Peripheral Nerve Injury

Question 1

Content: Neural Structures in the PNS (4)

Answer 1

1. Muscle spindle receptors
2. GTO
3. Motor Endings
4. Axons

Question 2

Q: What do the rami communicantes connect with?

Answer 2

Sympathetic Ganglia

Question 3

Diagram: Axon Characteristics Table

Answer 3

Question 4

Content: Mechanisms of Nerve Injury (5)

Answer 4

1. Compression or crush
2. Laceration
3. Stretch
4. Radiation
5. Electricity

Question 5

Content: Sedden’s Classification of Nerve Injury (3)

Answer 5

1. Neurpraxia
2. Axonotmesis
3. Neurotmesis

Question 6

Content: Neurapraxia (3)

Answer 6

1. Low severity injury
2. Nerve remains intact but electrical conduction is interrupted by ischemia/compression
3. Secondary injuries can be caused by vascular damage leading to intrafascicular edema

Question 7

Content: Axonotmesis (3)

Answer 7

1. Axon is disrupted by myelin sheath is intact
2. Typically due to a crush injury
3. If neuronal tubules are maintained, regeneration/restoration of sensory/motor may return

Question 8

Content: Neurotmesis (3)

Answer 8

1. Loss of nerve conduction and damage to surrounding nerve trunk CT
2. In extreme cases complete nerve transection occurs
3. Commonly a neuroma forms over the proximal stump preventing normal regeneration

Question 9

Diagram: Seddon’s Classification of Nerve Injury

Answer 9

Question 10

Diagram: Summary of Seddon’s Classification

Answer 10

Question 11

Content: Any Peripheral Nerve Injury in Extremity Trauma by %

1. After LE Fx
2. After UE wound
3. After Crush Injury

Answer 11

1. 1.77
2. 1.85
3. 1.91

Question 12

Q: What are the most common peripheral nerve injuries following extremity trauma?

Answer 12

Radial/Ulnar after Humerus Fx (1.03%) and Sciatic/lumbosacral plexus/femoral after Pelvis Fx (1.76%)

Question 13

Diagram: Signs and Symptoms of Mixed Peripheral Nerve Lesions (Axonotmesis or Neurotmesis)

Answer 13

Question 14

Q: What conditions can cause peripheral nerve injury due to compression of the nerve roots? (4)

Answer 14

1. Degenerative disc/joint disease
2. Spondylolisthesis
3. Spine deviations
4. Narrowing of the intervertebral foramen

Question 15

Q: Compression of the following nerves caues what UE syndrome?

1. Brachial Plexus
2. Ulnar n.
3. Radial n.
4. Medial n.

Answer 15

1. Thoracic outlet syndrome
2. cubital tunnel syndrome or compression on tunnel of Guyon
3. Radial n. compression
4. Carpal Tunnel Syndrome

Question 16

Q: Compression of the following nerves caues what LE syndrome?

1. Sciatic n.
2. Peroneal n.
3. Tibial n.

Answer 16

1. Piriformis syndrome
2. Peroneal n. compression
3. Tarsal tunnel syndrome

Question 17

Content: Upper Plexus Injury (C5-6) (4)

Answer 17

1. Shld depression and lateral felxion of neck
2. Loss of shld ABD, ER
3. Weakness of arm flexion and forearm supination
4. Waiter’s tip position

Question 18

Content: Lower Plexus Injury (C8-T1) (2)

Answer 18

1. Compression of the cervical rib or stretching the arm overhead
2. Paralysis of the intrinsic muscles of the hand

Question 19

Content: Thoracic Outlet Syndrome (TOS) (3)

Answer 19

1. Brachial plexus pain
2. Paresthesia, numbness, weakness
3. Nerve tension when the plexus is stretched

Question 20

Content: Axillary Nerve Injury

1. Nerve Root
2. Cause
3. Weakness
4. Sensroy

Answer 20

1. C5-6
2. Acute dislocation or Humeral Neck Fx
3. Squared shld from deltoid atrophy, Shld ABD/ER weakness,
4. Sensory loss on lateral deltoid

Question 21

Content: Musculocutaneous Nerve Injury

1. Nerve Root
2. Cause
3. Weakness
4. Sensory

Answer 21

1. C5-7
2. Projectile wounds
3. Atrophy along flexor surface of upper arm, elbow flexion/supination weakness
4. Sensory loss on radial side of forearm

Question 22

Content: Median Nerve Injury

1. Nerve Root
2. Cause
3. Clinical Presentation
4. Weakness
5. Sensory
6. Palsy

Answer 22

1. C6-8, T1
2. Impingement in hypertrophied pronator teres or carpal tunnel syndrome
3. Burning/tingling/itching/numbness in palm of hand/fingers/thumb/index/middle finger
4. No arm pronation/thumb ABD, weak grip
5. Sensory loss in the thenar region
6. Ape hand with thenar eminence atrophy

Question 23

Content: Ulnar Nerve Injury

1. Nerve Root
2. Cause
3. Clinical Presentation
4. Weakness
5. Sensory
6. Palsy

Answer 23

1. C8-T1
2. Cubital tunnel syndrome or compression of Guyon’s canal
3. Pain/numbness/tingling in ring and little fingers
4. Loss of 4th/5th digit spherical and cylindrical power grip, thumb ADD, finger ADD/ABD
5. Sensory loss in hypothenar region
6. Partial claw with atriphy b/t MT and hypothenar region

Question 24

Content: Radial Nerve Injury

1. Nerve Root
2. Cause
3. Clinical Presentation
4. Weakness
5. Sensory
6. Palsy

Answer 24

1. C5-8, T1
2. Compression of radial sulculs, radial head, ECRB and supinator
3. Pain and tenderness in the proximal forearm, lack of numbness
4. Weakness: finger extension, supination; Unable to: push (triceps), make fist/grip, stab wrist in extension
5. Sensory loss on posterior arm, forearm, and radial side of hand
6. Wrist drop

Question 25

Content: Sciatic Nerve Injury 1. Nerve Root 2. Cause 3. Clinical Presentation 4. Weakness 5. Sensory

Answer 25

1. L4-5, S1-3 2. Compression from tight piriformis, hip dislocation, femur fx. 3. Sciatica pain 4. Posterior thigh, leg/calf, foot atrophy, weak knee flexion, loss of ankle control 5. Sensory loss in lateral/posterior (lower)leg and plantar foot

Question 26

Content: Common Peroneal Nerve Injury 1. Nerve Root 2. Cause 3. Clinical Presentation 4. Weakness 5. Sensory

Answer 26

1. L4-S2 2. Compression from crossing leg, head/neck of fibula fx 3. Gait impairment during LR with foot slap and excessive hip flexion to clear toes 4. Deep = foot drop, Superficial = eversion weakness 5. Sensory loss anterior/lateral leg and dorsal foot

Question 27

Content: Tibial Nerve Injury 1. Nerve Root 2. Cause 3. Clinical Presentation 4. Weakness 5. Gait

Answer 27

1. L4-S3 2. Tarsal Tunnel Syndrome 3. Tingling/burning/electrical shock/numbness/(shooting) pain on medial ankel and plantar foot 4. Inability to flex ankle or toes 5. Gait impairment during terminal stance

Question 28

Content: Nerve Injury Management - Acute Phase 1. Description 2. Immobilization 3. Movement 4. Splinting/bracing 5. Pt. Education

Answer 28

1. Immediately after sx/injury 2. Time dictated by surgeon 3. Amount and intensity dictated by type of injury/sx repair 4. To prevent deformities or tension on the injuried site 5. Protection of the injury site

Question 29

Content: Nerve Injury Management - SubAcute Phase 1. Description 2. Motor retraining 3. Desensitization 4. Discrimative sensory reeducation

Answer 29

1. Signal of reinnervation (muscle contraction and increased sensitivity) 2. Hold in shortened position, electrical stimulaiton 3. Multiple texture for sensory stimulation and vibration 4. Identification of objects with/without visual cues

Question 30

Content: Nerve Injury Management - Chronic Phase 1. Description 2. Compensatory Function 3. Preventive Care

Answer 30

1. Reinnervation potential peaked with minimal or no signs of neurological recovery 2. Compensatory function is minimized during the recovery BUT is emphasized when full neurological recovery does not occur 3. Emphasis on lifelong care to involved region

Question 31

Content: Neural Mobilization for compression and neural tension (3)

Answer 31

1. Release tension, compression, or entrapment due to inflammatory conditions in the surrounding CT or nerves 2. Release adhesive scar tissue 3. Free up the nerve to slide in its sheath

Question 32

Content: Neural Testing and Mobilization for the Median n, (tx of TOS and CTS) (7)

Answer 32

1. Shoulder depression 2. Shoulder abduction (slightly) 3. Extend elbow 4. Shoulder ER 5. Supinated the forearm 6. Wrist and fingers extension 7. Contralateral cervical bending

Question 33

Content: Neural Testing and Mobilization for the Radial n. (tx of PINS, Tennis elbow, DeQuervain's) (7)

Answer 33

1. Shoulder depression 2. Shoulder abduction (slightly) 3. Extend elbow 4. Shoulder INTERNAL rotation 5. pronate the forearm 6. Wrist and fingers flexion 7. Contralateral cervical bending

Question 34

Content: Neural Testing and Mobilization for the Ulnar n. (tx of C8-T1, Lower BP) (7)

Answer 34

1. Wrist and fingers extension 2. Forearm supination 3. Elbow flexion 4. Shoulder depression 5. Shoulder external rotation 6. Shoulder abduction 7. Contralateral cervical bending

Question 35

Content: Neural Testing and Mobilization for the Sciatic n. (tx sciatic, tibial, sural, peroneal n. entrapment/compression) (6)

Answer 35

1. Straight-leg raise (SLR) 2. Ankle dorsiflexion Modifications: 1. Ankle plantar flexion/eversion: Tibial nerve 2. Ankle dorsiflexion/inversion: Sural nerve 3. Ankle plantar flexion/inversion: C. Peronealnerve 4. Adduction and IR increase tension

Question 36

Content: Principles of Treatment (5)

Answer 36

1. Greater irritability \> gentle the technique 2. Stretch force is applied to the tissue resistance slower 3. Neurological symptoms should not last when the stretch is released 4. Positioning the patient at the point of tension, passively move one joint at the time to further stretch the tissue. 5. Move the joint where the nerve is trapped at the end and carefully, respecting the symptoms