Download 13-Nerve Injuries

NERVE INJURIES OF
UPPER LIMB
By: Dr. Mujahid Khan
Brachial Plexus Injuries
(upper lesions)
 These
are caused by the excessive
displacement of the head to the opposite
side
 Depression
of the shoulder on the same
side
 This
causes excessive traction of C5 and
C6 roots of the plexus
Muscles to be Paralyzed

Supraspinatus (Abductor of shoulder)

Infraspinatus (lateral rotator of shoulder)

Biceps brachii (flexor of elbow)

Coracobrachialis (flexor of shoulder)

Deltoid (Abductor of shoulder)

Teres minor (lateral rotator of shoulder)
Erb-Duchenne Palsy
 The
limb hangs limply
by the side likened
to a waiter or porter
hinting for a tip
 There
will be a loss of
sensation down the
lateral side of arm
Brachial Plexus Injuries
(Lower lesions)
 Are
usually a traction injuries caused by
excessive abduction of the arm
 The
 The
first thoracic nerve is usually torn
hand has a clawed appearance
caused by hyperextension of
metacarpophalangeal joints & flexion of
interphalangeal joints
Brachial Plexus Injuries
(Lower lesions)
 Loss
of sensation will occur along the
medial side of the arm
 Lower
lesions can also be produced by a
presence of a cervical rib or malignant
metastases from the lungs in the lower
deep cervical lymph nodes
Axillary Sheath
 A brachial
plexus nerve block can be
obtained by injecting a local anesthetic
 The
position of the sheath can be verified
by feeling the pulsations of the 3rd part of
the axillary artery
Injuries of Long Thoracic Nerve

Can be injured by blows to or pressure on the
posterior triangle of the neck

Serratus anterior is paralyzed

The patient feels difficulty in raising the arm

The vertebral border & inferior angle of scapula
protrude posteriorly

Known as winged scapula
Injuries of Axillary Nerve

Can be injured by the pressure of a badly
adjusted crutch pressing upward into the armpit

It is vulnerable during the downward
displacement of the humeral head in shoulder
dislocations or fractures of the surgical neck of
the humerus

Paralysis of deltoid and teres minor muscles
results
Axillary Nerve

Loss of skin sensation over the lower half of the
deltoid muscle

Paralyzed deltoid wastes rapidly

Underlying greater tuberosity can be palpated

Abduction of the shoulder is impaired

Paralysis of teres minor is not recognized
clinically
Injuries of Radial Nerve
Can be injured by:
 Pressure
of badly fitting crutches
 Drunkard
falling asleep with one arm over
the back of a chair
 Fractures
or dislocation of the proximal
end of the humerus
Findings in Radial N. Injury

Triceps, anconeus and long extensors of the
wrist are paralyzed

Unable to extend the elbow joint, wrist joint and
fingers

Wrist drop or flexion of wrist occurs

Unable to flex the fingers firmly for gripping

Brachioradialis & supinator are paralyzed
Sensory Findings
 Little
loss of skin sensation over posterior
surface of lower part of the arm
 Sensory
loss on the lateral part of dorsum
of the hand
 Sensory
loss on the dorsal surface of the
roots of the lateral 3 & ½ fingers
In the Spiral Groove
 Radial
nerve can be injured in the spiral
groove at the time of fracture of shaft of
the humerus
 Wrist
drop occurs
 Sensory
loss on the dorsal surface of the
roots of the lateral 3 & ½ fingers
Deep Branch of Radial Nerve
 Can
be damaged in the fracture of the
proximal end of radius or during dislocation
of the radial head
 No
wrist drop as extensor carpi radialis
longus is undamaged
 No
sensory loss as this is a motor nerve
Injuries of Musculocutaneous
Nerve
 Rarely
injured due to its protected position
beneath the biceps brachii muscle
 If
injured high up in the arm, the biceps &
coracobrachialis are paralyzed &
brachialis is weakened
 Sensory
loss along the lateral side of the
forearm occurs
Injuries of Median Nerve
Can be injured:

Occasionally in the elbow region in
supracondylar fractures of the humerus

Commonly injured by stab wounds or broken
glass just proximal to the flexor retinaculum

Here it lies between the tendons of flexor carpi
radialis and flexor digitorum superficialis
Injury at Elbow
(motor)

Pronator muscles of forearm, long flexor
muscles of the wrist & fingers will be paralyzed

Forearm is kept in supine position

Wrist flexion is weak & accompanied by
adduction

No flexion at interphalangeal joints of index &
middle fingers
Injury at Elbow
(motor)
 When
the patient tries to make a fist, the
index & middle fingers tend to remain
straight
 Only
ring & little fingers flex
 Flexion
in these fingers is weakened by
the loss of the flexor digitorum superficialis
Injury at Elbow
(motor)
 Flexion
of terminal phalanx of thumb is lost
because of paralysis of flexor policis
longus
 The
thumb is laterally rotated and
adducted
 Muscles
 The
of thenar eminence are paralyzed
hand looks flattened and ape like
Injury at Elbow
(sensory)
 Skin
sensation is lost on the palmar aspect
of the lateral 3 & ½ fingers
 Sensory
loss occurs on the skin of the
distal part of the dorsal surfaces of the
lateral 3 & ½ fingers
 Total
area of anesthesia is less
Injury at Elbow
(vasomotor changes)
 The
skin areas involved in sensory loss
are warmer and drier than normal
 Arteriolar
dilatation and absence of
sweating resulting from loss of
sympathetic control
Injury at Elbow
(Trophic changes)
In long standing cases:
 Skin
 Nails
is dry and scaly
crack easily
 Atrophy
of the pulp of the fingers
Injury at Wrist
 Almost
all the clinical findings are same as
injury of the median nerve at elbow
 In
addition a delicate pincer like movement
is not possible
Carpal Tunnel Syndrome
 The
carpal tunnel is formed by the
concave anterior surface of carpal bones
and closed by flexor retinaculum
 Clinically,
the syndrome consists of a
burning pain or pins & needles along the
distribution of the median nerve
 Lateral
3 & ½ fingers are involved
Carpal Tunnel Syndrome
 The
exact cause is difficult to determine
 Condition
is relieved by decompressing
the tunnel by making a longitudinal
incision through the flexor retinaculum
Injury to the Ulnar Nerve
(motor at elbow)

Flexor carpi ulnaris & medial half of flexor
digitorum profundus are paralyzed

In a tightly clenched fist the tightening of the
tendon of profundus is absent

Profundus tendon to the ring & little fingers will
be functionless

Terminal phalanges of these fingers fail to flex
properly
Injury to the Ulnar Nerve
(motor at elbow)
 Flexion
of wrist joint will result in abduction
due to paralysis of flexor carpi ulnaris
 Small
muscles of hand will be paralyzed
except the muscles of thenar eminence
and first 2 lumbricals
 Adductor
pollicis longus is paralyzed so
the adduction of thumb is not possible
Injury to the Ulnar Nerve
(motor at elbow)
 Metacarpophalangeal
joints become
hyperextended due to the paralysis of
lumbrical and interosseous muscles
 Interphalangeal
joints are flexed due to the
same reason as mentioned above
 Dorsum
of hand will show hollowing due to
the wasting of dorsal interosseous
muscles
Injury to the Ulnar Nerve
(sensory at elbow)
 Loss
of skin sensation of anterior &
posterior surfaces of the medial 3rd of the
hand and medial 1 & ½ fingers
 The
skin areas involved in sensory loss
are warmer and drier than normal
 Arteriolar
dilatation and absence of
sweating resulting from loss of
sympathetic control
Injury to the Ulnar Nerve
(motor at wrist)
 Small
muscles of the hand will be
paralyzed
 Claw
hand is more obvious as flexor
digitorum profundus is not paralyzed
 Marked
occur
flexion of the terminal phalanges
Injury to the Ulnar Nerve
(sensory at wrist)

The sensory loss is usually confined to the
palmar surface of medial 3rd of the hand and the
medial 1 & ½ finger

Trophic changes are same as that injuries of
ulnar nerve at elbow

Unlike median nerve injuries, lesions of ulnar
nerve leave a relatively efficient hand

Pincer like action is good