Affiliation:
1. Department of Neurology, School of Medicine University of Patras Patras Greece
2. Department of Respiratory Medicine University Hospital of Patras Patras Greece
3. Institute of Computer Science, Foundation for Research and Technology Hellas Heraklion Greece
4. Department of Electrical and Computer Engineering Hellenic Mediterranean University Heraklion Greece
Abstract
AbstractIntroduction/AimsAmyotrophic lateral sclerosis (ALS) leads to diaphragmatic weakness at some point during its course, which is a major cause of respiratory insufficiency. The aim of this study was to evaluate ultrasound‐based measures for assessing the diaphragmatic competency and the need for ventilatory support.MethodsTwenty‐six subjects with ALS and 12 healthy controls were enrolled. All participants underwent B‐mode diaphragm ultrasound (DUS). Diaphragm thickness and thickening indices were recorded. In the subjects with ALS, further assessments included functional scales and spirometry. We investigated the diagnostic accuracy of DUS thickening indices in predicting diaphragmatic dysfunction and the correlation between clinical, spirometric, and DUS data.ResultsSignificant relationships were found between forced vital capacity and all diaphragmatic thickening indices. Similarly, all diaphragmatic thickening indices correlated with both Milano Torino staging and disease progression rate. Only thickening fraction (TFdi) correlated with score on the revised ALS Functional Rating Scale (r = 0.459, P = .024). TFdi had better accuracy in predicting diaphragmatic dysfunction (area under the curve [AUC] = 0.839, 95% confidence interval [CI] 0.643 to 0.953) and the need for initiation of noninvasive ventilation (NIV) (AUC = 0.989, 95% CI 0.847 to 1.000) compared with the other indices. A TFdi cut‐off point of 0.50 was a sensitive threshold to consider NIV.DiscussionDUS successfully identifies diaphragmatic dysfunction in ALS, being a valuable accessory modality for investigating respiratory symptoms. TFdi was found to be the most useful DUS index, which encourages further investigation.
Subject
Physiology (medical),Cellular and Molecular Neuroscience,Neurology (clinical),Physiology