Effect of pronator teres muscle botulinum neurotoxin type-A injection on proximal median nerve entrapment.

[PURPOSE] We aimed to evaluate the effect of botulinum neurotoxin type-A (Btx-A) injection into the pronator teres muscle in proximal median nerve entrapment (PMNE).

[METHODS] Intramuscular injection of 30 IU Btx-A into the pronator teres muscle was performed in 12 patients (14 extremities) diagnosed with PMNE. The injection was made under nerve stimulator control. One patient with thoracic outlet syndrome was excluded from the study and not included in the clinical evaluation. Grip and pinch strength, 2-point discrimination, Q-DASH score, and pain on VAS were evaluated and compared before and 6-8 months after injection. The patients were contacted again by phone after the first and fifth years and asked about PMNE symptomatology.

[RESULTS] None of the patients had complications. No significant difference in pinch strength was observed following Btx-A injection, but there was significant improvement in grip strength, 2-point discrimination, and Q-DASH and VAS pain scores.

[CONCLUSION] The outcomes of our study were promising: Btx-A injection improved symptoms in patients with PMNE.

[LEVEL OF EVIDENCE] Level IV.