ALS Patients Have No Distinct Swallowing Pattern, Which May Increase Choking Risk, Study Suggests

Amyotrophic lateral sclerosis (ALS) patients follow no distinct swallowing pattern, and this may account for the development of swallowing difficulties over time that can lead to life-threatening choking, a study reports.

The research, “The Importance Of The Reproducibility Of Oropharyngeal Swallowing In Amyotrophic Lateral Sclerosis: An Electrophysiological Study,” was published in the journal Clinical Neurophysiology.

Patients with neurological diseases, such as ALS, Alzheimer’s and Parkinson’s, have swallowing difficulties because their brain has trouble coordinating breathing, eating and drinking. These processes use organs that are close to each other inside the mouth, so coordination is necessary to avoid choking.

Oropharyngeal dysphagia, or swallowing difficulty, is one of the most frequent and critical symptoms of ALS. It may occur at any stage of the disease, but usually progresses over time.

Researchers decided to investigate the physiological and pathological facets of swallowing in ALS. They looked at 26 ALS patients with a mean age of 61, some of whom had signs of dysphagia and some of whom did not, and 30 age-matched healthy individuals.

The analysis consisted of assessing signals related to the oral phase and the pharyngeal phase of swallowing. The team used computer algorithms to determine the similarity index (SI) observed over repeated swallows. The oral phase is the mouth part of swallowing. The pharyngeal phase involves the pharynx, part of the throat.

Swallowing difficulty varied significantly in patients with and without signs of dysphagia, but more so in those who were dysphagic, the researchers found. The team also found that the SI in both phases of swallowing — oral and pharyngeal — had significant associations with dysphagia severity and ALS severity.

Together, the results indicated that ALS patients don’t have a fixed pattern of swallowing, in terms of muscle coordination in the mouth. This increases their risk of developing oropharyngeal dysphagia and choking, which can be life-threatening.

“In ALS, different pathophysiological mechanisms can alter the [pattern of] motor behaviors underlying normal swallowing, thus reducing the reproducibility of the swallowing act,” researchers wrote. “A decrease in swallowing reproducibility could be a preclinical sign of dysphagia and, beyond a certain threshold, a pathological hallmark of oropharyngeal dysphagia.

“[T]he present findings add new elements to our understanding of swallowing impairment in ALS, and could open up new interesting perspectives for objective monitoring of swallowing abnormalities and timely therapeutic interventions to continue safe oral feeding and preserve quality of life in these patients,” they concluded.