Introduction
Cubital tunnel syndrome is a condition causing numbness, tingling, pain and weakness in the hand. It is caused by compression / irritation of the ulnar nerve (one of the major arm nerves) at the level of the elbow.
The ulnar nerve is one of the major nerves supplying feeling and movement in the hand. It runs from the neck to the hand. It is most commonly compressed/irritated at the level of the cubital tunnel in the elbow.
The Cubital Tunnel is a groove on the inner aspect of the elbow (funny bone). The compression of the nerve may be due to scar tissue, ligament, muscle or bone at this level.
Cubital tunnel syndrome affects 1-2% of the population.
Causes
Pressure on Nerve
This pressure may be caused from local structures including muscle, ligament, scar tissue or bone.
Stretch of Nerve
The nerve may be stretched when the elbow is bent for long periods of time e.g.: sleeping.
The never may also be stretched if the elbow has an abnormal shape as a result of previous fracture.
Excessive Movement of nerve (Subluxation)
The nerve is normally stable in its position. However, if the nerve moves in and out of its position (subluxation) with elbow movement, this causes irritation of nerve.
Signs and symptoms
Diagnosis is based on patient symptoms and examination findings. Specific tests are only required when diagnosis is uncertain.
Reduced/loss of sensation
This affects the ring and little finger. It’s often worse when the elbow is bent for long periods e.g.: driving, sleeping or holding a phone.
Tingling
This may occur in the ring or little finger but other parts of hand and forearm can sometimes be affected. It’s often worse when the elbow is bent for long periods e.g.: driving, sleeping or holding a phone.
Finger Weakness
Finger movement may be weak or clumsy. This may be most evident when doing fine tasks such as playing instruments and using cutlery or dressing oneself.
Pain/Ache
This may affect the forearm or hand.
Tests
X-ray
This can show abnormalities of shape of bone or bone prominence that can irritate or cause pressure on nerve.
Ultrasound / MRI
These can show thickening of the nerve.
It can also demonstrate if there is any soft tissue structure causing pressure on nerve.
Ultrasound can sometimes demonstrate unstable nerve movement (subluxation) with elbow bending and straightening.
Nerve Conduction Test and EMG
This test is usually conducted by a Neurologist (nerve specialist). It is used to determine the conduction speed and signal strength of the Nerve. However, some patients with symptoms and signs of cubital tunnel syndrome may still have a normal test result.
Non-surgical treatment
Activity Modification
Keeping the elbow bent for prolonged periods can irritate the nerve. Avoiding such activities which cause the symptoms may help. For example:
- Changing jobs or changing roles at work.
- Avoid leaning on/bending elbow for prolonged periods.
Night splint / towels
A towel/splint can be used around the elbow to keep it straight when asleep to stop the stretching of nerve.
Pain Killers / Anti-inflammatory Medications
These assist with pain only.
Physical therapy
Nerve gliding exercises under the instructions of a therapist can provide symptom relief.