Carpal tunnel syndrome

and Christiane Fux, medical editor

Sophie Matzik is a freelance writer for the medical team.

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Christiane Fux studied journalism and psychology in Hamburg. The experienced medical editor has been writing magazine articles, news and factual texts on all conceivable health topics since 2001. In addition to her work for, Christiane Fux is also active in prose. Her first crime novel was published in 2012, and she also writes, designs and publishes her own crime plays.

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Carpal tunnel syndrome is caused by a bottleneck in the tendon compartment of the wrist. This pinches the middle arm nerve, which supplies various areas of the hand. The hand goes to sleep and the patients suffer from numbness, paresthesia, pain, later paralysis and dysfunction. Read here what exactly carpal tunnel syndrome is, how it develops and how it can be treated.

ICD codes for this disease: ICD codes are internationally recognized codes for medical diagnoses. They can be found, for example, in doctor's letters or on certificates of incapacity for work. G56

Carpal Tunnel Syndrome: Brief Overview

Description: narrowed carpal tunnel in the wrist puts pressure on the middle arm nerve
Causes: long-term overload of the wrist, predisposition, rheumatism, injuries, water retention, diabetes, obesity, kidney weakness
Symptoms: hand falling asleep at night, abnormal sensations, pain, later functional restrictions, paralysis, decreased sense of touch
Diagnostics: Queries about typical symptoms and possible risk factors, function and pain tests, measurement of the nerve conduction velocity
Treatment: nocturnal immobilization by splint, cortisone treatment, if necessary surgical widening of the carpal tunnel
Prognosis: complete healing with timely therapy, irreversible paralysis symptoms possible with delayed start of treatment

What is carpal tunnel syndrome?

In carpal tunnel syndrome, an important tendon compartment, the so-called carpal tunnel, is narrowed in the wrist. It then constricts a nerve that supplies certain areas of the hand. Possible consequences are abnormal sensations, pain and symptoms of paralysis.

"Nerves do not forgive damage"

Three questions for

Prof. Dr. med. Dennis von Heimburg,
Specialist in hand surgery
1
Who is particularly likely to get carpal tunnel syndrome?

Prof. Dr. med. Dennis von Heimburg
In theory, anyone can get carpal tunnel syndrome. In fact, it is mostly women of an advanced age, mostly after menopause. Because the nerve shares a canal with tendons, tendon sliding tissue and fatty tissue. And that can swell due to hormonal factors. The nerve is the weakest participant in the canal and is most likely to be depressed. This then causes the typical complaints that you should urgently investigate.
2
How do you know the nerve is not being constricted elsewhere?

Prof. Dr. med. Dennis von Heimburg
For the diagnosis it is important what the patient describes. In addition, I send almost every patient to a neurologist. It measures the nerve conduction speed and does nerve tests and can thus determine where the problem is. The nerve can also be pinched on the shoulder, for example - but this is much more difficult to treat than carpal tunnel syndrome. The patients are often symptom-free after the treatment.
3
Does carpal tunnel syndrome always have to be operated on?

Prof. Dr. med. Dennis von Heimburg
There are also conservative methods such as keeping your hand still at night or taking cortisone. In the long term, however, only an operation will help. There are patients who report improvement without treatment - but this is usually not a good sign. The nerve causes fewer complaints because it conducts even worse. So my advice: Let the neurologist check you up sooner rather than later and then treat you surgically. Nerves do not forgive damage!
Prof. Dr. med. Dennis von Heimburg,
Specialist in hand surgery
Prof. von Heimburg is also a specialist in plastic and aesthetic surgery. He practices in his practice clinic Kaiserplatz in Frankfurt am Main.

The carpal tunnel is formed by the carpal bones and a stabilizing ligament of connective tissue. Some hand tendons and the middle arm nerve (nervus medianus) run in its center. This runs from the shoulder over the upper and lower arm. In addition to two other nerves, it controls muscle movements and enables the hand's sense of touch.

Location of the carpal tunnel

In carpal tunnel syndrome, the median arm nerve comes under pressure and can be permanently damaged.

Bottleneck in the wrist

If the tunnel narrows, the pressure stresses and irritates the nerve. Then the typical symptoms of a carpal tunnel syndrome appear, such as numbness, pain later even symptoms of paralysis.

The problem is that the first signs of a carpal tunnel syndrome such as the hands falling asleep at night, tingling sensations and slight discomfort are often not taken seriously. Some sufferers only go to the doctor when permanent damage has already occurred.

Carpal tunnel syndrome: causes and risk factors

There are a number of triggers for carpal tunnel syndrome and various risk factors that make it more likely.

Narrow carpal tunnel: People who naturally have a rather narrow carpal tunnel get sick more often. Because of this, women are about three times more likely to get carpal tunnel syndrome than men.

Heredity: Congenital anatomical constriction is probably also the reason why carpal tunnel syndrome is particularly common in some families.

Wrist stress: People who do physical work are three to seven times more likely to develop carpal tunnel syndrome than people who do not do physical work. Certain occupational groups are therefore particularly at risk. This includes all professional groups who operate machines with strong vibrations (for example jackhammers), as well as those whose wrist is permanently exposed to high levels of movement such as upholsterers or farmers.

Recent studies have shown that 50 percent of female cleaners also develop carpal tunnel syndrome. People who work a lot on the computer do not belong to the particularly endangered occupational groups.

Injuries: Carpal tunnel syndrome can develop after an injury near the wrist, especially after a broken spoke.

Inflammation: Another possible cause is inflammation and swelling of the tendon sheaths, which are also located in the carpal tunnel and then press on the nerve.

Rheumatism: Inflammation in the joints mainly affects rheumatism patients. Every second rheumatoid patient therefore develops carpal tunnel syndrome. Often this is even the first sign of an incipient rheumatic disease.

Chronic kidney failure (kidney failure): People who often have to dialysis because of kidney failure can develop carpal tunnel syndrome on the arm that is connected to the dialysis machine (shunt arm).

Water retention: If more water is stored in the joints and the ligaments thicken, the space in the carpal tunnel is also reduced. There are different triggers for this:

Hyperthyroidism or hypothyroidism
diabetes
Obesity
hormonal changes (pregnancy / menopause)

Symptoms

At an early stage, people often do not take carpal tunnel syndrome seriously. But the longer the nerve is pinched on the wrist, the more likely it will be permanently damaged. Therefore, you should already have the first signs of a carpal tunnel syndrome examined neurologically.

Early symptoms

Hands falling asleep at night: A typical sign of carpal tunnel syndrome in the early stages is the fingers falling asleep at night. In the beginning it is usually sufficient to reposition the hand. Later on, there is very severe pain that can stretch up into the arm and shoulder. Those affected often wake up at night with sore fingers. In the morning the fingers are swollen and stiff.

Parasitic sensations: The carpal tunnel syndrome is usually announced by tingling sensations on the palm of the hand. Later they gradually expand to part of the fingers.

The middle arm nerve supplies the inside of the thumb, the index and middle finger and the thumb side of the ring finger. This is where the classic symptoms can develop. The side of the ring finger facing the little finger and the little finger itself are not affected by carpal tunnel syndrome, as they are supplied by a different arm nerve.

Supply areas of the nerves in the arm

In carpal tunnel syndrome, the median nerve is damaged.

Pain: Initially, pain only occurs when the wrist is particularly stressed. This includes, for example, gardening, renovating or cleaning. At a later stage, the symptoms also appear suddenly for no apparent reason ("spontaneously").

Worsened sense of touch, clumsiness: The sense of touch and sensation of the fingers also deteriorate in carpal tunnel syndrome. Those affected then have difficulties buttoning a piece of clothing or picking up small objects, for example.

Carpal tunnel syndrome: symptoms in the later stage

Loss of sensitivity: If the pressure on the nerves persists for a long time, it is increasingly damaged. Soon the unpleasant sensations in the fingers disappear. In return, they become largely numb. Paralysis occurs later.

Muscle breakdown in the thumb: A muscle in the thumb that is controlled by this nerve then gradually recedes. A visible dent occurs on the ball of the thumb (ball of the thumb atrophy).

The function of the thumb is severely restricted by muscle wasting. This can restrict those affected in everyday work. If the thumb can no longer be spread apart, it is difficult for the patient, for example, to pick up something or to grasp a bottle.

At this stage the nerve is already very badly damaged. If therapy is only started now, it is often too late - the damage to the nerve cannot be reversed. Lifelong numbness in the palm and paralysis of the thumb can result.

Carpal Tunnel Syndrome: Symptoms on Both Hands?

Usually the symptoms develop one after the other on both hands. However, months or years can lie in between.

Since the dominant hand is more stressed, the carpal tunnel syndrome usually occurs there first - i.e. in the right hand in right-handed people. The symptoms are usually more pronounced here than in the other hand.

Carpal tunnel syndrome: examinations and diagnosis

The first step in diagnosing carpal tunnel syndrome is to ask about your personal medical history (anamnesis). The doctor asks the patient, among other things, about his symptoms and possible risk factors such as physical work, previous illnesses and illnesses in the family.

Physical examination

As part of the physical examination, the doctor first palpates the ball of the thumb muscles. In this way, he checks whether the muscle has already regressed.

Thumb function: The function of the thumb is also tested. The doctor asks the patient to hold a bottle, for example. It is typical of a carpal tunnel syndrome that the patient can no longer spread the thumb well or not at all.

Sensitivity: The doctor tests the sense of sensation by stroking the patient's palm with a cotton ball. If this does not perceive the touch, the surface sensitivity is disturbed.

Sense of touch: To test the sense of touch, the patient is given the task of picking up coins or paper clips.

Provocation tests

Hoffman-Tinel test: In this carpal tunnel syndrome test, the skin over the carpal tunnel is tapped. If this causes pain and abnormal sensations in the patient, this is a sign of carpal tunnel syndrome.

Phalen's sign: For this test, the patient must put their hands together with the backs of their hands. The wrist is strongly flexed. If the pain increases, this also speaks for a carpal tunnel syndrome.

Neurological carpal tunnel syndrome test

Carpal tunnel syndrome can only be diagnosed with certainty on the basis of a neurological examination.

In order to rule out other diseases with similar symptoms, the doctor often also examines the elbow region and the neck and shoulder area. The middle arm nerve can also be constricted at these points.

Electronurography (ENG): With the help of electroneurography, the doctor can measure how quickly the middle arm nerve transmits received stimuli and transmits them to a muscle. In a so-called surface ENG, electrodes are glued to the skin. Then the conduction velocity of the middle arm nerve is compared with that of a healthy nerve. This examination is painless.

In some cases an exact measurement with a surface ENG is not possible. This can be the case, for example, if the nerve runs differently than normal. For a needle ENG, small needles are then inserted directly into the vicinity of the nerve, with the help of which the measurement is carried out. That can hurt a bit. However, the investigation is relatively short. As a rule, there are no further complaints afterwards.

Ultrasound, X-ray, MRI: imaging procedures provide information about the condition of the carpal tunnel and possible causes

Ultrasound (sonography): The ultrasound examination can determine how narrow the carpal tunnel is.
X-ray: With an X-ray examination, the doctor can check whether osteoarthritis-like changes are narrowing the wrist.
Magnetic resonance imaging (MRI): If the doctor suspects that a tumor could be causing the symptoms, magnetic resonance imaging can provide information.

Carpal tunnel syndrome: treatment

Lighter cases of carpal tunnel syndrome can be relieved without surgery. For example, by immobilizing the affected hand with a splint overnight. If an inflammation is causing the narrowing of the carpal tunnel, cortisone can help - in the form of tablets, sometimes also as an injection.

In some cases, however, an operation is necessary for carpal tunnel syndrome:

if conservative treatment approaches do not achieve significant improvement within four weeks

if the patient is in severe pain at night
if the numbness persists in the affected hand
when the conduction velocity of the nerve is markedly reduced.

You can read more about conservative treatment options for carpal tunnel syndrome and the operation in the article Carpal tunnel syndrome therapy.

Carpal tunnel syndrome: disease course and prognosis

Carpal tunnel syndrome can develop in anyone. Usually, sooner or later, both hands are affected. It is estimated that up to ten percent of the population will have symptoms of carpal tunnel syndrome. However, not all cases require treatment.

Both symptoms and the course of carpal tunnel syndrome can vary greatly from patient to patient.

In general, however, the symptoms worsen continuously as the disease progresses. They increase in particular after heavy stress such as gardening, renovation work, machine work, but also during pregnancy and after arm injuries.

More rarely, the symptoms caused by carpal tunnel syndrome remain constant over a long period of time. Some patients have only moderate symptoms for years, which are interrupted by long symptom-free intervals. In such cases, those affected often go to the doctor late. The nerve is then usually irreversibly damaged.

Early surgery, complete healing

If the operation is timely and successful, the carpal tunnel syndrome can be completely cured. The pain usually disappears the day after the procedure. The patient has to train mobility, the sense of touch and sensation again.

Exercise hands after surgery

Be sure to perform the recommended exercises regularly and have a neurologist check the healing process after the operation.

The healing process can take a few months, depending on the severity of the disease.

Complications such as rebleeding and infection are rare with carpal tunnel surgery. However, in some cases further surgery is necessary.

Unable to work with severe nerve damage

If the nerve is badly damaged, complete healing is no longer possible. The patients then suffer permanently from sensory disturbances in the hand and from paralysis in the area of the thumb. This can severely restrict everyday and professional life and in individual cases even lead to occupational disability.

Therefore, be sure to see a doctor at the first signs of carpal tunnel syndrome. The earlier treatment begins, the better the chances of recovery!