Long thoracic nerve paralysis associated with thoracic outlet syndrome.

Two cases of long thoracic nerve palsy associated with thoracic outlet syndrome are reported. Both patients had abnormal posture, with low-set shoulders and winged scapulae. Clinically there was weakness of the serratus anterior muscle with partial denervotion on electromyography. The diagnosis of thoracic outlet syndrome was based on positive vascular tests and brachial plexus nerve compression symptoms induced by the vascular testing positions. An orthosis that held the shoulder in an elevated position was used in both cases. Complete recovery of shoulder function and relief of the symptoms was achieved in both cases at 8 and 13 months, respectively, after application of the orthosis.