PERIPHERAL NERVE PALSY

Nerves function to provide mobility and sensation on the hand and upper limb. Part of the nervous system located between the cranial cavity and spinal cord is called central nervous system; and the parts from which they branch into the entire body are called peripheral nervous system. Palsy is a condition wherein peripheral nerve functions break down for any reason; hence the muscles to which the nerve or group of nerves transmits electric signals do not function any more.

Upper limb has five primary peripheral nerves. Axillar nerve, which is one of them, transmits electric signals to the deltoid, enabling the arm to open to the side. Radial nerve enables that the elbow, wrist and all of the fingers extend. Musculocutaneous nerve borrows its fibers to the biceps muscles, so the elbow is bent. Median and ulnar nerves enable touch sensation of our hand and bending movement of the wrist and fingers. Should any of the peripheral nerves cease to function and the patients become unable to do the aforecited functions.

The most common reason for the nerve palsy is cuts following a trauma. Otherwise, nerve compression, obtuse traumas that do not result in any cuts, tumors, although very rarely, a set of various neurological disorders that retain systemic or isolated nerves may appear to be influential factors.

On concluding that the nerve cannot recover on its own (which might take a couple of months), it becomes final with the help of a test called EMG that measures muscular and nervous functions. After this, a treatment is planned depending on the level of the nervous cut, age and profession of the patient and date of nervous cut. Palsy due to nervous cuts is treated in early periods by repairing it under the microscope. If a lot of time has passed, the treatment is made via tendon transplantation as irrevocable myolysis appear (Detailed information about tendon transplantations has been provided in this chapter). Physiotherapy is a compulsory and complementary part of many disorders in the field of hand surgery before and after the operation.

Source: peripheral nerve palsy

INJURY OF NERVES

Nerves are the transmission systems that transmit signals incoming from the brain to various parts of the body and vice versa. Nerves are made up of thousands of fibers, which progress in cables coiled in protective sheat as groups inside the nerves. The system that bears the cabled transmission is surrounded by a protective insulant.

There are two types of nerves as motor nerves that function to transmit signals from brain to muscles and control the movements, and sensory nerves that function to transmit pain, pressure, temperature and such sensations from various parts of the body.

Nerves can be damaged due to compression, pressure and cut-off. In case of stretching and pressure injuries, the structure of the protective layer surrounding the nerve is not interrupted, yet the transmission system breaks down due to fibers damages, hence the nervous system fails to function. In case of cut-off, not only the nerve fibers but also the surrounding protective layer is damaged. After damages, transmissions cannot be conveyed from brain to the muscles, hence they become dysfunctional or sensory transmissions received from different parts of the body cannot be transmitted to the brain.

Once the nerve fibers are damaged, the structure of the surrounding protective layer subsists. Part of the damaged nerve fibers up to upper transmission station die away and melt down, leaving the protective layer in the form of hollow tubes. Recovery period begins in a while. If the protective sheat is not damaged or the sheat is repaired, fibers continue to grow through the innards of hollow tubes and recovers up to the receptors of motor or sensory nerves. Nerves are the tissues that heal the most slowly in our body. If the protective sheat structure is not repaired, nerve endings that undergo a recovery period and grow on cannot find their way, hence cysts called neuroma are formed at the nerve ending. These cysts form painful electric signals when pressed on them.

If the nerves are fully cut, both nerve endings are identified for treatment and the surrounding protective sheat is repaired by way of thinnest stitches as possible (Fig. 1). Objective of the treatment is to ensure sustainability of the surrounding sheat structure and to enable the nerve fibers, which are now in a healing process, find their way up to the final transmission points. Nerve sheats should be treated carefully with the thinnest stitches as much as possible by way of microsurgery methods to avoid excessive scar tissue and pressure in the nerve healing area. Nerves thin down particularly on hand and finger levels and progress adjacent to vascular structures in general. When a damaged nerve is identified, the vascular damages are often identified in parallel. As very thin stitches are used, a 3-week plaster treatment is applied to protect the repaired area.

Nerve sheats are intended to be sewn back to their original place with the help of vascular structures upon nerves; however, hollow tubes do not often find their original place no matter how original the stitches are in terms of surgery. It is not possible for millions of fibrils to find their original place.

If the injury is very contaminated and is to be left open, nerves may not be sewn in the first surgical operation. In case of nervous defects, a nerve graft often collected from the leg is inserted in between to enable nervous sustainability.

It takes 3 to 4 weeks for nerve fiber to grow up against following the repairs. Fibrils usually progress 1 mm on average within the nerve tubes depending on the age of the patient, type of injury, smoking etc. For this purpose, sensory recovery may take up to 1 or 2 months and 6 or 8 months depending on the proximity of the injury to the target. During this time, the patient should be careful about finger tip injuries while touching warm objects and working. Activity of the muscles stimulated by the nerves should not be lost during the expected nerve recovery.

Source: injury of nerves

CUBITAL TUNNEL SYNDROME

Cubital tunnel syndrome is a condition where the ulnar nerve is exposed to a compression or pressure and causes some problems such as pain, swelling, numbness and loss of force. The nerve progresses between the two distinct starting point of the muscle (flexor carpi ulnaris) that bends our wrist. As nerve is very superficial in this area, it is open to the pressure and trauma.

When we bend our elbow, ulnar nerve stretches and compresses by being pushed to the bone projection that we call medical epicondyl. When a long time passes with this position, for example those who sleep by putting their hands under their heads (by bending the elbow) and those who has to lean the elbow; cubital tunnel syndrome formation is easy. The connective tissue that covers the nerve thicken by reacting against to the recurrent. When transmission quality of nerve fibers between the thickened connective tissue decreased, symptoms of the syndrome appear.

Symptoms of cubital tunnel syndrome include pain, weakness, numbness especially in 4th and 5th fingers and electric shock even after small crushes on the elbow level (Figure 2). In advanced phases, it is observed that it is difficult to move fingers to each other, and 4th and 5th fingers bend reversely while the person tries to hold the hand flat.

The disease is diagnosed by detection for the findings above and EMG (Electromyography) and nerve transmission test which will be performed by neurologists.

In early cases, less trauma is tried to be provided by describing positions that stretches the nerve and revealing these symptoms. In some cases, splinter which flattens the elbow helps to moderate symptoms. Surgery is required in long term and advanced patients. Only the arm is narcotized in the surgery (axillary block anesthesia). Ulnar nerve is carried to the front of the elbow by exiting from two projecting bones in the elbow. Numbness and electrification sense may disappear within several weeks-months. Physiotherapy is needed in some cases after the surgery.

Source: cubital tunnel syndrome