Preliminary Study Of Diffusion Tensor Imaging And Strategically Acquired Gradient Echo Imaging In The Pathogenesis Of Essential Tremor

Objective:Psychology and tremor scales were used to evaluate the clinical characteristics of essential tremor(ET),diffusion tensor imaging(DTI)and strategically acquired gradient echo(STAGE)imaging were used to analyze the differences in the parameters of the brain nuclei between ET patients and normal control group in order to provide support for the study of the pathological changes and pathogenesis of ET,help early clinical diagnosis of ET and improve the quality of life.Materials and Methods:31 patients with ET confirmed by the neurologist and 34 normal controls matched with age and gender were prospectively included.All subjects were evaluated by the professional neurologist on the Hamilton Anxiety Rating Scale(HAMA),Hamilton Depression Rating Scale(HAMD),Pittsburgh Sleep Quality Index(PSQI)and Fahn-Tolosa-Marin Tremor Rating Scale(FTMTRS)before magnetic resonance imaging(MRI).All subjects underwent MRI on a 3T magnetic resonance scanner.The MR protocol included conventional MRI,DTI and STAGE.The images were transmitted to a post-processing workstation for data processing as follows:1.With reference to the conventional image,bilateral red nucleus,substantia nigra and dentate nucleus of ET and normal control group were delineated manually on the apparent diffusion coefficient(ADC)map,the regions of interest were duplicated to fractional anisotropy(FA)and mean diffusivity(MD)maps,the FA,MD,ADC values of these brain structures were measured.2.The regions of interest containing bilateral red nucleus,substantia nigra,dentate nucleus and globus pallidus were manually drawn on the T2*map according to the susceptibility weighted imaging processed from the STAGE sequence.The T2*values of these structures were measured.SPSS 22.0 software was used to statistically analyze the obtained scale scores and the values of the brain nuclei,P<0.05 was considered as a statistical difference.Result1.Compared with normal control group,the scores of HAMA(16.45±8.43 vs 12.76±9.19),HAMD(8.77±8.38 vs 4.03±4.35)and PSQI(5.48±4.17 vs 3.12±1.85)in ET patients were higher,and the differences between the two groups were statistically significant(P=0.041,P=0.026,P=0.017;all P<0.05).The incidence of anxiety(61.29%vs 32.35%),depression(41.93%vs 11.76%)and sleep disorder(38.71%vs 14.71%)in ET patients was higher than that in the control group,and there were statistical differences between the two groups(P=0.042,P=0.005,P=0.028;all P<0.05).2.Statistical results showed that the red nucleus of ET patients had higher ADC values than the normal control group(0.79±0.02 vs 0.77±0.03),the dentate nucleus of ET patients had lower FA values than the normal control group(0.32±0.03 vs 0.37±0.03).Both parameters were statistically different(P=0.008,P<0.001).Although MD values of the dentate nucleus in ET was slightly higher than that in the control group(0.81±0.03 vs 0.79±0.05),there was no statistical difference(P=0.142>0.05),and the FA,MD,and ADC values of the substantia nigra between the two groups were not statistically different(all P>0.05).3.The T2*values of dentate nucleus(25.94±1.79 vs 28.32±1.79)and globus pallidus(26.00±1.93 vs 28.23±1.41)in ET patients were significantly lower than those in the control group,and there were statistical differences between the two groups(both P<0.001).Although the T2*value of substantia nigra in ET patients had a decreasing trend compared with the control group(26.37±1.88 vs 27.34±2.12),no statistical difference was found between the two groups.(P=0.056>0.05).4.No significant correlations were found among the disease course,HAMA,HAMD,PSQI,FTMTRS scores and the FA,MD,ADC,T2*values in each region of interest of patients(all P>0.05).5.The receiver operating characteristic curve results showed that the area under curve(AUC)of the FA value in the dentate nucleus was a maximum of 0.847,the sensitivity and specificity of diagnosis were 76.47%,and 77.42%in the single parameter.The AUC of the T2*value in the dentate nucleus was 0.823,the sensitivity and specificity were 70.59%?80.65%,respectively.After combining the FA value and T2*value of the dentate nucleus,the AUC would be further improved to 0.905,with sensitivity and specificity of 79.41%?83.87%,respectively.Conclusion1.The neuropsychological scales show that ET patients are more likely to be associated with anxiety,depression,and sleep disorder than normal people.2.The DTI could reflect the differences in the ADC value of red nucleus,FA value of dentate nucleus between ET patients and the control group,which may provide the theoretical basis for the research on the pathogenesis of ET.3.STAGE,as a new type of magnetic resonance imaging technology,could show the differences in the T2*values of dentate nucleus and globus pallidus between ET patients and the normal control group,which may be helpful for revealing the pathophysiological changes of ET.4.In the comparison between ET patients and normal control,the combination of FA value and T2*value of the dentate nucleus is the most effective for the differential diagnosis,which can help the diagnosis and evaluation of ET.5.New magnetic resonance technology will have broad application prospects in the pathogenesis research,diagnosis and detection of ET in the future.