Carpal tunnel syndrome affects one of the main nerves in the wrist area. The carpal tunnel is a space created by the natural arch of the wrist bones. A thick band called the transverse carpal ligament creates a roof to the tunnel. This means that the size of the tunnel cannot change, as the bones and ligament act like solid walls.
Nine tendons that bend the fingers and thumb and the median nerve pass through the tunnel. The median nerve provides feeling (sensation) to the skin of the thumb, index and middle fingers, as well as half the ring finger. The nerve also provides the communication line to the muscles at the base of the thumb (thenar muscles).
The most likely cause of carpal tunnel syndrome is extra pressure on the median nerve at the wrist inside the tunnel. This extra pressure can come from swelling (inflammation) of the contents inside the tunnel. When pressure results in nerve symptoms, it is called a compressive neuropathy. While the exact carpal tunnel syndrome causes are usually unknown and due to the patient’s personal anatomy, there are many factors that can contribute to the increased pressure or inflammation, including:
• Rheumatoid arthritis
• Psoriatic arthritis
• Arthritic spurs of the carpal bones
• Ganglion cysts
• Wrist fracture or dislocation of the wrist
• Repetitive motions performed at work or home like typing.
Even making a tight closed fist or holding the wrist in bent or extended positions can put increased pressure on the median nerve. A prolonged or constant fist or bend, like a fist during sleep or reading a book, may put enough pressure to cause the numbness or tingling. If the funny feeling in the fingers just began, this is easily resolved by moving the fingers back and forth and out of the position. If the pressure continues off and on for weeks to months, the symptoms may come on faster after the activity or wrist position is created. It may also take longer for the symptoms to go away after the activity stops. Eventually, symptoms can become constant.
Repetitive activities in the workplace with forceful or repetitive gripping or vibration can also increase symptoms. However, it is difficult to determine if the work activity is the main cause of the symptoms or if work is incidentally just aggravating a condition that is already present and unrelated to work. The determination of cause of symptoms requires experienced and specialised health care providers to provide an opinion, taking many factors into account.
Factors that increase the chances of getting carpal tunnel syndrome
• Gender: women are more likely than men to get it.
• Age increases the risk of carpal tunnel syndrome. It is rare in children and adolescents and more common in people ages 40 and over.
• Alcohol addiction,
• Pregnancy: hormonal changes and extra body fluid retention may add swelling and pressure onto the tunnel.
Signs and symptoms
Some of the symptoms of carpal tunnel syndrome may include:
• Numbness and tingling that is often worse at night
• Waking up at night and having to shake hand or hold over the side of the bed
• Fingers feeling swollen or fuzzy
• Unintentionally dropping objects
• Weak pinch
• Discomfort in wrist, hand or fingers
The main symptom of carpal tunnel syndrome is numbness and/or tingling in the thumb, index and middle fingers, and all or half of the ring finger (the side closest to the thumb). In most cases of carpal tunnel syndrome, the numbness/tingling comes on gradually. If mild, the symptoms may come and go for months or even years without worsening. The symptoms may vary based on time of day, activity or wrist position. Sometimes the fingers are numb, and other times there is normal feeling. If the condition becomes worse the numbness may become constant. The speed of symptom worsening can vary from very gradual, where it is hard to notice, or the symptoms may come on all of a sudden. In the most severe cases, the muscles at the base of the thumb become weak and shrink in size. ,
Diagnosis of carpal tunnel syndrome
The diagnosis of carpal tunnel syndrome is made in many patients based on their history of symptoms and a physical examination.
It is important to know which fingers experience the numbness or tingling and which fingers do not. When performing the physical exam, your doctor will perform sensation testing on the palm side and the back side of the fingers and hand. Your doctor may also perform some tests including the Phalen’s manoeuvre, the Tinel’s test, and a compression test. These are designed to increase pressure on the median nerve to cause your symptoms to appear.
Electromyogram studies and nerve testing may also be used in the diagnosis. These provide evidence of nerve function or dysfunction.
Magnetic resonance imaging and ultrasound studies are anatomic imaging tests that visualise the size of the median nerve and may also be used.
The main goal of treatment is to reduce or remove the causes of increased nerve pressure. This should result in a decrease in symptoms. Some non-surgical treatment options may include:
• Oral anti-inflammatory drugs.
• Steroid injection
• Wrist splints
Oral medications and injections are more effective when symptoms are present for a short period of time, infrequent and mild.
Wrist splinting, mainly at night, keeps the wrist out of a bent position. Wrist splints are most helpful with symptoms that are affected by the hand or wrist position
Surgical release of the carpal tunnel ligament is one of the most effective treatments. It takes the extra pressure off the nerve immediately and reliably. There are several different surgical techniques to cut the transverse carpal ligament. By opening the ligament, there is more room for the tendons and the nerve to pass through the tunnel without pressure.
Moving the fingers right away and frequently after a surgical procedure helps to limit stiffness, swelling, and adhesions. Adhesions are areas of scar tissue that can form and link the nerve to the tendons it rests on.
Better results will occur when carpal tunnel is recognised and treated earlier. This means seeking treatment when your symptoms are not severe, and they come and go. There will likely be complete return of feeling and muscle use after surgery. Relief may even be immediate.
Contact Dr Maxwell on 363-1807 or 757-5411.