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Radial Mononeuropathy

  • Author: Wayne E Anderson, DO, FAHS, FAAN; Chief Editor: Nicholas Lorenzo, MD, MHA, CPE  more...
Updated: Mar 30, 2016


Radial neuropathies result from injury due to penetrating wounds or fractures of the arm, compression, or ischemia. Most commonly, they present with a wrist drop. The pattern of clinical involvement is dependent on the level of injury.

Radial neuropathies can occur from surgical procedures such as humeral nailing performed to stabilize an acute humeral fracture.[1]

The terms Saturday night palsy and honeymooner's palsy refer to the concept of placing one's arm over another chair, with the resultant pressure causing injury to the radial nerve.



An introduction to radial nerve anatomy is essential for understanding the common mechanisms and location of its injury. The radial nerve branches from the posterior cord of the brachial plexus. It receives root innervation from C5-T1 spinal roots. In the upper arm, the radial nerve gives off a branch to the triceps muscle before it wraps around the humerus at the spiral groove. Three sensory branches, which supply the skin over the triceps and posterior forearm, also are given off at this level. Here, its proximity to the humerus makes it susceptible to compression and/or trauma.

After exiting the spiral groove, the radial nerve supplies the brachioradialis muscle before dividing into the posterior interosseous branch and a sensory branch. The posterior interosseous branch is a pure motor nerve that supplies the supinator. It then dives into the supinator through the fascia to supply the muscles of the wrist and finger extension. This fascia is another common site for nerve damage to occur. The sensory branch that arises approximately at the elbow travels down the forearm, becoming superficial at the wrist before it supplies the lateral aspect of the dorsum of the hand. See the image below.

The Radial Nerve from Gray's Anatomy (published 19The Radial Nerve from Gray's Anatomy (published 1918, public domain, copyright expired).



United States

Radial neuropathy is the fourth most common mononeuropathy.


No racial preponderance is known.


No gender predilection has been observed.


Radial neuropathy is reported in all age groups.

Contributor Information and Disclosures

Wayne E Anderson, DO, FAHS, FAAN Assistant Professor of Internal Medicine/Neurology, College of Osteopathic Medicine of the Pacific Western University of Health Sciences; Clinical Faculty in Family Medicine, Touro University College of Osteopathic Medicine; Clinical Instructor, Departments of Neurology and Pain Management, California Pacific Medical Center

Wayne E Anderson, DO, FAHS, FAAN is a member of the following medical societies: California Medical Association, American Headache Society, San Francisco Medical Society, San Francisco Medical Society, International Headache Society, California Neurology Society, San Francisco Neurological Society, American Academy of Neurology, California Medical Association

Disclosure: Received honoraria from Teva for speaking and teaching; Received grant/research funds from Allergan for other; Received honoraria from Insys for speaking and teaching; Received honoraria from DepoMed for speaking and teaching.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Neil A Busis, MD Chief of Neurology and Director of Neurodagnostic Laboratory, UPMC Shadyside; Clinical Professor of Neurology and Director of Community Neurology, Department of Neurology, University of Pittsburgh Physicians

Neil A Busis, MD is a member of the following medical societies: American Academy of Neurology, American Association of Neuromuscular and Electrodiagnostic Medicine

Disclosure: Nothing to disclose.

Chief Editor

Nicholas Lorenzo, MD, MHA, CPE Founding Editor-in-Chief, eMedicine Neurology; Founder and CEO/CMO, PHLT Consultants; Chief Medical Officer, MeMD Inc

Nicholas Lorenzo, MD, MHA, CPE is a member of the following medical societies: Alpha Omega Alpha, American Association for Physician Leadership, American Academy of Neurology

Disclosure: Nothing to disclose.

Additional Contributors

Aashit K Shah, MD, FAAN, FANA Professor and Associate Chair of Neurology, Director, Comprehensive Epilepsy Program, Program Director, Clinical Neurophysiology Fellowship, Detroit Medical Center, Wayne State University School of Medicine

Aashit K Shah, MD, FAAN, FANA is a member of the following medical societies: American Academy of Neurology, American Neurological Association, American Clinical Neurophysiology Society, American Epilepsy Society

Disclosure: Received consulting fee from UCB pharma for speaking and teaching; Received grant/research funds from UCB Pharma for other; Received consulting fee from Sunovion for speaking and teaching; Received consulting fee from Lundbeck for speaking and teaching.

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The Radial Nerve from Gray's Anatomy (published 1918, public domain, copyright expired).
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