The carpal tunnel is a confined space between the carpal bones dorsally and the transverse carpal ligament (flexor retinaculum ). In thls region, the median nerve is susceptible to pressure as it courses through the tunnel with the extrinsic finger flexor tendons on their way into the hand, Carpal tunnel syndrome (CTS) is characterized by the sensory loss and motor Weakness that occur when the median nerve is compromised in the carpal tunnel. Anything that decreases the space in the carpal tunnel or causes the contents of the tunnel to enlarge could compress or restrict the mobility of the median nerve, causing a compression or traction injury, ischemia, and neurological symptoms distal to wrist.
Causes of Symptoms
Etiology is multifactorial, include local and systematic factors. Local factors include synovial ‘thickness and scarrmg in the tendon sheaths (tendinosís) or irritation, inflammation, and swelling of the tendons (tendinitis) as a result of repetitive or sustained Wrist flexion, extension, or gripping activities. Because of this, CTS is frequently classified as a cumulative trauma or overuse syndrome. Swelling in the wrist area due t0 local trauma (e.g., a fall or blow to the Wrist, with or Without a carpal or distal radius fracture), carpal dislocation, 0r“ osteoarthritis, or systematic factors, such as pregnancy (hormonal changes and Water retention), rheumatoid arthritis, or diabetes’ could decrease the carpal tunnel space. Awkward wrist postures (flexion or extension), compressive forces from sustained equipment usage and vibration against the carnal tunnel could also lead to median nerve compression and trauma.
Examination Of Carpal tunnel Syndrome (CTS)
In a recent on the sensitivity and specificity of the various tests used when screening for CTS,Macdermid and Doherty summarized the key signs and symptoms that increase the probability of diagnosing CTS.History:-The patient describes sensory changes in the median nerve distribution of the hand ( excluding the palm,which is innervated by the palmar cutaneous branch of the median nerve arising proximal to the carpal tunnel) and nocturnal numbness and pain that is relieved by flicking the wrists.Positive clinical finding:- Depending on severity,there may be atrophy of the thenar eminence and an ape-hand posture.Results of tests include thener muscle weakness,positive phalen`s test,loss of two-point discrimination ,and positive Tinel`s sign ( tapping the median nerve).Electrophysiological studies ( nerve conduction and electromyography) are used to assist with a differential diagnosis.Associated areas to clear:- Because there can be other causes of median nerve symptoms,such as tension,compression,or restricted mobility of the nerve roots in the cervical intervertebral foramen,of the brachial plexus in the thoracic outlet,or of the median nerve as it courses through tissues in the forearm region(pronator syndrome and anterior interosseous nerve syndrome),each of these sites must be examined to rule them out determine if any is the cause of the median nerve symptoms.
Common structure and Functional Impairments:
- Increasing pain in the hand with repetitive use
- Progressive weakness or atrophy in the thenar muscles and first two lumbricals (ape hand deformity)
- Tightness in the adductor pollicis and extrinsic extensors of the thumb and digits 2 and 3
- Irritability or sensory loss in the median nerve distribution
- Possible decreased joint mobility in the wrist and metacarpophalangeal joint of the thumb and digits 2 and 3
- Sympathetic nervous system changes may develop
- Faulty forward head posture and decreased cervical rom
Nonoperative Management of CTS
In patients with mild to moderate symptoms,conservative intervention is directed toward minimizing or eliminating the causative factor
- Nerve protection. Initially,the wrist may have to be splinted to provide rest from the provoking activity.splint the wrist in the neutral position,so there is minimal pressure in the tunnel.
- Activity modification and patient education.Identify faulty wrist,cervical,and upper extremity postures and activities.
–Activity modification. Modify activities to keep the wrist in neutral and to reduce forceful prehension.
–Education. Teach the patient about the mechanisms of compression and their effect on the circulation and nerve pressure as well as how to modify or eliminate provoking postures and decreased sensitivity to avoid tissue injury.
–Home exercise program.Teach the patient safe exercises for a home exercise program.Emphasize the importance of compliance to reduce stresses on the nerve and tendinous structures.incorporate postural exercises for the spinal and shoulder girdle regions if indicated.
Mobilizations Techniques For Carpal Tunnel Syndrome ( CTS)
-Joint mobilization. If there is restricted joint mobility,mobilize the carpals for increased carpal tunnel space.
–Tendon-gliding exercises. Teach the patient tendon-gliding exercise for mobility in the extrinsic tendons.they should be performed gently to prevent increased swelling
–Median nerve mobilization. The six positions for median nerve mobilization in the wrist and hand are illustrated.Begin with position A and progress to each succeeding position until the median nerve symptoms just begin to be provoked ( tingling).This is the maximum position to use.Sustain that position for 5 to 30 seconds without making the symptoms worse .Then alternate between that position and the preceding position.When the patient can be moved into that position without symptoms,progress to the next stretch position and repeat the mobilizing routine.The mobilization exercise should be done three or four times per day so long as symptoms are not exacerbated.