Thoracic outlet syndrome

• Neurogenic thoracic outlet syndrome (NTOS)

• 353.0 Brachial plexus lesions

• G54.0 Brachial plexus disorders

• 4E: Impaired Joint Mobility, Motor Function, Muscle Performance, and Rang of Motion Associated with Localized Inflammation

Description

• 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

Demographics

• 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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