Peripheral Neuropathy

Question 1

What are the symptoms of large fibre damage?

Answer 1

Motor- weakness, unsteadiness, wasting

Sensory- numbness, paraesthesia, unsteadiness

Question 2

What are the symptoms of small fibre damage?

Answer 2

Pain

Dyesthesia

Question 3

What are the symptoms of autonomic fibre damage?

Answer 3

Dizziness (postural hypotension)
Impotence
Nausea and vomiting (gastroparesis)

Question 4

What are the changes in power in nerve damage?

Answer 4

Large motor- Reduced

Large sensory, small and autonomic- Normal

Question 5

What are the changes in sensation in large motor and autonomic nerve damage?

Answer 5

Normal

Question 6

What are the changes in sensation in large sensory and small nerve fibres?

Answer 6

Large sensory- vibration and JPS reduced

Small- pin prick and temperature reduced

Question 7

What are the changes in reflexes in nerve damage?

Answer 7

Large motor/sensory- Absent

Small/Autonomic- Present

Question 8

What are some conditions caused by nerve damage specific to location of damage?

Answer 8

Radiculopathy
Plexopathy
Peripheral neuropathy- mononeuropathy, mononeuritis multiplex, (length dependant) peripheral neuropathy)

Question 9

How can peripheral nerves be damaged?

Answer 9

Axonal Loss

Peripheral nerve demyelination

Question 10

What can be used to assess nerve status in demyelinating neuropathies?

Answer 10

NCS

Question 11

What is an acute demyelinating neuropathy?

Answer 11

Guillaine Barre/AIDP

Question 12

What are some chronic demyelinating neuropathies?

Answer 12

CIDP (chronic inflammatory demyelinating polyradiculopathy)

Hereditary sensory motor neuropathy (formerly Charcot-Marie-Tooth)

Question 13

What occurs in GBS?

Answer 13

Progressive paraplegia over days up to 4 weeks
Associated sensory symptoms proceed illness
Pain common

Question 14

When are the peak symptoms of GBS?

Answer 14

10-14 days after onset

Question 15

What can be a cause of GBS?

Answer 15

Infection eg. campylobacter

Question 16

How is GBS treated?

Answer 16

Ig infusion and/or plasma exchange (minimal role for steroids)

Question 17

Describe hereditary neuropathies

Answer 17

Hundreds of mutations
Pure motor, sensory, sensorimotor, small fibre (congenital insensitivity to pain syndrome) and autonomic variants
Demyelinating and axonal varieties
Genetic testing available for most common

Question 18

What can cause axonal neuropathies?

Answer 18

Idiopathic (age related)
Vasculitic
Paraneoplastic
Infections
Drugs/toxins
Metabolic

Question 19

What are the vasculitic (often mononeuritis multiplex) causes of axonal neuropathies?

Answer 19

ANCA +ve

Rheumatoid arthritis/Sjrogens syndrome (ANA/ENA +ve)

Question 20

What are the paraneoplastic causes of axonal neuropathies?

Answer 20

Myeloma
Antibody mediated (eg breast cancer/SCLC anti hu/yo)

Question 21

What are the infectious causes of axonal neuropathies?

Answer 21

HIV
Syphilis
Lyme
Hep B/C (cryoglobulin mediated)

Question 22

What are the drug/toxin-based causes of axonal neuropathies?

Answer 22

Alcohol
Amiodarone
Phenytoin
Chemotherapy (cisplatin, vincristine)

Question 23

What are the metabolic causes of axonal neuropathies?

Answer 23

Diabetes
B12/folate deficiencies (other)
Hypothyroidism
Chronic uraemia
Porphyria

Question 24

What are some chronic causes of autonomic neuropathy?

Answer 24

DM (i.e. gastroparesis)
Amyloidosis
Hereditary

Question 25

What are some acute causes of autonomic neuropathy?

Answer 25

GBS

Porphyria

Question 26

What is the treatment of axonal peripheral neuropathy?

Answer 26

Treat cause

Symptomatic treatment- physio, orthotics neuropathic pain relief

Question 27

What is the treatment of axonal (vasculitic) peripheral neuropathy?

Answer 27

Pulsed IV methylprednisolone + cyclophosphamide

Question 28

What is the treatment of demyelinating (inflammatory) peripheral neuropathy?

Answer 28

IVIg (pooled Ig from donors)
Steroids
Azathioprine, mycophenalate, cyclophosphamide