الفهرس 
Development of the nervous systemOnly 14 pages are availabe for public view
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Abstract
Entrapment neuropathy is compression over a peripheral nerve where it passes through its normal anatomical constrained area. Two types of compression may occur by fibro-osseous tunnels and fibro-tendinous arcades. Peripheral nerve trunks respond to chronic compression by inflammatory reaction characterized by intermittent nocturnal periods of nerve dysfunction.
The clinical evaluation of an entrapment syndrome and the determination of the site of compression are greatly aided by knowledge of the anatomic distribution of a nerve and its function. The condition is characterized by pain, paraesthesia or loss of function in distribution of the nerve under compression.
Signs of entrapment may include alteration of temperature or pain sensation and motor atrophy or weakness in the distribution of the peripheral nerve.
Symptoms may be reproduced or exacerbated by rendering the nerve relatively ischemic or increasing its entrapment by selected positional changes of parts of extremity. Brief percussion over a nerve rendered irritable by entrapment and may result in a dysesthetic electric like sensation radiating into the distribution of the nerve.
Electro-diagnostic studies help to correlate this clinical impression but not a substitute for a thorough examination.
Aspects of treatment of an entrapped peripheral nerve depend on the stage of compression, as conservative measures may be of value in relief of early compression whereas surgical decompression will reverse the changes which occur in an entrapped peripheral nerve partially or completely or if damage to the nerve is irreversible in chronic entrapment, surgical release will at least stop their progression.
The three common entrapment neuropathies are carpal tunnel syndrome, cuibtal tunnel syndrome and meralgia paraesthetica. The commonest entrapment encountered in clinical practice is the carpal tunnel syndrome.
To conclude, the most common example of anatomical constraints are the fibro-osseous tunnels such as the carpal tunnel in upper limb and the tarsal tunnel in lower limb, and fibro-tendinous arcades at the origin of certain muscles such as the supinator muscle and flexor carpi ulnaris muscle in upper limb, piriformis muscle in lower limb and compression of the neurovascular bundle at thoracic outlet in neck.
The pathophysiology involves both mechanical and ischemic factors and depend on the degree and duration of compression. Mild brief compression, produces transient conduction block, while in chronic compression, segmental demyelination occurs with slowing of conduction velocity and in acute compression a characteristic sequential invagination or telescoping of myelin sheath occurs.
Pain, paraesthesia or loss of function in distribution of the nerve under compression are the most common features of the peripheral nerve entrapment syndrome. Diagnosis in most cases is based on both clinical examination and electromyographic studies.
Indications for surgical release include failed conservative therapy, weakness, sensory loss or atrophy. It should be noted that any etiological factor should be treated first.
Open surgical release is the most common procedure performed, also modern technology like endoscopic release as in carpal tunnel syndrome has been advocated and has proven to provide equal outcomes.