BACKGROUND: Neurogenic thoracic outlet syndrome (NTOS) and pectoralis minor syndrome (PMS) are clinically similar syndromes that originate from different sites of neurovascular compression, respectively, at or below the thoracic outlet. Botulinum neurotoxin (BoNT) has demonstrated therapeutic relief for NTOS but has limited study in PMS.

CASE REPORT: We present a case of a 67-year-old woman who experienced graded improvement of PMS symptomatic relief with BoNT treatments. She received 5 rounds of BoNT treatments over 2 years, all with significant symptomatic relief that increased in duration and resulted in decreased severity of symptoms upon pain return.

CONCLUSIONS: Our case contributes to the limited body of evidence that BoNT can have therapeutic benefits for PMS. Additionally, this case also shows an interesting finding of graded improvement of symptomatic relief duration, which is not commonly seen with BoNT injections that typically provide neuromuscular relaxation for a predictable 3-4 months.

KEYWORDS: Pectoralis minor syndrome, botox, botulinum neurotoxin, case report, thoracic outlet syndrome