Expiratory Muscle Strength Training in ALS: Maintaining Respiratory Function and Improving Quality of Life

Abstract

Background: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects voluntary muscle movement. As the disease progresses, patients with ALS may have trouble with a variety of motor functions, including rapid decline in forced vital capacity (FVC) causing increased respiratory insufficiency including dysphagia leading to higher risks for aspiration pneumonia and mortality. Expiratory muscle strength trainer (EMST) is a device used to target the muscles involved in the oral and pharyngeal phases of swallowing including expiratory muscles. The device can help increase the strength and endurance of these muscles, which can lead to improved swallowing function and decreased risk of aspiration therefore, the purpose of the study was to assess for sustainability of cough effectiveness, decrease rapid decline of FVC and for any decrease in the risk of dysphagia leading to respiratory complications.

Methods: FVC measurements and swallow assessments for patients diagnosed with ALS were made prior to ordering EMST device. Patients with FVC measurements > 50% with good swallow and cough efforts, were ordered lower pressure, EMST75 Lite. Participants were instructed to use EMST75 Lite: five breath sets of breath for a total of 25 training breaths with a minute break between each set for five weeks. Patients were switched to a maintenance program of training three days a week using the final pressure setting achieved in week five of initial training. FVC measurements and swallow assessments were conducted within 3 to 6 months after initial administration of EMST75 Lite to confirm outcomes.

Results: 80% of the patients did not experience a significant decline in FVC. The average decline in FVC within 3 to 6 months was at 2%. 20% of the patients had slightly improved FVC measurements. All patients (100%) demonstrated good cough efforts and subjectively reported zero decline in their cough strength. 80% of the patients reported sustained swallow efforts while the remaining 20% reported taking cautionary measures when swallowing.

Conclusions: EMSTs can help increase strength and endurance of oropharyngeal muscles including diaphragm and abdominal muscles leading to improved swallow function and decreased risk of aspiration. Regular use of the EMST can also result in sustained cough and decrease in rapid decline of FVC in patients diagnosed with ALS.