Diaphragm ultrasound in the diagnosis of respiratory dysfunction in patients with amyotrophic lateral sclerosis

Diaphragm ultrasonography as a tool in assessing respiratory muscle involvement in amyotrophic lateral sclerosis/motor neuron disease

“…Significant reductions of DT i ( p < 0.0001) and DT e ( p < 0.001) values were observed in ALS/MND patients as compared to healthy controls, 8 as also reported by others 9 . Highly significant ( p < 0.0001) correlations were found between DUS parameters (particularly, the ΔDT i–e ) and spirometric data (primarily FVC), especially in ALS/MND patients with a bulbar‐onset 8 .…”

“…11,12 Significant reductions of DT i (p < 0.0001) and DT e (p < 0.001) values were observed in ALS/MND patients as compared to healthy controls, 8 as also reported by others. 9 Highly significant (p < 0.0001) correlations were found between DUS parameters (particularly, the ΔDT i-e ) and spirometric data (primarily FVC), especially in ALS/MND patients with a bulbar-onset. 8 Interestingly, significant (p < 0.001) correlations were also observed between ΔDT i-e and clinical scoresaccording to the revised ALS Functional Rating Scale, ALSFRS-R 14 -mainly in bulbar-onset patients.…”

“…4 Diaphragm ultrasonography (DUS) provides an useful and risk-free tool for functional assessment of respiratory muscle weakness. [5][6][7][8][9] Different measuring methods have been used, and the site for DUS changes among studies: for instance, some Authors used the space between the mid-axillary and antero-axillary lines, 7,8 whereas others explored the area between the mid-clavicular and anterior axillary line 10 or that one between the mid-axillary and the posteroaxillary lines. 11 Changes in diaphragm thickening (DT) measured as: (a) the difference (ΔDT i-e ) between DT at the end of inspiration (DT i ) and DT at the end of expiration (DT e ); (b) the ratio (DT i /DT e ) between DT i and DT e ; (c) the so called thickening fraction ΔDT i ([(DT i À DT e /DT e ] Â 100); and (d) the ratio (ΔDT max = V t DT i /TLC DT i ) between DT i at the end of tidal volume (V t ) and DT i after maximal inspiration up to total lung capacity (TLC) have been determined in various studies.…”

“…11 Changes in diaphragm thickening (DT) measured as: (a) the difference (ΔDT i-e ) between DT at the end of inspiration (DT i ) and DT at the end of expiration (DT e ); (b) the ratio (DT i /DT e ) between DT i and DT e ; (c) the so called thickening fraction ΔDT i ([(DT i À DT e /DT e ] Â 100); and (d) the ratio (ΔDT max = V t DT i /TLC DT i ) between DT i at the end of tidal volume (V t ) and DT i after maximal inspiration up to total lung capacity (TLC) have been determined in various studies. 8,9,11 According to previous data, ΔDT i < 20% 12,13 and ΔDT max > 0.75 (75% sensitivity and 85% specificity in identifying subjects with forced vital capacity [FVC] values lower than 50% of the predicted value) are considered thresholds for diaphragmatic dysfunction. 11,12 Significant reductions of DT i (p < 0.0001) and DT e (p < 0.001) values were observed in ALS/MND patients as compared to healthy controls, 8 as also reported by others.…”

“…In patients suffering from amyotrophic lateral sclerosis/motor neuron disease (ALS/MND) respiratory failure is an unavoidable step along illness progression 1–3 and a common cause of death 4 . Diaphragm ultrasonography (DUS) provides an useful and risk‐free tool for functional assessment of respiratory muscle weakness 5–9 …”