Understanding Radial Nerve Palsy

Radial nerve palsy is more commonly known as wrist drop or radial nerve dysfunction. A person affected with this condition cannot straighten or extend the wrist. Instead of extending normally, the wrist hangs limply.

The Radial Nerve

To better understand this condition, it's necessary to understand what the radial nerve is, and what it controls. Our nerves supply information to and from the brain to the rest of the body, including information that control and regulate the actions of the muscles. The radial nerve is a nerve that regulates movement in the upper arm, specifically the triceps muscle, as well as the muscles that move the wrist and the fingers. An injury to the radial nerve, or a disorder affecting the nerve, can consequently affect either the ability to move the forearm and/or the wrist and fingers normally, or the ability to experience any sensation of feeling in the arm, wrist, or fingers.

This nerve dysfunction is usually only a temporary condition, although at times it may be permanent. This depends on whether there has been unusual pressure placed upon the radial nerve, in which case any resulting problems usually go away soon after the pressure is removed, or whether the nerve has suffered permanent damage, in which case the palsy could be permanent as well.

A Cause Of Temporary Palsy

Radial nerve palsy is occasionally referred to as “Saturday night palsy”. A limp wrist can be caused by having the arm in an unusual position while sleeping, such that pressure is put on the nerve to the point where it no longer can regulate movement in the muscles of the wrist. Consequently the wrist will hang limply, though usually not for an extended period of time. The name Saturday night palsy is associated with the person who passes out from having had too much alcohol, and either sleeps on his arm, or has it dangling over the back of a chair. In addition to not being able to control wrist movement, the wrist may also be numb. We often experience a similar situation when we are sitting in an awkward position and our foot “goes to sleep”.

Collateral Damage

Most of the time, radial nerve palsy is quite temporary, and little more than a nuisance if and when we do experience it. If it is the result of an injury however, treatment and/or therapy may be needed to correct the condition. If the nerve itself has been irreparably damaged, the dysfunction will likely be permanent, although splinting the forearm or wrist may at times offer a partial fix. A wound, such as a stab wound, may not directly cause damage to the radial nerve, but if t is in close proximity to the nerve, it can sometimes adversely affect the nerve's function. An injury, such as a fractured bone in the arm, can often damage the radial nerve, as it lies in close proximity to the bone. A bone chip can place pressure on the nerve, causing the dysfunction.  Among the more common causes of radial nerve dysfunction or palsy is a dislocated elbow, since the nerve often can suffer what could be considered to be collateral damage. In such instances, once the injury has been effectively treated, the radial nerve will usually return to normal.

Surgery And Splints

Quite often it's not only the wrist that's affected, but the fingers and thumb as well. Not only might the wrist be limp, but the fingers cannot be extended, nor can the thumb. The hand, for all practical purposes, becomes useless. Splinting of the hand coupled with surgical tendon transfers is the usual method of treatment. This method of treatment often enables the hand to become useful again, since the tendon transfers result in some muscle movement capability being preserved or restored. The splint is kept in place until the radial nerve has healed, a process that can take anywhere from one month to a year. Because of the tendon transfers, the hand may function in a relatively normal fashion, as long as the splint is in place.

The splint itself may be a rather complicated apparatus, since the objective is to provide strength and support to the wrist, while at the same time promoting nearly normal manipulative ability in the hand. The two do not go hand in hand. A splint that is designed to give the wrist a great deal of strength and support may not assist the hand in manipulating small objects. Most surgeons prefer a splint that enables one to utilize a power grip when needed, sometimes at the expense of manipulation.

In summary, radial nerve palsy is something that most of us are apt to experience at one time or another, but we usually experience it as a very temporary condition, often lasting less than a minute. The situation can become more serious, and semi-permanent to permanent, if the radial nerve has suffered significant damage. Because of its proximity to the bones in the arm, this nerve is subject to injury if a bone is fractured or the elbow is dislocated. In cases of severe injury, a combination of splinting the wrist and tendon transfer is often the treatment of choice.