, part of which was not the lefthomologous region. Perhaps, the compensation was regulated via otherneural circuit, also declaring the brain plasticity.（3） The cerebelparticipated in the language adjustment, and the cross covariantrelationship between the right cerebel and the left front lobe was alsodemonstrated.（4） Abnormal bilateral hemispheric gray matter densityprevailingly involved the limbic system located in the frontal and temporallobe which were just the language areas，while the limbic system primarilyregulates the emotion, hinting that there is a potential commonneuroanatomical basis between emotion and language adjustment. A newneural basis was put forward from the study of brain structure by imaging. Namely, abnomal limbic brain structure resulted in positive and negativeemotion disorders in preschool children having negative mood chiefly,affecting healthy mood and mental state for normal language development,which may be the one of the reasons leading to DLD in preschool children.Meanwhile, language disorder influenced emotion adjustment, whichpossiblely induced the structural abnormality in the areas of emotionadjustment, and even contributing to psychiatric and neurologicaldisorders.（5） Wide range of decreased gray matter density in the lefthemisphere of the posterior peri-Sylvian areas and multi-gyrus located intemporal lobe, especially the Angular gyrus complicated by decreasedgray matter density and volume evidently, which meaned that the leftWernicke areas abnormality leading to language perception andacquisition ablity down, together with the Angular gyrus of comprehensivelanguage ability down caused the DLD in preschool children.（6） Normalinferior frontal gyrus of pars triangularis bilaterally which was the motorspeech area，and increased gray matter density in the left pars opercularisimplied the expressive language unimpaired，likely being of the potentialrecovery capability. Clinic observation also affirmed that part of childrenwith language disorder displayed obvious catching-up effect viaintervention, and early intervention will evidently reduce the short andlong-term effect because of language disorder.