MEDIAN NERVE

MEDIAN NERVE

ORIGIN AND ROOT VALUE

formed by two heads in axilla

COURSE

AXILLA

lies anterior to 3rd part of axillary artery ( काँख धमनी के सामने )

crosses artery from lateral to medial (

ARM

enters arm from axilla at inferior border of teres major

passes vertically downwards and

courses lateral to brachial artery ( पार्श्व स्थान पर जाता हैं_ )

between

biceps brachii above

brachialis below

then it crosses

anteriorly to run medial to brachial artery ( फिर भुज धमनी के मध्य स्थान पर जाता हैं

in cubital fossa

lies medial to brachial artery

passes under biceps

on to or medial to brachialis

gives articular branch to elbow

in Forearm

then between two heads of pronator teres

to bicipital aponeurosis

superficial to brachialis

crosses ulnar artery

separated by the head of pronator teres

then travels between

flexor digitorum superficialis above

flexor digitorum profundus below

then above 5cm above flexor retinaculum

merges between

the flexor digitorum superficialis (medially)

the flexor carpi radialis (laterally)

branches in forearm

supplies anterior compartment of forearm except

flexor carpi ulnaris

muscular branches

anterior interosseus branches

in

Enters the through carpal tunnel

passes to flexor retinaculum to reach palm of

along with tendons

branches in

sensory

palmar cutaneous branch leave median above wrist

runs superficial to flexor retinaculum

supply lateral palm skin

motor

lateral 2 lumbricals

abductor pollicis brevis

opponens pollicis

flexor pollicis brevis

Injury

Injury of median at different levels causes different syndromes with varying motor and sensory deficits.

At the shoulder

Injury can occur at the brachial plexus[9]

Above the elbow

Common mechanism of injury: a supracondylar humerus fracture

Motor deficit:

Loss of pronation of forearm, weakness in flexion of the at the wrist, loss of flexion of radial half of digits and thumb, loss of abduction and opposition of thumb.

Presence of ape deformity when the is at rest, due to hyperextension of index and thumb, and adducted thumb

Presence of benediction sign when attempting to form a fist, due to loss of flexion of radial half of digits

Sensory deficit: loss of sensation in lateral 3+1⁄2 digits including their beds, and the thenar area

At the elbow

Entrapment at the level of the elbow or the proximal forearm could due to the pronator teres syndrome.

Within the proximal forearm: anterior interosseous syndrome

Injury to the anterior interosseous branch in the forearm causes the anterior interosseous syndrome

Common mechanisms: tight cast, forearm bone fracture

Motor deficit: loss of pronation of forearm, loss of flexion of radial half of digits and thumb

Sensory deficit: none

At the wrist

Common mechanism: wrist laceration

Motor deficit:

Weakness in flexion of radial half of digits and thumb, loss of abduction and opposition of thumb

Presence of ape deformity when the is at rest may likely, due to hyperextension of index and thumb, and adducted thumb. Nevertheless, ape deformity is not a requirement for a carpal tunnel syndrome diagnosis.

Presence of a benediction sign when attempting to form a fist, due to weakness in flexion of radial half of digits

Sensory deficit: loss of sensation in lateral 3+1⁄2 digits including their beds, and the thenar area

Within the wrist: carpal tunnel syndrome

Common mechanism: carpal tunnel syndrome, injury by compression in the carpal tunnel, without transection of the median , due to overuse by activities as keyboard typing and cooking

Motor deficit:

Weakness in flexion of radial half of digits and thumb, weakness in abduction and opposition of thumb

Presence of ape deformity or when attempting to form a fist, the benediction sign, due to compression of the median , as opposed to complete median palsy

Sensory deficit: numbness and tingling in lateral 3+1⁄2 digits including their beds, but excluding the thenar eminence which is supplied by the palmar cutaneous branch of the median [10] Unlike in wrist laceration, sensation still occurs in the area of the central palm. Sensation is not lost because the palmar cutaneous branch runs above the flexor retinaculum, and is not affected in compression in carpal tunnel syndrome.