04/10/2025
The brachial plexus is a network of nerves formed by the C5-T1 spinal nerve roots that transmits motor and sensory signals from the spinal cord to the shoulder, arm, and hand. It is organized into roots, trunks, divisions, cords, and terminal branches. Injuries to the brachial plexus can result in symptoms like pain, numbness, weakness, or paralysis in the affected limb, and can occur due to trauma, compression, stretching, or inflammation.
The brachial plexus is composed of the following components, from proximal (closest to the spine) to distal (farthest from the spine):
Roots: The ventral rami of spinal nerves C5 through T1.
Trunks: Formed by the roots, these include the superior, middle, and inferior trunks.
Divisions: Each trunk splits into an anterior and posterior division, forming three cords.
Cords: These are the lateral, posterior, and medial cords, found near the axillary artery in the axilla.
Terminal Branches: Formed from the cords, these are the nerves that innervate the upper limb, such as the median, ulnar, and radial nerves.
Function
The primary role of the brachial plexus is to:
Send Motor Signals: Allow for movement in the shoulder, arm, and hand.
Send Sensory Signals: Convey sensations such as touch, pain, and temperature from the upper extremity to the brain.
Injuries
Brachial plexus injuries can occur due to various causes, including trauma from accidents, athletic injuries, tumors, inflammation (like brachial plexitis), or being stretched too far. Symptoms of injury can vary in severity but often include:
Limp or paralyzed arm
Loss of muscle control
Numbness or lack of sensation
Sudden, burning, or stinging pain
Treatment
Treatment depends on the type and severity of the injury and may include:
Conservative care: Monitoring, pain management, and physical therapy.
Surgery: In severe cases, nerve grafts or transfers may be necessary to restore function and sensation.