Compression Neuropathies

Question 1

What is neuropathy?

Answer 1

A change in the abilty of a nerve to function in a normal manner due to either a metabolic etioloy or a structural change from compression; typically results in numbness, tingling, muscle weakness and pain in the affected area

Question 2

What is an example of functional neuropathy?

Answer 2

Diabetic neuropathy

Question 3

What are some systemic causes of neuropathy?

Answer 3

Pregnancy, hypothyroidism and DM

Question 4

What is compression neuropathy?

Answer 4

Process whereby a nerve becomes entrapped as it passes thru a narrow tunnel or passage

Question 5

What are some pathological changes that occur during compression neurpathies?

Answer 5

Microvascular compression leading to ischemia, thickened epineurium, myelin thinning distortion, microtubule closure, and axonal degeneration

Question 6

What are some biomechanical causes of compression neuropathies?

Answer 6

Space occupying lesions (herniated discs, cysts), degenerative causes (foraminal stenosis), post traumatic causes (fracture, hematoma/compartment syndrome, compression from equipment), mechanical (muscle spasm, pinching from external or positional forces)

Question 7

What is a first degree nerve injury?

Answer 7

Neuropraxia which involves focal damage of myelin fibers around the axon; CT sheath remains intact

Question 8

How long does it take for recovery from neuropraxia?

Answer 8

Limited course (days-wks), least severe

Question 9

What is a 2nd degree nerve injury?

Answer 9

Axonotmesis which involves some disruption/injury to the axon iteelf; myelin sheath remains intact

Question 10

How long does it take to recover from axonotmesis?

Answer 10

Regeneration is possible but prolonged (months) without a full recovery

Question 11

What is a 3rd, 4th and 5th degree nerve injury referred to as?

Answer 11

Neurotmesis

Question 12

What does a 3rd degree neurotmesis involve?

Answer 12

Disruption of axon and endoneurium; recovery through axonal regeneration cant occur as intraneural fibrosis occurs

Question 13

What does a 4th degree neurotmesis involve?

Answer 13

Disruption of axon and endoneurium + perinerium (nerve fasciculi); large area of intraneural scarring at injury site -> precluded axon from advancing distal to the level of nerve injury

Question 14

How long does it take to recover from 4th degree neurotmesis?

Answer 14

No improvement in function —> surgery is used to restore neural continuity

Question 15

What does a 5th degree neurotmesis involve?

Answer 15

Disruption of axon and endoneurium + perineurium + epineurium; substantial perineural hemorrhage and scarring occur

Question 16

What is required to restore neural continuity in a 5th degree neurotmesis?

Answer 16

Surgery

Question 17

C5 root provides motor and sensation to which regions?

Answer 17

Deltiod and biceps; lateral arm; biceps reflex

Question 18

C6 nerve root provides motor innervation and sensation to which regions?

Answer 18

Wrist extension and elbow flexion; radial forearm, thumb and index finger; brachioradialis reflex

Question 19

C7 nerve root provides motor innervation and sensation to which regions?

Answer 19

Wrist flexion, elbow and finger extension; middle finger sensation; triceps reflex

Question 20

C8 nerve root provides motor innervation and sensation to which regions?

Answer 20

Finger flexion; ulnar forearm and pinky finger

Question 21

T1 nerve root provides motor innervation and sensation to which regions?

Answer 21

Finger abduction and medial arm

Question 22

What are the 3 stages of a herniated disc?

Answer 22

Protrusion, extrusion and herniation

Question 23

What is protrusion?

Answer 23

Only a few cartilage rings are torn; no leakage of central material

Question 24

What is extrusion?

Answer 24

Cartilage rings have torn in a small area; nucleus pulposus is able to flow out toward outer layer of disc

Question 25

What is herniation?

Answer 25

Tearing of the outer cartilage rings of disc allowing flow of NP posterior and laterally toward vertebral foramen

Question 26

L1-2 nerve roots provide motor innervation and sensation to which regions?

Answer 26

Hip flexion; inguinal crease (L1) and anterior thigh (L2)

Question 27

L2-3 nerve roots provide motor innervation and sensation to which regions?

Answer 27

Knee extension; anterior thigh (L2), anterior thigh just above knee (L3)

Question 28

L4 nerve root provides motor innervation and sensation to which regions?

Answer 28

Ankle dorsiflexion; medial leg and foot; patellar reflex

Question 29

L5 nerve root provides motor innervation and sensation to which regions?

Answer 29

Extensor hallucis longus; lateral leg and dorsum of the foot

Question 30

S1 nerve root provides motor innervation and sensation to which areas?

Answer 30

Ankle plantarflexion; lateral foot and plantar foot; achilles reflex