Sensory testing in the assessment of laryngeal sensation in patients with amyotrophic lateral sclerosis

Objectives: Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron disease of unknown cause. Mortality in the population is frequently due to aspiration pneumonia. Although typically considered to be a disorder limited to motor neuron involvement, some investigators have indicated that decreased sensory function in ALS patients additionally contributes to the disease process. The objective of this study was to evaluate laryngopharyngeal sensation in the ALS population in order to quantify the range of sensory deficits and correlate any abnormalities with demographic data to determine which patients are at risk of having sensory deficits. Methods: We examined the sensation of the larynx in 22 patients with ALS to determine whether a sensory deficit was present. After completion of a dysphagia questionnaire and medical history, patients underwent flexible endoscopic evaluation of swallowing with sensory testing (FEESST) to evaluate sensory function. Threshold values were determined and recorded for initiation of the adductor reflex. Results: The results of the sensory and swallowing function assessments performed on 22 patients demonstrate abnormal sensation in 54.5% of the tested population. Asymmetric findings were noted in 75% of these patients. There was no correlation noted between the presence of sensory deficits and the severity or duration of the disease. Conclusions: Progressive dysphagia in the ALS population has typically been attributed to muscle weakness. This study points to the presence of sensory deficits in the larynx, which can further affect proper swallowing function.