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Laryngeal Adductor Reflex Responses to Varying Stimulation Forces Assesses Sensory Dysfunction in Laryngopharyngeal Disorders

by Linda Kossoff •

What does a novel adaptation of a buckling force aesthesiometer used at specific subsites for delivery of calibrated tactile stimuli reveal about the state of laryngopharyngeal sensation?

BOTTOM LINE

Normative data for laryngeal adductor reflex (LAR) response rates to low, medium, and high stimulation forces are useful to assess sensory dysfunction in a variety of laryngopharyngeal disorders, including aspiration, dysphagia, chronic cough, and spasmodic dysphonia.

BACKGROUND: Laryngopharyngeal sensory dysfunction is a major contributor in a broad array of upper aerodigestive tract disorders. The use of air pulses to evaluate laryngeal sensory function has successfully identified hypo- and hyperfunction of certain conditions, but its broad adoption has been limited by uncertainty of stimulus delivery amplitude.

STUDY DESIGN: Cross-sectional study.

SETTING: Department of Otolaryngology–Head and Neck Surgery, University of California, San Francisco, Calif.

SYNOPSIS: Using a nylon monofilament buckling force aesthesiometer, researchers tested 22 healthy adults (12 males, 10 females, mean ages 37 and 36 years, respectively) for responses to tactile forces to map sensation of the aryepiglottic (AE) fold, lateral pyriform sinus (PS), and medial PS bilaterally. Air pulse pressure was delivered via 30-mm 6-0, 5-0, and 4-0 monofilaments. The outcome measures were the LAR and patient-reported rating of perceptual strength. Results showed the rates of triggered LAR response grew monotonically, with increasing tactile force across all three laryngopharyngeal subsites. The AE fold and medial PS were the most responsive; the lateral PS was the least responsive. Low force (6-0) response rate was ≤14% for all subsites. High force (4-0) response rate was 91% for AE fold and medial PS, and 23% for lateral PS. Based on these findings, authors concluded that normative data for LAR response rate to low, medium, and high stimulation forces are useful to assess sensory dysfunction in a variety of laryngopharyngeal disorders, and that information will guide future innovative treatments. Study limitations included the need for study replication with larger male/female cohorts to fully assess age and sex effects on laryngopharyngeal sensation.

CITATION: Strohl MP, Young VN, Dwyer CD, et al. Novel adaptation of a validated tactile aesthesiometer to evaluate laryngopharyngeal sensation. Laryngoscope. 2021;131:1324-1331.