Carpal Tunnel Syndrome

What is carpal tunnel syndrome?

It is the compression of the median nerve as it passes through the wrist. The median nerve is one of the 3 nerves of the hand. Its role is the sensation of the first 3 fingers of the hand and the motor function of the thumb. It therefore contributes to the strength and dexterity of the hand.

At the wrist level, it passes through a narrowed space - the carpal tunnel - between the wrist bones and a rigid and very resistant ligament, the flexor retinaculum. Along with it travel through this canal the flexor tendons of the fingers surrounded by synovium.

Carpal tunnel syndrome is the compression of the nerve in this space, whatever the cause. Most often it is not precisely identified, related to inflammation of the synovial sheath surrounding the tendons.

Many other causes exist, with the most common being: hypothyroidism, diabetes, hormonal changes including pregnancy, certain rheumatic diseases...

Sectioning the flexor retinaculum will relieve the compression on the median nerve

How does carpal tunnel syndrome usually present?

In most cases, the symptoms are related to nerve compression. Paresthesias ("pins and needles") are found in the first 3 fingers and clumsiness.

At the beginning

Paresthesias occur mainly at the end of the night, forcing one or more awakenings and shaking the hand often makes them disappear.

When the disease progresses

Paresthesias appear during the day, indicating the beginning of nerve damage.

Severe damage (after several years)

Thumb atrophy (muscle wasting) and permanent decrease in sensation (hypoesthesia) may occur.

This is the most classic presentation, but the disease presentation is sometimes more insidious or incomplete.

Diagnosis

The best way to confirm carpal tunnel syndrome is to perform an electromyogram (EMG).

This examination, performed by a specialist (usually a neurologist or rheumatologist), measures the nerve conduction velocity and looks for a slowdown as it passes through the wrist. This confirms the existence of the disease and specifies the state of the nerve, thus the severity of the problem.

I have carpal tunnel syndrome, what can be done?

Several parameters come into play for the treatment decision, such as age, severity of discomfort, EMG results, professional activity, speed of progression... all these parameters are best evaluated by your doctor and surgeon during consultation.

Conservative treatment

When the condition is very early, a splint or corticosteroid infiltration can reduce symptoms (often temporarily) and allow waiting until the discomfort is more significant to justify surgery.

Surgical treatment

When the disease is more advanced, surgical nerve decompression is often preferable and inevitable.

Surgery aims to section the flexor retinaculum to increase the volume of the carpal tunnel and thus decompress the nerve.

I'm going to have carpal tunnel surgery... what will happen to me?

It is a routine procedure of short duration, most often performed under regional anesthesia, in outpatient hospitalization.

Healing

Two weeks of healing are necessary, with a small dressing. For 1 month, it is not recommended to carry loads, otherwise there is a risk of recurrence of carpal tunnel syndrome.

Convalescence

The hand is often in convalescence for about 2 to 3 months (duration varies depending on individuals) with decreased strength and pain in the heel of the hand, due to muscular adaptation from the opening of the ligament. This situation resolves with ligament healing, time and hand re-strengthening through daily use.

Disappearance of symptoms

Symptoms disappear depending on the extent of nerve damage:

Nocturnal paresthesias: generally disappear quickly after compression is relieved
Daytime paresthesias, atrophy or hypoesthesia: indicate more severe nerve damage requiring nerve regrowth, which takes longer (several months) and is sometimes incomplete (depending on age, smoking, etc.)

Is carpal tunnel surgery risk-free?

No, of course not. Although it is a codified, routine and mastered procedure, the risk exists, as with any surgery, even if complications are rare.

We mainly find, even if all precautions are taken:

Healing difficulties
Hematoma
Local infection
Incomplete nerve release
Algodystrophy
Anesthetic complications
Section of a nerve branch
Reinnervation pain (exuberant nerve regrowth after release in severe forms)

Discomfort in the heel of the hand and on the scar is most common, but decreases with time and massage.

What is the risk of not having surgery?

The risk is the continuation of the disease leading to complete or almost complete destruction of the nerve: permanent anesthesia of the fingers, loss of thumb strength leading to major discomfort.

In addition, the destroyed nerve can cause neuropathic pain that is particularly difficult to control.

At this stage, surgical treatment is still offered, but the final result is often incomplete. Since the operative risks are the same at different stages of the disease, it is generally preferable to release the nerve before the appearance of a severe form.