Abstract

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease, in which impaired cough is common. Cough effectiveness is generally assessed by measuring Peak Cough Flow (PCF); ALS patients, however, are often unable to perform Respiratory Function Tests (RFT) including PCF. Ultrasound (US) can detect Diaphragmatic Expiratory Excursion (DEE), providing a reliable indirect estimate of the efficacy of cough in these patients.

The current state-of-the-art confirms that US evaluation of DEE predicts cough peak flow in healthy adults.

Diaphragmatic US could be used as an indication for the use of the In-Exufflator cough assist machine in ALS patients, whose excursion and thickness of the diaphragm are compromised.

21 patients with ALS and a control group of 25 healthy subjects were enrolled. RFT, PCF and expiratory excursion of the right hemidiaphragm were performed for each patient during cough.

The expiratory excursion of hemidiaphragm was lower among patients with ALS. Linear regression analysis demonstrated significant correlations:

A) between PCF and DEE in patients with ALS and in controls;

B) in all subjects, between Peak Expiratory Flow and DEE;

C) between Maximum Expiratory Pressure and DEE.

US evaluation of DEE proved to be a valid alternative to PCF in both ALS and healthy subjects. It’s simple, non-invasive, requires less cooperation and is useful for patients unable to perform conventional tests.