Symptoms can affect the following:

• The hand or forearm (dorsal surface)
• The "thumb side" (radial surface) of the dorsal hand
• The fingers nearest the thumb (2nd and 3rd)

The following symptoms may occur:

• Numbness, decreased sensation, tingling, or burning sensation
• Pain
• Abnormal sensations
• Difficulty extending the arm at the elbow
• Difficulty extending the wrist

A neuromuscular examination of the arm, hand, and wrist can identify radial nerve dysfunction. There may be weakness of the wrist and finger extension muscles (with decreased ability to extend the arm at the elbow), a minor decreased ability to rotate the arm outward (supination), and difficulty lifting the wrist or fingers (extensor muscle weakness).

Wrist drop or finger drop may be present, or there may be atrophy (muscle loss) of some of the muscles of the forearm. A detailed patient history may be needed to determine the possible cause of the neuropathy. Rarely, radial nerve dysfunction may be difficult to differentiate from a stroke in the brain.

Tests that reveal nerve dysfunction may include:

• EMG (a recording of electrical activity in muscles)
• Nerve conduction tests
• Nerve biopsy
• Head MRI (to rule out stroke)