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 15cmH 2 O to 38cmH 2 O) and peak cough flow (300L/min to 390L/min). Improvements were also seen in maximum inspiratory mouth pressure (26cmH 2 O to 52cmH 2 O) and sniff nasal inspiratory pressure (40cmH 2 O to 69cmH 2 O). 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.

Inspiratory Muscle Training in Nemaline Myopathy

“…Both MIP and SNIP assess inspiratory muscle strength, but in the current study IMT only showed an improvement of MIP. This is in contrast with previous studies reporting an effect of respiratory muscle training on SNIP [40,48,49]. SNIP evaluates diaphragm strength more specifically than MIP, as demonstrated in previous studies where SNIP generated higher transdiaphragmatic pressures than MIP [50,51].…”

Neuromuscular rehabilitation – what to do?

“…Another case study investigated 32 weeks of expiratory respiratory training with a patient with myotonic dystrophy type-1 (Table 1) [12]. Improvements in expiratory mouth pressure and peak cough flow, along with maximum inspiratory and sniff nasal pressures were observed.…”