Assessment of diaphragmatic thickness by ultrasonography in Duchenne muscular dystrophy (DMD) patients

Abstract

IntroductionIn Duchenne muscular dystrophy (DMD) the assessment of diaphragmatic function is crucial because respiratory muscle weakness can cause respiratory failure. We aimed to noninvasively assess diaphragmatic function in DMD by measuring diaphragmatic thickness by ultrasonography, under the hypothesis that the progressive decrease of lung function is related to alterations of diaphragmatic thickness.MethodsForty-four DMD patients and thirteen healthy controls were enrolled and subdivided into three age groups. Diaphragmatic thickness was measured during quiet breathing, inspiratory capacity, maximal inspiratory pressure and expiratory pressure maneuvers.ResultsIn DMD, absolute values of diaphragmatic thickness were significantly lower than in controls in the majority of the manoeuvers and diaphragmatic thickness significantly decreased with age at end-expiration, remaining constant at end-inspiration and during maximal inspiratory pressure maneuvers. Comparing to controls, absolute values of diaphragmatic thickness and diaphragmatic thickness variations were significantly lower (p<0.001), with the exception of quiet breathing and maximal expiratory pressure maneuvers in the youngest DMD. During maximal inspiratory pressure maneuver, variation of diaphragmatic thickness was not significantly different in the all groups, nevertheless maximal inspiratory pressure decreases with age.ConclusionsThe diaphragm is prone to pseudo-hypertrophy in the youngest DMD, and to progressive atrophy in middle-age and oldest DMD. Diaphragm impairment could be expressed as a dissociation between muscle drive and muscle developed force. Ultrasonography could be used as a noninvasive method to assess progressive diaphragmatic weakness.

Ageing of the Diaphragm Muscle

“…In fact, in the early stages of ageing, the ultimate process will lead to processes of atrophy, and we witness a remodeling of the muscle, trying to repair the weakening fibers and mimicking hypertrophy (pseudohypertrophy). The same mechanism is found in some initial pathological conditions such as Duchenne muscular dystrophy [22]. Another study on a human model and with ultrasound evaluation highlighted a thickening of the diaphragm muscle [23].…”

Diaphragm Involvement in Duchenne Muscular Dystrophy (DMD): An MRI Study

“…With respect to these studies, we directly related the fat fraction increase of the diaphragm to its excursion function; thus, the structure–function relationship was investigated free from any compensatory mechanisms. Studies performed by using ultrasonography (US) showed a progressive diaphragm atrophy with age and reduced excursion . Laviola et al reported that diaphragmatic thickness was similar to the control group in DMD patients younger than 14 years old, but that it was significantly lower in patients older than 14 years old.…”

“…Studies performed by using ultrasonography (US) showed a progressive diaphragm atrophy with age and reduced excursion . Laviola et al reported that diaphragmatic thickness was similar to the control group in DMD patients younger than 14 years old, but that it was significantly lower in patients older than 14 years old. Our results confirmed the diaphragm remodeling, with increased fat fraction after 15 years old, and the reduced excursion in DMD patients.…”

Ultrasound imaging for measuring muscle and subcutaneous fat tissue thickness of the anterior thigh: A two-year longitudinal study in middle age

“…32 The technique has been used to assess diaphragm thickness in Duchenne muscular dystrophy patients with the potential to monitor disease progression. 33 The reliability of US imaging of muscle is well established, 1 and the contribution of the present study was to demonstrate the robustness of US imaging measurements of the anterior thigh over a longer period of time (2 years), extending the use of ultrasound from research during observational cross-sectional studies to longitudinal studies.…”

“…In such cases, US imaging can be used to assess tissue quality, using specific techniques, such as grayscale analysis of echogenicity . The technique has been used to assess diaphragm thickness in Duchenne muscular dystrophy patients with the potential to monitor disease progression …”