Vocal cord electromyographic correlates of stridor in multiple system atrophy phenotypes. (January 2020)

• Record Type: Journal Article
• Authors: Todisco, Massimiliano; Alfonsi, Enrico; Isaias, Ioannis Ugo; Zangaglia, Roberta; Minafra, Brigida; Cosentino, Giuseppe; Terzaghi, Michele; Pozzi, Nicoló Gabriele; Manni, Raffaele; Pacchetti, Claudio
• Is Part Of: Parkinsonism & related disorders. Volume 70(2020)
• Page Start: 31
• Page End: 35
• Publication Date: 2020-01
• Subjects: Multiple system atrophy -- Stridor -- Electromyography -- Vocal cords -- Pathophysiology; Parkinson's disease -- Periodicals; Movement disorders -- Periodicals; Movement Disorders -- Periodicals; Nerve Degeneration -- Periodicals; Nervous System Diseases -- Periodicals; Parkinson Disease -- Periodicals; Tremor -- Periodicals; Parkinson, Maladie de -- Périodiques; Parkinson's disease; 616.833
• DOI: 10.1016/j.parkreldis.2019.11.025
• Languages: English
• ISSNs: 1353-8020

Abstract

Abstract: Introduction: Multiple system atrophy (MSA) is a neurodegenerative disorder characterized by dysautonomia in combination with parkinsonian and cerebellar signs. Stridor may also occur and it is associated with life-threatening events and poor prognosis. The pathophysiology of stridor in MSA is still debated. Objective: To define correlations between diurnal electromyographic (EMG) abnormalities of vocal cord muscles and stridor in MSA phenotypes. Methods: We recruited 60 patients with "probable" MSA (45 with parkinsonian [MSA-P] and 15 with cerebellar phenotype [MSA-C]). Nocturnal stridor was detected with video-polysomnography, whereas diurnal stridor was clinically noted when present. A diurnal kinesiologic EMG study of the adductor thyroarytenoid and the abductor posterior cricoarytenoid muscles was also performed. Results: Among subjects with nocturnal stridor, MSA-P patients predominantly showed a paradoxical burst-like activation of the adductor thyroarytenoid muscle during inspiration. This dystonic pattern was associated with nocturnal stridor in MSA-P (odds ratio [OR] = 23.64, 95% confidence interval [CI] 3.42–70.77, p < 0.001). Conversely, MSA-C patients with nocturnal stridor mainly had additional neurogenic findings of vocal cord muscles. This dystonic-plus pattern correlated with nocturnal stridor in MSA-C (OR = 17.21, 95% CI 4.17–74.92, p < 0.01). The findings of diurnal stridor paralleled the observations for nocturnal stridor. Conclusions: The pathophysiology of stridor may differ between MSA phenotypes, possibly related to dysfunctional supranuclear mechanisms in MSA-P (dystonic pattern) and to additional nuclear damage in MSA-C (dystonic-plus pattern). Highlights: Pathophysiology of stridor in MSA is still unclear. Dystonic EMG pattern of vocal cords is associated with stridor in MSA-P. Dystonic-plus EMG pattern of vocal cords correlates with stridor in MSA-C. Stridor may be related to dysfunctional supranuclear mechanisms in MSA-P. Stridor may be associated with additional nuclear damage in MSA-C vs. MSA-P.