Dados do Trabalho

Título

Muscle Ultrasound Changes Correlate with Respiratory Muscles Involvement and Functional Impairment in Spinal Muscular Atrophy.

Resumo

Introduction: Although new therapies modified the course of Spinal Muscle Atrophy (SMA), these treatments are costly and clinical trials have been substantially based on clinical assessments. Reliable techniques to evaluate disease progression and therapy response could support more robust clinical trials. Here we investigated ultrasound patterns of muscle involvement in different types of SMA and their correlation with functional status to determine the validity of this non-expensive, and easy-to-use assessment.
Methods: We examined 41 patients with SMA (types 1 to 4) and 46 age-, and gender-matched healthy controls using B-mode ultrasound (whole muscle method) for grey scale analysis (GSA), area (biceps brachii and rectus femoris) and diaphragm thickening ratio. Functional scales were applied to patients only. We analyzed ultrasound abnormalities in specific clinical subtypes and correlated findings with functional status. Also, we analyzed if it’s possible to predict respiratory involvement using GSA.
Results: Compared to controls, patients had reduced muscle area and increased mean GSA with correlation with the SMA severity, and the GSA of their intercostal muscles differed more in relation to the controls, as compared to differences in the diaphragm histograms. Biceps brachii GSA was correlated with diaphragm and intercostals GSA (p=0.019 and 0.008), and linear regression showed that it could predict respiratory muscle involvement (R=0.456 and 0.489 respectively).
Discussion: Muscles are affected on ultrasound in SMA patients with correlation with SMA severity. Biceps brachii GSA can possibly be used to predict respiratory involvement in SMA patients because it is correlated with diaphragm and intercostal muscle involvement.