Carpal tunnel syndrome is a compression of a large nerve located in the palm of your hand called the median nerve.The median nerve provides the sensitivity of the thumb, forefinger, middle finger and half of the ring finger. The nerve also provides the innervation of certain muscles at the base of the thumb. The nerve is compressed inside the carpal tunnel. This canal is inextensible between the bones of the wrist behind and a thick ligament forward. In addition to the median nerve, the nine flexor tendons of the fingers cross the carpal tunnel. Compression of the median nerve in the carpal tunnel Compression of the median nerve in the carpal tunnel Nerve compression is most often due to an increase in the volume of the tendons and their synovial envelopes, or to a tumor or cyst inside the canal. More rarely carpal tunnel syndrome is due to a narrowing of the canal by osteoarthritis or fracture.
On https://nydnrehab.com/what-we-treat/wrist-pain/carpaltunnel/ MRI section of the carpal tunnel you can see, the skin of the palm of the hand, the ligament that closes the front carpal tunnel (white arrow), the median nerve (yellow arrow) and the flexor tendons (red arrow)
Who is affected by carpal tunnel syndrome?
Carpal tunnel syndrome is very common. The number of cases diagnosed has increased sharply over the last 30 years in all developed countries. Women are twice as likely as men. A peak of frequency is described in women in their fifties. Hormonal status, particularly pregnancy and lactation, increases the occurrence of the carpal tunnel. a small peak of frequency among male manual workers performing repetitive activities between 30 and 50 years is found. However, recent studies have established that frequency and severity only increase with age. Patients between 70 and 80 years of age are the most affected.
Carpal tunnel syndrome is becoming more common with age. Women are more often affected due to a peak in their fifties. Carpal tunnel syndrome is becoming more common with age. Women are more often affected due to a peak in their fifties. Finally, some diseases that increase the thickness of the sheath around the tendons are more often associated with carpal tunnel syndrome: in particular hypothyroidism, rheumatoid arthritis, amyloidosis, diabetes, obesity or renal insufficiency Dialyzed. It has been shown recently that patients with metabolic syndrome often have more severe disease and recover more slowly. Mechanical deformation of the carpal tunnel after trauma of the wrist or tumor or cyst inside the canal can also cause the syndrome.
What are the symptoms of carpal tunnel syndrome?
Carpal tunnel syndrome typically manifests as pains, tingling and numbness in the thumb, forefinger and middle finger. Usually, this discomfort only affects the fingers, but the pain can spread to the entire hand and arm, up to the shoulder. Most often these symptoms appear at night, prevent sleeping around three in the morning and are temporarily relieved by shaking hands for a few minutes or putting them under cold or warm water. Tingling also sometimes occurs during the day, rather at rest, driving or reading a book. A sensation of awkwardness and swelling of the fingers is usual. The attack on both sides is very frequent. It is not always the dominant side that is reached first. Severe compression leads to a progressive loss of finger sensitivity and paralysis with atrophy of certain thumb muscles.