Superficial Radial Nerve
| |
| Superficial Radial Nerve | |
|---|---|
| Synonym | Superficial branch of the radial nerve |
| Nerve Type | Sensory nerve |
| Origin | Branch of the radial nerve, all roots are from C5-T1 of the brachial plexus. It arises under the proximal tendon of the brachioradialis in the upper to middle third of the forearm |
| Course | Through the posterior compartment of the forearm between the pronator teres and brachioradialis muscles. Heads to the anatomical snuffbox. |
| Major Branches | Medial and lateral terminal branches |
| Sensory innervation | Medial branch supplies ulnar aspect of dorsum of thumb, dorsum of index finger and middle fingers, and radial aspect of fourth fingers. Lateral branch supplies radial aspect of thumb and dorsal surface of base of thumb. |
The superficial radial nerve (SRN) is provides part of the sensory innervation of the hand. This article explores the anatomy, function, and clinical significance of the superficial radial nerve in depth.
Anatomy
The SRN is a terminal branch of the radial nerve, one of the major nerves originating from the brachial plexus. The radial nerve, after providing motor and sensory branches in the arm and forearm, bifurcates into the deep radial nerve and the superficial radial nerve.
The SRN emerges at the level of the lateral epicondyle, running between the brachioradialis and pronator teres muscles. The nerve then descends along the radial aspect of the forearm before piercing the deep fascia near the wrist. Finally, it branches out into multiple sensory branches to innervate the dorsum of the hand.
Function
The primary function of the superficial radial nerve is sensory innervation. It provides cutaneous sensation to the following areas:
- Medial branch supplies ulnar aspect of dorsum of thumb, dorsum of index finger and middle fingers, and radial aspect of fourth fingers
- Lateral branch supplies radial aspect of thumb and dorsal surface of base of thumb.
It is important to note that the SRN does not supply motor function, as the deep radial nerve carries motor fibers to the extensor muscles of the forearm.
Clinical Significance
Superficial radial nerve injuries can result from trauma, compression, or entrapment. Symptoms may include:
- Numbness or tingling on the dorsum of the hand
- Pain along the radial aspect of the forearm
- Loss of sensation in the innervated areas
Injury to the SRN can occur from various causes such as fractures, lacerations, and iatrogenic injuries from medical procedures. Conservative management typically involves rest, immobilization, and anti-inflammatory medications. In severe cases or if conservative management fails, surgical intervention may be necessary.
Wartenberg's syndrome, also known as superficial radial nerve entrapment or cheiralgia paresthetica, is a condition in which the superficial radial nerve is compressed as it passes through the forearm's fascial layers. This compression results in pain, numbness, and tingling in the distribution of the SRN. The condition is often caused by repetitive motion, trauma, or tight wristbands and bracelets.
