任務導向有氧運動訓練對慢性中風患者心肺適能及腦血流之效果

Abstract

研究背景及目的：有氧運動訓練對於慢性中風患者心肺適能之效益已有許多文獻證實，同時少部份文獻以功能性運動訓練指出中風後腦血流改善，然而給予功能性的任務導向有氧運動訓練對於慢性中風患者之效益則尚未有足夠之證據。故本研究目的在探討任務導向有氧運動訓練對慢性中風患者心肺適能、功能評量、身體活動及腦血流之效益與其相關性。方法：收入40位第一次缺血性中風超過6個月之患者，以修正Rankin中風等級評量及性別進行隨機分層分組（運動組、控制組），運動組給予12週任務導向有氧運動訓練，控制組不額外給予運動介入，僅每週電話問安鼓勵維持日常活動，並了解活動情形。運動介入前後分別進行症狀限制最大運動測試、六分鐘行走距離、10公尺行走測試（自選行走速度）、經顱都卜勒超音波腦血流測試，同時回答Rivermead移動指數、工具性日常生活活動評量及身體失能者活動評量表。本研究以SPSS 11.5（SPSS Inc., Chicago, USA）套裝軟體做統計分析，有效水平標準定義為雙尾檢定p<0.05，以獨立t檢定及卡方檢定比較兩組基準值之差別，以二維混合變異數分析比較兩組於運動測試、功能評量及身體活動等參數之差異，以年齡、性別及休息時平均血壓為共變數，利用2×2二維混合共變數分析比較兩組於腦血流差異，以淨相關係數分析各依變項改變量之間的相關性。結果：兩組受試者除一些合併症與呼吸交換率在前測值有顯著差異外，其餘各參數在前測值均無顯著差異。最大攝氧量、最大氧脈、最大每分鐘換氣量、六分鐘行走距離、自選行走速度及健側前大腦動脈血流速有顯著交互作用。Rivermead移動指數、身體活動量、健側內頸動脈血流速、血流量與健側顱外血流總量在運動組有組內差異。淨相關性分析顯示，自選行走速度改變量與工具性日常生活活動評量（r=0.469）、身體活動（r=0.676）、最大攝氧量（r=0.503）、最大氧脈（r=0.573）、最大每分鐘換氣量（r=0.649）之改變量有中度相關，最大功率改變量與患側前大腦動脈血流速改變量也有高度負相關（r=-0.800）。結論：慢性中風患者接受任務導向有氧運動訓練確實可改善心肺適能與行走能力，腦血流在健側局部區域（前大腦動脈流域）有顯著改善。腦血流之改善同時與心肺適能之進步存在相關性。

Background and purpose: Aerobic exercise training has beneficial effects on cardiorespiratory fitness in chronic stroke patients. Some studies have indicated that functional exercise training, known as the task-oriented exercise, improved cerebral blood flow. However, the effects of task-oriented aerobic exercise training on chronic stroke patients were unknown. The study was designed to investigate the effects of task-oriented aerobic exercise training on cardiorespiratory fitness, functional performance, physical activity, cerebral blood flow in patients with chronic stroke, and the association between the changes of measured outcomes. Methods: Patients with chronic ischemic stroke (post-stroke duration > 6 months) were recruited and assigned to exercise intervention group or control group by the stratified randomization according to the gender and severity of stroke. The intervention group underwent task-oriented aerobic exercise training for 12 weeks, while control group was asked to maintain regular physical activities by weekly telephone checks. Outcome measures included variables in a symptom-limited exercise test, 6-minute walk distance, selective walking speed from a 10-meter walk test, Rivermead mobility index (RMI), instrumental activity of daily living scale (IADL), physical activity scales for individuals with physical disabilities (PASIPD) and Doppler measurements before and after 12 weeks. All statistical analyses were performed by SPSS 11.5 (SPSS Inc., Chicago, USA). A two-tailed p value less than 0.05 were considered statistically significant. Independent t test and chi-square test were used to compare baseline data between two groups. A mixed model ANOVA was used to compare the exercise capacity, functional performance and physical activity between groups across time. A 2×2 two-way ANCOVA was performed to analyze the cerebral blood flow between two groups with age, gender and resting mean blood pressure as covariates. The relationships between changes of outcomes were analyzed by partial correlation coefficient. Results: There were no significant group differences in baseline data except comorbidity and respiratory exchange ratio derived from the exercise test. Significant interaction was noted in variables of peak oxygen consumption, peak oxygen pulse, peak minute ventilation, 6 minute walk test, selective walking speed and mean blood flow velocity of anterior cerebral artery in non-affected hemisphere. In addition, participants in exercise group showed significant time main effect without interaction in RMI, PASIPD, mean flow velocity and flow volume of internal carotid artery in non-affected hemisphere, and total flow volume of extracrainial arteries in non-affected hemisphere after 12 weeks. The change of selective walking speed moderately correlated with the change of IADL (r=0.469), PASIPD (r=0.676), peak oxygen consumption (r=0.503), peak oxygen pulse (r=0.573), and peak minute ventilation (r=0.649). Moreover, the change of peak workload and the change of mean flow velocity of anterior cerebral artery in affected hemisphere showed moderate negative correlation as well (r=-0.800). Conclusion: Task-oriented aerobic exercise training improved cardiorespiratory fitness, ambulatory capacity and cerebral blood flow of specific region (territory of anterior cerebral artery in non-affected hemisphere) in our chronic stroke patients. The improvement in cerebral blood flow demonstrated significant correlation with the improvement in cardiorespiratory fitness.