The ability to cough is essential component of pulmonary defenses. In people with neurogenic disease, this ability can be seriously compromised by both respiratory muscle dysfunction and/or inadequate laryngeal function. Amyotrophic lateral sclerosis (ALS) is a neurogenic disease that leads to respiratory impairments and cough dysfunction. Difficulty with coughing and clearing secretions contributes to risk for aspiration pneumonia and respiratory failure. The mechanisms for impaired cough in those with bulbar involvement are most likely distinct from those with primarily limb involvement. For those with limb involvement, cough dysfunction occurs due to weakened respiratory muscles. Although cough dysfunction in those with bulbar involvement is not well understood, it is recognized that people with bulbar ALS frequently experience laryngeal dysfunction. Cough dysfunction in those with bulbar ALS might result from obstruction or airflow resistance related to weakness or reduced coordination of true vocal fold (TVFs) abduction during cough, rather than weakened respiratory muscles. To date, however, no studies have directly examined the relationship between TVF movements and cough dysfunction in bulbar ALS. This research will examine the laryngeal contribution to volitional cough dysfunction in bulbar ALS. Specifically, a cross-sectional, observational study design will be used to examine the relationship between cough-related airflow measures and cough-related TVF kinematic and timing measures in subjects with bulbar ALS and normal controls during a volitional cough task. The long-term objectives are to determine mechanisms that contribute to reduced peak expiratory cough flow in people with bulbar ALS, and to examine TVF movements during cough in people without disease to further inform normal expectations. In this study, TVF movements during cough will be measured by applying techniques previously used to measure TVF movements during phonation. These measurement techniques will be used to examine potential associations between cough related airflow measures and laryngeal dysfunction in normally functioning people and people with bulbar ALS. Knowledge of associations between laryngeal and cough dysfunction in bulbar ALS may contribute to future studies examining measures that might be predictive of respiratory and cough decline in bulbar ALS and may contribute to knowledge that might facilitate interventions to improve cough effectiveness and swallowing safety in persons with bulbar ALS.
The mission of the National Institute on Deafness and er Communication Disorders (NIDCD) includes research focused on the special biomedical problems associated with people who have communication impairments or disorders. Amyotrophic lateral sclerosis (ALS) is a neuromuscular disease that results in severe communication impairments. The long-term goal for this research is to contribute toward an improved understanding of the underlying mechanism of cough impairment in persons with bulbar ALS. This project is in line with the mission of NIDCD to reduce or alleviate biomedical problems experienced by people with communication impairments, as it may contribute knowledge relevant for further development of clinical predictors for survival in this population. Furthermore, understanding in this area may facilitate treatment options for cough and swallowing dysfunction for those with bulbar ALS.
|Britton, Deanna; Benditt, Joshua O; Merati, Albert L et al. (2014) Associations between laryngeal and cough dysfunction in motor neuron disease with bulbar involvement. Dysphagia 29:637-46|