作業優先性對巴金森氏症患者於雙重作業重心轉移訓練之影響

Abstract

研究背景與目的: 姿勢-上姿勢雙重作業之定義為執行一個姿勢作業時，同時執行另一項任務(上姿勢作業)。適當的注意力資源分配是雙重作業執行之關鍵。巴金森氏症患者因注意力資源不足與動作自動化能力下降，造成雙重作業表現不佳。近期研究指出，使用適當的作業優先性可促進巴金森氏症患者雙重作業表現。但目前仍無研究探討使用不同作業優先性，對於雙重作業訓練的影響。此外，重心轉移能力缺損亦是巴金森氏症患者平衡不佳的重要原因，但重心轉移尚未被結合至雙重作業訓練。本篇研究目的為探討作業優先性(姿勢優先、上姿勢優先)對巴金森氏症患者於雙重作業重心轉移訓練之影響，其學習效果將由行為表現與大腦活動改變進行探討。 研究方法: 本研究共招募28位巴金森氏症患者，受試者們隨機分配至姿勢作業優先組(14人)和上姿勢作業優先組(14人)，進行雙重作業訓練。訓練時，姿勢作業優先組將主要的注意力配置於重心轉移(姿勢作業)；而上姿勢作業優先組則將主要的注意力配置於托盤旋轉動作(上姿勢作業)。本訓練為一次性訓練，受試者須進行六回合、每回合六次的雙重作業練習。評估的時間點分別為訓練前測、立即後測、二天後之延遲測試、三週後之延遲測試。評估項目包含雙重作業行為表現、功能前伸與側伸測試(包含往前、往症狀較嚴重側、往症狀較輕微側)、腦電圖參數。 研究結果：經雙重作業重心轉移訓練後，姿勢優先組與上姿勢優先組在重心轉移與托盤旋轉精準度均有進步，且此進步情況可持續至三週後之延遲測試。特別的是，於重心轉移精準度上，姿勢優先組在訓練後的立即後測比起上姿勢優先組有更多的進步量；然而，雖然上姿勢優先組在訓練後的立即後測進步量較少，但在二週後的延遲測試時，比起立即後測、二天後之延遲測試有更佳的精準度。功能前伸測試中，在側伸向症狀較嚴重邊的表現於兩組都有顯著進步。而大腦活動結果顯示，相較於前測，兩組的alpha頻帶強度有均有顯著上升；此外，上姿勢優先組在兩次延遲後測時比起姿勢優先組，均有較大的theta頻帶強度。 結論與重要性: 本篇研究藉由神經電生理、行為數據來瞭解作業優先性對於雙重作業訓練的影響。其結果發現一天性的雙重作業種新轉移訓練，其訓練效果可持續至三週後，此外，使用上姿勢優先學習策略，有較佳的延遲進步效果。本實驗除了是首篇結合重心轉移與雙重作業訓練之研究，其結果也可提供臨床巴金森氏症患者雙重作業訓練指引。

Background and Purpose: The postural-suprapostural dual task is defined as performing a postural task with an additional task (suprapostural task). Appropriate resource allocation is one of the critical factors for dual-task control. Due to insufficient resource capacity and impaired motor automaticity, patients with Parkinson’s disease (PD) have more dual-task interference than the healthy population. Recently, studies have shown performing the postural-suprapostural task with proper task prioritization can enhance the performances under dual-task contexts. However, how task prioritization affects dual-task training has not been investigated. In addition, weight-shifting has not been acted as the postural component of dual-task training paradigms. The purpose of this study is to investigate the effect of task prioritization on dual-task weigh shifting training in PD. Methods: Twenty-eight subjects with idiopathic PD were recruited and randomly assigned to the postural-focus (PF) or suprapostural-focus (SF) dual-task training groups. There were 14 participants in the PF group, and 14 participants in the SF group. During training, the PF group has to focus on weight-shifting (postural task); and the SF group has to focus on a tray-rotating movement (suprapostural task). Dual-task behavioral performances (postural error and suprapostural error), distance of functional reach tests (forward reach and lateral reach) and brain activities recorded by electroencephalogram were recorded in pre-test, immediate post-test, 2-days retention test and 3-weeks retention test. Results: After dual-task weight-shifting training, both postural error and suprapostural error decreased in the PF and SF groups. Although the PF group had smaller postural error than the SF group at immediate post-test, the postural error of SF group decreased at 3-weeks retention test relative to immediate post-test and 2-days retention test. The distance of functional reach toward more affected side increased in both groups. For brain activity, increased alpha power was observed at immediate post-test in both groups. In addition, the SF group had greater theta power at 2-days retention test and 3-weeks retention test than the PF group. Conclusion and Significance: This study was the first study to integrate weight-shifting in dual-task training in PD. In addition, this study provided neurophysiological and behavioral evidence of the interaction between task prioritization and dual-task training. With SF learning strategy, patients with PD had better delayed gains in postural learning relative to PF learning strategy. Based on study results, we could provide appropriate guidance of dual-task training for PD in clinic.