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  • Neurogenic thoracic outlet syndrome (NTOS)

  • 353.0 Brachial plexus lesions

  • G54.0 Brachial plexus disorders


  • Entrapment of the neurovascular bundle comprising the brachial plexus, subclavian artery and/or subclavian vein, neurogenic or vascular types (venous and arterial)
  • Symptomatology and management is different depending on the primary structure compressed
    • Compression on the brachial plexus
      • Direct compression can occur at:
        • Scalene triangle
        • Cervical rib/first rib
        • Pectoralis minor
        • Costoclavicular space
        • Unstable humeral head in an anterior/inferior position2

Essentials of Diagnosis

  • Diagnosis is made by clinical examination and thorough diagnosis of exclusion
  • Most common to least common incidence is brachial plexus, subclavian artery, and subclavian vein compression, respectively3
  • Thoracic outlet syndrome involving the subclavian vein and artery requires immediate medical attention and is often the result of trauma or clot.4
  • Worse with repetitive postural habits, pain at rest, night pain5

General Considerations

  • No gold standard of diagnostic imaging exists for certain diagnosis.
  • Neurological examination and diagnostic imaging is required to rule out the most common differential diagnoses.
  • Double crush syndrome is a possibility.6


  • Young and middle-aged adults most commonly affected7
  • Females to males 3:17
  • Can develop spontaneously, gradual onset due to poor posture or post-trauma
  • Teenagers with a cervical rib
  • There is increased incidence with participation in sports
  • Correlated with a high incidence of forward head carriage and rounded shoulders8

Signs and Symptoms

  • Intermittent numbness and tingling in the forearm, wrist and hand.
    • Most often in the medial forearm and hand in the distribution of C8/T1 nerve roots but can be whole hand
  • Feeling of weakness and fatigue in the upper extremity (UE) especially with arm overhead
  • Pain in the arm, neck, shoulders, and upper back
  • Aggravated by overhead activities, repetitive activities, and activities that depress the shoulder girdle5
  • Pain is worse at night.5,9
  • Pain can be better with rest.
  • Postural examination may reveal low lying shoulder girdle on affected side, forward head carriage, and anteriorly rounded shoulders7
  • Isolated venous type of thoracic outlet syndrome presents with unilateral upper extremity edema, pain, cyanosis, paresthesia, fatigue, and heaviness of the UE5
  • Isolated arterial type of thoracic outlet syndrome presents with cool extremities, absent arterial pulse, possible distal gangrene, muscle cramps in the hand, paresthesia, swelling/heaviness of the UE5

Functional Implications

  • Difficulty with overhead activities
  • Pain with repetitive occupational fine motor tasks such as typing
  • Pain/difficulty with prolonged seated postures
  • Difficulty carrying a bag on the ipsilateral side
  • Inability to sleep on the affected side

Possible Contributing Causes


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