Peripheral Neuropathy

Question 1

What is the PNS?

Answer 1

Everything out-with the the spinal cord and brain

Question 2

What are the four different types of nerve fibre?

Answer 2

Large motor fibre - A alpha
Large sensory fibre - A alpha, beta, delta and C
Small sensory fibre - A alpha, beta, delta and C
Autonomic fibre - A delta and C

Question 3

What are the symptoms of large motor fibre peripheral neuropathy?

Answer 3

Weakness, wasting and unsteadiness

Question 4

Describe the power, sensation and reflexes of large motor fibre peripheral neuropathy

Answer 4

Power - reduced
Sensation - normal
Reflexes - absent

Question 5

What are the symptoms of large sensory fibre peripheral neuropathy?

Answer 5

Numbness, parasthesia, unsteadiness

Question 6

Describe the power, sensation and reflexes of large sensory fibre peripheral neuropathy

Answer 6

Normal power
Vibration then joint position sense reduced sensation
Reflexes are absent

Question 7

What is the symptom of small fibre peripheral neuropathy?

Answer 7

Pain

Question 8

Describe the power, sensation and reflexes of small fibre peripheral neuropathy

Answer 8

Power - normal
Sensation - Pin prick and temp reduced
Reflexes - present

Question 9

What are the symptoms of autonomic peripheral neuropathy?

Answer 9

Dizziness, impotence, nausea and vomiting

Question 10

Describe the power, sensation and reflexes of autonomic peripheral neuropathy

Answer 10

Normal power
Normal sensation
Normal reflexes

Question 11

Define radiculopathy

Answer 11

Nerve root pathology

Question 12

Define plexopathy

Answer 12

Nerve plexus pathology

Question 13

Name three types of peripheral neuropathy

Answer 13

• mononeuritis multiplex
• mononeuropathy
• length dependant symmetrical

Question 14

Describe the distribution of mononeuritis/mononeuropathy

Answer 14

Patchy discrete nerves often due to systemic disease

Question 15

What is the most common plexopathy?

Answer 15

Long thoracic nerve causing scapular winging

Question 16

What are the two pathological process that can occur in peripheral neuropathy?

Answer 16

Axonal Loss

Demyelination

Question 17

What investigation can help determine between demyelination and axonal loss?

Answer 17

Nerve conduction studies or biopsy

Question 18

What is seen on nerve conduction studies in a demyelination neuropathy?

Answer 18

Latency is delayed and amplitude preserved - temporal disperation - AP jitters

Question 19

Give an example of acute demyelination neuropathy

Answer 19

Guillaine Barre Syndrome

Question 20

How does guillaine barre syndrome present?

Answer 20

Progressive paraplegia over days up to 4 weeks, associated with sensory symptoms that proceed to weakness. Pain is very common.
Most common - proximal muscles of hip, reflexes are reduced and become slowly absent

Question 21

How does guillaine barre arise?

Answer 21

Post infective - e.g campylobacter

Question 22

What is the treatment for guillaine barre?

Answer 22

IV Ig infusion

Plasma exchange if unresponsive to two infusions

Question 23

Name chronic demyelinating neuropathies

Answer 23

Hereditary neuropathy

Chronic inflammatory demyelinating polyradiculopathy

Question 24

Who is affected by hereditary neuropathy?

Answer 24

Young people due to a variety of mutations

Question 25

How does HMSN1 present?

Answer 25

Champagne bottle deformity due to wasting of tibial muscles, long standing arthropathy due to reduced peripheral nerve function - arches in feet and distal joint dysfunction

Question 26

What can cause axonal neuropathies?

Answer 26

Idiopathic, vasculitis, paraneoplastic, infections, drugs/toxins, metabolic

Question 27

What can cause autonomic neuropathies?

Answer 27

Chronic - diabetes, amyloidosis, hereditary

Acute - GBS, porphyria

Question 28

How is peripheral neuropathy managed?

Answer 28

Vasculitic - IV methylprednisolone and cyclophosphamide

Demyelinating - IVIg, steroids, azathioprine/mycophenolate/cyclophosphamide