Department of Rehabilitation Medicine, Kinki University, Faculty of Medicine, Osaka, Japan.
Respiration. 2011;82(6):492-500. doi: 10.1159/000324571. Epub 2011 Apr 7.
Exertional dyspnea is the primary symptom that limits exercise in patients with chronic obstructive pulmonary disease (COPD). It is unknown which activated brain area is associated with this symptom in COPD patients.
To investigate the activation of cortical areas associated with dyspnea during exercise in COPD patients.
COPD patients (n = 10) and age-matched controls (n = 10) performed mild-intensity constant work rate cycle exercise (40% of their symptom-limited peak work rates) for 10 min, while cerebral hemodynamics and oxygenation were measured by near-infrared spectroscopy (NIRS). Ventilatory responses (breathing pattern and pulmonary gas exchange) and Borg scale ratings of dyspnea and leg fatigue were measured during exercise. Three NIRS probes were placed over the prefrontal and temporoparietal cortical regions of the subjects' heads. Changes in cortical oxyhemoglobin (oxy-Hb), deoxyhemoglobin (deoxy-Hb), and total hemoglobin (total Hb) concentrations from baseline recordings were measured. Increased oxy-Hb (oxygenation) was assumed to reflect cortical activation.
Oxy-Hb concentration was significantly increased in the prefrontal region during exercise in both groups but not in the temporoparietal regions. The change in prefrontal oxy-Hb concentration of COPD patients was not different from that of controls. Dyspnea scores were positively correlated with changes in oxy-Hb concentrations of the prefrontal regions in both groups. Multivariate analysis showed that oxy-Hb concentration in the prefrontal region was the best predictor of dyspnea in both groups.
Exertional dyspnea was related to activation (oxygenation) of the prefrontal cortex in COPD patients and control subjects.
运动性呼吸困难是慢性阻塞性肺疾病（COPD）患者限制运动的主要症状。目前尚不清楚 COPD 患者中哪个被激活的大脑区域与该症状相关。
探讨 COPD 患者运动性呼吸困难时相关皮质区的激活情况。
10 例 COPD 患者和 10 例年龄匹配的对照者进行轻度等强度恒功自行车运动（40%的症状限制峰值工作率），10 min 期间测量近红外光谱（NIRS）脑血流动力学和氧合。运动期间测量通气反应（呼吸模式和肺气体交换）和呼吸困难及腿部疲劳的 Borg 量表评分。将三个 NIRS 探头置于受试者头部的前额和颞顶皮质区。测量从基线记录中得出的皮质区氧合血红蛋白（oxy-Hb）、脱氧血红蛋白（deoxy-Hb）和总血红蛋白（total Hb）浓度的变化。假设 oxy-Hb 浓度增加（氧合）反映皮质激活。
两组患者在运动期间前额区的 oxy-Hb 浓度均显著增加，但颞顶区没有增加。COPD 患者前额区 oxy-Hb 浓度的变化与对照组无差异。呼吸困难评分与两组前额区 oxy-Hb 浓度变化呈正相关。多变量分析显示，前额区 oxy-Hb 浓度是两组呼吸困难的最佳预测因子。
运动性呼吸困难与 COPD 患者和对照者的前额皮质激活（氧合）有关。
