Selective botulinum chemodenervation of the scalene muscles for treatment of neurogenic thoracic outlet syndrome

Patients with thoracic outlet syndrome (TOS) who improve temporarily after anesthetic blockade of the anterior scalene muscles have been shown to impr ove after ultimate surgical decompressions at the interscalene triangle. An esthetic blockade of the scalene muscles, even with the addition of steroid s, however, rarely produces any prolonged relief as patients are awaiting d efinitive surgery. The present study was undertaken to determine ii more ef fective and prolonged relief might be obtained with electrophysiologically and fluoroscopically guided selective injection of the scalene muscles with botulinum toxin, which has been used in the past for treating conditions a ssociated with spasm of cervical muscles. In 14 of 22 patients (64%) with a clinical diagnosis of TOS, there was more than a 50% reduction of symptoms measured by a 101-point scale for at least 1 month after botulinum chemode nervation of the scalene muscles. Only 4 of the 22 patients (18%) had a 50% reduction of symptoms for at least 1 month after injection with lidocaine and steroids. In no patient were the results of lidocaine and steroid injec tion superior to botulinum chemodenervation. Chemodenervation had a mean du ration of effect of 88 days. No significant side effects were encountered w ith botulinum chemodenervation except for mild transient dysphagia in two c ases. These results appear to demonstrate that botulinum chemodenervation o f the scalene muscles may be helpful in alleviating symptoms in patients wi th TOS awaiting definitive surgical decompression. DOI: 10.1007/s1001699100 79.