Radial Nerve Palsy

RADIAL NERVE PALSY

• Radial nerve injury may be high or low.

1. High radial nerve palsy

• Injury is before the spiral groove.
• All muscles supplied by radial nerve are paralysed. 

2. Low radial nerve palsy

• Injury is after the spiral groove.
• Low radial nerve palsy may be of two types:-

i. Type I: Injury occurs b/w the spiral groove and elbow joint. Muscles involvement is:

• Elbow extensors (Triceps, anconeus) are spared.
• Wrist, elbow & finger extensors are paralysed
• Sensory loss in first web space (on dorsal side)

ii. Type II: Injury occurs below the elbow joint:

• Elbow extensors (triceps, anconeus), brachioradialis & wrist extensors (ECRL) are spared.
• Finger extensors (extensor digitorum, extensor digiti minimi, extensor indicis), ECRB and thumb extensors (extensor pollicis longus & brevis) are paralysed.
• Sensory loss in first web space (on dorsal side).

CLINICAL FEATURES OF RADIAL NERVE PALSY

• Clinical features depend upon the site of lesion.

1. If lesion is high

• Wrist drop, thumb drop & finger drop.
• Inability to extend elbow, wrist, thumb & fingers (MP joint).
• Patient can extend interphalangeal joints due to action of lumbricals & interossei.
• Sensory loss over posterior surface of arm & forearm and lower lateral half of forearm.

2. If lesion is low

a. Type I

• Wrist drop, thumb drop and finger drop.
• Elbow extension is preserved.
• Sensory loss over the dorsum of first web space.

b. Type II

• Thumb drop & finger drop
• Elbow & wrist extension is preserved
• Sensory loss over the dorsum of first web space