This study aimed to clarify whether the relationship between neural mechanisms and the degree of improvement in upper extremity paralysis differs by region of the upper extremity.
The subjects were 18 chronic stroke patients (age 65.4 ± 9.0 y, 70.2 ± 38.4 months post-stroke). The intervention involved repetitive facilitative exercise under continuous electrical stimulation for 6 weeks at 100 min per day. Motor function was assessed using the Fugl-Meyer Assessment (FMA) pre and post the intervention, with the difference between the two measurements defined as the intervention effect. In this study, the upper extremity FMA was classified into three categories: total score (upper extremity FMA), score for wrist and hand items (distal FMA), and score for items excluding distal and coordination functions (proximal FMA). DTI was used for brain imaging evaluation. DTI was conducted using the Ingenia 3.0T CX Duo (PHILIPS) and Intelli Space Portal analysis software, with imaging performed during the hospitalization period. The region of interest (ROI) was set manually in the midbrain cerebral peduncle with a FA threshold of 0.2. The Mann-Whitney U test was used for the intervention effects of the upper extremity, distal, and proximal. Associations between rFA and pre-FMA, change in distal FMA, and change in proximal FMA from pre- to post-intervention were compared using Spearman's rank correlation coefficient. Partial correlation analysis was conducted using pre-FMA as a control variable to examine the relationship between rFA and change in distal and proximal FMA. Partial correlation analysis was conducted using pre-FMA as a control variable to examine the relationship between rFA and change in distal and proximal FMA.
The intervention led to significant improvements in both upper extremity FMA score, distal, and proximal FMA (p0.05). A correlation between motor function and rFA was found between upper extremity FMA and rFA (ρ=0.84, p0.05) as well as between changes in distal FMA and rFA (ρ=0.77, p0.05). However, the correlation between changes in proximal FMA and rFA (ρ=0.34, p=0.15) was not significant. Partial correlation analysis revealed a correlation between changes in distal FMA and rFA (r =0.50, p0.05), but no significant correlation was observed between changes in proximal FMA and rFA (r=-0.19, p=0.45).
Regardless of the FMA pre-intervention, we observed a moderate correlation between changes in the distal region and rFA, unlike the proximal region. This suggests that rFA changes in distal function may be more closely related to than changes in proximal function.
Even in patients with low FA, the possibility that proximal paralysis may improve, unlike distal paralysis, could be useful in guiding treatment decisions.
chronic stroke
upper extremity motor function
