Traumatic Injuries of Peripheral nerves

Question 1

What are the constutions of the Nerve

Answer 1

• Axon
• Dendrites
• Endoneurium
• Perineurium
• Epineurium

Question 2

Endoneurium?

Answer 2

surrounds undividual axon

Question 3

Perineurium?

Answer 3

a layer of connective tissue that
surrounds groups of axons called fascicles

Question 4

Epineurium?

Answer 4

a layer of connective tissue that
covers the outer surface of your nerve.

Question 5

What is the first thing to do in front of nerve injury

Answer 5

determine whether the
injury results in an open or closed lesion.

Question 6

What are the two classification of peripheral nerve injury?

Answer 6

• Seddon’s classification
• The Sunderland classification

Question 7

Seddon’s classification vs Sunderland classification?

Answer 7

• The Sunderland classification is an expansion of the Seddon classification, which divides axonotmesis into 3 stages and contains 5 grades.

Question 8

stages of Seddon’s classification?

Answer 8

• neuropraxia,
• axonotmesis,
• Neurotmesis

Question 9

Neuropraxia?

Answer 9

• the mildest type
• A temporary blockage of nervous conduction caused by a segmental demyelinization( compression, stretshing)
• Motor paralysis, and some proprioceptive and tactile sensitivity loss
• maintenance of thermal and pain sensitivity in most cases
• no distal axonal degeneration.
• recovery in days or weeks
• Grade 1 of the Sunderland classification

Question 10

Axonotmesis?

Answer 10

• the loss of axonal continuity.
• nerve connective tissue framework is preserved
• spontaneous regeneration is s possible- weeks to months
• wallerian degeneration occurs in the nerve segment distal to the injury

Question 11

Whata are the three grades of Axonotmosis depending on The Sunderland classification?

Answer 11

• Grade 2: Loss of continuity of the axon and its myelin sheath, endoneurium, epineurium and perineurium are preserved
• Grade 3: : The axon and the endoneurium are damaged but not the perineurium
• Grade 4: The axon, the endoneurium and the perineurium are damaged but the epineurium is preserved

Question 12

Neurotmesis?

Answer 12

• A rupture occurs in the epineurium with macroscopic loss of nerve continuity
• complete sensory and motor
  deficits.
• wallerian degeneration : the nerve segment distal to the injury
• No spontaneous regeneration < surgical
  treatment.
• grade 5 of the Sunderland
  classification

Question 13

What the Musculo-cutaneous nerve innervate ?

Answer 13

• innervates the three muscles of the anterior compartment of the arm: the coracobrachialis, biceps brachii, and brachialis muscles
• cutaneous innervation of the lateral forearm

Question 14

What are the symptoms of Musculo-cutaneous nerve injury?

Answer 14

• weakness in elbow flexion or shoulder
  flexion,
• atrophy of the biceps brachii
• pain or paresthesia at the lateral
  forearm.

Question 15

What causes the Musculo-cutaneous nerve injury?

Answer 15

• iatrogenic causes secondary to prolonged
  positioning of the arm during an unrelated
  surgery.
• direct injury to the nerve during surgery.
• Repetitive, vigorous upper extremity
  activity (e.g. lifting, throwing, or carrying),
  or a single forceful extension of the upper
  extremity (e.g. pushing or wrestling)

Question 16

What the axillary nerve innervate?

Answer 16

• teres minor and deltoid muscles
• skin of the shoulder

Question 17

What are the symptoms of Axillary nerve injury?

Answer 17

• A weakness in shoulder abduction
• numbness to the lateral shoulder area.
• weakness in glenohumeral external rotation; may not be apparent due to the infraspinatus.

Question 18

What does the Median nerve innervate?

Answer 18

• the flexor muscles of the forearm and hand.
• skin of the hand

Question 19

What are the symptoms of Median nerve injury at the level of the wrist?

Answer 19

Carpal tunnel syndrome:
- Thenar weakness, Thenar amyotrophy
- Numbness in the radial three and one-half fingers, and paresthesias.
- Burning like pain
- worse at night
- Positive Tinel and Phalen tests
- Cubital fossa tenderness or swelling

Question 20

What are the syndroms that can ocure when the median nerve is injured at the leve of the elbow?

Answer 20

• Pronator Syndrome
• Anterior Interosseous Neuropathy

Question 21

What are the symptoms of the Pronator Syndrome?

Answer 21

• the pronator teres compresses the median
  nerve- Passes between its two head
• discomfort in their forearm with activity.
• numbness and tingling of the thumb, and the first two digits.
• Nagative Phalen and Tinel signs

Question 22

What are the symptoms of the Anterior Interosseous Neuropathy?

Answer 22

• No sensory deficit
• unable to approximate the thumb and index finger- he cannot make ok sign

Question 23

what does the radial nerve innervate?

Answer 23

• triceps brachii
• the brachioradialis and extensor carpi radialis longus (muscles of the posterior forearm)
• the skin on the dorsum of the hand

Question 24

Injury of the radial nerve at the axilla?

Answer 24

• Saturday night palsy- Compression
• loss of extension of the forearm, hand, and fingers (wrist drop).
• sensory loss in the lateral arm and in the
  posterior aspect of the forearm, radiating to the radial aspect of the dorsal hand and digits.

Question 25

injury of the radial nerve the albow?

Answer 25

- weakness in the extension of the hand and fingers and the presence of finger drop and partial wrist drop.

Question 26

Posterior interosseous nerve syndrome?

Answer 26

- pain in the forearm and wrist, along with weakness with finger metacarpal extension and wrist extension.

Question 27

Wartenberg syndrome?

Answer 27

- No motor deficit - numbness and tingling in the radial half of the dorsum of the hand and the dorsum of the radial 3 1/2 digits.

Question 28

Injury of the ulnar nerve at the elbow?

Answer 28

- Numbness and paresthesia, radiating distally to the ulnar aspect of the hand, the fifth digit and the ulnar aspect of the fourth digit. - Decrease in handgrip and pinch strength (Froment sign) - sever: claw hand

Question 29

Injury of the ulnar nerve at the wrist?

Answer 29

- Hypothenar atrophy - weakened finger abduction and adduction - weakened thumb adductor (froment sign) - sensory loss and pain: the palmar surface of the fifth digit and medial aspect of the fourth digit & the dorsum of medial aspect of the fourth finger and the dorsum of the fifth finger - claw hand - sign of Benediction

Question 30

Femoral nerve injury?

Answer 30

- weakness in hip flexion and knee extension - sensory disturbances: * the front of the thigh * The medial side of the knee, leg, and foot. * The patellar reflex is reduced abolished.

Question 31

Obturator nerve injury?

Answer 31

- sensory loss in the medial thigh - Weakness of the adduction and internal rotation of the thigh - medial thigh wasting

Question 32

Tibial nerve injury- Tarsal tunnel syndrome?

Answer 32

- knee and ankle injury - altered sensation: the sole of the foot - loss of plantar flexion, loss of flexion of toes and weakened inversion

Question 33

Mechanisms of Common fibular nerve injury?

Answer 33

- Knee disclocation - fibula trauma - habitual leg crossing

Question 34

Symptoms of Common fibular nerve injury?

Answer 34

- weakness of ankle dorsiflexion < foot drop. - Steppage gait (foot drop gait) - oss of sensation: the lateral leg, dorsal foot, the first toe webspace.

Question 35

two common pathologies involving the damage to the superficial fibular nerve?

Answer 35

- entrapment: ankle sprains or twisting of the ankle - direct damage: fracture of the fibula, or by a perforating wound to the lateral side of the leg.

Question 36

the symptome of superficial fibular nerve injury?

Answer 36

- loss of eversion. - A loss of sensation: the dorsum, the anterolateral aspect of the lower leg

Question 37

Mechanism of Sciatic nerve injury?

Answer 37

- Trauma - hip dislocation, acetabular fracture - Iatrogenic causes

Question 38

Functions of the sciatic nerve?

Answer 38

- Motor functions: * Innervates the muscles of the posterior thigh (biceps femoris, semimembranosus and semitendinosus) and the hamstring portion of the adductor magnus - Sensory functions: * Indirectly (via its terminal branches) the skin of the lateral leg, heel, and both the dorsal and plantar surfaces of the foot.

Question 39

The symptoms of sciatic nerve injury?

Answer 39

- foot drop - The pain can occasionally be exacerbated by internal rotation of the lower limb at the hip. - Atrophy of muscles, sensory deficit

Question 40

Piriformis syndrome?

Answer 40

- compression of the sciatic nerve by the piriformis muscle.