Peripheral Neuropathy

Question 1

What are some features of damage to large motor fibres?

Answer 1

Symptoms = weakness, unsteadiness, wasting

Normal sensation but reduced power and absent reflexes

Question 2

What are some features of damage to large sensory fibres?

Answer 2

Symptoms = numbness, paraesthesiae, unsteadiness
Normal power but absent reflexes
Vibration and JPS reduced

Question 3

What are some features of damage to small nerve fibres?

Answer 3

Symptoms = pain, dysaesthesia
Normal power and present reflexes
Pin prick sensation and temperature reduced

Question 4

What are some features of damage to autonomic nerves?

Answer 4

Symptoms = dizziness, impotence, nausea/vomiting
Normal power and sensation
Present reflexes

Question 5

What is pseudoathetosis?

Answer 5

Abnormal writhing movements = due to failure of proprioception, usually fingers, indicates disruption of proprioceptive pathway

Question 6

What does bilateral foot drop usually indicate?

Answer 6

Lower motor neuron disease = presents with high stepping gait

Question 7

What causes a radiculopathy?

Answer 7

Damage to the posterior primary ramus

Question 8

What are some features of a radiculopathy?

Answer 8

Due to pinching of nerve root in the spinal column

Presents with pain, weakness, numbness or tingling

Question 9

What does damage to the neuromuscular junction cause?

Answer 9

A plexopathy = affects area of lumbosacral or brachial plexus, pain with loss of motor control and sensory deficits

Question 10

What causes a peripheral neuropathy?

Answer 10

Damage to a peripheral nerve = will cause mononeuropathy, mononeuritis multiplex are length dependent peripheral neuropathy

Question 11

What is mononeuritis multiplex?

Answer 11

Damage to one or more different nerve areas

Question 12

What are the types of demyelinating neuropathies?

Answer 12

Acute (days-weeks) = Guillaine Barre syndrome

Chronic = chronic inflammatory demyelinating polyradiculopathy (CIDP), hereditary sensory motor neuropathy

Question 13

What is Guillaine Barre syndrome?

Answer 13

Progressive paraplegia over days up to 4 weeks = associated sensory symptoms precede weakness, pain very common

Question 14

When do the symptoms of Guillaine Barre syndrome peak?

Answer 14

10-14 days after onset

Examination in initial phases may be normal

Question 15

How is Guillaine Barre syndrome treated?

Answer 15

Ig infusion and/or plasma exchange
25% require mechanical ventilation
10% die due to autonomic failure

Question 16

What are the types of axonal neuropathies?

Answer 16

Idiopathic = age related
Vasculitic and metabolic
Paraneoplastic = myeloma, antibody mediated
Infectious = HIV, syphilis, Lyme disease, hepatitis B/C
Drug = alcohol, amiodarone, phenytoin, chemotherapy

Question 17

What are some features of vasculitic axonal neuropathies?

Answer 17

Often a mononeuritis multiplex

ANCA positive, rheumatoid arthritis and Sjogren’s syndrome all implicated

Question 18

What are some causes of metabolic axonal neuropathies?

Answer 18

Diabetes, B12 and folate deficiencies, hypothyroidism, chronic uraemia, porphyria

Question 19

What are the types of autonomic neuropathy?

Answer 19

Chronic = diabetes, amyloidosis, hereditary
Acute = Guillaine Barre syndrome, porphyria

Question 20

How are axonal neuropathies treated?

Answer 20

Treat cause an give symptomatic relief = physio, analgesia etc

Question 21

How are vasculitic axonal neuropathies treated?

Answer 21

Pulsed IV methylprednisolone and cyclophosphamide

Question 22

How are dymyelinating inflammatory neuropathies treated?

Answer 22

IV Ig, steroids, azathioprine/mycophenalate/cyclophosphamide