Ulnar Nerve - Location, Function, Possible Nerve Disorders, and Treatment

What Is the Ulnar Nerve, and Where Is It Located?

The ulnar nerve is one of the major nerves present in one’s arm. There are two ulnar nerves in the body on either arm. It comes out of a network of nerves called the brachial plexus present in one’s neck and shoulders. All of these nerves emerge from the spinal cord, which is a downward extension of the brain protected by the bones of the spine. The ulnar nerve helps one move the hands, forearms, and fingers. It also carries the sensations one feels from these parts to the brain. When the nerve gets compressed or injured, one faces pain, numbness, and trouble using the arms.

What Is the Function of the Ulnar Nerve?

The ulnar nerve controls most of the small muscles in the arms. It starts from the armpit area and runs down to reach the muscles of the forearm, hand, and fingers. It branches out to form three additional nerves (muscular branch, dorsal cutaneous branch, and palmar cutaneous branch). The branches of the ulnar nerve communicate the commands sent from the brain to the muscles so that they can move in the desired manner. It also helps pass on feelings like touch, pain, pressure, vibration, heat, and cold to the brain. This nerve enables one:

• To grip and hold things.

• Write with a pen, button up a shirt, and turn the pages of a book.

• Bend and straighten the little finger and ring finger.

• Give feelings to the palm, little finger, part of the ring finger, and outer half of the hand towards the side of the little finger.

What Are the Disease Conditions Affecting the Ulnar Nerve?

Injuries can happen to the ulnar nerve anywhere on its path. A sudden traumatic injury may damage the nerve affecting its functions. Whereas long-term wear and tear in the body causing injury to the nerve displays slow progress of symptoms. Major causes of ulnar nerve injury are:

1. Dislocation of the elbow joint.

2. Fracture and formation of bony spikes around the nerve.

3. Arthritis and diabetes.

4. Leaning on the elbow or sleeping with the elbow in a bent position for a long time.

5. Tumors or cysts around the nerve.

6. As a result of surgical complications (a carpal tunnel or shoulder fracture repair).

What Are the Major Disorders Affecting the Ulnar Nerve?

• Cubital Tunnel Syndrome - This is caused by compression of the ulnar nerve (compression neuropathy) behind the elbow of the arm.

• Guyon Canal Syndrome - Also known as handlebar palsy, it often affects cyclists while gripping the handlebar of the cycle. Compression of the ulnar nerve in the wrist region is the reason behind this condition. One may develop small fluid-filled lumps (ganglion cysts) within the wrist, which may compress the nerve. Fractures in the small bones of the wrist can also result in nerve compression.

• Contusion Injuries to the Ulnar Nerve- Also known as funny bone injuries. One may experience a strange sensation of sharp electric shock-like pain, tingling, and numbness along the ulnar nerve after getting hit at a certain area behind the elbow.

• Traumatic Injuries to the Nerve - The trauma may be from a motor vehicle collision, falls, or sharp objects like a knife or broken glass. And it usually causes a cut, tears, or crushing injury to the nerve. The ulnar nerve suffers sudden severe damage in such events and loses its function.

What Are the General Symptoms Related to Ulnar Nerve Injuries?

Compression or injury to the ulnar nerve at the level of the elbow or wrist may cause:

1. Pain and weakness in the hand. Inability to write, type or grasp objects.

2. Pain in the elbow joint and wrist.

3. Tingling and numbness inside the palm and on the ring finger and little finger. Those two fingers tend to curl in like a claw.

4. The hand may become extremely sensitive to cold.

How Are the Ulnar Nerve Disorders Clinically Diagnosed?

The doctor will listen to all the symptoms one experiences, including their duration and progress. If there was an event of trauma leading to the nerve disorder, the doctor needs to know that too. Understanding the underlying cause of nerve injury is very important in planning the treatment. Secondly, the doctor will perform a neurological examination to identify the level of nerve function. There are various tests to evaluate the performance of the ulnar nerve from the muscle movements and pattern of response to stimulations. One may also conduct the following:

• Test for Tinel Sign - Where tapping on the area of suspected nerve injury may cause pain, numbness, or tingling along the path of the nerve.

• X-ray - Of the arm to look for bone fractures, bony spikes (bone spur), or other abnormalities compressing the nerve.

• Computed Tomography (CT) Scans and Magnetic Resonance Imaging (MRI) - These techniques give a better view of the underlying causes, such as tumors, lumps, or ganglions which may compress the nerve. A high-resolution ultrasound scan (USG) is helpful too.

• Electromyography (EMG) - This test helps measure the strength and speed of electrical signals passed from the nerve to the muscles. One can understand the level of nerve function from this test.

What Is the Treatment for Ulnar Nerve Disorders?

The first priority in treating ulnar nerve injury is to relieve the pressure and tension on the nerve. The doctor will treat the symptoms as well. One may adopt the following method of treatment:

1. Restrict the movement of the affected arm, joints, and wrist using protective padding or splints. One should avoid activities and movements that put pressure on the ulnar nerve.

2. Doctors may prescribe anti-inflammatory or steroid medications to control inflammation in the nerve. This also helps to reduce symptoms like pain.

3. Severe damage to the nerve requires surgical repair. The doctor may rejoin the severed nerve or do a nerve graft. One may repair a fractured bone that pinches the ulnar nerve or remove a mass or growth by compressing it, as per requirement.

4. One may perform an ulnar nerve transposition. It is a process where the nerve is relocated from the back of the elbow to the front so that it does not suffer strain while bending the elbow.

5. Physical therapy and occupational therapy exercises also help with weakness and mobility issues.

Conclusion:

Activities that put frequent heavy pressure on the elbows and wrists may injure the ulnar nerve. This is why certain people are at a higher risk of ulnar nerve compression. For instance, tennis players, golfers, bicyclists, and baseball players are at a higher risk. Smokers, construction workers, longtime keyboard users, and weightlifters also belong to a risk category. One should make the necessary lifestyle changes at home and work to relieve the pressure on the ulnar nerve. And seek medical help at the earliest if there is pain, weakness, or numbness in the arm.