Bilateral Thyroarytenoid Botulinum Toxin Type A Injection for the Treatment of Refractory Chronic Cough.

JAMA Otolaryngology

PubMedID: 27367917

Sasieta HC, Iyer VN, Orbelo DM, Patton C, Pittelko R, Keogh K, Lim KG, Ekbom DC. Bilateral Thyroarytenoid Botulinum Toxin Type A Injection for the Treatment of Refractory Chronic Cough. JAMA Otolaryngol Head Neck Surg. 2016;142(9):881-8.
IMPORTANCE
Refractory chronic cough is a debilitating condition with limited therapeutic options. Laryngeal botulinum toxin type A (BtxA) has been anecdotally reported to benefit patients with chronic cough. We report on our experience with the use of BtxA for the treatment of patients with refractory chronic cough.

OBJECTIVE
To describe the effects of electromyography (EMG)-guided thyroarytenoid (TA) BtxA injection for the treatment of refractory chronic cough.

DESIGN, SETTING, AND PARTICIPANTS
For this single tertiary referral center retrospective case series, we included all patients with refractory chronic cough who received bilateral EMG-guided TA BtxA injections (n?=?22) between July 1, 2013, and July 31, 2014, at the Mayo Clinic in Rochester, Minnesota.

INTERVENTION
Bilateral TA BtxA injection.

MAIN OUTCOMES AND MEASURES
The primary outcome is a self-reported improvement of 50% or more in cough severity and/or symptoms by a 2-month follow-up telephone call. Adverse events and patient-reported quality measures were also assessed.

RESULTS
A total of 22 patients (median [interquartile range] age 61 [57.5-85] years; 19 of 22 women) underwent 31 distinct laryngeal BtxA treatment sessions. The primary outcome of self-reported improvement of 50% or more of cough severity and/or symptoms was achieved in 16 of 31 (52%) treatment sessions. Eleven patients (50%) reported greater than 50% improvement after the first BtxA injection. No major complications occurred. Postprocedural liquid dysphagia had a positive predictive value of 84% and negative predictive value of 100% for response to therapy.

CONCLUSIONS AND RELEVANCE
In this case series, laryngeal BtxA injection was well tolerated in patients with refractory chronic cough with half of participants experiencing at least short-term improvement in their cough. The occurrence of liquid dysphagia after a BtxA injection appeared to be predictive of a beneficial response. The durability of response, patient selection criteria, and optimal BtxA dosage remains to be determined.