Brachial plexus injuries

The brachial plexus is a network of nerves originating from the cervical and upper thoracic spinal cord (C5–T1). These nerves converge to supply the shoulder, arm, wrist, and hand — controlling both movement (raising the arm, gripping, fine finger movements) and sensation (feeling temperature, pressure, and pain in the arm and hand).

Brachial plexus injuries occur when these nerves are stretched, compressed, torn, or avulsed (ripped away from the spinal cord). Severity varies widely: - **Neuropraxia:** minor stretching with temporary conduction block — usually recovers within weeks - **Axonotmesis:** more severe stretch causing axon damage — recovery possible but slower - **Neurotmesis / avulsion:** complete nerve rupture or root avulsion from the spinal cord — most severe; surgical reconstruction needed

**Causes in adults:** - Blunt trauma (motor vehicle accidents, falls) - Contact sports (football "stingers" — temporary burning/numbness from nerve stretching) - Gunshot wounds - Surgical positioning or injection injury - Tumour invasion or radiation treatment

**Birth injuries:** Occur in 1–2 per 1,000 births. Large babies, breech presentation, prolonged labour, and shoulder dystocia increase risk. - **Erb's palsy** — upper brachial plexus (C5–C6); shoulder/elbow weakness; classic "waiter's tip" posture - **Klumpke's palsy** — lower brachial plexus (C8–T1); hand and wrist weakness; intrinsic hand muscle paralysis

**Symptoms** depend on which roots are injured: - Numbness or loss of sensation in the hand or arm - Inability to control the shoulder, arm, wrist, or hand - Arm hanging limply - Burning, stinging, or severe pain in the shoulder or arm

Mild injuries (neuropraxia) may resolve without treatment. More severe injuries require rehabilitation, and some need surgery — ideally within 6 months of injury, since nerve tissue heals slowly and delayed repair reduces outcomes.