It is the compression neuropathy of the median nerve in the carpus deep to the flexor retinaculum. Flexor retinaculum muscle maintains the concavity of wrist and extends laterally from trapezium and scaphoid to pisiform and hook of the hamate medially.
Carpel tunnel is formed by carpal bones behind and flexor retinaculum in front. It contains median nerve and long flexor tendons of fingers and thumb of your hand. Ulnar nerve lies superficially, not in the carpal tunnel.
The median nerve gets compressed if the space of the carpal tunnel gets reduced. The carpal tunnel syndrome diagnosis is discussed in the main article.
- The carpal tunnel syndrome causes are enlisted below:
- Lunate dislocation, malunited Colle’s fracture
- Radiocarpal arthritis, flexor tendon tenosynovitis.
- Myxoedema, acromegaly, pregnancy
- Clinical features
- Common in females
- Tinglings, numbness, paraesthesia and burning sensation in the lateral three and a half fingers supplied by the median nerve. Burning sensation gets aggravated at night.
- Ape thumb deformity, wasting of thenar muscles, weakness of opponents pollicis and abductor pollicis brevis, i.e. features of low median nerve palsy.
- When Blood Pressure cuff is inflated, the patient feels the typical pain in the fingers of the affected hand.
- Tapping the median nerve at the distal end of the forearm with the wrist held in extension aggravates the carpal tunnel syndrome symptoms and carpal tunnel syndrome diagnosis.
- Condition is often bilateral.
- Phalen’s test (wrist flexion test): flexion of the wrist causes exacerbation of the carpal tunnel syndrome symptoms will disappear as the wrist is straightened.
- Cervical spondylosis
- Cervical rib syndrome
Carpal tunnel syndrome diagnosis can be done using a combination of the patient’s history, physical examination and the test that are enlisted below.
- Nerve conduction studies
- Xray/ MRI neck
A physical examination includes a detail evaluation of your hand, wrist, shoulder and neck to check any other causes for the nerve compression. Your doctor will look at your wrists for the signs of tenderness, swelling or any other deformities. The doctor will check the sensation of your finger and the strength of the muscle in your hand.
Nerve conduction studies are a diagnostic test that can measure the conduction speed of nerve of your hand. If nerve impulse is slower than normal as the nerve passes into the hand, carpal tunnel syndrome diagnosis will be confirmed.
Surgical decompression of median nerves by cutting both superficial and deep part of flexor retinaculum completely, by ‘s’ shaped incision.
Surgery is usually done under local anaesthesia. General or brachial block can be used. Torniquet is commonly used. Vertical crease incision is made in the proximal part of the palm with the convexity of the incision towards the ulnar side.
The skin incision is deepened. Palmar cutaneous branch of the median nerve should be preserved carefully. The incision is deepened to identify the flexor retinaculum. Entire length, both superficial and deep parts should be cut properly. It is cut towards the ulnar side of the wound. Only skin is sutured using interrupted nonabsorbable 3 zero polypropylene or polyethene sutures.
Complications are incomplete fasciotomy and recurrence, nerve injury.
Using small proximal incision, endoscopy can be passed to visualise and cut the entire flexor retinaculum-minimal access surgery.
Postoperatively good physiotherapy is required.
Condition is permanently curable.
Carpal tunnel syndrome can be prevented by making lifestyle changes that reduce the risk factors for developing it. Treating conditions such as diabetes, hypertension, and arthritis reduces the risk of developing carpal tunnel syndrome. Paying careful attention to the hand postures or wrist postures and avoiding activities that overextend your wrist are also important strategies for reducing carpal tunnel symptoms. Physical therapy and other different types of yoga exercises may be helpful as well as.
If the carpal tunnel syndrome diagnosis is done effectively, treatment with physical therapy, lifestyle changes or surgery can lead to significant long term improvement, and eliminate its symptoms.
Although unlikely, untreated carpal tunnel syndrome can lead the permanent damage of your nerve, and loss of hand functions.