Expiratory muscle strength training improves measures of pressure generation and cough strength in a patient with myotonic dystrophy type 1.

ABSTRACT

Expiratory muscle strength training (EMST) exercise programmes aim to improve respiratory function by increasing the force generating capability of expiratory muscles by resistance training. In neuromuscular conditions, in which cough flow generation is often decreased, there is increasing interest in EMST as a therapeutic intervention. We present data showing efficacy of EMST in a patient with adult onset Myotonic Dystrophy Type 1 (DM1). A domiciliary training programme (5 days per week over 32 weeks) resulted in increases in maximum expiratory mouth pressure (from 15 cmH2O to 38 cmH2O) and peak cough flow (300 L/min to 390 L/min). Improvements were also seen in maximum inspiratory mouth pressure (26 cmH2O to 52 cmH2O) and sniff nasal inspiratory pressure (40 cmH2O to 69 cmH2O). No changes were detected in speech or swallowing. This novel study demonstrates that cough flow generation in DM1 may be increased by a programme of expiratory muscle training. A clinical trial of EMST in DM1 is warranted.