121 CEREBRAL ADAPTATION ASSOCIATED WITH PERIPHERAL NERVE RECOVERY IN NA 6 Results There were no significant group differences in age (t(25) = -0.84, p = 0.41), sex (χ2(1) = 0.05, p = 0.82), or disease characteristics at baseline (time since last attack: U = 75.00 z = -0.64 p = 0.54; persistent pain: U = 62.00 z = -1.64 p = 0.20; SRQ-DLV: t(25) =-0.90, p = 0.38), see Table 1. There was an overall learning effect from baseline to follow for the task: across groups, patients made significantly fewer errors at follow-up (3.3% ± 3.3%) compared to baseline (6.2% ± 5.2%) (TIME: F(1,25) =25.16, p < 0.001, part. η2 = 0.50), and tended to be faster (TIME: F(1,25) = 3.71, p = 0.07, part. η2 = 0.13). Main hypothesis tests Task-related cerebral activity Neither the whole brain analysis, nor the ROI-analyses revealed any significant group differences in change in activity between baseline and follow-up for the main contrast of interest (no GROUP x TIME x LATERALITY interaction for contrast right > left, complex trials only). Interestingly, there was a significant two-way interaction between TIME and LATERALITY in the parieto-occipital sulcus ROI, independent of GROUP. Specifically, across both groups, NA patients showed a significant increase in brain activity from baseline to follow-up when performing imagery of biomechanically complex movements with their affected limb, compared to their unaffected limb (right > left, complex trials only). This increase was observed in five sub-clusters within the parieto-occipital sulcus ROI (see Figure 3D and Supplementary Table 3). When we included biomechanically easy trials, we found similar results as above in the whole brain analysis: there was no significant three-way interaction with GROUP, but there was a significant interaction between TIME and LATERALITY. Specifically, NA patients showed a significant increase in activity from baseline to follow-up when performing imagery with their affected limb, compared to their unaffected limb, in four clusters within the occipito-parietal cortex. Three sub-clusters were located in the right, ipsilateral dorsal visual stream (two in the superior lateral occipital cortex and one in the extrastriate cortex), and one cluster in the left cuneus, partly overlapping with the parieto-occipital sulcus ROI) (see Figure 3E and Supplementary Table 3). Behavioral task performance We found no significant three-way GROUP x TIME x LATERALITY interactions for ERs (F(1,25) = 1.48, p = 0.23, part. η2 = 0.06) or RTs (F(1,25) = 0.004, p = 0.95, part. η2 ≤ 0.001). Similar to the cerebral activity, we did find a significant two-way TIME x LATERALITY interaction for ERs (F(1,25) = 5.11, p = 0.03 part. η2 = 0.17; see Figure 3C). Specifically, post-hoc testing revealed that ERs for complex trials decreased for both the affected (F(1,26) = 17.58, p < 0.001, part. η2 = 0.40) and unaffected (F(1,26) = 5.53, p = 0.03, part. η2 = 0.18) limb from baseline to follow-up, but the significant interaction effect indicates that this decrease was significantly greater for the affected limb.
RkJQdWJsaXNoZXIy MjY0ODMw