Cubital Tunnel Syndrome

What is cubital tunnel syndrome?

Cubital tunnel syndrome, also called ulnar nerve entrapment, happens when your ulnar nerve gets irritated or compressed (squeezed) at the inside of your elbow.

Nerves are bundles of string-like fibers that send and receive messages between your brain and your body via electrical and chemical changes in the cells. There are three main nerves in your arm: the median, the ulnar and the radial. The ulnar goes from your neck down your arm and to your hand.

You may have cubital tunnel syndrome if your ulnar nerve is compressed or irritated at the elbow. The nerve may also be affected higher on the arm or at the wrist.

What does the ulnar nerve do?

Did you know that your funny bone isn’t a bone? It’s a nerve. That unique, almost electric sensation you feel when you hit your funny bone is actually the compression of your ulnar nerve.

Your ulnar goes through a tunnel of tissues called the cubital tunnel, which travels under a bony bump on the inside of your elbow called the medial epicondyle. The space is narrow, and there's only a little tissue protecting it. That spot is where your ulnar nerve is most vulnerable. After the medial epicondyle, the ulnar nerve continues under the muscles on the inside of your forearm and into your hand — on the side that has your little finger (pinky). When it enters your hand, it goes through another tunnel called Guyon's canal.

Because of your ulnar nerve, you can control some of the bigger muscles in your forearm (the ones that help you grip objects), feel your little finger, feel half of your ring finger and control many of the muscles in your hand. Those muscles in your hand help you perform fine movements such as typing on a keyboard and playing a musical instrument.

Who is at risk for cubital tunnel syndrome?

Some factors that put you at risk for cubital tunnel syndrome include:

• Arthritis of your elbow.
• Bending your elbow for a long time.
• Bone spurs.
• Cysts near your elbow joint.
• Past elbow dislocation.
• Past elbow fracture.
• Swelling of your elbow joint.

Just because you’ve had these symptoms doesn’t mean you’ll automatically get cubital tunnel syndrome. It just means that you’re more at risk than the average person.

What’s the difference between cubital tunnel syndrome and carpal tunnel syndrome?

Cubital tunnel syndrome affects your pinky and ring finger. Carpal tunnel syndrome affects your thumb, index finger and middle finger.

What causes cubital tunnel syndrome?

Your healthcare provider might not be able to narrow down the exact cause of your cubital tunnel syndrome. Possible causes include:

• Anatomy: Over time, the soft tissues over your ulnar nerve might get thicker, or there might be extra muscle. Both of those issues can stop your nerve from working right and cause cubital tunnel syndrome.
• Pressure: A seemingly simple use of your elbow, like leaning it on an armrest, can press on the ulnar nerve. When the nerve gets compressed, you might feel your arm, hand, ring finger and pinky finger fall asleep.
• Snapping: Your ulnar nerve might not stay where it’s supposed to. It might snap over the medial epicondyle when you move it. Snapping it repeatedly irritates the nerve.
• Stretching: If you bend your elbow for a long time, like when you sleep, you might overstretch the nerve. Too much stretching could result in cubital tunnel syndrome.

What are the symptoms of cubital tunnel syndrome?

See your healthcare provider if you've had the following symptoms for more than six weeks or if they're severe. You could get muscle wasting in your hand if you wait too long to get treatment for the compressed nerve. But if you do get treatment, your symptoms should improve or go away.

Symptoms of cubital tunnel syndrome include:

• Difficulty moving your fingers when they’re numb or tingling (falling asleep).
• Numbness in your hand and fingers that comes and goes.
• Pain on the inside of your elbow.
• Tingling in your hand and fingers that comes and goes.

Inner elbow pain and numbness and tingling in your hand are the most common symptoms. This happens most often when your elbow is bent. Your elbow might be bent when you:

• Drive.
• Hold a phone.
• Sleep.

How is cubital tunnel syndrome diagnosed?

Your healthcare provider will likely start the diagnosis process by asking questions about your symptoms. Then they’ll order several tests, which may include:

• Blood tests for diabetes or thyroid disease.
• Electromyogram (EMG), which will show your provider how your nerves and nearby muscles are acting.
• X-rays to check for bone spurs, arthritis and places where bone might compress the ulnar nerve.

What questions might a healthcare provider ask to diagnose cubital tunnel syndrome?

Your healthcare provider might ask the following questions at your appointment:

• What are your symptoms?
• How long have you had these symptoms?
• What medications do you take?
• Do you feel numbness?
• Do you feel like your hand or fingers are falling asleep?
• Do you feel pins and needles?
• How bad is the pain?
• Are you able to perform fine movements like typing?
• Have you ever had a fractured or dislocated elbow?

How is cubital tunnel syndrome treated?

There are both surgical and nonsurgical treatments for cubital tunnel syndrome. Healthcare providers prefer non-invasive treatments first and usually start with the nonsurgical options. They include:

• Bracing or splinting: Wearing a padded brace or splint when you sleep might help keep your elbow straight.
• Exercise: Nerve gliding exercises might help your ulnar nerve to slide more easily through the cubital tunnel. These exercises might also prevent stiffness in your arm and wrist. One exercise you could try is holding your arm in front of you with your elbow straight, then curling your wrist and fingers toward your body. Then, push them away from you and bend your elbow. Check with your healthcare provider to see if nerve gliding exercises are right for you.
• Hand therapy: A hand therapist might help you learn ways to avoid putting pressure on your ulnar nerve.
• Nonsteroidal anti-inflammatory drugs (NSAIDs): Medications such as Ibuprofen (Advil®, Motrin®) might help. They can reduce the swelling around your nerve and lessen your pain from cubital tunnel syndrome.

If nonsurgical treatments don't improve your cubital tunnel syndrome, your nerve is very compressed or the compression has caused muscle weakness, your healthcare provider might recommend surgery. You'll get sent to an orthopaedic surgeon. There are a few types of surgeries that help with cubital tunnel syndrome. They include:

• Cubital tunnel release: The roof of your cubital tunnel is a ligament. This type of surgery cuts and divides your ligament, making the tunnel bigger and decreasing pressure on your ulnar nerve. New tissue will grow where your ligament gets cut.
• Ulnar nerve anterior transposition: In this surgery, your surgeon moves your ulnar nerve from behind the medial epicondyle to the front (closest to your skin). The procedure stops the nerve from getting caught on your bone.
• Medial epicondylectomy: This surgery removes part of the medial epicondyle to release your nerve.

These procedures are usually outpatient, but you might need to stay one night at the hospital. You’ll likely need to wear a splint on your arm for about two to three weeks. Physical therapy is sometimes necessary to regain your motion and strength.

Surgery doesn’t guarantee that cubital tunnel syndrome will go away permanently. However, the outcome is generally positive.

How long does it take to recover from cubital tunnel syndrome?

Recovery can take many months. Nerves don’t heal as quickly as other parts of your body.

How can I reduce my risk of cubital tunnel syndrome?

Although it might not be possible to prevent cubital tunnel syndrome, there are a few ways you can help reduce your risk:

• Avoid leaning on your elbow.
• Avoid putting pressure on the inside of your arm.
• Don't rest your elbow on your computer chair armrest if you use it frequently. Keep your chair high.
• Sleep with your elbow straight.
• Stay away from anything that makes you bend your arm for a long time.

What happens if cubital tunnel syndrome goes untreated?

You might experience a problem called atrophy (muscle wasting in your hand) if you don’t get treatment for cubital tunnel syndrome. Your muscles could weaken. Your hand might look bony and not function as well.

When should I contact my healthcare provider?

Contact your healthcare provider if your symptoms of cubital tunnel syndrome are severe or if they’ve lasted for more than six weeks. It’s important to get treatment because cubital tunnel syndrome can weaken and shrink the muscles in your hand (muscle wasting), causing clumsiness and additional pain.

What questions should I ask my healthcare provider about cubital tunnel syndrome?

Consider asking your healthcare provider the following questions:

• What caused my cubital tunnel syndrome?
• What nonsurgical methods of treatment should I try?
• Do I need surgery?
• Will I have to stay in the hospital overnight after surgery?
• Do I need physical therapy?
• How long will it take my nerve to heal?

A note from Cleveland Clinic

A healthy ulnar nerve is important for arm and hand use and sensation of your pinky and half of your ring finger. It helps you control muscles in your forearm and muscles in your hand. When that nerve is compressed or irritated, you might have symptoms including pain, numbness, tingling and the sensation that your extremity is falling asleep. See your healthcare provider if you experience these symptoms of cubital tunnel syndrome.

No one wants to be in pain all day. You don’t just have to put up with the symptoms of cubital tunnel syndrome. Treatment might improve your quality of life, and the sooner you get treatment, the sooner you’ll be in less pain.