Guyon's Canal Syndrome

What is Guyon's canal syndrome?

It's an irritation or compression of the ulnar nerve on the inner side of the wrist, within its tunnel.

Specifically, what is Guyon's canal?

It's a tunnel through which several tendons and the ulnar nerve pass. The tunnel is formed by wrist bones and ligaments.  

If the space in Guyon's canal is too small for the ulnar nerve to move freely, irritation of this nerve can develop, which is known as Guyon's canal syndrome.

What is a nerve?

A nerve is a body structure responsible for transmitting information to our nervous system. Information travels through the nerve in the form of electricity. For example, nerves allow us to feel our skin when we touch a part of our body. They also allow us to send electricity to our muscles to contract them and move our limbs.

What is the ulnar nerve?

The ulnar nerve is one of the three main nerves in the arm. It starts in the neck, runs down the inside of the arm, elbow, and forearm, and passes through Guyon's canal on the inner side of the wrist, splitting into smaller branches towards the 4th and 5th fingers. The ulnar nerve is responsible for sensation in the 5th finger and half of the 4th finger. It also provides the electrical signal to several muscles in the wrist and fingers.

What are the causes of Guyon's canal syndrome?

The syndrome is caused by a combination of compression and stretching of the ulnar nerve, leading to circulation problems within the nerve.

The exact cause of the syndrome varies from person to person. Here are several factors that may be associated with Guyon's canal syndrome:

• Repetitive hand and wrist movements
• History of overload to the hand and wrist
  
  • For example: gymnasts who do a lot of handstand pirouettes
• Direct trauma to the wrist (falling on the hand)
• Prolonged pressure on the inside of the wrist
  
  • For example: cycling for long periods, doing a lot of floor exercises while supporting yourself on your hands (push-ups, planks on hands)

What are the symptoms of Guyon's canal syndrome?

The main symptoms are:

• Pain, burning, numbness, or tingling in the fingers
  
  • Often in the 4th and 5th fingers
• Feeling of loss of hand strength
• Change in sensation in the hand or fingers

Symptoms can also be felt in the wrist, the inner side of the forearm, and even at the inner elbow. When symptoms extend up the entire arm, it also indicates brachial neuralgia. See the brachial neuralgia section.

How is Guyon's canal syndrome diagnosed?

Diagnosis is made based on a review of your symptoms and a clinical examination.

Sometimes, an EMG (electromyographic examination) may be necessary to evaluate nerve function. However, the vast majority of Guyon's canal syndrome cases are treated without this test.

When should you consult a physiotherapist for Guyon's canal syndrome?

You should consult a physiotherapist if you have symptoms as described above or if your doctor has already ruled out any other cause that may be responsible for your pain.

You do not need to see a doctor before consulting a physiotherapist. If your condition requires you to see a doctor, your physiotherapist will be able to tell you.

What physiotherapy treatments are available for Guyon's canal syndrome?

Your physiotherapist will conduct an assessment to determine why your ulnar nerve is irritated. To do this, they will evaluate the following:

• Your joint mobility
• The gliding of your nerves
• Your postural habits
• The quality of your movements
• Your strength and stability

Based on the assessment results, your physiotherapist will:

• Mobilize the ulnar nerve with specific nerve techniques to reduce pain and improve movement.
• Mobilize the joints that prevent the nerve from moving properly (wrist, elbow, shoulder, neck).
• Provide you with specific nerve exercises to do at home to address the cause of the problem and relieve pain.
• Teach you how to properly manage your daily activities and hobbies to optimize healing
• Give you advice for your posture and movements.
• Advise you on the ergonomics of your workstation.

What can you do at home for Guyon's canal syndrome?

Temporarily stop doing movements that cause too much pain, and then gradually start doing them again.

Here are some other tips that may help:

• Sometimes, wearing a wrist splint temporarily, especially at night, can help reduce pain.
• If you have pain at night or morning stiffness, make sure your neck is well supported while sleeping with a pillow that fills the hollow of your neck.
• Avoid sleeping with your arm behind your head or under the pillow. Keep your arm along your body or supported with a pillow.

If you don't see any improvement after 10 days, you should consult a physiotherapist.

Sources

• Aleksenko D, Varacallo M. Guyon canal syndrome.