Fig. 2
Tract-based spatial statics analysis: A correlation analysis between diffusion tensor imaging scalars and electrophysiological data. Correlation analysis adjusted for age, sex, and disease duration between electrophysiological data and diffusion tensor imaging (DTI) scalars was performed using tract-based spatial statistics analysis. (A) The split-hand index (SHI) was positively correlated with the AD value on the ipsilateral and contralateral sides of the posterior limb of the internal capsule (PLIC), cerebral peduncle (CP), anterior corona radiata (ACR), superior corona radiata (SCR), external capsule (EC), body of the corpus callosum (BCC), and middle cerebellar peduncle (pFWE−corrected<0.05). In addition, SHI positively correlated with MO values on both the ipsilateral and contralateral sides of the PLIC, CP, and superior cerebellar peduncle (SCbP). (B) The compound muscle action potential (CMAP) amplitude of the abductor pollicis brevis (APB) was positively correlated with AD and MO values on the ipsilateral and contralateral sides of the PLIC (pFWE−corrected<0.05). (C) The CMAP amplitude of the first dorsal interosseous (FDI) muscle was positively correlated with the FA value in the ipsilateral and lateral sides of the PLIC (pFWE−corrected<0.05); the AD value in the ipsilateral and contralateral sides of the PLIC, MCbP, ACR, SCR, and BCC (pFWE−corrected<0.05); and the MO value in the ipsilateral and contralateral sides of the PLIC, SCbP, and SCR (pFWE−corrected<0.05). (D) The CMAP amplitude of the abductor digiti minimi (ADM) was positively correlated with the AD value in the ipsi- and contra-lateral side of the PLIC and ipsilateral SCR (pFWE−corrected<0.05), and MO value in the contra-lateral side of PLIC (pFWE−corrected<0.05). Abbreviations: FA, fraction anisotropy; AD, Axial diffusivity; MO, mode of anisotropy; TFCE, Threshold-Free Cluster Enhancement; FWE, the familywise error; SHI, split-hand index; APB, abductor pollicis brevis; FDI, first dorsal interosseous; ADM, abductor digiti minimi; PLIC, posterior limb of internal capsule; CP, cerebral peduncle, ACR, anterior corona radiata; SCR, superior corona radiata; MCbP, middle cerebellar peduncle; EC, external capsule; BCC, body of corpus callosum.
