UPPER LIMB- ENTRAPMENT NEUROPATHIES
3 MAIN NERVES
MEDIAN NERVE
MEDIAN NERVE ENTRAPMENT @ THE ELBOW
SYMPTOMS
1. Pain, parasthesia or loss of skin sensation on the lateral 2/3 of the palm of the hand and the palmar aspect of the
lateral 3 ½ fingers.
2- Pain, parasthesia or loss of skin sensation on the skin of the distal phalanges of the dorsal surfaces of the lateral 3 ½
fingers.
3- The skin areas involved in sensory loss are warmer and drier than normal (The arteriolar dilatation and absence of
sweating resulting from loss of sympathetic control).
4- In long-standing cases, changes are found in the hand and fingers. The skin is dry and scaly, the nails crack easily,
and atrophy of the pulp of the fingers is present.
CLINICAL FINDINGS
1. Forearm is kept in the supine position
2. Wrist flexion is weak and is accompanied by adduction.
(Pronator muscles of the forearm and the long flexor muscles of the wrist and fingers, with the exception of the
flexor carpi ulnaris and the medial half of the flexor digitorum profundus, will be paralyzed.) (Wrist flexion being
accompanied by adduction is caused by caused by the paralysis of the flexor carpi radialis and the strength of the
flexor carpi ulnaris and the medial half of the flexor digitorum profundus.)
3- Flexion of the proximal interphalangeal joints of the 1st-3rd digits is lost and flexion of the 4th and 5th digits is
weakened.
4- Flexion of the distal interphalangeal joints of the 2nd and 3rd digits is lost.
5- The ability to flex the metacarpophalangeal joints of the 2nd and 3rd digits is affected (The digital branches of the
median nerve supply the 1st and 2nd lumbricals (although the interossei will help in that, making the
metacparhophalangeal joints of these two fingers weak rather than impossible).
6- Hand of Benediction (Pope’s Blessing): When the patient tries to make a fist, the index and to a lesser extent the
middle fingers tend to remain straight (partially extended), whereas the ring and little fingers flex during the formation
of the fist. The latter two fingers are, however, weakened by the loss of the flexor digitorum superficialis.
7- Ape hand deformity: Thenar muscle function (function of the muscles at the base of the thumb) is also lost, as in
carpal tunnel syndrome. Flexion of the terminal phalanx of the thumb is lost because of paralysis of the flexor pollicis
longus. The muscles of the thenar eminence are paralyzed and wasted so that the eminence is flattened. The thumb is
laterally rotated and adducted. The hand looks flattened and “ape-like”.
CARPAL TUNNEL SYNDROME
Entrapment of the median nerve in the Carpal Tunnel- Most common mononeuropathy of the upper limb
Same as above except sensory problems not exist on the thenar eminence & central palm as the palmar
branch of the median nerve is saved passing over the flexor retinaculum.
ULNAR NERVE
CUBITAL TUNNEL SYNDROME
Entrapment of the ulnar nerve in the Cubital Tunnel- Second most common mononeuropathy of the upper limb
SYMPTOMS
1- Pain and with paresthesia over the small and ring fingers (Paresthesias present early in the disease and progress to
motor dysfunction as the compression of the nerve becomes more severe and chronic.)
Loss of sensation, pain or parasthesia complaints
over the anterior and posterior surfaces of the medial third of the hand and the medial ½ fingers
2- Claw hand “ main en griffe”: The interphalangeal joints are flexed, owing again to the paralysis of the lumbrical
and interosseous muscles, which normally extend these joints through the extensor expansion. The flexion deformity
at the interphalangeal joints of the fourth and fifth fingers is obvious because the first and second lumbrical muscles of
the index and middle fingers are not paralyzed. In longstanding cases the hand assumes the characteristic “claw”
deformity (main en griffe).
3- The skin areas involved in sensory loss are warmer and drier than normal because of the arteriolar dilatation and
absence of sweating resulting from loss of sympathetic control.
CLINICAL FINDINGS
1
UPPER LIMB- ENTRAPMENT NEUROPATHIES
3 MAIN NERVES
1- Intrinsic muscle weakness, as well as, weakness of flexor digitorum profoundus of small and ring fingers can be
seen in more advanced disease, which presents as clawing.
Motor weakness of the medial half of flexor digitorum profundus: Problem in flexing the distal phalanges of the ring
and little fingers.
2- Flexion of the wrist joint results in abduction (owing to paralysis of the flexor carpi ulnaris).
3- The medial border of the front of the forearm might show flattening (owing to the wasting of the underlying
ulnaris and profundus muscles).
4- The patient is unable to adduct and abduct the fingers and consequently is unable to grip a piece of paper placed
between the fingers.
5- Unable to adduct the thumb because the adductor pollicis muscle is paralyzed.
6- The metacarpophalangeal joints become hyperextended because of the paralysis of the lumbrical and interosseous
muscles, which normally flex these joints. (Because the first and second lumbricals are not paralyzed (they are
supplied by the median nerve), the hyperextension of the metacarpophalangeal joints is most prominent in the
fourth and fifth fingers).
7- Froment’s sign: Positive. If the patient is asked to grip a piece of paper between the thumb and the index finger, he
or she does so by strongly contracting the flexor pollicis longus and flexing the terminal phalanx.
8- Wasting of the paralyzed muscles results in flattening of the hypothenar eminence and loss of the convex curve to
the medial border of the hand. Examination of the dorsum of the hand will show hollowing between the metacarpal
bones caused by wasting of the dorsal interosseous muscles.
GUYON’S CANAL SYNDROME
Same as above except as the dorsal branch of ulnar nerve will be saved (5 cm above the wrist), there will
be no dorsal aspect sensation problems, the medial half of the flexor digitorum profundus will also be
not affected, the patient will be able to flex the distal phalanges of the last two fingers better, Claw hand
deformity will be more obvious. Flexion of the distal phalanges is good for the hand looking like a claw.
RADIAL NERVE
RADIAL NERVE INJURY @ THE AXILLA
SYMPTOMS
1- Small loss of skin sensation down the posterior surface of the lower part of the arm and down a narrow strip on the
back of the forearm.
2- A variable area of sensory loss on the lateral part of the dorsum of the hand and on the dorsal surface of the roots of
the lateral three and a half fingers. The area of total anesthesia is relatively small because of the overlap of sensory
innervation by adjacent nerves.
CLINICAL FINDINGS
1- Motor loss in extending the elbow, wrist and the fingers
2- Wristdrop, or flexion of the wrist, occurs as a result of the action of the unopposed flexor muscles of the wrist.
RADIAL NERVE INJURY @ THE SPIRAL (RADIAL) GROOVE
SYMPTOMS
A variable small area of anesthesia over the dorsal surface of the hand and the dorsal surface of the roots of the lateral
3 ½ fingers.
CLINICAL FINDINGS
The patient is unable to extend the wrist and the fingers, and wristdrop occurs.
DEEP BRANCH OF RADIAL NERVE INJURY
No sensory loss: A motor branch
No wristdropn seen
The nerve supply to the supinator and the extensor carpi radialis longus will be undamaged, and because the latter
muscle is powerful, it will keep the wrist joint extended, and wristdrop will not occur
SUPERFICIAL BRANCH OF RADIAL NERVE INJURY
Variable small area of anesthesia over the dorsum of the hand and the dorsal surface of the roots of the lateral 3 ½
fingers (roots= proximal and middle phalanges)
2