What is the epidemiology of brachial plexopathy?

Epidemiology of Brachial Plexopathy

Traumatic brachial plexus injuries primarily affect young males (94.6%) with an average age of 28.4 years, with motorcycle accidents accounting for 79% of cases according to large epidemiological studies. 1

Etiology and Classification

Brachial plexopathy can be categorized based on causative factors:

Traumatic Causes (Most Common)

• Road traffic accidents account for 94% of traumatic brachial plexus injuries, with 90% involving two-wheelers 2
• Traumatic injuries can be classified as:
  • Preganglionic (root avulsion) or postganglionic injuries 3
  • Complete or partial lesions (46.1% of cases are complete lesions) 1
• Distribution of partial lesions:
  • C5/C6 root involvement: 30.1% of cases 1
  • C5/C6/C7 root involvement: 20.9% of cases 1
  • C8/T1 (lower roots) involvement: 2.9% of cases 1

Non-Traumatic Causes

• Neoplastic involvement:
  • Primary tumors (benign peripheral nerve sheath tumors - schwannomas and neurofibromas) 4
  • Secondary involvement through direct invasion or metastasis (most commonly from lung and breast cancer) 4
• Inflammatory/immune-mediated:
  • Parsonage-Turner syndrome (neuralgic amyotrophy or brachial plexitis) 4, 5
  • Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) 4
• Radiation-induced plexopathy (delayed complication of radiation therapy) 4
• Iatrogenic causes (surgical positioning):
  • Approximately 1% incidence in laparoscopic colorectal surgery 6

Demographic Patterns

• Gender distribution: Males are significantly more affected (94.6%) than females (5.4%) 1
• Age distribution: Average age of 28.38 years, primarily affecting young adults 1
• Side involvement: Left side (54.1%) slightly more affected than right side (45.9%) 1

Associated Injuries and Complications

• Brachial plexus injury forms part of multitrauma in 54% of cases 2
• Common associated injuries include:
  • Head trauma: 34.2% of cases 1
  • Long bone fractures: 38.8% of cases 1
  • Clavicle fractures: 25.9% of cases 1
  • Thoracic trauma: 12.9% of cases 1

Regional Predilection and Anatomical Considerations

• Most traumatic lesions are supraclavicular in location 1
• The brachial plexus is formed from the ventral rami of C5-T1 nerve roots, with occasional contributions from C4 and/or T2 4
• The complex anatomical structure makes it vulnerable to trauma and secondary involvement from adjacent structures 7

Recovery and Rehabilitation

• Average time interval from injury to surgical exploration: 127 days 2
• Return to work: 57% of patients return to work by an average of 8.6 months post-injury 2
• For patients with global brachial plexus injuries, it takes an average of 6.8 months to write with the non-dominant hand 2

Diagnostic Considerations

• MRI is the gold standard for evaluation due to superior soft-tissue contrast and spatial resolution 3
• Imaging for traumatic cases should be delayed until approximately 1 month after injury to allow for resolution of hemorrhage and edema 3
• Distinguishing between preganglionic and postganglionic lesions is crucial as treatment approaches differ 4

Clinical Implications

• Complete nerve ruptures generally have worse outcomes and often require early operative management 3
• Symptoms may overlap with radiculopathy, making diagnosis challenging 3
• The regional predilection of most brachial plexus disorders necessitates a regional approach to assessment 7