Working Diagnosis:
Traumatic acute sports-related long thoracic nerve injury (mononeuropathy) in a pediatric patient with a previously undiagnosed underlying non-traumatic demyelinating polyneuropathy.

Treatment:
Given the results of her nerve conduction study, she was referred to a medical geneticist for further workup of possible hereditary underlying demyelinating polyneuropathy. For the confirmed long thoracic nerve injury, she was referred to physical and occupational therapy for treatment, strictly advised to cease return to sport until cleared, prescribed nonsteroidal anti-inflammatory drugs for pain, and will be followed in the sports medicine clinic.

Outcome:
At her seven-week follow-up, her symptoms persisted. However, she was making mild improvement in her range of motion and strength. She was awaiting a scheduled appointment with medical genetics and was committed to continued treatment with physical and occupational therapy. We hope for a full recovery.

Author's Comments:
This case is unique because it demonstrates a never-before-reported potential association between acute sports-related nerve injury and underlying demyelinating polyneuropathy. Several studies have pointed towards genetic mutations in peripheral myelin proteins or Schwann cells, resulting in increased susceptibility to neuropathies. Thus, it is reasonable to assume that the patient's underlying demyelinating polyneuropathy could have conveyed a predisposition to increased incidence or severity of nerve injury. Thus, this highlights an important association to consider when evaluating a patient with repeated nerve injury.

Editor's Comments:
An injury to the long thoracic nerve often is a traction injury to the arm that can occur in a variety of sports. This is a purely motor nerve arising from the ventral rami of C5-C7. Non-operative management is very effective in these cases but can sometimes take up to 2 years for full neurologic recovery. This case highlights an important presentation of acute muscle weakness following trauma concerning for long thoracic nerve injury with additional paresthesia that must broaden the differential diagnoses for further pathology or underlying processes. A medical genetics referral is very prudent given the athletes age and bilateral neuropathies.

References:
Aval, Soheil M. MD; Durand, Pierre Jr MD; Shankwiler, James A. MD. Neurovascular Injuries to the Athlete's Shoulder: Part I. Journal of the American Academy of Orthopaedic Surgeons 15(4):p 249-256, April 2007.

Return To The Case Studies List.