1. MEDIAN NEUROPATHY.pdf

ANATOMY, CAUSES OF INJURY, SIGN & SYMPTOMS, INVESTIGATION , SURGICAL & PHYSIOTHERAPY TREATMENT

1. MEDIAN
NEUROPATHY
P/B :-DR NIYATI PATEL 1

2. ANATOMY
The median nerve controls coarse movements of the
hand, as it supplies most of the long muscles of the front
of the forearm. It is, therefore, called the 'labourer's
nerve'.
ROOT VALUE-C5,C6,C7,C8,T1
Arising from medial and lateral cords of brachial plexus
Motor supply
◦Pronator teres
◦Flexor digitorumsuperficialis
◦Flexor digitorumprofundus(1
st
& 2
nd
)
◦Flexor carpi radialis
◦Palmaris longus
◦Flexor pollicislongus
◦Pronator quadratus
◦1
st
& 2
nd
lumbricals
◦Thenarmuscles
P/B :-DR NIYATI PATEL 2

3. P/B :-DR NIYATI PATEL 3

4. CAUSES
Axilla
• Axillary aneurysm
• Traction injury
Arm
◦Penetrating injury
Elbow
• Penetrating injury
• Hansen’s disease
• Golfer’s elbow
P/B :-DR NIYATI PATEL 4

5. Forearm
Pronator teressyndrome; A fibrous band that
travels between the deep and superficial head of
the pronator terescan compress the median nerve
due to over use or violent contraction of the
muscle.
A fibrous arch which originates just proximal to the
origin of the flexor digitorumsuperficialiscan
compress the median nerve causing selected
paralysis of FDS and FDP.
P/B :-DR NIYATI PATEL 5

6. Wrist
Glass cut injury can cause isolated involvement of
the median nerve or alongwiththe ulnar nerve.
Anterior interosseous nerve can get involved due
to fracture or laceration of the forearm. It can be
compressed by the flexor digitorumsuperficialisor
pronator teres..
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7. Carpal tunnel syndrome
This is a syndrome characterised by the compression of the
median nerve as it passes beneath the flexor retinaculum
P/B :-DR NIYATI PATEL 7

8. P/B :-DR NIYATI PATEL 8

9. The patient is generally a middle aged woman
complaining of tingling, numbness or discomfort in the
thumb and radial one and a half fingers i.e., in the
median nerve distribution.
Tingling is more prominent during sleep. There is a
feeling of clumsiness in carrying out fine movements.
Nerve conduction studies show delayed or absent
conduction of impulses in the median nerve across the
wrist. Treatment is by dividing the flexor retinaculum,
and thus decompressing the nerve.
P/B :-DR NIYATI PATEL 9

10. SIGN AND SYMPTOMS
Sensory
There will be loss of sensation over the volar
aspect of lateral 3½ fingers up to the distal
phalanx on the dorsal side, skin overlying the
thenareminence. The autonomous zone for
the median nerve is the pulp of the thumb.
P/B :-DR NIYATI PATEL 10

11. Motor
The muscles supplied by the median nerve
namely the pronator teres, flexor carpi
radialis, flexor digitorum superficialis,
palmaris longus, flexor digitorumprofundus(
the lateral half), pronatusquadratus, flexor
pollicislongus, thenarmuscles, the first and
second lumbricals
P/B :-DR NIYATI PATEL 11

12. Deformity
The deformity seen in median nerve
palsy are as follows depending upon
the site and extent of lesion.
1. The commonest deformity seen is
ape hand or monkey hand which
occurs due to flattening of the
thenareminence, lack of opposition
of the thumb because of which the
thumb is held beside the index finger
due to over action of the adductor
pollicisand extensor pollicislongus.
P/B :-DR NIYATI PATEL 12

13. 2. Partial claw hand occurs due
to paralysis of the first and
second lumbricalsdue to which
there is unopposed action of
the extensor digitorumgiving
rise to hyperextension of the
metacarpophalangealjoint of
the index and middle finger
alongwithflexion of the
interphalangealjoint of these
fingers.
P/B :-DR NIYATI PATEL 13

14. 3. Pointing index finger: When
there is a higher lesion involving
even the long flexors of the hand,
on asking to make a fist the index
finger will point forward.
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15. 4. When patient with
anterior interosseous nerve
palsy is asked to make a tip to
tip pinch using the index and
the thumb then due to
paralysis of the flexor
digitorumprofundusand
flexor pollicislongusthe tip
to tip pinch will show a tear
drop appearance instead of
‘O’.
P/B :-DR NIYATI PATEL 15

16. RECOVERY SIGN
The first sign of recovery of median nerve
following its lesion in the wrist will be the
ability of the thumb to rotate when the
thumb is supported in slight amount of
palmar abduction and flexion.
P/B :-DR NIYATI PATEL 16

17. SPECIAL TESTS
Phalen'stest:In carpal tunnel syndrome palmar
flexion of the wrist to 90 degrees for one minute
exacerbates or reproduces the symptoms.
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18. Tinel'ssign:Tapping over the dorsum of the wrist
precipitates pain in the median nerve distribution
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19. Carpal Compression Test.:
The examiner holds the supinated
wrist in both hands and applies
direct, even pressure over the
median nerve in the carpal tunnel
for up to 30 seconds .
Production of the patient's
symptoms is considered to be a
positive test for carpal tunnel
syndrome.
P/B :-DR NIYATI PATEL 19

20. Wrinkle (Shrivel) Test
The patient's fingers are, placed in warm
water for approximately 5 to 20 mintues. Then
removes the patient's fingers from the water and
observes whether the skin over the pulp is wrinkled
.
Normal fingers show Tinkling, but denervated
ones do not. The test is valid only within the first
few months after injury.
P/B :-DR NIYATI PATEL 20

21. ULTT
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22. INVESTIGATION
RADIOGRAPH :-shows whether there is presence of fracture
MRI :-To delineate complete avulsion of nerve roots
SD CURVE:-abnormality in conduction can be verified. Sharp
curve, long chronaxie, low rheobaseand the absence of
contraction with repetitive stimuli indicates denervation. If it is
done 2-3 weeks after injury, it shows the sign of denervation and
to find out whether it is moderate or severe injury
NCV:-To find out the severance of nerve fiberswith wallerian
degeneration.
EMG:-it will help to find out reversible and irreversible nerve
damage and will help map out whether it pre ganglionic/ post
ganglionic lesion
P/B :-DR NIYATI PATEL 22

23. P/B :-DR NIYATI PATEL 23

24. TYPES OF INJURIES
In Neuropraxia pain, numbness, muscle weakness,
minimal muscle wasting is present. Recovery occurs within
minutes to days
In Axonotmesis there is pain, evident muscle wasting,
complete loss of motor, sensory and sympathetic functions.
Recovery time–months (axon regeneration at 1-1.5
mm/day)
In Neurotmesis no pain, complete loss of motor, sensory
and sympathetic functions. Recovery time –months and
only with surgery
P/B :-DR NIYATI PATEL 24

25. SURGICAL TREATMENT
The basic requirement for hand function in median nerve
injury consist of the following component.
◦Thumb abduction to perform opposition
◦Flexion across the metacarpophalangealjoint of the thumb
◦Flexion of the index and middle finger
◦Sensation over the thenareminence and pulp of the thumb.
Tendon transfer surgeries
Transfer of FDS of ring finger to abductor pollicisbrevis
Transfer of Brachioradialis to flexor pollicislongus
Transfer of FDP of ring and little finger to middle and index
finger
Following surgery, immobilisation with POP for 3 weeks and
opposition splint can be given for another 6 weeks
P/B :-DR NIYATI PATEL 25

26. PHYSIOTHERAPY TREATMENT
Passive movement to the wrist and fingers to keep the
parts mobile
Gentle stretching of the long flexors to prevent any form of
tightness
IG stimulation to all the muscles supplied by the median
nerve
Care of the anaesthetic hand
Splints: Opposition splints are given to maintain the thumb
in opposition and also to prevent contracture of the first
web space.
The two types of splints which are commonly given are C-bar
and cockup splints.
P/B :-DR NIYATI PATEL 26

27. C-BAR This is used to maintain
the first web space and is held in
place with the help of 3 velcro
straps one over the index finger, one
over the thumb and one at the
deepest part of the first web space
COCK UP SPLINT an opposition
out trigger is also used to maintain
the thumb in opposition
P/B :-DR NIYATI PATEL 27