Dr Shams Amir

Radial Tunnel Syndrome

Radial tunnel syndrome is caused by compression or irritation of the radial nerve around the outer side of the elbow and proximal forearm.

Classically, it presents predominantly as aching pain rather than numbness and can be difficult to distinguish from tennis elbow.

What does radial tunnel syndrome feel like?

Typical symptoms include:

Some patients describe discomfort extending further down the forearm.

What about numbness or shooting pain?

Classical radial tunnel syndrome mainly causes pain around the outer elbow and upper forearm. Numbness is not a defining feature.

Occasionally, in my practice, patients with radial tunnel symptoms also describe tingling or numbness radiating towards the back of the thumb and index finger. In these patients, I suspect that the superficial radial nerve—the branch carrying sensation from this part of the hand—may also be compressed near the region of posterior interosseous nerve entrapment.

This is a possible explanation based on my clinical observations, rather than an established mechanism of classical radial tunnel syndrome. These symptoms warrant assessment of the radial nerve and other possible causes along the upper limb.

Radial tunnel syndrome or tennis elbow?

The two conditions can look very similar and can also coexist.

Tennis elbow usually produces tenderness around the lateral epicondyle and pain related to loading the common extensor origin.

Radial tunnel symptoms are generally located slightly further down the forearm along the course of the radial nerve.

During examination, I therefore assess both the lateral epicondyle and radial tunnel rather than assuming that lateral elbow pain automatically represents tennis elbow.

How is radial tunnel syndrome diagnosed?

Radial tunnel syndrome is primarily a clinical diagnosis.

I look for localised tenderness along the radial tunnel and whether direct pressure reproduces the patient’s characteristic aching or radiating symptoms.

I also assess muscles supplied by the radial nerve and compare strength between the two upper limbs.

Patients may have subtle differences in power rather than complete muscle weakness.

Electrodiagnostic studies are frequently normal in classical radial tunnel syndrome.

In selected patients, I use dynamic ultrasound to assess the radial nerve during movement and look for possible sites of compression.

A normal investigation does not automatically exclude the diagnosis when the history and examination demonstrate a convincing clinical pattern.

Can more than one nerve be compressed?

Yes.

In my practice, I sometimes see radial tunnel symptoms occurring together with proximal median nerve compression such as pronator syndrome or with other areas of radial nerve irritation.

Anatomical variations and communications between nerves may also influence how an individual patient’s symptoms appear.

For this reason, I prefer to assess the entire upper limb and the pattern of symptoms rather than relying on one symptom or investigation alone.

How is radial tunnel syndrome treated?

Initial treatment is usually non-surgical and may include:

In my practice, treatment is directed not only at the painful area but also at contributing tightness or dysfunction elsewhere in the upper limb.

Surgical decompression may be considered when persistent symptoms remain functionally limiting despite appropriate non-operative treatment.

When should I seek assessment?

Persistent lateral elbow or proximal forearm pain deserves assessment when it interferes with work, sport or daily activities, particularly when previous treatment for presumed tennis elbow has not improved the symptoms.