單次有氧運動對於青少年注意力不足過動症之大腦神經生理及執行功能之介入成效

Abstract

研究背景：注意力不足過動症（ADHD）是一種常見的兒童神經發展障礙症，影響全球約5%的人口。青少年ADHD患者常見執行功能缺損，特別是抑制控制、工作記憶和認知規劃。過去研究已發現神經生理與執行功能缺損之間存在相關性，但較少文獻使用可間接檢測GABA和麩氨酸活性的非侵入性經顱磁刺激術（TMS）來探討GABA和麩氨酸等神經傳導物質對於執行功能的影響。有氧運動已被證實對ADHD患者的神經生理和執行功能有益處。然而，鮮有研究同時探討有氧運動對青少年ADHD患者神經生理和執行功能的影響，並探討經有氧運動後兩者間的可能關係。 研究目的：本研究結合TMS和執行功能任務，探討單次有氧運動對青少年ADHD患者神經生理和執行功能的影響。此外，探討休息狀態下的神經生理和執行功能之間的關聯，以及經單次有氧運動後神經生理和執行功能的變化是否存在相關性。 研究方法：本實驗共招募12名青少年ADHD患者，隨機分配到有氧運動（AE）組和對照組。他們在進行20分鐘的有氧運動或對照干預前後接受TMS和執行功能任務評估。TMS用於評估皮質興奮性，而CANTAB軟體中的停止訊號測試（SST）、空間工作記憶（SWM）任務和劍橋河內塔（SOC）任務分別用來評估抑制控制、工作記憶和認知規劃能力。使用2因子混合模型ANOVA比較組間（有氧運動 vs. 對照）和組內（前測 vs. 後測）差異，並用皮爾森相關係數探討休息狀態下神經生理數據與執行功能之間以及單次有氧運動後神經生理數據與執行功能變化量之間的相關性。 研究結果：在神經生理方面，單次有氧運動後活動運動閾值（AMT）顯著降低(p=0.014)。在執行功能方面，組間（有氧運動 vs. 對照）和組內（前測 vs. 後測）比較中無顯著差異。在基線相關性方面，短間隔皮質內抑制（SICI）與停止試驗中的錯誤次數（DES）呈顯著正相關（r=0.647，p=0.031），皮質內促進（ICF）與執行試驗中的錯誤次數（DEG）和DES分別呈顯著正相關（r=0.604，p=0.049和r=0.662，p=0.026）。在單次有氧運動後神經生理和執行功能變化的相關性分析，SICI與DES變化量呈顯著負相關（r=-0.914，p=0.011）。SICI與總錯誤變化量呈臨界顯著正相關（r=0.794，p=0.059）。 結論：儘管本研究中單次有氧運動未顯示對青少年ADHD患者的神經生理和執行功能有顯著影響，但神經生理與執行功能之間的相關性可能表明執行功能缺損歸因於影響皮質興奮性的神經傳導物質，如興奮性麩氨酸或抑制性GABA。本研究可為了解青少年ADHD患者執行功能缺損（如抑制控制和工作記憶）與其神經生理過程之間的關聯性提供一些實證應用。

Backgrounds: Attention-deficits/hyperactivity disorder (ADHD) is a common childhood neurodevelopmental disorder affecting 5% of the population around the world. Executive function deficits are common in adolescents with ADHD, especially inhibitory control, working memory, and cognitive planning. Previous studies have found a relationship between neurophysiology and executive function deficits, though limited literature has examined the impacts of neurotransmitters like GABA and glutamate on executive functions using non-invasive transcranial magnetic stimulation (TMS), which could indirectly detect the activation of GABA and glutamate. Aerobic exercise has beneficial effects on neurophysiology and executive functions in ADHD. However, there is little research exploring the effects of aerobic exercise on the neurophysiology and executive functions simultaneously and investigating the possible association between them in adolescents with ADHD. Purpose: This study would combine TMS and executive function tasks to explore the effects of a single bout of aerobic exercise on neurophysiology and executive functions in adolescents with ADHD. Besides, the association between baseline neurophysiology and executive functions and the changes in neurophysiology and executive functions following a single bout of aerobic exercise would be investigated. Methods: 12 adolescents with ADHD were recruited and randomly allocated into aerobic exercise (AE) group and control group. They were assessed by TMS and executive function tasks before and after a 20-minute single bout of aerobic exercise or a control intervention. TMS was used to assess cortical excitability, and the Stop signal test (SST), Spatial working memory (SWM) task, and Stockings of Cambridge (SOC) task in CANTAB software were chosen to examine the inhibitory control, working memory, and cognitive planning respectively. 2-way mixed model ANOVA was applied to compare both between-group (aerobic exercise vs. control) and within-group (pre-test vs. post-test) differences, and Pearson's correlation coefficient (r) was employed to explore the correlation between baseline neurophysiological data and executive functions and the changes in neurophysiological data and executive functions following a single bout of aerobic exercise. Results: Regarding the neurophysiology, there was a significantly lower active motor threshold (AMT) after a single bout of aerobic exercise (p=0.014). Concerning the executive functions, there were no significant differences in between-group (aerobic exercise vs. control) and within-group (pre-test vs. post-test) comparisons. Regarding the baseline correlation, there was a significant positive correlation between the short interstimulus interval intracortical inhibition (SICI) and direction errors: stop trial (DES) (r=0.647, p=0.031), and a significant positive correlation between the Intracortical facilitation (ICF) and direction errors: go trial (DEG) (r=0.604, p=0.049) and DES (r=0.662, p=0.026). Concerning the correlation between changes in neurophysiology and executive functions following a single bout of aerobic exercise, there was a significant negative correlation between the change in SICI and the change in DES (r=-0.914, p=0.011). There was a borderline significant positive correlation between the change in SICI and the change in total errors (r=0.794, p=0.059). Conclusion: Although a single bout of aerobic exercise didn’t show significant effects on the neurophysiology and executive functions in adolescents with ADHD in this study, the correlation between the neurophysiology and executive functions might indicate that executive function deficits are attributed to cortical excitability influenced by neurotransmitters like excitatory glutamate or inhibitory GABA in such a population. This study might provide some clinical application for understanding the association between executive function deficits, such as inhibitory control and working memory, and its underlying neurophysiological processes in adolescents with ADHD.