Kinesiological evaluation of respiration in patients with Parkinson’s disease using optoelectronic plethysmography
Aspiration pneumonia, a common cause of mortality in patients with Parkinson’s disease (PD), is associated with impaired coughing ability in addition to dysphagia. Kyphosis, bradykinesia, and muscle rigidity reportedly may be involved in the decline of coughing ability; however, the details are unknown. This study aimed to investigate the respiratory impairment that causes the decreased coughing ability in patients with PD using a three-dimensional motion analysis and surface electromyography in terms of respiratory pattern and respiratory muscle activity. The participants were seven patients with PD without history of respiratory or spinal diseases, and seven healthy men of age and matched for body mass index. Using optoelectronic plethysmography, the participants were placed in a sitting posture, and the volume changes of the upper and lower thorax and abdomen were measured during quiet breathing and during deep breathing in the same manner as in the measurement of lung capacity. Surface electromyograms (EMG) were recorded from the second intercostal muscle, the rectus abdominis muscle, and the external oblique abdominal muscle. The normalized EMG data were divided into inspiratory and expiratory times, and the inspiratory and expiratory times were divided into four equal parts over time to examine the trend of changes in muscle activity during deep breathing. In the patients with relatively unadvanced PD, no significant differences from the control in the amount of change in the angle of the spinal column during deep breathing, ratio of each compartment of the chest wall during deep breathing, whereas abdominal compartment was dominant in patients with PD during quiet breathing, and no significant difference in asynchrony between the chest and abdomen was observed. The PD group did not demonstrate increased respiratory muscle activity toward the end of inspiration and expiration, which was observed in the control group. Although the respiratory patterns of the thorax and abdomen in the PD group, whose disease has not relatively progressed, are not different from those of the control group, a significant difference was observed on the EMG, and it is possible that the respiratory muscles could not be effectively utilized according to the inspiratory and expiratory conditions from an early stage.