Carpal tunnel syndrome

Dr M K Mam
Carpal tunnel syndrome also called entrapment neuropathy is a fairly common condition whereone of the main nerves of hand i.e. median nerve is compressed incarpal tunnellocated at the base of the palm. It is a fibro-osseous tunnel where floor is a bony arch formed by the carpal bones and the roof is formed by the fibrous but rigid transverse carpal ligament i.e.the flexor retinaculum. Flexor tendons to fingers and thumb along with their sheaths, and the median nerve pass from the forearm into the palm through this tunnel.
People in jobs involving exposure to high force, repetitive use of vibrating tools or manipulating objects with firm grip are more likely to have CTS. There is a general notion in the people that use of computer is associated with CTS , however it is somewhat controversial. There are lot many studies that are not supportive of this notion and it has been reported that there is no positive association between computer use and CTS.
Clinical features: The patient complains of pain associated with tingling and numbness of thumb , index, middle fingers and outer side of ring finger i.e. the area supplied by median nerve. One thing is very clear that little finger is spared. The symptoms get worse during night. Patient is frequently woken during night with burning pain, tingling sensation and numbness. Shaking or flicking the hand usually relieves the symptoms. In the latter stages there occurs wasting- thinning and weakness of the muscles of thenar eminence-ball of thumb.The patients experience clumsiness with activities requiring wrist flexion- bending down and also with fine works such as fastening a button. Patients also report falling of things from the hand as they cannot feel with fingers. On examination there may be wasting and weakness of the thenar muscles along with decrease or loss of sensation in the median nerve distribution area i.e. thumb, index, middle fingers and outer side of ring finger. Some of the patients may notice the symptoms only on vigorous activity and may show minimal findings on a routine examination. Various provocative clinical tests help to corroborate the diagnosis. CTS is more common in women than in men. It can appear on one or both sides. In lot many patients it usually starts with one hand and subsequently becomes evident in other unaffected hand also. It can occur in any age, however it is more commoner in 40-60 years age group. It is much more commoner in diabetics than nondiabetics.
CTS is of two types- acute and chronic. Acute CTS is uncommon and occurs when there is a rapid and sustained increase in the pressure in the carpal tunnel as can happen in fractures of distal radius, dislocation of carpal bone or local infection. Chronic form is much more common and symptoms persists for months or years.
CTS has to be differentiated from nerve root compression in the neck i.e. radiculopathy that commonly happens ina very common neck problem – cervical spondylosis or cervical disc prolapse. At times it may be there along with radiculopathy associated with neck problems. We have also to keep in mind thatmedian nerve can also be affected because of neuropathic factors as is seen in diabetes, alcoholism or some vitamin deficiency. This can produce symptoms similar to CTS, however the pressure within the carpal tunnel may not be increased.
Diagnosis is made with the help of a detailed history and thorough clinical examination with provocative tests. Electrodiagnostic tests like nerve conduction studies (NCS)do help in localising the problem.NCS is considered to be the gold standard in the diagnosis of CTS because it is an objective test that provides information on the physiological health of the median nerve across the carpal tunnel. Relevant lab tests are also done to rule out the medical problems that can result in CTS.
Treatment optionsare nonsurgical and surgical.
Nonsurgical treatmentis useful in patients with mild to moderate symptoms,pain and numbness are intermittent and there is no wasting or weakness of the thenar muscles. Nonsteroidal anti-inflammatory medication (NSAIDs) helps in decreasing swelling and pain.Supplements of vitamin B6 and B12 are useful.Wrist splint that holds wrist and hand in neutral position, preventing bending of the wrist does help and can be used during night or day.Single injection of hydrocortisone carefully given directly in the carpal tunnel isconsidered in patients with mild to moderate symptoms. It is believed to act by decreasing the swelling of flexor tendon synovitis. It does improve the symptoms however they recur within few months or so.When there is a specific cause like hypothyroid or rheumatoid arthritis , that has to be treated accordingly.
Surgical treatment is done in patients who do not respond to nonsurgical treatment or when symptoms and signs are severeor sensory and motor deficit is progressive.Surgery involves cutting of transverse carpal ligament, with the result the space of the carpal tunnel increases andthe pressure on the nervedecreases. Surgery is supposed to be the cure of CTS as it addresses the root cause i.e. the small volume of carpal tunnel. It gives quick relief and good to excellent long-term outcomes in most of the patients. Surgical decompression can be done either by open or by endoscopic method (pin hole surgery) and this does depend on availability of the local expertise. Open carpal tunnel release has been the traditional- very commonly used method and gives good symptomatic relief in majority of patients with low complication rate, although endoscopic release may allow patient to return to work sooner.
The author is Formerly, Vice Principal, Professor. & Head. Of Orthopaedics, Christian Medical College, Ludhiana)