Radial neuropathy.

Radial neuropathy is the third most common upper limb mononeuropathy after median and ulnar neuropathies. Muscle weakness, particularly wrist drop, is the main clinical feature of most cases of radial neuropathy, and an understanding of the radial nerve's anatomy generally makes localizing the lesion straightforward. Electrodiagnosis can help confirm a diagnosis of radial neuropathy and may help with more precise localization of the lesion. Nerve imaging with ultrasound or magnetic resonance neurography is increasingly used in diagnosis and is important in patients lacking a history of major arm or shoulder trauma. Radial neuropathy most often occurs in the setting of trauma, although many other uncommon causes have been described. With traumatic lesions, the prognosis for recovery is generally good, and for patients with persistent deficits, rehabilitation and surgical techniques may allow substantial functional improvement.