Low Dose Botulinum Toxin Injection in Retrograde Cricopharyngeal Dysfunction.

Retrograde cricopharyngeal dysfunction or R-CPD has a variety of symptoms including the inability to belch. Often, physical examination and additional testing reveal no abnormalities. Botulinum toxin injections into the cricopharyngeal muscle is the most described treatment in patients with R-CPD. Dosages range from 10 to 200 units, injected in one or several sites of the cricopharyngeal muscle. This study is a retrospective case series study of 3 consecutive patients referred for botulinum toxin injection in the cricopharyngeal muscle after diagnostic work-up for inability to belch. The dose ranged from 12.5 to 17.5 units. A clinical swallowing evaluation was carried out by a speech-language pathologist either before or after surgery in 2 out of 3 patients. Low dose botulinum toxin injection resulted in symptomatic improvement in all 3 patients. Two out of the 3 patients did require revision surgery for this improvement to occur. There were no intraoperative or postoperative complications. A clinical swallowing evaluation demonstrated a hypertonia of the neck musculature combined with weak tongue strength in 2 out of the 3 patients. Low dose botulinum toxin injection is an effective but unpredictable treatment in this case series of three patients. All patients had an improvement of symptoms but 2 patients required revision surgery for this improvement to occur.