What Is Ulnar Nerve?
The ulnar nerve runs around or near the ulna bone (long bone found in the upper forearm). The ulnar nerve is a single nerve network in the peripheral nervous system that carries information from the brain through the spinal cord. The ulnar nerve helps in moving the little and ring fingers and helps in grasping objects. It also transfers sensory information, such as pain, temperature, and touch.
What Is Ulnar Nerve Entrapment?
Ulnar nerve entrapment is one of the second most common types of peripheral compression neuropathy. It occurs when heavy pressure is put on the ulnar nerve in the elbow or wrist. When the nerve is compressed, it may lead to inflammation that leads to nerve damage or neuropathy. It is also known as bicycler’s neuropathy, Guyon's canal syndrome, tardy ulnar palsy, and cubital tunnel syndrome.
What Are the Ulnar Nerve Entrapment Types?
The types of ulnar nerve entrapment include the following:
- Guyon’s Canal Syndrome - This type is when the ulnar nerve entrapment occurs in the wrist area.
- Cubital Tunnel Syndrome - This type is when the ulnar nerve is stretched or pulled in the elbow region. It is the second most common type of peripheral neuropathy.
What Causes Ulnar Nerve Entrapment?
Ulnar nerve entrapment can occur due to excess force given on the ulnar nerve. Depending on the type, the causes vary. In cubital tunnel syndrome, the ulnar nerve entrapment occurs in the elbow region. The causes include:
- Elbow Injury - While playing a sport, driving a vehicle, falling on the elbow side, and sleeping with elbows bent.
- Bone and Joint Disease - One of the most common types of bone and joint disease is osteoarthritis. It is a very common type of arthritis that causes the cartilage cushions of the bones to wear down over time.
- Repeated Bending or Leaning - When an individual bend or lean continuously due to old age or day-to-day activities.
- Diabetes - Diabetic patients are more prone to weaker bones which leads to ulnar nerve entrapment.
- Hereditary Neuropathy with Pressure Palsies (HNPP) - It is an inherited condition that causes tingling and numbness in the limbs and muscles. The peripheral nerves are affected.
In Gyon’s canal syndrome, the wrist is affected, and the causes include:
- Laceration - Laceration refers to open cuts or skin wounds. In some lacerations, the soft body tissue is torn, and peripheral nerves are damaged, which leads to ulnar nerve entrapment.
- Ganglion Cyst - It is a noncancerous fluid sac that generally occurs around the wrist. Around 40 percent of the Guyon canal syndrome cases are due to this condition.
- Direct Trauma - Sudden or direct trauma to the wrist due to an accident or lifting heavy weights can affect the ulnar nerve.
What Are the Clinical Features of Ulnar Nerve Entrapment?
Common symptoms of ulnar nerve entrapment are listed below:
- Pain in wrist or elbow.
- Pain worsens at night while lifting objects or performing basic tasks like buttoning the shirt.
- Tingling sensation in the arm.
- Numbness around the affected area.
- Sensitivity to cold.
- Muscle loss in the ring or little finger.
- Curved ring and little finger.
- Tenderness in the elbow.
How Is Ulnar Nerve Entrapment Diagnosed?
Some of the diagnostic methods for ulnar nerve entrapment are listed below:
- Physical Examination - Some of the basic physical examinations, such as Froment's test, in which the doctor will ask the patient to hold a piece of paper between the index finger and thumb which will help in observing the flexing at the interphalangeal joint of the thumb if a nerve injury is there. Another test is Tinel’s test, in which the doctor examines the elbow’s funny bone or the ulnar nerve to see an extreme shock-like sensation in the little finger.
- Magnetic Resonance Imaging (MRI) - It is done to see the compressed nerves and other abnormalities like arthritis. A healthcare professional will ask the patient to lie down on the bed of the machine. Once the patient is settled, the expert will operate the machine in a different chamber. The machine will take several scans, which take around half an hour to complete.
- Electromyography (EMG): It is done to see how well the signals from the nerves stimulate the muscles.
How Is Ulnar Nerve Entrapment Managed?
Some of the treatment options include:
- To reduce nerve pain and swelling, nonsteroidal anti-inflammatory drugs (NSAIDs) are advised.
- Therapies like occupational and physical therapy helps in strengthening the muscles, improving flexibility, and doing basic tasks like lifting objects.
- To support the elbow or wrist, braces or splints are given.
- If the condition does not improve, surgery can help in releasing the pinched ulnar nerve and remove any cyst or tumor.
- In elbow surgery, an incision is made on the elbow to decompress the nerve, and in some cases, the nerve is moved to the inner part of the arm to give the elbow a more direct position.
- In wrist surgery, an incision is made to get clear access to the ulnar nerve, and the decompression is done. In most cases, full recovery is made within four to six weeks, and till then, no exerting physical activities are allowed.
Conclusion
Ulnar nerves carry the information from the brain and are transported to the spinal cord. Many types of entrapment of the ulnar nerve are there that can either affect the wrist or the elbow. If the ulnar nerve is compressed, it can cause a tingling or numbing sensation in the arm and cause severe pain. It can be diagnosed by an MRI or a physical examination. The swelling can be controlled by giving NSAIDs, and in some cases where the nerves are still compressed, a simple surgical procedure is one. Post-surgery, it is important to take good care of and rest of the arm and visit the doctor frequently.
