1.Anatomy
a.Course
b.Motor distribution
c.Sensory distribution
2.Common sites affected
3.Level of median nerve injury
4.Clinical feature with various test performed
5.Various syndromes related to median nerve
6.Treatment
7.Summary
2. Outline
• Anatomy
Course
Motor distribution
Sensory distribution
• Common sites affected
• Level of median nerve injury
• Clinical feature with various test performed
• Various syndromes related to median nerve
• Treatment
• Summary
3. C5
C6
C7
C8
T1
Median nerve (C5, 6, 7, 8, T1)
This nerve is formed by the joining of branches
from the lateral and medial cords of brachial
plexus.
ROOTS
TRUNKS
CORDS
TERMINAL
BRANCHES
ANATOMY: COURSE
4. In the arm, the median nerve descends
adjacent to the brachial artery.
brachial artery
Median nerve
The nerve enters the forearm between the two
heads of the pronator teres
Course in the forearm
5. • It then passes deep to the tendinous bridge of the origin of the flexor
digitorum superficialis, proximal third of the forearm.
• In the mid-forearm it descends between
the flexor digitorum superficialis and flexor
digitorum profundus
• About 5 cm above the wrist, it comes to lie
on the lateral side of the flexor digitorum
superficialis.
• It becomes superficial just above the
wrist, where it lies between the tendons
of the flexor digitorum superficialis and
flexor carpi radialis.
6. Course in the hand:
• The nerve passes deep to the flexor
retinaculum and enters the palm.
• Here a short and stout muscular branch from
it supplies the muscles of the thenar
eminence
1. abductor pollicis brevis,
2. opponens pollicis and
3. flexor pollicis brevis
7. • The median nerve finally divides into 4 to 5
palmar digital branches supplying the area of
skin
• Also, motor branches are given to the first and
second lumbrical muscles at this level.
8.
9. Motor distribution
(A) Hand: the thenar muscles and the lateral two
lumbricals.
(B) Forearm (through its anterior interosseous
branch): flexor pollicis longus, half of flexor
digitorum profundus, pronator quadratus.
(C) Near the elbow: flexor digitorum superficialis ,
flexor carpi radialis, palmaris longus and pronator
teres
11. (A) In the carpal tunnel (e.g.
carpal tunnel syndrome, and some fractures
and dislocations about the wrist).
(B) At the wrist (e.g. from lacerations).
(C) At the elbow (e.g. after elbow dislocations
in children).
(D)In the forearm (anterior interosseous
nerve) from forearm bone fractures, or by a
tight tissue band at the origin of the
superficialis.
(E) Just distal to the elbow, in the pronator
teres nerve entrapment syndrome
Median nerve: common sites affected
12. Level of median nerve injury
High median nerve palsy (injury
proximal to the elbow):
Low median nerve palsy (injury in the
distal-third of the forearm):
• This will cause paralysis of all the
muscles supplied by the median nerve
in the forearm and hand.
• There will be sparing of the forearm
muscles, but the muscles of the
hand will be paralysed.
• In addition to lower nerve lesion, the
long flexors to the thumb, index and
middle fingers, the radial wrist
flexors and the forearm pronator
muscles are all paralysed
• The patient is unable to abduct the
thumb, and sensation is lost over
the radial three and a half digits.
13. High median nerve palsy Low median nerve palsy
• Typically the hand is held with the
ulnar fingers flexed and the index
straight (the ‘pointing sign’).
• Also, because the thumb and index
flexors are deficient, there is a
characteristic pinch defect:
instead of pinching with the thumb and
index fingertips flexed, the patient
pinches with the distal joints in full
extension
• In long standing cases the thenar
eminence is wasted and trophic
changes may be seen
14.
15. Clinical features
• Lack of ability to abduct and oppose the
thumb due to paralysis of the thenar muscles.
This is called "ape-hand deformity".
• Sensory loss in the thumb, index finger, long
finger, and the radial aspect of the ring finger
• Weakness in forearm pronation and wrist and
finger flexion
18. .
Flexur policis longus
Loss of power here may also occur in median nerve lesions proximal to the anterior
interosseous branch
19. Flexur digitorum superficialis and Lateral
half of flexor digitorum profundus
• If the patient is asked to clasp his hand, the
index finger will remain straight, the so-called
'pointing index'.
• This occurs because both the finger flexors,
superficialis as well as the profundus of the
index finger are paralysed;
20. Flexur carpi radialis
In paralysed patient
• wrist deviates to the ulnar side while palmar
flexion occurs. In addition, one cannot feel the
tendon of the flexor carpi radialis getting taut.
21. Muscle of thenar eminence
• Opponens policis
The function of this muscle is to appose the tip
of the thumb to other fingers
25. Carpal tunnel syndrome
• caused by compression of the median nerve
as it passes under the carpal tunnel.
• Nerve conduction velocity tests through the
hand are used to diagnose CTS.
• Physical diagnostic tests include the Phalen
maneuver or Phalen test and Tinel's sign
• To relieve symptoms, patients may describe a
motion similar to "shaking a thermometer",
another indication of CTS.
28. Pronator teres syndrome
• is compression of the median nerve between
the two heads of the pronator teres muscle
• The Pronator teres test—the patient reports
pain when attempting to pronate the forearm
against resistance while extending the elbow
simultaneously.
• The key to discerning this syndrome from
carpal tunnel syndrome is the absence of pain
while sleeping.
29. Extend the patient’s elbow and feel for contraction in the muscle as he
attempts to pronate the arm against resistance. Loss indicates a lesion at or
above the elbow. Accompanying pain and tenderness over pronator teres is
found in the pronator teres entrapment syndrome
Testing pronator teres.
30. Anterior interosseous syndrome
• AIN syndrome is purely neuropathic.
• AINS is considered as an extremely rare 1% of
neuropathies in the upper limb.
• Patients have impaired distal interphalangeal
joint, because of which they are unable to pinch
anything or make and "OK" sign with their index
finger and thumb.
• The syndrome can either happen from pinched
nerve, or even dislocation of the elbow
31.
32. Treatment
Conservative treatment
• 1st step -rest and modify daily activities that
aggravate the symptoms.
• CTS-
anti-inflammatory drugs,
Physical or Occupational therapy,
splints for the elbow and wrists, and
corticosteroid injections
• In pronator teres syndrome- immobilization of the
elbow and mobility exercise within a pain-free
range are initially prescribed.
33. Surgical Treatment
• If the patient is not relieved of symptoms after
a usual 2 to 3 month refractory period, then
decompression surgery may be required.
• Surgery involves excising the tissue or
removing parts of the bone compressing the
nerve.
34. Treatment
• If the nerve is divided, suture or nerve grafting
should always be attempted.
• Postoperatively the wrist is splinted in flexion to
avoid tension; when movements are commenced,
wrist extension should be prevented.
• If there has been no recovery, the disability is
severe because of sensory loss and deficient
opposition.
35. Rehabilitation
• In high median nerve palsy patients, recovery time
varies from as early as four months to 2.5 years.
• Initially, patients are immobilized in a neutral position
of the forearm and elbow flexed at 90° in order to
prevent further injury.
• Additionally, gentle exercises and soft tissue massage
are applied.
• The next goal is strengthening and flexibility, usually
involving wrist extension and flexion; however, it is
important not to overuse the muscles in order to
prevent re-injury.
36. Summary
• Median nerve (C5, 6, 7, 8, T1), by joining lateral and
medial cords
• Motor branches in forearm are all the flexor muscle of
the forearm except flexor carpi ulnaris and medial half
of flexor digitorum profundus; and in hand, thenar
muscles and first two lumbricals
• Sensory functions- Gives rise to the palmar cutaneous
branch, which innervates the lateral part of the palm,
and the digital cutaneous branch, which innervates the
lateral three and a half fingers on the anterior (palmar)
surface of the hand.
37. • Level of median nerve injury High median
nerve palsy (injury proximal to the elbow) and
Low median nerve palsy (injury in the distal-
third of the forearm
• Ape hand deformity is usually seen
• Carpel tunnel syndrome, Pronator syndrome,
Anterior interosseous syndrome
• Treatment includes both conservative and
surgical treatment with rehabilitation
The term "hand of benediction" refers to damage of the median nerve. However the name is misleading as the patients with this median nerve problem usually can flex all fingers except for the index finger. The index finger is still flexed at the metacarpophalangeal joint (MCP joint) when the ulnar nerve innervated muscles (the interossei muscles) are still working. The index finger is not flexed at the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints, which looks like a pointing finger. Pointing Finger is therefore a much better term to recognize this condition.
Ape hand deformity, also known as simian hand, is a deformity in humans who cannot move the thumb away from the rest of the hand. It is an inability to abduct the thumb.[1] Abduction of the thumb refers to the specific capacity to orient the thumb perpendicularly to the ventral (palmar) surface of the hand. Opposition refers specifically the ability to "swing" the first metacarpal such that the tip of the thumb may touch the distal end of the 5th phalanx and if we put the hand on the table as the palm upward the thumb can not point to the sky. The Ape Hand Deformity is caused by damage to the proximal median nerve, and subsequent loss of opponens pollicis muscle function. The name "ape hand deformity" is misleading, as apes have opposable thumbs.
Test the power of flexor pollicis longus in the thumb, and flexor digitorum profundus in the index by asking the patient to try to flex the appropriate distal joint while you support the phalanx proximal to it. Loss of power here may also occur in median nerve lesions proximal to the anterior interosseous branch
though the available medial-half of the flexor digitorum profundus (supplied by the ulnar nerve) makes flexion of the other fingers possible.
flexor pollicis brevis-he superficial head is usually innervated by the lateral terminal branch of the median nerve. The deep part is often innervated by the deep branch of the ulnar nerve (C8, T1).
To test it, begin by placing the patient’s hand, palm upwards, on a flat surface. Hold your index finger above the palm
Now ask the patient to raise his thumb and try to touch your finger. If he tends to move his hand while doing so, steady it with your other hand. Assess his ability to carry out the movement (he may not be able to do it), and look for contraction in the muscle
Ask the patient to resist while you attempt to force the thumb back down to the starting position. Note the resistance offered; palpate the muscle to confirm its tone and bulk, and compare the power on the affected side with that of the other.
A syndrome is a set of medical signs and symptoms that are correlated with each other. The word derives from the Greek σύνδρομον, meaning "concurrence".
carpel tunenel-A passageway from the wrist to the hand, the carpal tunnel is made of tendons, ligaments and bones. The median nerve passes through the tunnel and provides sensation to your thumb, index finger, middle finger and the thumb side of the ring finger.
The area over the median nerve is tapped gently at the anterior (palmar) surface of the wrist. If this produces tingling in the median nerve distribution,then the test is positive.
For the Phalen test, the patient sits comfortably with the wrists and elbows flexed
The test is positive if the patient experiences numbness or tingling throughout the median nerve distribution of the hand
within 45 seconds.
Depending on the severity of the lesion, physicians may recommend either conservative treatment or surgery