Assessment of dysarthria and dysphagia in patients with amyotrophic lateral sclerosis: Review of the current evidence

Bulbar dysfunction is a common presentation of amyotrophic lateral sclerosis (ALS) and significantly impacts quality of life of people with ALS (PALS). The current paper reviews measurements of dysarthria and dysphagia specific to ALS to identify efficient and valid assessment measures. Using such assessment measures will lead to improved management of bulbar dysfunction in ALS. Measures reviewed for dysarthria in PALS are organized into three categories: acoustic, kinematic, and strength. A set of criteria are used to evaluate the effectiveness of the measures' identification of speech impairments, measurement of functional verbal communication, and clinical applicability. Assessments reviewed for dysphagia in PALS are organized into six categories: patient reported outcomes, dietary intake, pulmonary function and airway defense capacity, bulbar function, dysphagia/aspiration screens, and instrumental evaluations. Measurements that have good potential for clinical use are highlighted in both topic areas. Additionally, areas of improvement for clinical practice and research are identified and discussed. In general, no single speech measure fulfilled all the criteria, although a few measures were identified as potential diagnostic tools. Similarly, few objective measures that were validated and replicated with large sample sizes were found for diagnosis of dysphagia in PALS. Importantly, clinical applicability was found to be limited; thus, a collaborative team focused on implementation science would be helpful to improve the clinical uptake of assessments. Overall, the review highlights the need for further development of clinically viable and efficient measurements that use a multidisciplinary approach.