Spinal accessory neuropathy

Background

Lateral neck, with accessory nerve seen between the sternocleidomastoid and trapezius muscles.
  • CN XI which innervates the sternocleidomastoid and trapezius muscles[1]
  • Commonly removed during radical neck dissection for head and neck cancers

Causes

  • Iatrogenic
    • Radical or modified neck dissection
  • Trauma
  • Stroke

Clinical Features

  • Trapezius atrophy
  • Weakness of shoulder abduction
  • Scapular dyskinesis

Differential Diagnosis

Upper extremity peripheral nerve syndromes

Median Nerve Syndromes

Ulnar Nerve Syndromes

Radial Nerve Syndromes

Proximal Neuropathies

Other

Evaluation

  • Usually a clinical diagnosis
  • Positive scapular flip sign
  • Outpatient EMG or nerve conduction studies

Management

  • NSAIDs
  • Shoulder sling
  • Physical therapy
  • Surgical repair

Disposition

  • Discharge with neurology follow up

See Also

External Links

References

  1. Kelley MJ et al. Spinal Accessory Nerve Palsy: Associated Signs and Symptoms. J Orthop Sport Phys. 2008;38(2):78-86.