Aesthesiometer‐Based Testing for Laryngopharyngeal Hyposensitivity

Abstract

Objectives/Hypothesis To develop a method for threshold estimation of the laryngeal adductor reflex (LAR) response using Cheung‐Bearelly monofilaments. Study Design Cross‐sectional. Methods Twenty‐two healthy adults (12 men, 10 women) were tested for LAR response outcome using 30 mm 5–0 and 4–0 nylon monofilaments. Tactile stimuli were delivered to the aryepiglottic (AE) fold and medial pyriform sinus (MPS). Dichotomous classifier features and performance (area under the curve (AUC)), the LAR response outcome agreement and disagreement matrix, and test–retest reliability were examined. From those data, a test protocol that would minimize patient burden to estimate the LAR triggering threshold was formulated. Results Classifier performance of 5–0 monofilament stimulation of the AE fold (sensitivity = 0.63, specificity = 0.63, PPV = 0.74, NPV = 0.25) and MPS (sensitivity = 0.45, specificity = 0.77, PPV = 0.74, NPV = 0.23,) was slightly below that of 4–0 monofilament stimulation of the AE fold (sensitivity = 0.82, specificity = 0.50, PPV = 0.82, NPV = 0.50) and MPS (sensitivity = 0.84, specificity = 0.64, PPV = 0.90, NPV = 0.56), based on AUC. LAR response outcome agreement for 5–0 and 4–0 stimulations was high (93%) for 5–0 positive response, but low (29%) for 5–0 negative response. Aesthesiometer test–retest reliability for LAR response outcome was excellent (Cronbach's alpha = 0.97). Conclusions Threshold estimation of the LAR response may be operationalized by adopting a decision tree protocol. For negative LAR response to initial 5–0 monofilament stimulation and positive response to subsequent 4–0 monofilament stimulation, the higher threshold is confirmed. Positive LAR response to 5–0 or 4–0 monofilament stimulation is expected in over 90% of asymptomatic adults. Negative LAR response to 4–0 monofilament stimulation identifies patients at risk for laryngopharyngeal hyposensitivity. Level of Evidence 3b Laryngoscope, 132:163–168, 2022

Assessment of Laryngeal Sensory Function using a Tactile Aesthesiometer in Healthy Adults

“…In previous work by Strohl and colleagues, 14,20,21 laryngeal sensation was evaluated in patients less than 60 years of age, with 6-0, 5-0, and 4-0 monofilaments, and with the most medial laryngeal location tested being the aryepiglottic fold (AEF). In this current study, we expand on this prior work by examining a new intermediate force (4.5-0), a new laryngeal site (false vocal fold (FVF)) and an older cohort of healthy adults.…”

Abnormal Laryngopharyngeal Sensation in Adductor Laryngeal Dystonia Compared to Healthy Controls

“…12,13 This methodology has previously shown promise as part of a paradigm to identify patients with laryngopharyngeal sensory abnormalities. 33 Results from the current study demonstrates the ability of this technique to identify laryngopharyngeal hypersensitivity as well, with higher laryngeal adductor reflux response rates in patients with AdLD than normal controls, particularly with smaller, arguably harder-to-discern stimuli.…”

“…This study reports the first objective assessment of laryngopharyngeal sensation in patients with AdLD using a validated novel method to deliver reliable, accurate tactile stimuli using adapted Cheung‐Bearelly monofilaments 12,13 . This methodology has previously shown promise as part of a paradigm to identify patients with laryngopharyngeal sensory abnormalities 33 . Results from the current study demonstrates the ability of this technique to identify laryngopharyngeal hypersensitivity as well, with higher laryngeal adductor reflux response rates in patients with AdLD than normal controls, particularly with smaller, arguably harder‐to‐discern stimuli.…”

An Ex Vivo Investigation of Tactile Aesthesiometer Force in Laryngopharyngeal Sensory Testing

“…[1][2][3] Recently, nylon monofilaments were used to create Cheung-Bearelly aesthesiometers which assess laryngeal sensation, delivering tactile stimuli to laryngopharyngeal sites via the channeled port of a flexible video laryngoscope. [7][8][9] These aesthesiometers overcome several hurdles associated with previous devices used in sensory evaluation by providing specific and constant stimuli to targeted structures. 10 Specifically, the aesthesiometer delivers increasing force from its tip to a surface of contact, reaching maximal pressure when the aesthesiometer buckles 10%-30%, called the "buckling force.…”

“…Aviv and Colleagues developed a method of quantifying laryngeal sensation by delivering graded air pulse stimuli to laryngopharyngeal structures but was limited by broad area of stimulation and varied distance of stimuli delivery to target sites 1–3 . Recently, nylon monofilaments were used to create Cheung–Bearelly aesthesiometers which assess laryngeal sensation, delivering tactile stimuli to laryngopharyngeal sites via the channeled port of a flexible video laryngoscope 7–9 . These aesthesiometers overcome several hurdles associated with previous devices used in sensory evaluation by providing specific and constant stimuli to targeted structures 10 .…”