Sleep-related breathing disorders in the Shy-Drager syndrome. Observations on investigation and management

Stridor in multiple system atrophy: Consensus statement on diagnosis, prognosis, and treatment

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.

Movement Disorders and Voice

The primary movement disorders affecting the voice are laryngeal dystonia (including spasmodic dysphonia), essential voice tremor, and Parkinson disease. Diagnosis of these conditions is clinical and based on a detailed history, voice evaluation, and physical and laryngoscopic examination. Laryngeal dystonia and essential voice tremor are hyperfunctional disorders and are treated most commonly with botulinum toxin injections. Parkinson disease is a hypofunctional disorder that may affect the voice and most commonly is treated with Lee Silverman Voice Treatment.

Surgical management of airway dysfunction in Parkinson's disease compared with Parkinson-plus syndromes

OBJECTIVES

We sought to compare the laryngeal symptoms of Parkinson's disease (PD) with those of multiple system atrophy (MSA), a Parkinson-plus syndrome; to review the differences in surgical management of upper airway dysfunction between patients with PD and those with MSA; and to present a treatment algorithm for management of upper airway disorders in patients with PD and MSA.

METHODS

We analyzed the airway manifestations of each disease, including clinical and physiological test results and management outcomes, in a case series of 30 patients (24 with PD and 6 with MSA).

RESULTS

Vocal fold atrophy causing bowing with a midfold glottic gap was common in patients with PD. One third of patients with PD underwent vocal fold augmentation with noticeable improvement in vocal volume and phonation time. Tracheostomy was required for life-threatening sleep apnea in 50% of the patients with MSA. Systemic medications and speech therapy were integral components of the management regimen.

CONCLUSIONS

Surgical management of laryngeal disorders in patients with PD should focus on restoring bulk to atrophic vocal folds to minimize glottic gaps, thus improving vocalization efficiency even in the presence of impaired respiratory effort. Conversely, the autonomic dysfunction that characterizes MSA results in upper airway obstruction, and thus surgical management focuses primarily on maintaining an adequate airway, which frequently necessitates tracheostomy.

Sleep and quantitative EEG in neurodegenerative disorders

This paper reviews current knowledge on sleep problems, sleep architecture changes and quantitative EEG alteration brought on by various neurodegenerative diseases, such as Alzheimer's disease (AD), progressive supranuclear palsy (PSP), REM sleep behavior disorder (RBD), Parkinson's disease (PD), dementia with Lewy bodies (DLB), multiple system atrophy MSA, Huntington's disease and Creutzfeldt-Jakob disease, in comparison to normal aging. The study of sleep variables and that of the spectral composition of the EEG can provide valuable information for understanding the pathophysiology and for assisting the diagnosis of neurodegenerative diseases.

Continuous positive air pressure eliminates nocturnal stridor in multiple system atrophy. Barcelona Multiple System Atrophy Study Group

We prospectively studied the sleep patterns and laryngeal function of 20 patients with multiple system atrophy and found sleep disturbances in all subjects and vocal cord abduction dysfunction in 14 (70%). In three patients with nocturnal stridor and complete vocal cord abductor dysfunction, continuous positive airways pressure eliminated laryngeal stridor, obstructive apnoea, and haemoglobin desaturation.