Transcript 13 - Upper limb nerve injuries.ppt

Nerve Injuries of
the Upper Limb
Dr. Zeenat Zaidi
Upper limb is supplied by
the branches of the brachial
plexus, formed by the
ventral rami of the spinal
nerves C5, 6, 7, 8, and T1
Since the spinal nerves are mixed nerves carrying
sensory, motor and autonomic fibers, their injuries
result in sensory, motor and autonomic
disturbances
Symptoms & Signs of Peripheral Nerve Injury
Depend on the site and extent of the lesion
Motor changes: The innervated muscles become
paralyzed. The reflexes in which the muscles
participate are lost
Sensory changes: Loss of cutaneous sensibility over
the area exclusively supplied by the nerve
Trophic changes: Due to interruption of postganglionic
sympathetic fibers:


There is loss of vascular control: the skin at first becomes
red & hot. Later becomes blue and colder than normal. The
nail growth becomes retarded
The sweat glands cease to produce sweat and the skin
becomes dry and scaly
Upper Limb Tendon Reflexes
Biceps brachii reflex: C5,
6 (flexion of elbow joint by
tapping the tendon of
biceps muscle)
Triceps brachii reflex: C6,
7, 8 (extension of elbow
joint by tapping the tendon
of triceps muscle)
Supinator (brachioradialis)
reflex: C5, 6, 7 (supination
of radioulnar joint by
tapping the tendon of
brachioradialis muscle)
A spinal nerve may get injured:
1.
at the level of its roots within
the vertebral canal
2.
at the level of its passage
through the intervertebral
foramen
3.
At any level in its peripheral
course
Injuries 1 & 2 may result due to:

Fracture of the vertebra

Narrowing of intervertebral
foramina

Herniation of the
intervertebral disc

Degeneration of the
intervertebral disc
Brachial plexus injuries
May involve the roots, trunks,
divisions, cords & branches
Supraclavicular injuries involve
the roots and the trunks,
infraclavicular injuries will affect
the divisions and cords
Result due to:
 Compression
 Traction
 Stab wounds
Symptoms depend on the site of
injury & involvement of nerve
fibers
Brachial plexus injuries
Are of two types:
 Upper lesions usually involving C5 & C6
 Lower lesions usually involving (C8), T1
Upper Lesions of the Brachial Plexus
(Erb-Duchenne Palsy)
• These are usually the result of
traction & tearing of the 5th and
6th root of the brachial plexus
• This may occur:
•
In infants during a difficult
delivery
•
In adults following a fall on
or a blow to the shoulder.
• It involves the:
•
Nerve to sublavius
•
Suprascapular nerve
•
Axillary nerve
•
Musculocutaneous nerve
The muscles affected are:
 Abductors (supraspinatus &
deltoid) and lateral rotators
(Infraspinatus &teres minor) of
the shoulder
 Subclavius, biceps, brachialis &
coracobrachialis
Thus:

The limb hangs limply by the
side, and is medially rotated
 The forearm is pronated and
extended
 There is loss of sensation down
the lateral side of the arm & the
forearm
Another name for this lesion is
'porters tip'
Lower Lesions of the Brachial Plexus
(Klumpke Palsy)
These are usually caused
by excessive abduction of
the arm as a result of:
 Someone clutching for
an object when falling
from a height
 Difficult delivery in which
baby’s upper limb is
pulled excessively.
 Result of malignant
metastases from the
lungs in the lower deep
cervical lymph nodes
 A cervical rib
Usually the lowest root (T1) of the brachial
plexus is involved
The fibers from this segment of the spinal cord
supply the small muscles of the hand
(interossei and lumbricals).
Paralysis and wasting of small muscles of
hand occurs
There is also sensory loss along the medial
side of the forearm, hand and medial 2 fingers
Often associated with Horner’s syndrome
(drooping of upper eyelid & constricted pupil)
due to traction of sympathetic fibers
The hand has a clawed
appearance due to:
 Hyperextension of the
metacarpophalangeal joints
(the extensor digitorum is
unopposed by the lumbricals
and interossei and extends
the metacarpophalangeal
joints).
 Flexion of the interphalangeal
joints (the flexor digitorum
superficialis and profundus
are unopposed by the
lumbricals and interossei, the
middle and terminal
phalanges are flexed).
Long Thoracic Nerve Lesion
(Nerve to Serratus Anterior)
This nerve may be injured by:
 Blows or pressure in the
posterior triangle of the
neck
 During a radical
mastectomy surgical
procedure.
The serratus anterior muscle:
 Pulls the medial border of
the scapula to the
posterior thoracic wall and
stabilizes it there.
 Rotates scapula during the
abduction of arm above a
right angle
The patient shows
difficulty in raising the
arm above the head
If patient is asked to
push against a wall, the
medial border of the
scapula will be pushed
away from the thoracic
wall and protrude like a
wing, on the side of the
lesion. 'winged scapula'.
Axillary Nerve Lesion
Axillary nerve may get injured:
 Due to downward
dislocation of humeral head
in shoulder dislocation
 Fracture of the surgical
neck of humerus
Deltoid and teres minor
muscles become paralyzed
Abduction of the shoulder is
impaired. The paralyzed
deltoid wastes rapidly (loss of
rounded contour of the
shoulder)
Loss of sensation over the
lower half of deltoid muscle
Radial Nerve
The radial nerve is commonly
damaged:
 in the axilla
 in the radial groove
 Injury to the deep branch (in the
supinator tunnel)
 Injury to the superficial branch
Radial Nerve Injury in the Axilla
In the axilla the nerve may
be injured by:
 Pressure of the upper end
of badly fitting crutch
pressing up in to the
armpit (crutch palsy)
 The drunkard falling
asleep with his arm over
the back of a chair
(saturday night palsy).
 Fractures or dislocations
of the upper end of the
humerus
Motor:
Triceps, anconeus and long extensor
of the wrist are paralysed.
The patient is unable to extend the
elbow joint, wrist joint and fingers.
“Wrist drop” or flexion of the wrist
occurs as a result of the unopposed
flexor muscles of the wrist.
This is a very disabling injury, since a
person can't flex the fingers strongly
for gripping an object with the wrist
fully flexed.
The brachioradialis and supinator
muscles are paralyzed, but
supination can still be performed due
to intact biceps brachii.
Sensory: Due to the overlap
of sensory innervation by
adjacent median & ulnar
nerves, the area of total
anaesthesia is relatively
small, overlying the first
dorsal interosseous muscle
(between the 1st and 2nd
metacarpal bones)
Radial Nerve Injury in the Radial
Groove
The most common lesion of
the radial nerve resulting
because of the:
 Fracture of the shaft of
humerus
 Callus formation
 Pressure on the back of
the arm on the edge of the
operating table in an
unconscious patient
 Prolonged application of
tourniquet.
The injury to radial nerve occurs
most commonly in the distal part
of the groove beyond the origin of
the nerve to the triceps &
anconeus (so that extension of
the elbow is possible), and
beyond the origin of the
cutaneous nerves
Motor :The long extensors of the
forearm are paralyzed and this
will result in a "wrist drop".
Sensory: Loss of sensation from
small area overlying the first
dorsal interosseous muscle
Injury to the Deep Branch of the Radial
Nerve
It may be damaged in fractures of the proximal end
of the radius or during dislocation of the radial
head.
Motor:.


Intact forearm extension and flexion with intact hand
extension. Only weakness of finger extensors.
Nerve supply to the supinator and extensor carpi radialis
longus will be undamaged and because the later muscle
is powerful it will keep the wrist joint extended and wrist
drop will not occur.
Sensory: There will be no sensory loss since this
is a motor nerve.
Injury to the Superficial Branch of the Radial
Nerve
It may be damaged as a result of stab injury, or
pressure from handcuffs & tight bangles
Motor: There will be no motor loss since this is a
sensory nerve.
Sensory: There is a small loss of sensation
over the dorsal surface of the hand and the
dorsal surfaces of the roots of the lateral three
fingers
Median Nerve Lesions
Injury of median nerve at
different levels cause different
syndromes.
The most serious disability of
median nerve injuries is the:
 Loss of opposition of the
thumb. The delicate pincerlike action is not possible
 Loss of sensation from the
thumb and lateral 2½
fingers & lateral ⅔ of the
palm
Median Nerve Lesions
Median nerve can be damaged:
 In the elbow region
 At the wrist above the flexor retinaculum
 In the carpal tunnel
Median Nerve Lesion in the Elbow Region
Damaged in
supracondylar fracture of
humerus
Muscles affected are:
 Pronator muscles of the
forearm
 All long flexors of the
wrist and fingers except
flexor carpi ulnaris and
medial half of flexor
digitorum profundus
Motor:
Loss of pronation. Hand is kept in
supine position
Wrist shows weak flexion, and ulnar
deviation
No flexion possible on the
interphalangeal joints of the index
and middle fingers
Weak flexion of ring and little finger
Thumb is adducted and laterally
rotated, with loss of flexion of
terminal phalanx and loss of
opposition
Wasting of thenar eminence
Hand looks flattened and “apelike”,
and presents an inability to flex the
three most radial digits when asked
to make a fist.
Sensory: Loss of sensation
from:
 The radial side of the palm
 Palmer aspect of the lateral
3½ fingers
 Distal part of the dorsal
surface of the lateral 3½
fingers
Trophic Changes:



Dry and scaly skin
Easily cracking nails
Atrophy of the pulp of the
fingers
Median Nerve Lesion at the Wrist
Often injured by penetrating wounds (stab
wounds or broken glass) of the forearm
Motor: Thenar muscles are paralyzed and
atrophy in time so that the thenar eminence
becomes flattened. Opposition and abduction of
thumb are lost, and thumb and lateral two
fingers are arrested in adduction and
hyperextension position. “Apelike hand”
Sensory & trophic changes are the same as in
the elbow region injuries
Carpal Tunnel Syndrome
Compression of median
nerve in the carpal tunnel
Motor: Weak motor function
of thumb, index & middle
finger
Sensory: Burning pain or
‘pins and needles’ along the
distribution of median nerve
to lateral 3½ fingers
No sensory changes over the
palm as the palmer
cutaneous branch is given
before the median nerve
enters the carpal tunnel
Ulnar Nerve Lesion
Ulnar nerve can be damaged:
 At the elbow, where it lies behind the
medial epicondyle
 At the wrist, where it lies with the ulnar
artery superficial to the flexor
retinaculum
Ulnar Nerve Lesion at the Elbow
Often injured with fractures of the
medial epicondyle
Motor paralysis involves:
 Flexor carpi ulnaris
 Medial half of flexor digitorum
profundus
 Small muscles of the hands,
except the muscles of thenar
eminence and first two
lumbricals.
 Adductor pollicis
Sensory loss over the anterior &
posterior surfaces of the palm &
medial one and half finger
Trophic changes: because of loss
of sympathetic control
Flexion of the wrist will result in
abduction
The thumb is abducted and extended
with the distal phalanx flexed
(difficulty in holding a piece of paper
between thumb and index finger).
The adduction and abduction of
fingers is lost (difficulty in holding a
piece of paper between fingers).
The lateral two fingers are fully
extended with a slight flexion of the
distal phalanges.
The medial two fingers are
hyperextended at the
metacarpophalangeal joints but
flexed at the distal phalangeal joints.
Wasting of the hypothenar
eminence
The dorsum of the hand
shows hollowing between
the metacarpal bones
The hand resembles a
"claw" and is called a claw
hand.
The clawing becomes
most obvious when the
person is asked to
straighten their fingers.
Ulnar Nerve Lesion at the Wrist
Commonly occur due to cuts and stab wounds
Motor: The small muscles of the hands are
paralyzed, except the muscles of thenar eminence
and first two lumbricals. The claw hand is more
obvious as the flexor digitorum profundus is intact
Sensory loss over the anterior surfaces of the palm
and the anterior & posterior surfaces of the medial
one and half finger. (The posterior surface of the
hand is spared as the posterior cutaneous branch
arises above the level of wrist)