2. • Mixed nerve (contain motor & sensory fibers).
• Root value: C 5,6,7,8 & T1
• Runs in the median plane of the forearm , so its
called median nerve
3. • Arises in the axilla by 2 roots (lat
&med):
1) lat .root : from the lat . Cord of the
brachial plexus
2) med .root : from the med . Cord
of the brachial plexus .
4. In axilla
• Median nerve is formed by lateral root from lateral cord and medial
root from medial cord of brachial plexus
• Median nerve runs lateral side of axillary artery
5. In arm
• median nerve continues to run on the lareral side of brachial artery till the
middle of arm , where it crosses infront of the artery and passes anterrior
to the elbow joint into forearm
6. In forearm
• Enters to the forearm b/w two heads of pronator teres .
• Then deep to fibrous arch of flexor digitorum superficialis , in
proximal third
• In mid forearm descends b/w flexor digitorum superficialis and
flexor digitorum profundus .
• About 5 cm above wrist , it comes to lie on the lateral side of the
flexor digitorum superficialis , becomes superficial just above wrist
7.
8. In hand
• Nerve passes deep to the flexor
retinaculum and enters the palm
• Muscular braches supply muscles of
thenar eminence ( abductor pollicis
brevis , opponens pollicis and flexor
pollicis brevis )
9. • Finally divides into 4 to 5 palmar
digital branches supplying lateral
three and half digit and their nail
beds
• Also , motor braches are given to
the first and second lumbrical
muscles
10. Branches
• In arm : vascular branches to the brachial
• In the forearm : muscular branches to all superficial flexor
muscles ( pronator teres , flexor carpi radialis , palmaris longus
and flexor digitorum superficialis )
Anterior interosseous , which comes off the median nerve
supplies lateral half of flexor digitorum profundus , flexor pollicis
longus and pronator quadratus
11. Articular branches supply the elbow joint and proximal ulnar
joint
Palmar cutaneous branch supply skin over thenar eminence
and central part of palm
12. INJURY TO MEDIAN NERVE
• Median nerve is most commonly injured near the wrist or
high up in the fore arm
• Muscles supplied by median nerve affected acc. To level of
median nerve injury.
1. High median nerve palsy
2. Low median nerve palsy
13. Low median nerve palsy
• Injury in the distal third of the forearm
• Cuts infront of wrist or by carpal dislocation
• There will be sparing of the forearm muscles , but the
muscles of the hand will be paralysed
• There will be anaesthesia over the median nerve
distribution in the hand
14. cont
• Thenar eminence is wasted and thumb abduction and
opposition are weak
• Sensation is lost over the radial three and half digits and
trophic changes may seen
15. High median nerve palsy
• Injury proximal to the elbow
• Generally due to forearm fractures or elbow dislocation
• Stabs and gunshot wounds may damage the nerve at any
level
• This will cause paralysis of all the muscles supplied by the
median nerve in the forearm and hand
16. • Muscles examined:
• 1) flexor pollicis longus : this muscle is tested by holding
thumb at its base and patient asked to bend the terminal
phalanx
17. • 2) flexor digitorum superficialis and & profundus (lateral half
)…..Ochsner’s clasping test is : when the patient is asked to clasp
the hands , the index finger of affected side fail to flex
• 3) flexor Carpi radialis : the hand deviate to ulnar side when it is
flexed against resistance
18. • 4) muscles of thenar eminance
• abductor pollicis brevis…….pen test : the patient is
asked to lay his hand flat on the table , a pen is held above the
palm and the patient is asked to touch the pen with his thumb
• opponens pollicis : brings the tip of the thumb
towards the tips of other fingers
19. Median nerve compression
• Three separate syndromes are recognised
1. Carpal tunnel syndrome
2. Pronator syndrome
3. Anterior interosseous syndrome
20. It is compressive neuropathy of median nerve as it
passes through the carpal tunnel of the wrist joint.
21.
22. causes
• Ideopathic - Most common
• Inflamatory - Rheumatoid Arthritis
- Wrist osteoarthritis
• Post traumatic - Bone thickening
• Endocrine - Myxoedema
- Acromegaly
23. • High prevelance rates have been reported in persons who
perform certain repetitive wrist motions ( frequent
computer users )
• Pregnancy
• Gout
24. Symptoms and Signs
Symptoms include
• Pain of the hand and wrist associated with tingling and
numbness, classically distributed along the median
nerve (the palmar side of the thumb, the index and
middle fingers, and the radial half of the ring finger)
• Typically, the patient wakes at night with burning or
aching pain and shakes the hand to obtain relief and
restore sensation.
• Thenar atrophy and weakness of thumb opposition and
abduction may develop late.
32. • If symptoms persist or recur or if hand
weakness and thenar wasting develop, the carpal
tunnel can be surgically decompressed by using
an open surgical division of the transverse carpal
ligament
33.
34. Complications of surgery
• Injury to palmar or cutaneous or recurrent motor branch of the
median nerve
• Hypertrophic scarring
• Hematoma
• Artery injury
35. Pronator teres syndrome
• Pronator teres syndrome is a compression
neuropathy of the median nerve at the elbow
between heads of pronator teres
• It is rare compared to compression at the wrist
(carpal tunnel syndrome) or isolated injury of the
anterior interosseous branch of the median nerve
(anterior interosseous syndrome).
36. • Symptoms are similar to those of carpal tunnel syndrome ,
although night pain is unusual and forearm pain is more
common
• phalen’s test obviously be negative
• Symptoms can be provoked by resisted elbow flexion with
forearm supinated ( tightening of bicipital aponeurosis )
• By resisted forearm pronation with the elbow extended (
pronator tension )
37. • Tinel’s sign may be positive over the nerve proximally but
not at carpal tunnel
38. Anterior interosseous syndrome
Is a medical condition in which damage to the
anterior interosseous nerve, a motor branch of
the median nerve, causes pain in the forearm
and a characteristic weakness of the gripping
movement of the thumb and index finger.(
unable to make ok sign )
• Most cases are due to compression of the nerve
as a result of trauma at the elbow, often
associated with haemorrhage into the deep
musculature.
