Thoracic Outlet Syndrome from Bilateral Cervical Ribs -A Clinical Case Report

Introduction: Cervical rib is a mesenchymal or cartilaginous elongation of the transverse process of usually the seventh, rarely the sixth, and very rarely the fifth cervical vertebrae. It is an important cause of thoracic outlet syndrome as it has been reported in 5-% of patients with thoracic outlet syndrome. Bilateral cervical rib is a rare anomaly with a prevalence of 0.56% in Enugu, South Eastern Nigeria. This case is reported to emphasize the possibility of bilateral cervical rib as a cause of thoracic outlet syndrome in our environment.

Case report: A 28-year-old female soldier was referred to the spine surgery unit with neck and right shoulder pain of 3 years duration. Pain radiated into the hand and was worsened at night and by elevation of the right upper limb as well as the use of the limb. She had episodes of paresthesia, loss of sensation to both fine and crude touch at C8 and T1 dermatomes, coldness, and swelling of the right upper limb. Right-hand interossei muscle power was 4/5 (MRC grading).X-rays of the cervical spine showed bilateral cervical ribs which were longer on the right than on the left. Magnetic resonance imaging of the cervical spine showed short segment cervical cord syrinx formation at C2/C3 level and bilateral cervical rib with brachial plexus compression on the right side. Right cervical rib excision was done under general anesthesia through an anterior approach with the patient in supine position. Intraoperative findings were of a complete cervical rib. There was complete resolution of all symptoms by the 5-month follow-up visit.8 months after the initial operation, she re-presented at the outpatient department with similar symptoms on the left upper limb. She had excision of the left cervical rib which intraoperatively was noted to be an incomplete cervical rib with a fibrous cord tethering the brachial plexus. At 12-month follow-up visit, the patient had full resolution of all symptoms with the full use of both upper limbs.

Conclusion: Bilateral cervical rib, though rare, is a possible differential diagnosis for neck and upper limb pain and neurologic claudication which can mimic cervical radiculopathy and myelopathy.