Neurology 2019 10;93(14):630-639
From the IRCCS (P.C., G.C.-B., G.G., F.P., L.V.), Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy; Dipartimento di Scienze Biomediche e Neuromotorie (P.C., G.C.-B., G.G., P.M., F.P.), Università di Bologna, Bologna, Italy; Department of Neurology (E.E.B., P.A.L.), Mayo Clinic, Rochester, MN; Multidisciplinary Sleep Unit (A.I.), Neurology Service, Hospital Clinic de Barcelona, IDIBAPS CIBERNED, Barcelona, Spain; UCL Queen Square Institute of Neurology (N.Q.), Queen Square, London; Parkinson's Disease and Movement Disorders Unit (E.T.), Neurology Service, Hospital Clinic de Barcelona; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) (E.T.), University of Barcelona (UB), and Centre for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED), Barcelona, Spain; Department of Neurology (G.K.W.), Innsbruck Medical University, Innsbruck, Austria; Department of Neuroscience (G.A.), Rehabilitation, Ophthalmology, Genetics and Maternal Child Health, University of Genoa, Genoa, Italy; The Multiple System Atrophy Coalition, Inc. (P.B.), Charlotte, NC; Neurophysiopathology Unit (E.A.), IRCCS "C. Mondino" Foundation, Pavia, Italy; Department of Clinical Neurophysiology (I.G.), CHU de Bordeaux, Bordeaux, France; Université de Bordeaux (I.G.), Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Bordeaux, France; CNRS (I.G.), Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, Bordeaux, France; Department of Neurology (T.O.), Uonuma Institute of Community Medicine, Niigata University Medical and Dental Hospital, Minami Uonuma, Niigata, Japan; Parkinson's Disease and Movement Disorders Unit (C.P., N.G.P.), IRCCS "C. Mondino" Foundation, Pavia; Dipartimento di Medicina Specialistica (C.V.), Diagnostica e Sperimentale (DIMES), University of Bologna, Bologna, Italy; Dipartimento di Scienze biomediche e chirurgico specialistiche (C.V.), University of Ferrara, Ferrara, Italy; Department of Neurosciences (A.A.), University of Padua, Padua, Italy; Department of Clinical and Motor Neuroscience (A.P.B.), UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London; Spinal Unit (J.B.), Montecatone Rehabilitation Institute, Imola, Italy; Department of Neurology (H.K.), New York University School of Medicine, New York, NY; Department of Medicine (M.T.P.), Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Salerno, Italy; "Luigi Sacco" Department of Biomedical and Clinical Sciences (N.P., A.S.), University of Milan, Milan, Italy; Service de Neurologie (F.T., W.G.M.), CRMR Atrophie Multisystématisée, CHU Bordeaux, Bordeaux, France; Univ. de Bordeaux (F.T., W.G.M.), Institut des Maladies Neurodégénératives, Bordeaux, France; and Department Medicine (W.G.M.), University of Otago, Christchurch, and New Zealand Brain Research Institute, Christchurch, New Zealand.
Multiple system atrophy (MSA) is a neurodegenerative disorder characterized by a combination of autonomic failure, cerebellar ataxia, and parkinsonism. Laryngeal stridor is an additional feature for MSA diagnosis, showing a high diagnostic positive predictive value, and its early occurrence might contribute to shorten survival. A consensus definition of stridor in MSA is lacking, and disagreement persists about its diagnosis, prognosis, and treatment. An International Consensus Conference among experts with methodological support was convened in Bologna in 2017 to define stridor in MSA and to reach consensus statements for the diagnosis, prognosis, and treatment. Stridor was defined as a strained, high-pitched, harsh respiratory sound, mainly inspiratory, occurring only during sleep or during both sleep and wakefulness, and caused by laryngeal dysfunction leading to narrowing of the rima glottidis. According to the consensus, stridor may be recognized clinically by the physician if present at the time of examination, with the help of a witness, or by listening to an audio recording. Laryngoscopy is suggested to exclude mechanical lesions or functional vocal cord abnormalities related to different neurologic conditions. If the suspicion of stridor needs confirmation, drug-induced sleep endoscopy or video polysomnography may be useful. The impact of stridor on survival and quality of life remains uncertain. Continuous positive airway pressure and tracheostomy are both suggested as symptomatic treatment of stridor, but whether they improve survival is uncertain. Several research gaps emerged involving diagnosis, prognosis, and treatment. Unmet needs for research were identified.