Surface-evoked laryngeal sensory action potential evaluation in neurogenic chronic cough

Abstract

Objectives: Neurogenic chronic cough is currently a diagnosis of exclusion. We hypothesized that surface-evoked laryngeal sensory action potential (SELSAP) testing could be used to help establish a diagnosis of laryngeal sensory neuropathy as a cause of chronic cough, based on altered SELSAP waveform morphology.

Study design: Retrospective cohort study.

Methods: Laryngeal electromyographic (EMG) data including SELSAP waveform testing from patients with chronic cough were directly compared with a control population without significant laryngeal symptoms, and statistical analysis of unilateral and bilateral neuropathy injury subgroups was performed.

Results: Thirty patients with a chief complaint of chronic cough underwent laryngeal EMG testing since January 2000 with needle EMG and surface nerve conduction studies. SELSAP waveform analysis of unilateral and bilateral laryngeal neuropathy demonstrated significantly lowered median SELSAP peak amplitude compared with controls (P < 0.01).

Conclusions: Patients with suspected neurogenic chronic cough demonstrate statistically significant alterations in SELSAP waveform that can support a diagnosis of laryngeal sensory neuropathy.

Keywords: Chronic cough; Evoked potential; Laryngeal EMG; Neurogenic; Neuropathy; SELSAP.