Long thoracic neuropathy

Background

Nerves of the left upper extremity. (Long thoracic labeled vertically at shoulder, to left of artery.)

The right brachial plexus with its short branches, viewed from in front. (Long thoracic labeled at center, third from top.)

• Motor nerve which originates from the C5/C6/C7 levels and innervates the serratus anterior
• Due to its long and relatively superficial course along the lateral aspect of the thorax it is more susceptible to injury

Clinical Features

• Deficits are related to the weakness of the serratus anterior and subsequent "winging" of the scapula"

Differential Diagnosis

• Parsonage-Turner syndrome
• Direct trauma or compression
• Overuse injuries

Evaluation

Workup

• To evaluate for winging have the patient press the affected arm against a wall; the inferior tip of the scapula should project from the thorax if positive

Diagnosis

• Clinical diagnosis

Management

• Varies depending on the underlying etiology of neuropathy
  • Neuropathy secondary to Parsonage-Turner syndrome improves over the course of one to three years
  • Overuse injuries should be managed by avoiding the precipitating movement(s) and avoid carrying significant weight over the shoulder

Disposition

• Outpatient follow-up and physical therapy referral