DTI Research On Optic Radiation In Patients With Multiple Sclerosis And Neuromyelitis Optica

PART 1 THE STUDY OF DTI IN BILATERAL OPTIC RADIATION IN RELAPSING-REMITTING MULTIPLE SCLEROSISObjective: To investigate the correlations between visual impairment and bilateral optic radiation in relapsing-remitting multiple sclerosis(RRMS) by diffuse tensor imaging(DTI).Methods: 25 cases RRMS patients with visual impairment and 25 cases age- and sex- matched healthy volunteers received DTI. Bilateral optic radiation were measured the fractional anisotropy(FA) value and mean diffusivity(MD) value, all RRMS patients were evaluated by the expanded disability status scale(EDSS). The results were evaluated by the SPSS 17.0, on Both sides of the FA value and MD value both the RRMS patients and healthy controls were analyzed by paired t test, respectively.the bilateral optic radiation FA values and MD values between the patients and the control group were analyzed by two sample t test, respectively.Results: The bilateral optic radiation FA value( t = 0.41, P = 0.68; t= 0.09, P = 0.92) and MD value( t = 0.72, P = 0.48; t = 0.20, P = 0.84)both patients and the control group were not significantly different( P >0.05), respectively. Both sides of optic radiation FA values( t = 8.29, P =0.00; t = 8.42, P = 0.00) were significantly decreased than that of the normal control group; the MD values( t = 7.17, P = 0.00; t = 6.58, P =0.00) were significantly higher than that of the normal control group( P <0.05). There were not correlations between both FA( r =-0.244, P = 0.30;r =-0.133, P = 0.58) and MD( r = 0.160, P = 0.50; r = 0.307, P = 0.19)values of bilateral optic radiation and EDSS scores( P > 0.05).Conclusion: There is a correlation with the white matter fiber bundle damage in the bilateral optic radiation of the visual impairment in patients with RRMS; DTI can provide image help for understanding the pathological mechanism of the visual impairment in patients with RRMS.PART 2 THE STUDY OF DTI IN BILATERAL OPTIC RADIATION IN RELAPSING-REMITTING MULTIPLE SCLEROSIS AND RELAPSING NEUROMYELITIS OPTICAObjective: To investigate whether there are differences in diffusion tensor imaging(DTI) indexes between relapsing-remitting multiple sclerosis(RRMS) and relapsing neuromyelitis optica(RNMO) in the apparent normal optic radiation by DTI.Methods: 20 cases RRMS and RNMO patients and 20 cases ageand sex- matched healthy volunteers received DTI.Fractional anisotropy(FA) value and mean diffusivity(MD) value was acquired on bilateral optic radiation individually., and all RRMS and RNMO patients were evaluated by the expanded disability status scale(EDSS). We compared FA and MD value of bilateral optic radiation in each group using t test.We compared FA and MD value of bilateral optic radiation between each patient group and normal control group using one-way analysis of variance(one-way ANOVA) and Dunnett-t test. To evaluate the association between DTI value and EDSS score we used Spearman. All statistical analyses were conducted using SPSS 17.0.Results:(1)In each group, The bilateral optic radiation FA value(t =0.41, P = 0.68; t = 0.10, P = 0.92; t = 0.63, P = 0.54)and MD value(t =0.72, P = 0.48; t = 0.20, P = 0.84; t = 0.20, P = 0.84) were not significantly different(P > 0.05), respectively.FA value(P = 0.00; P = 0.00) of bilateral optic radiation in patient group was significantly lower than normal control group, while MD value(P = 0.00; P = 0.00) was significantly higher than normal control group(P < 0.05). FA value(P = 0.02) in RNMO patients was decreased than that of the RRMS patients, but the MD value(P = 0.50)was not significantly different.(2)There were not correlations between both FA(r =-0.19, P = 0.42; r = 0.20, P = 0.41) and MD(r = 0.11, P = 0.64; r=-0.33, P = 0.15) values of bilateral optic radiation and EDSS scores(P >0.05) in RRMS and RNMO.Conclusions: The appearing-normal optic radiation of both RRMS and RNMO patients was involved, but the involvement degree was not consistent in the two groups. FA value has potential applications to identify MS and NMO, as an important biological indicator for monitoring clinical course progress.