Origin and In-Office Treatment of Retrograde Cricopharyngeus Dysfunction.

[IMPORTANCE] Retrograde cricopharyngeus dysfunction (R-CPD) is an emerging disorder associated with disabling symptoms. The origin of R-CPD remains unknown.

[OBJECTIVE] To investigate the development of symptoms, diagnosis approach, and therapeutic outcomes of R-CPD in patients treated with in-office botulinum toxin injection (BTI) into the cricopharyngeus.

[DESIGN, SETTING, AND PARTICIPANTS] This was a case series including patients with R-CPD who were consecutively and prospectively recruited from April 2022 to May 2024 in an academic hospital. Semistructured interviews were conducted to collect and analyze data on each patient's clinical history, potential causes or factors associated with R-CPD development, diagnostic approaches, and symptom presentation.

[INTERVENTION] Clinic-based (in-office) BTI into the cricopharyngeus.

[OUTCOMES AND MEASURES] Associations with laryngopharyngeal reflux disease, patients' Reflux Symptom Score-12 (RSS-12), and BTI effectiveness, revisions, and complications were evaluated.

[RESULTS] The case series comprised 106 patients with R-CPD treated with BTI (52 females [49.1%] and 54 males [51.9%]). Their mean (SD) age at symptom onset was 13.6 (7.7) years, and at diagnosis, 30.4 (6.4) years. Sixty-eight patients (64.2%) had potential congenital R-CPD, according to the parents' testimonies. A family history was reported in 18 of 62 cases (29.0%). In 105 cases (99.1%), patients made the diagnosis themselves despite medical consultations (n = 162), empirical treatments (n = 113), and additional examinations (n = 92). The cumulative success rate of BTI was 90.6% (96 of 106 patients). In 26 cases (24.5%), additional injections were administered to address the symptoms. Family history of R-CPD was a negative predictor of single-BTI success. Dysphagia was the primary adverse effect occurring after 89 of 126 BTIs (70.6%) and lasted a mean (SD) of 16.3 (12.0) days. In 10 cases, operating-room BTI was administered after primary in-office BTI.

[CONCLUSIONS AND RELEVANCE] R-CPD is an emerging and poorly known disorder associated with high rates of ineffective consultations, additional examinations, and self-diagnosis by patients. In-office BTI was associated with a high rate of partial or total symptom relief and long-term effectiveness.