Laryngeal Electromyographic Findings in a Cohort of Recalcitrant Chronic Neurogenic Cough Patients

Abstract

Objectives: To evaluate the laryngeal electromyography findings of bilateral thyroarytenoid muscles in 10 patients with chronic, intractable coughing.

Methods: This is a retrospective cohort case series. Clinical records were reviewed for demographic information, symptoms, and findings on bilateral laryngeal EMG for 10 patients referred for chronic coughing.

Results: All thyroarytenoid muscles tested demonstrated electromyographic evidence of neuropathy, with signs of denervation and reinnervation. There was reduced recruitment in all 20 thyroarytenoid muscles studied. In addition, polyphasic motor units were seen in all thyroarytenoid muscles, with increased amplitude in 18 of 20 thyroarytenoid muscles and increased duration in 17 of 20 thyroarytenoid muscles. Additionally, there was electromyographic evidence of synkinesis in 19 of 20 thyroarytenoid muscles studied, a sign of aberrant reinnervation.

Conclusion: Patients with intractable coughing, despite numerous modalities of treatment, potentially have bilateral neuropathy of the recurrent laryngeal nerves suggesting the potential peripheral as well as central neuropathic changes as the etiology.

Keywords: Chronic cough; Electromyography; Neurogenic.