Postviral Vagal Neuropathy: What Is the Role of Laryngeal Electromyography in Improving Diagnostic Accuracy?

OBJECTIVES

To investigate the convenience of laryngeal electromyography (EMG) findings in patients with chronic cough thought to be postviral vagal neuropathy (PVVN) with the clinical symptoms.

STUDY

DESIGN

Prospective cohort study.

METHODS

We applied PVVN questionnaire and chronic cough quality of life (QoL) questionnaire, which is for determining the effect of chronic cough on the QoL, to 20 chronic cough applicants who has no explanatory cause in differential diagnosis. We also carried out videolaryngostroboscopy (VLS) and laryngeal needle EMG in these patients.

RESULTS

The mean duration of persisting cough was 1.875 months (SD ±0.825). The overall mean symptom score of chronic cough questionnaire was 58.80 (SD ±9.89). There was a significant positive correlation between total EMG score and chronic cough score (Spearman r, 0.489, P < 0.05). The correlation between VLS findings and either chronic cough scores or EMG scores did not reach statistical significance.

CONCLUSIONS

Cranial nerves might be affected by inflammatory processes as occur in the PVVN, which must be considered in the etiology of chronic cough. We showed that the laryngeal EMG can be used as an appropriate diagnostic tool for these patients.