Rehabilitation of Swallowing and Cough Functions Following Stroke: An Expiratory Muscle Strength Training Trial

Objective To determine the effect of expiratory muscle strength training (EMST) on both cough and swallow function in stroke patients. Design Prospective pre-post intervention trial with 1 participant group. Setting Two outpatient rehabilitation clinics. Participants Adults (N=14) with a history of ischemic stroke in the preceding 3 to 24 months. Intervention EMST. The training program was completed at home and consisted of 25 repetitions per day, 5 days per week, for 5 weeks. Main Outcome Measures Baseline and posttraining measures were maximum expiratory pressure, voluntary cough airflows, reflex cough challenge to 200μmol/L of capsaicin, sensory perception of urge to cough, and fluoroscopic swallow evaluation. Repeated measures and 1-way analyses of variance were used to determine significant differences pre- and posttraining. Results Maximum expiratory pressure increased in all participants by an average of 30cmH2O posttraining. At baseline, all participants demonstrated a blunted reflex cough response to 200μmol/L of capsaicin. After 5 weeks of training, measures of urge to cough and cough effectiveness increased for reflex cough; however, voluntary cough effectiveness did not increase. Swallow function was minimally impaired at baseline, and there were no significant changes in the measures of swallow function posttraining. Conclusions EMST improves expiratory muscle strength, reflex cough strength, and urge to cough. Voluntary cough and swallow measures were not significantly different posttraining. It may be that stroke patients benefit from the training for upregulation of reflex cough and thus improved airway protection.