Exploring the Impact of Amyotrophic Lateral Sclerosis on Otolaryngological Functions

Abstract

Importance: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by progressive degeneration of upper and lower motor neurons at the spinal or bulbar level.

Objective: We aim to describe the most frequent otolaryngology (ORL) complaints and voice disturbances in patients with bulbar onset ALS.

Design: Retrospective cohort study.

Setting: Single-center study with combined ORL and ALS clinic evaluation.

Participants: Patients with a confirmed diagnosis of ALS following an ORL visit and who underwent comprehensive voice assessments between January 2021 and January 2023.

Exposure: Objective voice assessments.

Main outcomes and measures: Glottal functional index (GFI), voice handicap index (VHI), reflux system index (RSI), and voice quality characteristics such as shimmer, jitter, maximum phonation time (MPT), and other essential parameters were assessed.

Results: One hundred and thirty-three patients (age 62.17 ± 10.79, 54.48% female) were included. Three patients were referred from the ORL department to the ALS clinic. The most frequent symptoms were; dysphagia, dysarthria, facial weakness, pseudobulbar affect, and sialorrhea. The mean of forced vital capacity was 59.85%, EAT-10 15.91 ± 11.66, RSI 25.84 ± 9.03, GFI 14.12 ± 5.58, VHI-10 42.81 ± 34.94, MPT 15.22 s ± 8.06. Many patients reported voice impairments mainly related to spastic dysarthria and the combination of lower and upper motor neuron dysarthria, hypernasality, reduced verbal expression, and articulatory accuracy. Shimmer was increased to 8.46% ± 7.20, and jitter to 2.26% ± 1.39.

Conclusions and relevance: Based on our cohort, this population with bulbar onset ALS has a higher frequency of voice disturbance characterized by hypernasality, spastic dysarthria, and reduced verbal expression.

Level of evidence: Level 3.

Keywords: ALS; Bulbar onset ALS; Dysarthria; Dysphagia; Pseudobulbar affect; Sialorrhea.