Is the Botulinum Toxin Injection Into the Cricopharyngeal Sphincter Precipitate Laryngopharyngeal Reflux Symptoms in Patients With Retrograde Cricopharyngeal Dysfunction?

[OBJECTIVE] To investigate the potential relationship between retrograde cricopharyngeal dysfunction (R-CPD) and laryngopharyngeal reflux disease (LPRD) at baseline and whether cricopharyngeal sphincter paralysis botulinum toxin injection (BTI) is associated with an increase of LPRD symptoms in treated R-CPD patients.

[METHODS] Patients with clinical diagnosis of R-CPD were prospectively recruited from two European hospitals. Controls included individuals unable to burp without troublesome symptoms (CT1) and healthy subjects able to burp (CT2). All participants completed the Burp Score and Reflux Symptom Score-12 (RSS-12) at baseline. R-CPD patients underwent office-based electromyography-guided BTI followed by a 3- to 6-month follow-up evaluation.

[RESULTS] Forty-two R-CPD patients and 133 gender- and age-matched controls (30 CT1, 103 CT2) completed baseline evaluations. Burp scores were significantly higher in the R-CPD and CT1 groups compared to CT2, with CT1 subjects presenting mild symptom scores significantly exceeding CT2 levels. No significant differences in RSS-12 total scores were observed between R-CPD and CT2 subjects. Among 38 R-CPD patients completing postBTI evaluation (22 responders), RSS-12 total scores remained stable. Dysphonia and dysphagia scores significantly increased post treatment, potentially representing BTI-related adverse events.

[CONCLUSION] This preliminary clinical study supports that R-CPD and LPRD are distinct clinical disorders, with BTI treatment improving R-CPD symptoms without significantly increasing LPRD symptoms.