Dr Shams Amir

Cubital Tunnel Syndrome

Cubital tunnel syndrome occurs when the ulnar nerve is compressed or irritated around the inner side of the elbow.

It commonly causes numbness or tingling in the little finger and part of the ring finger and may eventually affect hand strength.

What does cubital tunnel syndrome feel like?

Common symptoms include:

Because the ulnar nerve supplies many of the small intrinsic muscles within the hand, more advanced compression can result in weakness and eventually muscle wasting.

Why does bending the elbow make symptoms worse?

The ulnar nerve passes along the inner side of the arm, behind the medial epicondyle at the elbow and into the proximal forearm.

Potential sites of compression include the region of the arcade of Struthers, the area behind the medial epicondyle and Osborne’s ligament, and the region where the nerve enters between the heads of the flexor carpi ulnaris.

Elbow position can change the tension and pressure around the nerve.

This is why patients may notice symptoms while sleeping with the elbow bent or during prolonged activities such as driving or other activities that keep the elbow flexed for long periods.

Repeated elbow flexion and extension may also aggravate symptoms in some patients.

How is cubital tunnel syndrome diagnosed?

Diagnosis starts with the clinical history and physical examination.

I examine the ulnar nerve along the inner side of the arm and elbow and look for areas where direct compression reproduces numbness, tingling or pain.

I also assess whether sustained elbow flexion reproduces the symptoms and examine hand strength and the small intrinsic muscles of the hand.

The ulnar nerve can sometimes move or sublux over the medial epicondyle during elbow movement.

I therefore assess the position and movement of the nerve during elbow flexion and extension when appropriate.

Nerve conduction studies can help assess ulnar nerve dysfunction, although the findings need to be interpreted alongside the clinical examination.

Dynamic ultrasound can also be useful in selected cases, particularly when assessing the nerve during elbow movement or looking for a specific site of compression.

A normal investigation does not necessarily exclude a clinically meaningful compression if the history and examination are convincing.

Cubital tunnel or Guyon’s canal?

The ulnar nerve can also become compressed at the wrist in an area known as Guyon’s canal.

Both conditions can produce symptoms involving the little and ring fingers.

The pattern of symptoms, examination of the hand and forearm, and whether symptoms are affected more by elbow or wrist position can help determine where the nerve is being affected.

Could the symptoms come from the neck or brachial plexus?

Yes.

Symptoms affecting the ulnar side of the hand can sometimes arise more proximally.

C8 or T1 cervical nerve pathology may produce symptoms extending from the neck or shoulder down the arm.

If symptoms involve several different nerve territories rather than the distribution of a single peripheral nerve, I also consider conditions affecting the brachial plexus, including neurogenic thoracic outlet syndrome.

How is cubital tunnel syndrome treated?

For mild or moderate disease, treatment may include:

If symptoms remain persistent or there is significant nerve dysfunction, weakness or muscle wasting, surgery may be considered.

Surgery may involve decompression of the ulnar nerve alone or, in selected patients, moving the nerve to a new position in front of the elbow — known as anterior transposition.

In advanced cases with substantial motor weakness or muscle wasting, additional nerve reconstruction procedures may occasionally be considered to support motor recovery.

When should I seek assessment?

Persistent numbness in the little and ring fingers should be assessed, particularly when it is accompanied by hand weakness.

Visible wasting of the small muscles of the hand or progressive loss of hand function warrants earlier specialist assessment.