Carpal tunnel involves compression on the median nerve in the wrist. Compression on the median nerve causes pins and needles in the thumb index finger and middle finger. Carpal tunnel syndrome is widely misunderstood and there are thousands of treatments and gadgets that claim to relieve the pain. Understanding what causes the pain will make you think for yourself.
What is the Carpal Tunnel made up of?
The carpal tunnel is a narrow passageway in the wrist about 2.5 cm wide. The floor and sides of the tunnel consist of eight small wrist bones called the carpal bones. Furthermore the roof of the tunnel is a strong band of connective tissue called the transverse carpal ligament. As the boundaries are very rigid it therefore has little capacity to stretch or increase in size.
Within this tunnel there is a group of tendons as well as a nerve called the median nerve. They run from the forearm to the wrist. Think of these tendons and the nerve inside the tunnel as a group of cables inside a pipe. When one of these cables becomes swollen it can put pressure on the nerve resulting in nerve pain.
What does the median nerve do?
The median nerve is the power cable that supplies the thumb, index finger and middle finger with all the movement signals as well as feeling to the skin. This includes touch, temperature and a variety of other feelings.
How does Carpal Tunnel Syndrome happen?
The nerve is the “cable” from the brain to the muscles, pinching of the nerve can cause a disruption in the signal. A once off pinch will cause symptoms for a short while whereas continuous pinching will cause damage to the nerve therefore resulting in longer lasting symptoms.
When constant pressure is applied on the tendons and the nerve, they become irritated and swollen.
Due to the limited room for expansion, the swelling in the confined space will lead to more compression and the pain doesn’t abate.
Causes of Carpal Tunnel Syndrome
Overuse of certain muscles in the forearm can cause irritation on the tissue around the nerve, especially when these movements happen repeatedly throughout the day. It is very common in manual work when the wrist bends forwards and backwards combined with bending of the fingers and turning the forearm inwards. During this specific motion the pressure in the carpal tunnel is very high.
Symptoms of Carpal Tunnel Syndrome
Carpal tunnel type pain leads to abnormal feeling in the thumb, index finger and middle finger. This pain does not necessarily have to be constant, although it usually starts quite slow and gets worse over time. In some cases the nerve pain can start suddenly.
- Sit on the edge of a table and hold your forearm flats on the table with your hand hanging over the edge.
- Drop your wrist down towards the floor ( insure that your wrist bends the full 90 Degrees)
- Hold your wrist in this position for 60 seconds
- If you feel the same sensation or pain that you usually feel in this position the test is positive
- Put both of your palms together ( as if praying)
- Insure that your wrist and fingers are in full extension
- Use one hand to push you wrist and fingers over to one side
- Hold your wrist in this position for 60 seconds
- If you feel the same sensation or pain that you usually feel such as tingling, pins & needles or numbness in the palm and fingers the test is positive
- The examiner taps with his fingers or with a tendon hammer on the inside of the wrist onto the median nerve at the level of the carpal tunnel.
- The test is positive if you experience a tingling sensation in your hand and fingers.
- Hold your arms above your head as straight as possible and hold this position for a minimum of 2 minutes
- Test is positive when you experience the same sensation or pain the same sensation or pain that you usually feel (tingling, pins & needles or numbness in the palm and fingers)
- The patient sits facing the examiner with his arms at his sides, elbows bent and hands outstretched with his wrists in a neutral position.
- The patient has to resist the examiner movement. (Stop the examiner from bringing the two hands together)
- The examiner with his hands on the forearms and the wrist tries to push the patients hands together
- The patient must resist and prevent the examiner from bringing the hands together
- Examiner then scratches the median nerve at the level of the carpal tunnel and the exercise is repeated.
- When the exercise is repeated there will be a significant loss of muscle strength to resist the hands from coming together
- The affected side will not be able to stop the examiner (a brief loss of external rotation)
- The test is positive when you are unable to control and resist the examiner from pushing your hands together from the first to the second test.
- You apply pressure directly over the carpal tunnel on the median nerve
- Test is positive when you experience the same sensation or pain that you usually feel (tingling, pins & needles or numbness in the palm and fingers)
How bad is it?
A nerve irritation is usually when you are doing the same movement over and over again and the nerve becomes irritated and inflamed. Its outer barrier gets damaged and causes swelling that comes and goes. This is one of the earliest signs.
Nerve irritation progresses to compression.
If the swelling and the surrounding tissue is not given enough time to heal, this will lead to constant pressure on the nerve. The feeling will change from a dull discomfort to a sharp pain. The outer protective layer of the nerve becomes damaged. The pain will become more frequent and the intensity will increase. Weakness in the fingers during this phase is quite prominent. The nerve can get trapped between the surrounding structures and it’s normal slide and glide movement is compromised. Inevitably you will end up with permanent nerve pain.
Diagnosis of Carpal Tunnel Syndrome
This is a test where needles are inserted into the muscles that the median nerve supplies. It measures the electrical activity produced by muscles. The electrical activity of the muscles will be tested when you contract and relax these specific muscles. This test can determine if there is any nerve damage.
An ENMG is performed by a Neurologist and is often referred to as ‘Nerve conduction studies’. This test examines both the sensory (feeling) and the motor (ability to contract or relax muscles) function of the median nerve. It is able to show the weakening of the impulse traveling through the median nerve when passing through the carpal tunnel. It is considered abnormal when the impulse travels slower, and weakens between 2 points (conduction velocity), mainly between the wrist, the palm of the hand & fingers.
An ultrasound can visualize the structures inside the carpal tunnel and show a decrease in space around the median nerve as well as swelling of the tendons surrounding the median nerve. We will compare the non-affected side to the painful side.
Carpal tunnel questionnaire:
The questionnaire consists of 2 sections, each is scored on a 5 point rating scale. The questionnaire is an accurate and reliable test to determine how bad your symptoms are, but also determines how it affects your daily life.
X-rays can be helpful to see if there are any fractures, dislocations, in the carpal bones. We will be able to see if there are any bone spurs growing into the tunnel that could make the space inside the tunnel smaller. We’ll only take X-rays if you have fallen and your pain starts suddenly.
How we test it:
We are experienced in testing the different types of problems that can cause your wrist pain. Our specialists use a variety of nerve gliding and neural tissue mobilisation to determine the extent of the damage on the median nerve. We mainly test the two components of the nerve, the first involves feeling and the second, your ability to control the small movements in your fingers.
Why is my nerve pain not going away?
A tingling sensation in the fingers, pins and needles, will progressively get worse until the fingers feel numb or dead. At first the feeling of tingling and pins & needles will come and go, only to progress to a constant feeling of burning and numbness as the pressure increases on the median nerve.
The Sensations often appear while holding an object like a cell phone or steering wheel. Generally it starts at the wrist and progressively moves up towards your elbow. In most cases it develops slowly and the symptoms will start off being worse at night or early in the morning.
Progression of Compression
The end results of an untreated median nerve irritation and compression will cause you to experience weakness when trying to grip or hold an object. A very clear sign of long term median nerve compression we see the muscles wasting away at the base of the thumb. You will be unable to lift your thumb and grip a mug of coffee or accidentally let things drop out of your hand.
The compression on the median nerve prevents feedback signals to your brain which causes clumsiness and weakness, which will make you feel like you have lost power in your fingers especially your thumb. Weakness and atrophy of the thumb muscles is a very clear sign of median nerve compression.
What makes Carpal Tunnel Syndrome Worse
The following leads to swelling within the carpal tunnel:
- Health problems or illnesses that can cause swelling in the joints and soft tissue, or reduce blood flow (obesity, rheumatoid arthritis, diabetes, lupus, hyperthyroidism, multiple sclerosis)
- Pregnant women can suffer from short-term symptoms especially later in their pregnancy as they very often struggle with swelling of the wrists
- Hand & wrist movements that require you to do repetitive motions especially where the wrist is bent repeatedly
- Smoking can affect the blood flow to the median nerve
- Broken wrist bones, fractures or dislocation of the Carpal bones
- New bone growth from healing bones or bone Spurs
- Normal wear & tear of the tissues in the hand & wrist caused by aging
- Exposure to vibrations
- Cold temperatures
Structural Abnormalities of the Carpal tunnel
The shape, position, dislocation and subluxation of the carpal bones. (These abnormalities will modify the wall of the tunnel and can cause compression)
- Fractures or screws in the forearm closer to the wrist can also be a source of pain.
- Arthritis or inflammation of the joints between the carpal bones (Rheumatoid Arthritis)
A big problem we see with Carpal Tunnel Syndrome these days:
After a patient has had surgery, there is scar tissue formation on the wound that forms into a scar. Scar tissue is a dense tissue that looks like a spider web. It helps to close a wound very well, but in some cases, it can restrict the normal slide of the nerve. Seeing a therapist is very important to ensure that scar tissue is guided to prevent any restriction on the median nerve tissue.
Wait too long
When you wait too long before getting treatment, the nerve damage can progress too far, making it very difficult to regain full use of the hand. Research has shown that if moderate symptoms occur for longer than 6 months the effects of conservative treatment is poor. If your pain does not relieve in 2 weeks you might want to consider asking our advice.
Braces can make it worse
There is a wide variety of generic braces, sleeves and splints on the market. The problem we see with these braces are that they most often do not fit well and can end up causing more pressure on the median nerve. Make sure you know what you are dealing with before you go buy something that can make it worse.
Be careful what you buy
Generic products sold to help the position of the hand, an example is an ergonomic mouse pad. These products can increases pressure on the Carpal Tunnel and therefore increase the pressure on the nerves running in your wrist. Rather ask for advice before you buy certain products.
Treatment of Carpal Tunnel Syndrome
During a physical examination we will check the feeling and muscle strength of your fingers, hand, wrist, elbow and all the way to your neck. We will also perform special techniques and tests to assess the median nerve. In some cases we may refer you to a neurologist for specialized nerve conduction tests.
- Splinting – We protect the median nerve by offloading the pressure from the median nerve using a custom splint. The splint is made on the hand and will fit perfectly.
- Exercises – We focus on getting the muscles stronger by guiding your through a gradual progression as you get stronger.
- Nerve Gliding – Getting the nerve free from the obstruction and the restoring its normal slide through the carpal tunnel.
- Sensory retraining – To restore the normal feeling in your fingers.
- Oedema management – Reduce swelling in and around the wrist.
- Ergonomics – Changing or adapting activities, tasks or the environment to reduce the pressure on the Carpal Tunnel.
- Carpal bone manipulations
- Median nerve tissue mobilization
- Range of movement exercises of the wrist and hand
- Ultrasound and electromagnetic field therapy
Splinting and wrist brace
A brace can help because it keeps your wrist in a straight, neutral position. You may find that it will help to wear a brace during the day especially during activities that flare up your pain. It will prevent you to put excessive strain on your wrist and avoid repetitive movements. Sleeping with your wrist brace will be very helpful as we bend our wrists when we sleep. This can also put pressure on the median nerve, it must be prevented at all cost.
Phases of Rehabilitation & Treatment:
- Pain management in the inflammatory phase
- Reduce the swelling in and around the Carpal Tunnel
- Prevent and stop the regression of the damage on the nerve
- Reduce scar formation after the surgery
Intermediate Phase 1
- Achieve pain free range of motion
- Improve sensation in the fingertips
- Functionality in light activities of daily living
- Modifying activities that increase the symptoms (ergonomics)
Intermediate Phase 2
- Achieving fine motor coordination and task such as fastening buttons and writing
- Functionality in moderate weight activities of daily living with weight of about 2kg
Intermediate Phase 3
- Focus on muscle strength and the progression of being able to do more difficult tasks without pain or symptoms
Symptoms of Carpal Tunnel Syndrome
- Occasional tingling, numbness or pain in your fingers or hand
- Have gradually developed little or no feeling in your fingers or hand
- Numbness or dead feeling in your fingers or hand
- Cannot do simple hand movements, or you accidentally drop things.
- Unable to pinch your thumb and index finger together( Pinch is weak)
- Cannot use your thumb normally (reduced strength)
- Have problems at work because of pain in your fingers or hand
In most cases carpal tunnel syndrome react very fast when caught early and we can expect a full recovery within 4 to 6 weeks. The recovery time is directly linked with the onset time of the symptoms. The longer the symptoms occur without treatment the longer the recovery time will be. In my professional opinion nerves heal very slowly.
We recommend that we see you twice a week for the first two weeks, thereafter depending on your progress we will follow up once a week for usually 4 weeks.
If left untreated you will lose the ability to use your hand.
Doctors tend to inject corticosteroids. When used with therapy we see much quicker results.
Some GP’s only prescribe anti-inflammatories only to reduce the swelling and pain. The improvements only last a while.
Surgery of Carpal Tunnel Syndrome
Surgical intervention must be left for a last resort if your symptoms failed to respond to conservative treatment.
Surgical treatment aim to decompress the median nerve using 2 surgical techniques:
Open carpal tunnel release (OCTR)
They first cuts open the skin over your wrist and makes an incision through the transverse carpal ligament to release the pressure inside the carpal tunnel and allow room for the structures in the carpal tunnel to expand outside the confines of the tunnel. This allows the pressure to be taken off the median nerve.
Endoscopic carpal tunnel release (ECTR)
This type of surgery is less invasive, but requires precision. The surgeon uses a camera to see what is happening on the inside. He also makes an incision through the transverse carpal ligament to allow expansion of the tissue inside the carpal tunnel.
Both surgical methods’ risks of complications to nerves, blood vessels and tendons are very low.
Dynamic carpal tunnel syndrome:
It is usually caused by excessive manual work repetitive extension and flexion movements of the wrist combined with bending of the fingers and turning the forearm inwards. During this specific motion the pressure in the carpal tunnel increases.
Compression of the median nerve in the carpal tunnel can be caused by an over use of the muscles of the flexor digitorum & superficialis, Flexor pollicis longus. Injury or inflammation to these tendons.
- Flexor digitorum superficialis: Bends the first and second knuckle (digit) of the 2nd to 5th finger. Also closes the hand, and bends the Wrist forward
- Flexor digitorum profundus: Bends the last knuckle or digit of the 2nd to 5th finger. Also closes the hand, and bends the Wrist forward.
- Flexor pollicis longus: Bends the last knuckle of the thumb
Acute carpal tunnel syndrome (sudden pain)
- Direct trauma like a blow to the wrist ( falling onto the wrist or crushing of the wrist)
- Bleeding( haemorrhage)
- High pressure injection
- Acute thrombosis of the artery
Differential diagnosis (conditions that it could also be)
These are conditions present with similar pains to carpal tunnel syndrome but the cause may be a totally different structure.
- Nerve pains from any other nerve (Ulnar or Radial Nerve)
- Pinching of the median nerve between the digits in the palm of your hand
- Pinching of the median nerve at the elbow
- Cervicobrachial syndrome as a result of a pinched nerve roots in the neck
C7-C8 Radiculopathy (this is compression on the C7 cervical nerve root usually due to a hernia of a disc in the neck)
- Intracranial neoplasms ( the pattern of weakness and dead feeling will not be limited to the area of the median nerve)
- Multiple sclerosis ( in urological evaluation will show reactions in multiple areas and not isolated to the area of the median nerve)
- Cervical Radiculopathy ( most common neurological condition which can be confused with carpal tunnel syndrome, in this case there will be weakness or numbness in the forearm progressing to the upper arm)
- Brachial plexus injury
- Thoracic outlet syndrome (It has symptoms involving the Ulnar nerve as well)
How to prevent carpal tunnel & median nerve compression
- Try to keep your wrist in a neutral position( straight in-line with your forearm)
- Use your whole hand and not just your fingers to hold objects
- When sitting at your desk, if your wrist straight with your hand a little higher than your wrists in order to prevent direct pressure on the carpal tunnel
- Switch hands often when you repeat movements( throwing a ball, moving furniture)
If you suspect that you may have carpal tunnel syndrome you should:
- Stop Any activities that may cause your pain to be worse
- Ice your wrist for 10 to 15 minutes 2 times a day for 3 days.
- If your pain does not subside you should give us a call so we can confirm the diagnosis and help you through a program to relieve the pressure off the median nerve.
- The sooner you start treatment the better your chances of stopping the symptoms and preventing long-term nerve damage