Peripheral Neuropathy

Question 1

features of large motor fibre damage?

Answer 1

weakness
unsteadiness
wasting
reduced power
normal sensation
absent reflexes

Question 2

features of large sensory fibre damage?

Answer 2

numbness
paraesthesia
unsteadiness
normal power
vibration and JPS reduced
absent reflexes

Question 3

features of small fibre damage?

Answer 3

pain
dyesthesia
normal power
pin prick and temperature sensation reduced
reflexes present

Question 4

features of autonomic nerve damage?

Answer 4

dizziness
impotence
nausea and vomiting
normal power
normal sensation
reflexes present

Question 5

types of motor fibre?

Answer 5

myelinated A alpha

Question 6

sensory fibres?

Answer 6

myelinated A alpha/beta (touch, vibration, proprioception)
thinly myelinated A delta (cold, pain)
unmyelinated C (heat, pain)

Question 7

autonomic fibres?

Answer 7

thinly myelinated A delta

unmyelinated C fibres

Question 8

pseudoathetosis?

Answer 8

due to loss of proprioception (A alpha/beta fibres)

causes writhing hand motion when eyes are closed

Question 9

radiculopathy?

Answer 9

nerve root is damaged

- most common cause = disc prolapse but can be an inflammatory cause

Question 10

plexopathy?

Answer 10

damage in plexus

Question 11

peripheral neuropathy?

Answer 11

damage to peripheral nerve

Question 12

3 examples of types of peripheral neuropathy?

Answer 12

mononeuropathy (e.g wrist drop)
mononeuritis multiplex (lost of nerves picked off)
length dependant peripheral neuropathy

Question 13

length dependant peripheral neuropathy?

Answer 13

weakness/sensory loss in length dependant pattern

classic glove and stocking pattern but can be more severe and spread to more central areas

Question 14

symmetrical vs asymmetrical wasting in muscle?

Answer 14

symmetrical = more likely to be length dependant peripheral neuropathy
asymmetrical = more likely to be compression on single nerve (carpal tunnel/compression by tumour) or something worse like MND

Question 15

what is mononeuritis multiplex?

Answer 15

associated with vasculitis
asymmetrical patchy neuropathy in context of other illness
lots of nerve affected

Question 16

radiculopathy follows what pattern?

Answer 16

spinal nerve dermatomes and myotomes

Question 17

most common plexopathy?

Answer 17

traction injury in arm (e.g erbs palsy)

Question 18

presentation of plexopathy?

Answer 18

often have a lot of pain
widespread symptoms (e.g whole limb)

Question 19

old people vs young people with nerve damage?

Answer 19

old = axonal loss
young = demyelination (e.g guillan barre)

Question 20

neurophysiology?

Answer 20

testing which can determine whether axonal loss of demyelination

Question 21

features of demyelinating neuropathy?

Answer 21

acute (days to weeks)
- e.g Guillaine barre syndrome or AIDP)
chronic (months to years)
- CIDP (chronic inflammatory demyelinating polyradiculopathy)
- hereditary sensory motor neuropathy neuropathy (AKA charcot-Marie-Tooth disease)

Question 22

what is GBS?

Answer 22

progressive paraplegia over days up to 4 weeks
associated sensory symptoms precedes weakness
can be fairly normal initially then go “off legs” and loose reflexes
often after illness/infection
pain very common
peak symptoms 10-14 days into illness
can have normal examination initially

Question 23

how is GBS managed?

Answer 23

IV immunoglobulin infusion and/or plasma exchange

Question 24

cause of death in GBS?

Answer 24

autonomic failure (cardiac arrhythmia)

Question 25

what is hereditary neuropathy?

Answer 25

AD, AR, X linked
pure motor, sensory, sensorimotor…..
….
typically have wasted (champagne bottle deformity) of tibial muscles
deforming arthropathy of hands and feet (e.g pes cavus)

Question 26

types of axonal neuropathy?

Answer 26

idiopathic
vasculitis (likely to cause disability?)
paraneoplastic
infections (HIV, syphilis, lyme, hepatitis)
drugs/toxins (alcohol, amiodarone, phenytoin, chemo)
metabolic (diabetes, hypothyroid)

Question 27

chronic autonomic neuropathy?

Answer 27

diabetes (gastroparesis)
amyloidosis
hereditary

Question 28

acute autonomic neuropathy?

Answer 28

GBS

porphyria

Question 29

treatment of axonal peripheral neuropathy?

Answer 29

treat cause
symptomatic treatment (physio, orthotics, neuropathic pain relief)

Question 30

how can radiculopathy and peripheral nerve compression be differentiated?

Answer 30

radiculopathy = shooting pains