What are the symptoms and treatment options for a brachial plexus injury?

Brachial Plexus Injury: Symptoms and Treatment

Brachial plexus injuries require prompt diagnosis and treatment, with surgical intervention necessary within 1-3 months post-injury for complete nerve ruptures to achieve optimal functional outcomes. 1

Symptoms

Clinical Presentation

• Pain in shoulder and arm (neuropathic pain in multiple peripheral nerve distributions)
• Dysesthesia and/or burning/electric sensations
• Weakness or paralysis of the affected limb
• Sensory loss in the affected areas
• Flaccid loss of tendon reflexes
• Potential temperature and color changes in the limb due to autonomic nervous system damage 2, 3

Distribution of Symptoms

• Upper trunk injuries (C5-C6): Shoulder and elbow dysfunction
• Lower trunk injuries (C8-T1): Hand and wrist dysfunction
• Complete plexus injury: Total limb paralysis 2, 4

Diagnosis

Timing of Imaging

• Imaging to determine extent of plexus injury should ideally be delayed until approximately 1 month after trauma
• This allows time for pseudomeningocele development and resolution of blood/soft-tissue edema 2, 1

Imaging Modalities

1. MRI of the brachial plexus (first-line):

   • Gold standard with 84% sensitivity and 91% specificity for traumatic plexopathy
   • Should include T1-weighted, T2-weighted, fat-saturated T2-weighted or STIR sequences
   • Can differentiate preganglionic vs. postganglionic injuries (critical for treatment planning)
   • Can detect pseudomeningocele, a key finding in nerve root avulsion injuries 2, 1

2. CT myelography:

   • Alternative for detecting traumatic cervical nerve root avulsions
   • Limited to evaluating preganglionic nerve root injury 2

3. Electrodiagnostic studies:

   • Confirm clinical diagnosis
   • Assess for complete nerve rupture (absence of motor units) 1, 3

Treatment

Initial Management

• Penetrating and open injuries: Early surgical exploration
• Blunt and closed injuries: Initially managed conservatively with monitoring 2, 5

Surgical Intervention

• Timing: Optimal window is within 1-3 months post-injury
• Indications for surgery:
  • Complete nerve rupture (absence of motor units on EMG)
  • C7 nerve root avulsion with traumatic meningocele
  • No signs of recovery within 3-6 months 1, 5

Surgical Techniques

1. Neurolysis: Freeing the nerve from surrounding scar tissue
2. Nerve grafting: For repairing nerve gaps
3. Nerve transfers: Redirecting functioning nerves to denervated muscles
4. Free functional muscle transfers: For long-standing injuries
5. Tendon transfers: For improving specific functions
6. Joint arthrodesis: For stabilizing joints 1, 3, 4

Expected Outcomes

• Better recovery of shoulder and elbow function compared to hand function
• Without intervention for significant injuries, permanent disability is likely
• Surgical repair offers the best chance for functional recovery in patients with significant deficits 1

Special Considerations

Types of Injuries

• Preganglionic injuries (involving intraspinal nerve roots): Worse prognosis
• Postganglionic injuries (involving plexus lateral to dorsal root ganglion): Better prognosis
• Mixed patterns: Require comprehensive approach 2, 1

Mechanisms of Injury

1. Traction injuries:
   • Downward traction: Upper cervical nerve root lesions
   • Upward traction: Lower cervical nerve root lesions (C8-T1)
2. Direct impact
3. Compression from hematoma or fracture 2, 6

Risk Factors

• High-energy trauma (motorcycle accidents)
• Shoulder dislocations (especially in elderly women and young men after high-energy injuries)
• Longer period from dislocation to reduction 2, 5

Complications and Monitoring

• Incomplete recovery
• Nerve transfer donor site morbidity
• Chronic pain syndromes
• Risk of infection
• Psychological impacts requiring mental health support 1, 3

Successful management requires a multidisciplinary approach including peripheral nerve surgeons, neurologists, hand therapists, physical therapists, pain management specialists, and mental health professionals 3.