DTI Assessment Of Brain White Matter Structural Changes In Parkinson's Disease Patients

Background and purposeParkinson's disease(PD)is a chronic neurodegenerative disease in the elderly with a morbidity which is only second to Alzheimer's disease.Its clinical manifestations mainly include motional symptoms such as quiescent tremor,motor retardation,myotonia,postural gait disorder,and non-motor symptoms for instance olfactory disorder,visual disorder,gastrointestinal dysfunction,sleep disorder,mental disorder and constipation.The primary features of pathological changes are egeneration and death of substantia nigra dopaminergic neurons and reduction of striatal dopamine transmitters which occurred in the substantia nigra striatum system.Parkinson's disease patients can not be cured and reversed.Early symptoms of patients are relatively hidden and it takes about five years from the beginning of pathological changes to the latency of clinical symptoms.Late patients are prone to lose self-care ability,which causes serious psychological and physiological burden to patients themselves,families and society.In recent years,with the development of functional magnetic resonance imaging(fMRI),some studies have confirmed that the pathological changes of PD not only exist in the substantia nigra striatum system,but also involve white matter fibers,resulting in changes in brain morphology and a series of complex clinical symptoms.Diffusion tensor imaging(DTI)is a new diffusion imaging technology in recent years,which can display the information of the microstructure,morphology and density of white matter fibers without trauma.The diffusion parameters consist of fractional anisotropy(FA),mean diffusion coefficient(MD),axial diffusivity(AD)and parallel diffusion coefficient(RD)reflect their tiny structure and changes by quantifing white matter fibers.In this study,the tract-based spatial statistics(TBSS)method were used to analyze the whole brain DTI data of PD patients and healthy volunteers,so as to explore the change of white matter microstructure and the potential relationship between white matter structural damage and clinical indicators in Parkinson's disease patients,so that to further revealed the changes of white matter microstructures in PD patients.Materials and methodsA total of 160 patients with Parkinson's disease in the Department of Neurology,First Affiliated Hospital of Zhengzhou University(including 79 males and 81females),and 99 normal controls matched for age and sex were collected.All the measurements consisting of conventional MRI sequences and DTI sequences were carried out by Prisma 3.0 T magnetic resonance scanner.The DTI data were pre-tested by TBSS,and the age and gender were used as covariates to perform statistical tests on patients with Parkinson's disease and the control group.SPSS 17.0software was used to analyse the different results,The Spearman was carried out to investigate clinical course,UPDRS total score,H-Y classification and olfactory test score.The test level ? was 0.05.1.Use DTI sequence axial scan.2.Measurements were evaluated by Hoehn-Yahr(H-Y)classification,Unified Parkinson's Disease Rating Scale(UPDRS),and olfactory reagent.3.Using TBSS analysis method composed of the data preprocessing,nonlinear registration,skeleton mapping,skeleton statistics,generating statistical difference map based on skeleton mapping,etc,to extract the diffusion index values in thedifference map.4.Statistical analysis: The general linear model of FSL was performe to study two-sample t-test independently,which used FA values,MD values,AD values,and RD values of diffusion parameters to compare patients with Parkinson's disease and healthy controls.We use SPSS 17.0 statistical softwar to investigate the diffusion index of abnormal fiber bundle skeleton and clinical course,UPDRS total score,H-Y classification and olfactory test score was analyses by Spearman.The test level ?value was set to 0.05 during each statistical analysis(the difference possess statistical significance when P < 0.05).Results1.Compared with control group,Parkinson's disease in the cerebellum,pons interchanges,corpus callosum knee,volume and pressure,on both sides before corona radiata,fornix,corticospinal tract,medial lemniscus,cerebellum and waste on foot,on both sides corona radiata,cerebral peduncle,bilateral internal capsule forelegs and hind legs,the part after the bilateral internal capsule of the lens,bilateral thalamus after radiation(including radiation),the longitudinal beam and under the pillow,external capsule on both sides,bilateral cingulate,fornix(CRES)/final lines,double lientang corona radiata,longitudinal fasciculus,pillow beam,beam hook,tapetum multiple cerebral white matter area a FA value lower(p < 0.05).Corpus callosum knee(r = 0.158,p = 0.047),the right side of the internal capsule forelimbs(r= 0.244,p = 0.002),the right side of the former radial(r = 0.209,p = 0.008),the left side of the former radial(r = 0.235,p = 0.003),on the right side of the thalamus(including radiation)after radiation(r = 0.177,p = 0.025),the right side of the outer capsule(r = 0.221,p = 0.005),the right side of the hook beam(r = 0.166,p = 0.036)in the brain and negatively correlated with the clinical course of FA value;FA values in the genu of corpus callosum(r=-0.158,p=0.047),left external capsule(r=-0.244,p=0.002),left superior frontal occipital tract(r=-0.209,p=0.008)were negatively correlated with the total score of UPDRS.Fornix(r=-0.164,p=0.038),right posterior radiated crown(r=-0.174,p=0.028),left anterior internal capsule(r=-0.193,p=0.015),left posterior thalamic radiation(including optical radiation)(r=-0.158,p=0.046),left external capsule(r=-0.177,p=0.025),right lateral fornix(CRES)/terminal stria(r=-0.184,p=0.020),left superior frontal occipital bundle(r=-0.288,p=0.000),right tapetal layer(r=-0.170,P =0.032)FA values of these brain regions were negatively correlated with h-y classification.FA values in the left uncinate tract(r=0.161,p=0.042)were positively correlated with olfactory test scores.2.Compared with control group,the foot in the cerebellum in patients with Parkinson's disease pons cross road,on both sides before corona radiata,corpus callosum knee,volume and pressure,the vault,bilateral corona radiata,corticospinal tract,medial lemniscus,cerebellum and waste on foot,cerebral peduncle,bilateral internal capsule forelegs and hind legs,the part after the bilateral internal capsule of the lens,double lientang corona radiata,the longitudinal beam and under the pillow,bilateral ectocyst,bilateral cingulate cortex,hippocampus,fornix(CRES)/end grain,bilateral thalamus after radiation(including radiation),on the longitudinal fasciculus,pillow beam,hook,tapetum multiple cerebral white matter area appears the MD value(p < 0.05).The anterior limb of the right internal capsule(r=0.253,p=0.001),the right anterior radial crown(r=0.179,p=0.024),the right external capsule(r=0.240,p=0.002),the left external capsule(r=0.159,p=0.045),and the right hook bundle(r=0.165,p=0.037)were positively correlated with the clinical course.MD values of the fornix(r=-0.176,p=0.026),left internal capsule forelimb(r=-0.182,p=0.021),left external capsule(r=-0.167,p=0.034),and left hook bundle(r=-0.170,p=0.031)were negatively correlated with olfactory test scores.3.Compared with control group,Parkinson's disease and pressure in the corpus callosum knee and body,both sides before corona radiata,fornix,the left side of the corticospinal tract,bilateral corona radiata,on the left side of the cerebral peduncle,bilateral internal capsule forelegs and hind legs,the part after the bilateral internal capsule of the lens,the longitudinal beam and under the pillow,external capsule on both sides,bilateral cingulate,double lientang corona radiata,fornix(CRES)/end lines,and the longitudinal fasciculus,pillow beam,bilateral thalamus after radiation(including radiation),hook,the right side of the tapetum multiple cerebral white matter district in AD value(p < 0.05).AD values in these brain regions werepositively correlated with clinical course.AD values in the corpus callosum(r=-0.176,p=0.026)and the left posterior extremity of internal capsule(r=-0.165,p=0.039)were negatively correlated with the total score of UPDRS.AD values of these brain regions were positively correlated with UPDRS(r=0.164,p=0.037).Body part of corpus callosum(r=-0.179,p=0.023),pressor part of corpus callosum(r=-0.219,p=0.005),fornix(r=-0.211,p=0.008),right anterior limb of internal capsule(r=-0.171,p=0.030),left anterior limb of internal capsule(r=-0.196,p=0.013),left posterior capsule(r=-0.190,p=0.029),right cingulate gyrus(r=-0.307,p=0.000).AD values in the left cingulate gyrus(r=-0.234,p=0.003)and the left superior longitudinal tract(r=-0.200,p=0.011)were negatively correlated with olfactory test scores.4.Compared with control group,Parkinson's disease and pressure in the corpus callosum knee and body,both sides before corona radiata,fornix,corticospinal tract,cerebellum on foot,cerebral peduncle,bilateral corona radiata,bilateral internal capsule forelegs and hind legs,the part after the bilateral internal capsule of the lens,the longitudinal beam and under the pillow,outside capsule on both sides,bilateral cingulate cortex,hippocampus,thalamus on both sides after radiation(including radiation),fornix(CRES)/end lines,and the longitudinal fasciculus,pillow beam,double lientang corona radiata,hook,tapetum RD value on multiple cerebral white matter(p < 0.05).The RD values of the right anterior capsule(r=0.276,p=0.000),the right anterior capsule(r=0.209,p=0.008),the left anterior capsule(r=0.167,p=0.035),the right external capsule(r=0.224,p=0.004),the left external capsule(r=0.169,p=0.032),and the right hook bundle(r=0.178,p=0.025)were positively correlated with the clinical course.Left external capsule(r=0.162,p=0.040)the RD values of these brain regions were positively correlated with the total score of UPDRS.Left internal capsule forelimb(r=0.171,p=0.031),right external capsule(r=0.155,p=0.050),left external capsule(r=0.183,p=0.020),right tapetal layer(r=0.176,p=0.026).The brain region RD values of the forelock(r=-0.163,p=0.039),left internal capsule forelimb(r=-0.160,p=0.043)and left hook bundle(r=-0.206,p=0.009)were positively correlated with olfactory test scores.Conclusions1.Parkinson's disease patients have extensive white matter injury,mainly manifested in the corpus callosum,fornix,anterior radiation corona,upper radiation corona,posterior radiation corona,internal capsule,external capsule,posterior thalamic radiation,uncinate tract and other brain areas,FA value decreased,MD,AD,RD value increased.2.The FA,MD,AD and RD values of different brain regions in Parkinson's disease patients were correlated with clinical course,UPDRS total score,H-Y grade and olfaction test score,which indicated that the changes of white matter structure affected the function of corresponding brain regions.