Transcript File

Peripheral nerve injuries
By : - Dr .Sanjeev
Structure of a nerve
• It has an outer covering
which forms a sheath
around the nerve, called
the epineurium.
• Nerve fibers, which are
axons, organize into
bundles known as
fascicles with each
fascicle surrounded by
the perineurium.
• Between individual
nerve fibers is an inner
layer of endoneurium.
Peripheral nerve injury
Dermotome :
• is an area of skin supplied by a single
spinal root
Myotome :
• Represents a muscle unit supplied by a
single spinal root
Seddon's classification
Neurapraxia -- temporary paralysis of a nerve
caused by lack of blood flow or by pressure on
the affected nerve with no loss of structural
continuity.
Axonotmesis –
• neural tube intact, but axons are disrupted.
• nerves are likely to recover.
Neurotmesis –
• the neural tube is severed.
• Injuries are likely permanent without repair.
Classification of Nerve Injuries
myelin axon endoneurium perineurium epineurium
Degree of Injury
I Neuropraxia
+/-
II Axonotmesis
yes
yes
no
no
no
III
yes
yes
yes
no
no
IV
yes
yes
yes
yes
no
V Neurotmesis
yes
yes
yes
yes
yes
Sunderland`s classification
• Grade I
– Same as Seddon's neuropraxia.
• Grade II
– Same as Seddon's axonotmesis.
• Grade III
– Neurotmesis with preservation of the perineurium.
• Grade IV
– Neurotmesis with preservation of the epineurium.
Everything else is disrupted.
– Nerve grossly appear edematous.
– Nerve grafting is required.
• Grade V
– Complete transection of the nerve trunk.
Typical deformities :
• Wrist drop ---- radial nerve injury
• Claw hand ---- ulnar nerve injury
• Foot drop ---- lateral popliteal nerve injury
• Ape thumb ---- median nerve injury
• Winging of scapula ---- thoracodorsal nerve
injury
• Pointing index ---- median nerve injury
Simple screening tests
• Ulnar nerve injury :
– Loss of pain at tip of the little finger
• Medial nerve injury :
– Loss of pain at tip of index finger
• Radial nerve injury :
– Inability to extend thumb
Incidence of Peripheral nerve injury
• Radial nerve ------ commonly injuried
• Ulnar nerve ------- 30 %
• Median nerve ----- 15 %
• Lumbosacral plexus ---- 3 %
Ulnar nerve injury
Causes :
General causes : metabolic diseases , collagen
diseases , malignancies , endogenous or
exogenous toxins , chemical or mechanical
trauma , etc.
Local causes :
Causes in the axilla :
– Crutch pressure
– Aneurysm of the axillary vessels
Causes in the arm :
– # shaft of humerus
– Gunshot and penetrating injuries
Cont ..
Causes at the elbow :
–
–
–
–
–
Compression by the accessory muscles
# lateral epicondyle of humerus
Repeated occupational strains
Recurrent subluxation of the nerve
Compression by the osteophytes as in rheumatoid
and osteoarthritis
Causes in the forearm :
– # both bones forearm
– Incised wounds , gunshot wounds and penetrating
injuries of the forearm
Cont ..
Causes at the wrist :
–
–
–
–
Compression by osteophytes
# hook of the hamate
Compression by ganglion
Wrist injuries
Causes in the hand:
– Blunt trauma
– Penetrating injuries
• Ulnar nerve injuries gives rise to claw hand
deformity
Claw hand deformity
• It is a deformity with
hyperextension of
the MCP joints and
flexion of the IP
joints of the fingers
( loss of flexon at
MCP and extension
at IP joints )
Clinical features
• Loss of sensation along the ulnar
nerve distribution
and
• Wasting of the hypothenar muscles ,
intrinsic muscles of the hand leading to
hollow intermetacarpal spaces on the
dorsum of the hand
.
Levels of the lesion
High : above the level of elbow , entire nerve
function is lost
Low :
Below the elbow at the junction of the middle
and lower third of forearm :
Spared :
- function of FDP and FUC
Lost :
– Motor : HTM ,Its , Lum ,PB
– Sensory : dorsal aspect of hand and one and half
fingers
Cont ..
Proximal to Guyon`s
canal :
– Spared : FDP , FCU and
dorsal sensation
– Lost : same as above +
loss of volar sensation
Cont ..
Distal to Guyon`s canal : • Spared : FDP , FCU , HTM , PB, dorsal and
volar sensation
• Lost : interossei and lumbricals
–
–
–
–
–
–
FCU – flexor carpi ulnaris
FDP – flexor digitorum profundus
HTM – hypothenar muscles
PB – palmaris brevis
Lum – lumbricals
Its - interossei
Clinical tests :
• Froment's sign. When the
patient attempts to pinch with
the thumb and index finger, the
long flexor of the thumb is used
to substitute for the thumb
adductor, resulting in flexion of
the thumb at the interphalangeal
joint.
• This characteristic appearance
is present in this patient's left
hand, caused by an ulnar nerve
lesion at the elbow
Card test
• Inability to hold a card or paper in between
fingers due to loss of adduction by the
palmar interossei
Pen test
• Unable to touch the pen due to the loss of
action of abductor pollicic brevis
Egawa test ( median nerve injury )
• With palm flat on the table the patient is asked to
move the middle finger sideways( test for the
dorsal interossei of middle finger )
• In total clawing median nerve is also injuried
Pointing index or oschner`s clasp test :
• When both the hands are clapsed together , index
and middle fingers , fail to flex due to the loss of
action of long finger flexors of the index and
middle fingers which are supplied by the median
nerve .
Treatment of ulnar nerve injury
• Unless there is a lot of muscle
wasting, (nonsurgical treatment )
Prevention
• Avoid frequent use of the arm with
the elbow bent
• If you use a computer frequently,
make sure that your chair is not too
low. Do not rest the elbow on the
armrest.
• Avoid putting pressure on the inside
of the arm (do not drive with the arm
resting on the open window ).
• Keep the elbow straight at night
when you are sleeping (done by
wrapping a towel around the straight
elbow, wearing an elbow pad
backwards, or using a special brace )
Loosely wrapping a
towel around the arm
with tape can help
you to remember not
to bend the elbow
during the night
Nonsurgical Treatment
• If symptoms have only
just started,
• Anti – inflammatory
drugs, ibuprofen,( to
reduce swelling around
the nerve ).
• Steroid (cortisone)
injections around the
ulnar nerve are not
generally used because
there is a risk of damage
to the nerve.
• Exercises ( prevents arm
and wrist from stiffness ).
With your arm forward and the elbow
straight, curl the wrist and fingers
toward the body, then extend them
away from you and then bend the
elbow
With the arm to the side, curl the wrist and fingers
toward the shoulder and then turn the palm up and
then stretch the neck to the other side.
Surgical Treatment
• If the nerve is very compressed; or if there is
muscle wasting
Surgery :
• Around the elbow and the wrist or both
• More commonly, the nerve is moved from its
place behind the elbow to a new place in front of
the elbow. This is called an anterior
transposition of the ulnar nerve.
The nerve can be moved : – under the skin and fat (subcutaneous
transposition),
– within the muscle (intermuscular transposition) or
– under the muscle (submuscular transposition).
.
For anterior transposition of the ulnar nerve, an incision
along the inside of the elbow is used. Nerve moved from
behind the elbow to in front of it and will make sure that
it is not compressed by any other structures.
.
Entrapment of the ulnar nerve at Guyon's canal.
If ulnar nerve is compressed at the wrist, make an incision
and free the nerve where it is compressed.
Ulnar paradox
• The higher the lesion of the median and
ulnar nerve injury , the less prominent is
the deformity and vice versa, because in
higher lesions the long finger flexors are
paralysed .
• The loss of finger flexion makes the
deformity look less obvius
Radial nerve injury
Causes : General causes : metabolic diseases , collagen
diseases , malignancies , endogenous or
exogenous toxins , chemical or mechanical
trauma , etc.
Local causes : In the axilla :
– Aneurysm of the axillary vessels
– Crutch palsy
In the shoulder:
– Proximal humeral #
– Shoulder dislocation
Cont..
In the spiral groove ( 5 `s )
– Shaft #
– Saturday night #
– Syringe palsy
– `S ` march`s tourniquet palsy
Between spiral groove and
lateral epicondyle :
– # shaft humerus
– Supracondylar # humerus
– Lateral epicondyle # of humerus
– Penetrating and gunshot injuries
– Cubitus valgus deformity
Cont …
At the elbow :
– Posterior dislocation of elbow
– # head of radius
– Monteggia #
Causes in the forearm :
– # both bones of forearm
– Penetrating and gunshot injuries
Levels of lesion
High above spiral groove---- total palsy
Low :
Type 1 (Between the spiral groove and the lateral
epicondyle ) : Spared : - elbow extensor
Lost : – Motor : wrist extensor , thumb extensor , finger
extensor
– Sensory : dorsum of first web space
Cont ..
Low
• Type 2 ( below the elbow ) :
Spared :
– Elbow extensor
– Wrist extensor
Lost :
– Motor : thumb extensor , finger extensor
– Sensory :
– First web space
Clinical features
Depend upon the site of the injury: Lesions in or above the axilla :
• Paralysis and wasting of all the muscles
innervated.
• Clinically, this is manifest as:
– weakness of forearm extension and flexion triceps and brachioradialis
– wrist drop and finger drop - paralysis of the
extensors of the wrist and digits
– weakness of the long thumb abductor and
extensor muscles
Cont ..
• Sensory loss on the dorsum of hand and
forearm appropriate to the cutaneous distribution
• Lesions around the humerus
– spare brachioradialis and
– extensor carpi radialis longus.
• Posterior interosseous palsy (due to a
dislocation or fracture of the elbow ).
– weakness of finger extension, and of thumb extension
and abduction.
– little or no wrist drop, and usually, no sensory loss.
Fig : - Wrist drop
• .
Tests
• Muscles supplied by the radial nerve and how to test each:
•
C7,8: triceps - ask patient to extend elbow against resistance.
•
C5,6: brachioradialis - ask patient to flex elbow with forearm half way between
pronation and supination.
•
C6,7: extensor carpi radialis longus - ask patient to extend wrist to radial side
with fingers extended.
•
C5,6: supinator - with arm by side, ask patient to resist hand pronation.
•
C7,8: extensor digitorum - ask patient to keep fingers extended at MCP joint.
•
C7,8: extensor carpi ulnaris - ask patient to extend wrist to ulnar side.
•
C7,8: abductor pollicis longus - ask patient to abduct thumb at 90° to palm.
•
C7,8: extensor pollicis brevis - ask patient to extend thumb at MCP joint.
•
C7,8: extensor pollicis longus - ask patient to resist thumb flexion at IP joint.
Sensation:
• The cutaneous
branches of the radial
nerve supply the dorsal
aspect of the forearm
from below the elbow
down over the lateral
part of the hand to
include the thumb to the
interphalangeal joint and
the fingers to the distal
interphalangeal joint.
Exams and Tests
An examination of the arm, hand, and wrist identify
radial nerve dysfunction.
– Decreased ability to extend the arm at the elbow
– Decreased ability to rotate the arm outward (supination)
– Difficulty lifting the wrist or fingers (extensor muscle
weakness)
– Muscle loss (atrophy) in the forearm
– Weakness of the wrist and finger
– Wrist or finger drop
Tests for nerve dysfunction :
• EMG
• MRI of the head, neck, and shoulder
• Nerve biopsy
• Nerve conduction tests
Treatment
Closed fracture
CONTROL OF SYMPTOMS
• Analgesics ( to control pain neuralgia)
• Phenytoin, carbamazepine, or tricyclic antidepressants (amitriptyline) to
reduce stabbing pain
• Steroids (prednisone) to reduce swelling
Other treatments include:
• Braces, splints,
• Physical therapy to help maintain muscle strength
• Occupational therapy, or job counseling
• Surgery : • Failure of conservative by 12 to 18 months
Surgery ( open # )
Clean wound :
Primary repair , splint , physiotherapy
Contaminated wound :
Delayed primary repair and secondary repair
Late cases :
– Tendon transfers
– Arthrodesis
Splints
Complications
• Mild to severe deformity of the hand
• Partial or complete loss of feeling in the
hand
• Partial or complete loss of wrist or hand
movement
• Recurrent injury to the hand
Sciatic nerve injury
•
•
•
•
Thickest nerve in the body
Leprosy is the commonest cause
High stepping gait is the characterisic
Conservative treatment is indicated up to
one year
Foot drop
Causes
• General causes : metabolic diseases , collagen
diseases , malignancies , endogenous or
exogenous toxins , chemical or mechanical
trauma , etc.
Local :
At the spine :
– Spina bifida
– Tumors
– Disc prolapse
Cont …
At the hip :
– Posterior dislocation of the hip
– # around the hip
– # acetabulum
At the gluteal region :
– Deep I.M injections
At the thigh :
– # shaft femur
– Penetrating injury and gunshot
injury
Cont …
At the knee ( common causes )
– Forcible inversion of the knee
– Dislocation of knee
– # lateral condyle of tibia
– Tight plaster casts around the knee
– Surgical damage during application of skeletal
traction
– Gunshot injuries , incised and penetrating
injuries
Levels of lesion
High lesion ( above knee ) :
• Both tibial and common peroneal nerve are
paralysed
Low lesion ( below knee )
Type 1 ( anterior tibial nerve injury )
– Lost : tibialis anterior , extensor hallucis longus ,
extensor digitorium longus
– Sensation : over first web space is lost
Type 2 ( musculocutaneous nerve injury ):
– Spared : all the above muscles innervated by anterior
tibial nerve
– Lost : peroneous longus and brevis
– Sensation : over outer leg and foot
Clinical features
Foot drop :
Complete ( sciatic or lateral popliteal
nerve injury )
Incomplete ( superficial or deep peroneal
nerve )
– High lesions ------total foot drop
– Low lesions ------ incomplete foot drop
Low lesions
Type 1 :
– Dorsiflexion and inversion is not possible
– Front of the leg is wasted
– Sensation over the dorsal web space is lost
Type 2 :
– Cannot evert but can dorsiflex and invert the foot
– Wasting of the outer half of the leg
– Sensation lost over outer leg and foot
• Gait : - high stepping gait is characteristic .
Treatment
• Braces or splints.
• Physical therapy.
• Nerve stimulation :
– In some cases, a small, battery-operated electrical
stimulator is strapped to the leg just below the knee.
– In other cases, the stimulator is implanted in the leg.
• Surgery.
– Tendon transfer ( for mobile foot drop )
– Tendon – Achilles lengthening ( in fixed )
Treatment
• Different types of braces
(also known as ankle-foot
orthotics or AFOs) are used .
• Two standard motions that
occur at the ankle joint –
“dorsiflexion” and
“plantarflexion”.
• Plantarflexion (toes point
downward ).
• Dorsiflexion ( foot points
upward ).
• Dropfoot ( partial or
complete weakness of the
muscles that dorsiflex the
foot at the ankle joint ).
Types of AFOs
– Short leg fixed AFOs
– Dorsiflexion assist short leg AFOs
– Solid ankle AFO (with or without posterior
stop). Also available with dorsiflexion assist.
– Full leg posterior leaf spring AFO
Short Leg AFO with Fixed Hinge
(doesn’t flex at ankle joint)
Dorsiflexion Assist AFO
(dorsiflex the ankle) :
Plantarflexion Stop AFO:
Solid AFO:
(stops plantarflexion and also stops
or limits dorsiflexion).
Posterior Leaf Spring AFO
• Patients who have instability of the knee
along with their dropfoot.
Brachical plexus injuries
Causes
Closed injury :
– Due to birth or
– Due to bike trauma
Open injury :
–
–
–
–
–
–
–
Due to penetrating or gunshot injuries
Others ( less common )
Traction injuries
Tumor removal
Shoulder dislocations
Surgical excision of cervical ribs
Abnormal pressures due to faulty posture
Types of lesions
• Supraclavicular lesion:
1 . Preganglionic lesion :
– Cause could be either birth or bike trauma
Characteristic feature :
– Presence of Horner`s syndrome.
2 . Postganglionic lesion : - absence of Horner`s syndrome
- prognosis is slightly better than the preganglionic
lesion
- positive Tinel`s sign ( tapping above the clavicle ,
produces tingling sensation in the anaesthetic limb )
Horner`s syndrome
Remember ( 5 P`s ) : – Ptosis of the eyelid
– Pupils which are small
and constricted
– Protrusion of the eyeball
which is slight
– Pain even at rest
– Poor prognosis
Assessment of brachial plexus
injury
In preganglionic lesion
• Horner`s syndrome --present
• Unable to elevate
scapula
In postganglionic lesion
• Horner`s syndrome ---absent
• Able to elevate scapula
• Tinel`s sign --- present
in the later stages
Investigation
• X – ray ( to rule out # )
• CT scan ( study cross – section anatomy )
• MRI ( study the soft tissue damages )
• Electromyogram (EMG or electromyography)
• Nerve conduction study
Treatment
1 . Splinting
• Aeroplane splint
Cont ..
2 . For pain control :
• TENS method ( 'Transcutaneous
Electrical Nerve Stimulation‘ )
• Mild electrical impulses are
transmitted through the skin
• Cause body to release
endorphins, the body’s own
pain-relieving hormones.
• These 'positive signals' to the
brain block the slower-moving
pain messages.
Surgical measures
• Types of surgery
Nerve graft : • the damaged part
of the brachial
plexus is removed
and replaced with
sections of nerves
cut from other
parts of body
Nerve transfers
• Done in the
most serious
types of brachial
plexus injuries,
called avulsions,
when the nerve
root has been
torn out of the
spinal cord.
Muscle transfers
• Needed if
arm muscles
have
atrophied
from lack of
use.
ERBS PALSY
Erb's palsy
• paralysis of the muscles in a
baby's arm, caused by injury
of the nerves in the shoulder
at birth (during delivery).
• The baby lies with one arm
and hand twisted backward
and does not move the arm
as much as the other.
• If the full range of motion of
the arm is not kept through
regular exercise,
contractures will develop .
Clinical features
At the shoulder :
– Loss of shoulder abduction and external rotation ( due
to paralysis of the deltoid , supra and infraspinatus
and teres minor muscles )
At the elbow :
– Loss of flexion of the elbow joint ( due to paralysis of
the biceps and brachialis )
At the forearm :
– Loss of supination of the forearm
• May be sensory loss on the outer aspects of the
arm and forearm both in the front and back .
Policeman or Waiter`s tip
• Shoulder --- internally
rotated
• Elbow ----- extension
• Forearm --- pronated
• Wrist ------ flexion
Treatment
1 . Splinting
– Aeroplane splint
2 . For pain control :
– TENS method
• Types of surgery
- Nerve graft .
- Nerve transfers .
- Muscle transfers .
- release of soft tissue contractures .
With the baby, start range-ofmotion exercises 2 times a day.
When the child is old, have him do exercises himself, for
range of motion and to increase strength.
Cont ..
Cont ..