Carpal Tunnel Syndrome

What is the carpal tunnel?

The carpal tunnel is a narrow “channel” on the palm side of the wrist. Its “walls” are formed by the bones of the wrist and, on the palm side, by a strong ligament (the transverse carpal ligament). The tendons that bend the fingers pass through this narrow space, together with the median nerve.

The median nerve is responsible for sensation in the thumb, the index finger, the middle finger and half of the ring finger, as well as for the movement of certain muscles of the thumb. When, for any reason, the space inside the tunnel is reduced or the pressure increases, the median nerve is compressed — and carpal tunnel syndrome develops.

Causes and risk factors

In most cases, there is no single clear cause. Certain factors, however, are associated with an increased risk:

• Repetitive movements of the wrist and use of vibrating tools
• Female sex (the condition is clearly more common in women)
• Pregnancy (due to fluid retention — it often resolves after childbirth)
• Diabetes mellitus and thyroid disorders
• Rheumatoid arthritis and other inflammatory conditions
• Previous fractures or injuries of the wrist
• Hereditary predisposition (a narrower carpal tunnel)

Clinical picture – Symptoms

The symptoms of carpal tunnel syndrome are characteristic:

• Numbness and “pins and needles” in the thumb, the index finger, the middle finger and half of the ring finger — that is, in the area supplied by the median nerve.
• Worsening at night: Very characteristically, the symptoms wake the patient at night, who often feels the need to “shake” or move the hand to find relief.
• Pain, which may radiate towards the forearm.
• Weakness and clumsiness: Difficulty with fine tasks, a tendency to “drop” objects from the hand.
• In advanced cases: Atrophy (loss of bulk) of the muscles at the base of the thumb and permanent loss of sensation.

Diagnosis

Diagnosis is based on the characteristic history and on the clinical examination, which includes special tests that reproduce the symptoms (such as the Tinel and Phalen tests). The main confirmatory investigation is electromyography (EMG) and a nerve conduction study, which document the compression of the median nerve, assess its severity and rule out other causes. In selected cases, ultrasound is also used.

Treatment

Treatment depends on the severity of the symptoms and the findings of the electromyography.

Conservative treatment

In the mild and moderate stages, treatment can be conservative:

• A wrist splint, especially at night, which keeps the wrist in a neutral position and relieves the compression.
• Modification of activities that aggravate the symptoms.
• Anti-inflammatory medication.
• Local corticosteroid injections, which can offer significant, although often temporary, relief.

Surgical treatment

When the symptoms are severe or persistent, or when there is documented significant compression of the nerve with a risk of permanent damage, surgical decompression is indicated. The procedure —division of the transverse carpal ligament— “opens” the carpal tunnel, decompressing the median nerve. It is a short procedure, often performed under local anaesthesia and as a day case. The results are, as a rule, excellent, with rapid relief of the symptoms.

Why early treatment matters

Early treatment of carpal tunnel syndrome is important, as prolonged, severe compression of the median nerve can cause permanent damage — loss of sensation and atrophy of the thumb muscles, which are not fully reversed even after decompression. For this reason, persistent or worsening symptoms —especially when weakness or atrophy appears— should not be ignored.

Recovery

Recovery after surgical decompression is, as a rule, rapid. The patient can use the hand for light activities soon after the procedure, while full strength returns gradually over a period of weeks. Any pre-existing atrophy or severe loss of sensation may improve more slowly or only partially, depending on the severity and duration of the damage before surgery.

How it progresses without treatment

Carpal tunnel syndrome is, as a rule, a progressive condition. In the early stages, the symptoms are intermittent —appearing mainly at night or with certain activities— and subside with rest. As the compression of the nerve continues, the symptoms become more frequent and more persistent, appearing during the day as well.

In the advanced stages, the nerve damage can become permanent, with constant loss of sensation and atrophy of the muscles at the base of the thumb. It is this progression that makes early diagnosis and treatment so important: the earlier the nerve is decompressed, the more complete the expected recovery.

Cost of treatment

The cost depends on the type of treatment (conservative or surgical), the type of anaesthesia, the clinic, as well as the insurance cover. In most cases of surgical treatment, private insurance policies and insurance funds cover a significant part of the expense.

Precise information is given on an individual basis, after the clinical assessment. The practice is at your disposal for any relevant information.

More on the factors that determine the cost and on cover by insurance funds: Cost of surgery.

Differential diagnosis

Numbness in the hand is not always due to carpal tunnel syndrome. Similar symptoms can be caused by compression of a nerve at another site —for example, in the neck (cervical radiculopathy) or at the elbow (cubital tunnel syndrome)— as well as by other neurological or metabolic conditions. The distribution of the numbness helps to tell them apart: carpal tunnel syndrome characteristically affects the thumb, the index finger, the middle finger and half of the ring finger, while it leaves the little finger unaffected.

Precisely for this reason, the correct diagnosis —with clinical examination and, above all, with electromyography— is important, in order to confirm that it is indeed carpal tunnel syndrome and to rule out other causes that would require different treatment.

Frequently asked questions

Which fingers go numb in carpal tunnel syndrome?

Characteristically, the thumb, the index finger, the middle finger and half of the ring finger — the area supplied by the median nerve. The little finger is, as a rule, not affected.

Why does it get worse at night?

Worsening at night is very characteristic and is due, in part, to the position of the wrist during sleep. Many patients wake up and feel the need to “shake” their hand to find relief.

Is surgery always needed?

No. In the mild and moderate stages, a splint, modification of activities and injections can provide relief. Surgery is indicated in severe, persistent cases or when there is a risk of permanent nerve damage.

Is the operation difficult?

It is a short, safe procedure, often performed under local anaesthesia and as a day case. The results are, as a rule, excellent.

Is the cost covered by insurance?

In most cases of surgical treatment, private insurance policies and insurance funds cover part or all of the expense. The practice can give you detailed information.

Is it related to computer use?

Prolonged use of a keyboard and mouse can aggravate the symptoms in predisposed individuals, although it is not considered a main cause in itself. An ergonomic workstation set-up and regular breaks help.