Defective Motor Control of Coughing in Parkinson's Disease

Publisher Website
Google Scholar
Abstract
The high incidence of serious chest infections in patients with Parkinson's disease is unexplained, but an impairment in cough reflex may have a role. Maximal voluntary cough (MVC) and reflex cough (RC) to inhalation of ultrasonically nebulized distilled water were analyzed in patients with Parkin- son's disease and age-matched control subjects by monitoring the integrated electromyographic ac- tivity (IEMG) of abdominal muscles. The peak amplitude of IEMG activity (IEMG P ) was expressed as a fraction of the highest IEMG P value observed during MVC corrected to account for possible losses in abdominal muscle force due to reduced central muscle activation. Cough intensity was indexed in terms of both the IEMG P and the ratio of IEMG P to the duration of the expiratory ramp (T EC ), i.e., the rate of rise of IEMG activity. Cough threshold was slightly higher in patients than in control subjects, but the difference failed to reach statistical significance. Compared with control subjects, patients displayed a lower IEMG P during maximal expiratory pressure maneuvers (P Emax ), MVC, and RC (p al- ways , 0.01); T EC during RC was longer (p , 0.01) than in controls. Consequently, the rate of rise of IEMG activity during cough was always lower in patients (p , 0.01), especially during RC. Finally, P Emax , and both the peak and rate of rise of IEMG activity during RC were inversely related to the level of clinical disability (Spearman rank correlation coefficient, r s 5 2 0.88, 2 0.86, and 2 0.85, respec- tively, p always , 0.01). The results indicate that the central neural mechanisms subserving the re- cruitment of motor units and/or the increase in their frequency of discharge during voluntary and, even more markedly, RC are impaired in patients with Parkinson's disease. Fontana GA, Pantaleo T, Lavorini F, Benvenuti F, Gangemi S. Defective motor control of coughing in Parkinson's dis- ease.

This publication has 19 references indexed in Scilit: