步態訓練後進行有氧運動對於促進帕金森氏症患者行走表現之效果

Abstract

背景：步態障礙為帕金森氏症患者常見的動作症狀。臨床上，步態訓練為改善帕金森氏症患者異常步態的主要方式。然而，由於動作學習能力的受損，帕金森氏症患者需要更高的訓練劑量才能達到臨床上有意義的進步量。因此，找到可以促進帕金森氏症患者動作學習的方法對於臨床復健是相當重要的。有氧運動已被證實可以促進健康人的動作學習能力，且背後的神經生理機制已被廣泛討論，但目前尚未有研究探討長期的動作技巧學習加上有氧運動對於帕金森氏症患者動作表現的效果。此外，也尚未有研究探討相關的神經生理變化。 研究目的：探討步態訓練後進行有氧運動對於帕金森氏症患者行走表現以及皮質興奮程度的效果。 研究方法：本研究為一單盲隨機控制試驗，召募了原發性帕金森氏症患者並隨機分配至有氧運動組或傳統物理治療組。每位受試者皆接受了12次的治療介入（每次一小時，每週2到3次）。每次治療的前30分鐘為跑步機步態訓練，接續5分鐘的地上步態訓練。步態訓練後，有氧運動組使用固定式腳踏車進行25分鐘的中等至高強度有氧運動，傳統物理治療組則進行25分鐘的傳統物理治療。主要的結果評量為步態參數，包括行走速度、步幅及步頻，並且會分別在單一與雙重任務情境下進行評估；次要的結果評量則包括統一帕金森氏症評定量表的動作功能部分 (UPDRS-III)、計時起走測試 (Timed Up-and-Go test)、五次坐站測試 (Five-Time Sit-to-Stand test)、六分鐘行走測試 (6-minute walking test)、蒙特利爾認知評估 (Montreal Cognitive Assessment)、帕金森病人生活品質量表 (Parkinson’s Disease Questionnaire)及皮質興奮程度變化。受試者於介入前 (前測)、完成12次介入後 (後測)、以及介入結束後一個月 (追蹤測試) 進行結果評量。 結果：本次實驗共召募了30位受試者，其中28位完成了介入以及追蹤測試。經過12次的治療介入後，有氧運動組與傳統物理治療組在單一任務行走的速度 (p < 0.001) 及步幅 (p < 0.001)、雙重任務行走的速度 (p = 0.014) 及步幅 (p = 0.018)皆有進步。兩組在步態表現的變化上沒有差異。在次要結果評量上，兩組在統一帕金森氏症評定量表的動作功能部分、計時起走測試、五次坐站測試以及蒙特利爾認知評估皆有明顯的進步，且兩組之間無顯著差異。至於皮質興奮程度在介入後的變化，兩組在任一評量時間點皆沒有顯著的改變，亦沒有組間差異。然而，有氧運動組在介入後皮質抑制性的增加程度高於最小可偵測變化值，顯示出長期進行有氧運動可能可以將皮質興奮程度正常化。由於並非所有在有氧運動組的受試者都有達到目標心跳，我們另外進行了次群組分析以了解運動強度的影響。結果發現有達到40%以上儲備心率的受試者在單一任務行走速度的進步程度高於沒有達到40%儲備心率的受試者。雖然因為樣本數太小而沒有統計上的顯著差異，步態表現在組別與時間的交互作用上具有中等程度的效果值。 結論：在步態訓練後加入有氧運動並沒有比加入傳統物理治療更為有效，只有能夠達到中等運動強度以上的受試者會因為加入有氧運動有更好的訓練效果。由於有氧運動對於動作學習的效果會受到運動強度的影響，以有氧運動作為促進步態訓練的方法不一定適合每一位帕金森氏症患者。因此，復健計畫仍需要考量個別狀況以達到最佳的治療效果。

Background: Gait disability is a common motor symptom in people with Parkinson’s disease (PD), and gait training is the major approach to ameliorate gait disorders. Due to impairment in motor learning, people with PD tend to require higher repetitions of practice to achieve clinical meaningful improvement. Therefore, finding methods to facilitate motor learning may be helpful to enhance rehabilitation effects in people with PD. Aerobic exercise has been shown to improve motor learning in non-disabled adults, and the associated neurophysiological mechanisms have been well-demonstrated. Whether adding aerobic exercise after gait training for multiple sessions can facilitate gait performance in people with PD has not been investigated. Additionally, the associated neurophysiological mechanisms have not been established. Study purpose: To determine the effects of adding aerobic exercise after gait training on walking performance and corticomotor excitability changes in people with PD. Methods: This study was a single-blinded randomized control trial. People with idiopathic PD were recruited, and randomly assigned into the aerobic exercise (AEX) group or conventional physical therapy (CPT) group. Participants received 12 sessions of intervention (1 hour/session, 2 to 3 sessions/week). The intervention started from 30-minute treadmill gait training and 5-minute overground gait training. After that, the AEX group performed moderately high-intensity aerobic exercise for 25 minutes, and the CPT group received conventional physical therapy for 25 minutes. The primary outcome was gait performance, which included gait velocity, stride length and cadence under the single-task and dual-task conditions. Secondary outcomes included the motor subscale of Unified Parkinson’s Disease Rating Scale (UPDRS-III), Timed Up-and-Go (TUG) test, Five-Time Sit-to-Stand test (FTSST), 6-minute walking test (6MWT), Montreal Cognitive Assessment (MoCA), Parkinson’s Disease Questionnaire (PDQ-39), and corticomotor excitability changes. The outcomes were assessed before the intervention (pre-test), after 12 intervention sessions (post-test), and one month after the interventions (follow-up test). Two-way mixed repeated measure analysis of variance (ANOVA) was used to compare the changes of outcome measures in both groups after intervention. Results: Thirty participants were recruited into the study, and 28 of them have completed all the intervention sessions and the follow-up test. After intervention, both groups showed significant improvement in gait velocity (p < 0.001) and stride length (p < 0.001) under the single-task condition, and also in gait velocity (p = 0.014) and stride length (p = 0.018) under the dual-task condition. There were no significant group differences in the change of gait performances. For the secondary outcomes, both groups showed significant improvements in the UPDRS-III, TUG test, FTSTS and MoCA without significant group differences. As for the corticomotor excitability, there were neither significant changes within the groups nor group differences found at different assessment time points. However, the changes in corticomotor inhibition (i.e., cortical silent period) in the AEX group exceeded the minimal detectable change reported in previous studies, which suggested a potential normalization of corticomotor excitability after long-term aerobic exercise. Since not every participant in the AEX group achieved the prescribed aerobic level during training, additional subgroup analysis was performed to determine whether the achieved exercise intensity would influence the results. The participants who achieved 40% or higher HRR during exercise seemed to have greater improvement in gait performances than those who did not achieve 40% HRR after intervention. Although there was no significant group difference due to the small sample size, the group by time interaction in gait velocity and stride length reached moderate effect size. Conclusions: Our results showed that adding aerobic exercise after gait training was not more effective than conventional physical therapy. It was found that only the participants who were able to achieve moderate or higher intensity of aerobic exercise during training could benefit from the program. Since the effects of aerobic exercise on motor learning may be influenced by exercise intensity, applying aerobic exercise to facilitate gait training may not benefit every participant with PD. Therefore, personalized rehabilitation program is needed to optimize the treatment effects.