Clinical correlates of respiratory disorders in patients with severe multiple sclerosis: A cross-sectional cohort.

Background: Respiratory disorders remain incompletely described in multiple sclerosis (MS), even though they are a frequent cause of death.
Methods: The objective was to describe respiratory disorders in MS patients with Expanded Disability Status Score (EDSS) ⩾ 6.5. Diaphragm dysfunction was defined by at least two of the seven criteria: clinical signs, inspiratory recruitment of neck muscles during wakefulness, reduced upright vital capacity (VC) < 80%, upright-to-supine VC ⩾ 15% of upright VC, decrease in Maximal Inspiratory Pressure < 60%, phasic activation of inspiratory neck muscles during sleep, and opposition of thoracic and abdominal movements during sleep. Cough weakness was defined by a peak cough flow < 270 L/min and/or need for cough assist. Sleep apnea syndrome was defined by an apnea-hypopnea index ⩾ 15.
Results: Notably, 71 MS patients were included: median age 54 [48, 61] years; median disease duration 21.4 [16.0, 31.4] years. Of these, 52 patients had one or more respiratory disorders; diaphragm dysfunction was the most frequent ( n = 34). Patients with diaphragm dysfunction and cough weakness were more disabled. The fatigue score and the cognitive evaluations did not differ between the groups. Five patients required non-invasive ventilation.
Conclusion: Respiratory disorders are frequent in severe MS, mostly diaphragm dysfunction. Of interest, instrumental interventions are available to address these disorders.
Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: No disclosure relevant to the manuscript. E.M. reports research support from Biogen and personal fees for lectures and advisory boards from Alexion, Biogen, Horizon, Janssen, Merck, Novartis, Roche, Sanofi, and Teva. C.Lo. has received consulting, speaker or travel fees from Merck, Roche, Biogen, Novartis, Teva, and Sanofi, and an IIT grant from Biogen. S.R., M.H., E.C., P.L., A.U., and I.A. report no disclosure. B.S. reports research support from Roche, Sanofi, and Merck and personal fees for lectures or advisory boards from Novartis, Sanofi, Biogen, Janssen, and Merck. C.P. reports research personal fees for lectures and advisory boards from Alexion, Biogen, Horizon, Merck, Novartis, Roche, and Sanofi. B.B. reports research support from Biogen and personal fees for lectures and advisory boards from Novartis, Roche, Sanofi, and Merck. C.Lu. reports research support from Merck and participates in advisory boards for Biogen, Merck, Rewind, and Roche. T.S. reports personal fees for consulting and teaching activities from AstraZeneca France, Chiesi France, KPL consulting, Lungpacer Inc., OSO-AI, TEVA France, and Vitalaire; he is a shareholder of startups Hephaï and Austral Dx. C.M.P. reports personal fees from AstraZeneca, Chiesi, ADEP Assistance, SOS Oxygène, ISIS, ResMed, Menarini, GSK, Fisher & Paykel, Vivisol, Air Liquide, Lowenstein, and Orkyn outside the submitted work.