Radial neuropathy

"Handcuff Neuropathy" redirects here. For other uses, see Handcuff Neuropathy (disambiguation).

Radial neuropathy
Classification and external resources
The suprascapular, axillary, and radial nerves.
ICD-10	G56.3
ICD-9	354.3
eMedicine	neuro/587
MeSH	D020425

Radial neuropathy (or radial mononeuropathy) is a type of mononeuropathy which results from acute trauma to the radial nerve that extends the length of the arm.

It is known as transient paresthesia when sensation is temporarily abnormal.

Cultural references

There are a number of colloquial terms used to describe radial nerve injuries, which are usually dependent on the causation factor:

• Saturday night palsy from falling asleep with one's arm hanging over the arm rest of a chair, compressing the radial nerve at the spiral groove.
• Honeymoon palsy from another individual sleeping on and compressing one's arm overnight. This can also refer to Anterior interosseous nerve palsy from compression on the forearm resulting in an inability to flex the index and thumb tips. In this interpretation, it is a branch of the median nerve and not the radial nerve which is affected.
• Handcuff Neuropathy from tight fitting handcuffs compressing the superficial branch of the distal radial nerve; this is also referred to as cheiralgia paresthetica.
• Crutch palsy from poorly fitted axillary crutches.

Presentation

Symptoms vary depending on the severity and location of the trauma; however, common symptoms include wrist drop (the inability to extend the wrist upward when the hand is palm down); numbness of the back of the hand and wrist; and inability to voluntarily straighten the fingers. Loss of extension is due to paralysis of the posterior compartment of forearm muscles; although the arm extensors are also innervated by the radial nerve, their innervation is usually spared.

Causes

There are many ways to acquire radial neuropathy.

The term Saturday Night Palsy refers to nerve damage that can occur if a drunk person falls asleep with the back of their arms compressed by a bar edge, bench back, or like object. Radial neuropathy is also called honeymooners palsy, since it can be acquired by sitting with an arm draped over the back of a neighboring chair (or movie-theater seat) for a long time, or when somebody sleeps with his/her head rested on another persons arm.

Both Saturday night palsy and honeymooners palsy refer to the fact that the nerve damage is generally forewarned by arm pain to a degree that only excessive love or liquor would drive a person to keep their arm in such an uncomfortable position.

Breaking the humerus and deep puncture wounds can also cause the condition.

Improperly sitting in a chair for several hours such that the armrest compresses the underside of the forearm is another potential cause.

Prognosis

Radial neuropathy is not necessarily permanent. Peripheral nerve regeneration is an imperfect and slow process, and full restoration of ability may take months, years, or may never occur.