Activation of the Prefrontal Cortex Is Associated with Exertional Dyspnea in Chronic Obstructive Pulmonary Disease

作者：Higashimoto Yuji^*; Honda Noritsugu; Yamagata Toshiyuki; Matsuoka Toshiki; Maeda Kazushige; Satoh Rhyuji; Nishiyama Osamu; Sano Hiroyuki; Iwanaga Takashi; Miyara Takayuki; Muraki Masato; Tomita Katsuyuki; Kume Hiroaki; Miyai Ichiro; Tohda Yuji; Fukuda Kanji

来源：Respiration, 2011, 82(6): 492-500.

DOI：10.1159/000324571

• Chronic obstructive pulmonary disease
• Dyspnea
• Exercise
• Near-infrared spectroscopy

Background: 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. Objectives: To investigate the activation of cortical areas associated with dyspnea during exercise in COPD patients. Methods: 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 (oxyHb), deoxyhemoglobin (deoxy-Hb), and total hemoglobin (total Hb) concentrations from baseline recordings were measured. Increased oxy-Hb (oxygenation) was assumed to reflect cortical activation. Results: 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 oxyHb 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. Conclusions: Exertional dyspnea was related to activation (oxygenation) of the prefrontal cortex in COPD patients and control subjects.

• 出版日期2011