Peripheral Neuropathy

Question 1

does MS cause peripheral neuropathy

Answer 1

no

Question 2

loss of reflexes means a problem where

Answer 2

peripheral nerves- large motor or sensory fibres

Question 3

which type of fibres conduct the slowest

Answer 3

C- unmyelinated

Question 4

what do Aalpha fibres do

Answer 4

motor- muscle control

Question 5

what do large sensory Aalpha/ beta fibres do

Answer 5

touch, vibration, position perception

Question 6

what do thinly myelinated Adelta sensory fibres do

Answer 6

cold perception

pain

Question 7

what do un myelinated C sensory fibres do

Answer 7

warm perception

pain

Question 8

what are the type of autonomic nerve fibres

Answer 8

Adelta- thinly myelinated

C- unmyelinated

Question 9

what are the symptoms when a large motor fibre is affected

Answer 9

weakness, unsteadiness, wasting

Question 10

what are the symptoms when a large sensory fibres is affected

Answer 10

numbness
paraesthesia
unsteadiness

Question 11

what are the symptoms when a small sensory fibre is affected

Answer 11

pain dyesthesia (painful itchy sensation)

Question 12

what are the symptoms when autonomic fibres are affected

Answer 12

dizziness due to postural hypotension
impotence
nausea and vomiting (gastroparesis)

Question 13

what peripheral fibres are affected when there is reduced power

Answer 13

large motor fibres (Aalpha)

Question 14

what fibres are affected when there is reduced vibration and joint position sensation

Answer 14

large sensory (Aalpha/beta)

Question 15

what fibres are affected when there is reduces pin prick and temperature sensation

Answer 15

small sensory fibre (Adelta/ C)

Question 16

what is pseudoathetosis

Answer 16

abnormal writhing movement (usually of the fingers) due to failure of proprioception

Question 17

what does a high stepping gate result from

Answer 17

foot drop due to weakness of ankle dorsiflexion
DDx
-peroneal palsy 
-L5 root lesion 
-motor neuropathy

Question 18

what is damages in a radiculopathy

Answer 18

nerve root

Question 19

what commonly causes radioculopathy

Answer 19

prolapse

can be inflammatory

Question 20

what is damaged in plexopathy

Answer 20

plexus

Question 21

what is peripheral neuropathy

Answer 21

damage to the nerve distal to the plexus

Question 22

what are the types of peripheral neuropathy

Answer 22

mononeuropathy (single nerve, e.g trauma)
mononeuritis multiplex (progressive sensory or motor deficits in a specific distribution of peripheral nerves caused by systemic illness- vasculitis, hypersensitivity, drugs etc)
length dependent peripheral neuropathy- small fibre
polyneuropathy- symmetrical distribution

Question 23

what is the distribution of length dependent peripheral neuropathy

Answer 23

glove and stocking, usually symmetrical

Question 24

what is the most common type of peripheral neuropathy

Answer 24

length dependent

Question 25

what is symmetrical wasting suggestive of

Answer 25

PN, if asymmetrical less likely

Question 26

what is the pattern of loss in mononeuritis/ mononeuropathy

Answer 26

loose function very quickly (blood supply lost due to inflammation)
asymmetrical
patchy sensory loss

patient can present with e.g. wrist drop/ foot drop

Question 27

what is the pattern of loss in radiculopathy

Answer 27

loss of reflex and muscle function

asymmetrical

Question 28

what most commonly causes a plexoathy

Answer 28

traction injury

Question 29

how can peripheral nerves be damaged

Answer 29

axonal loss

demyelination (not MS)

Question 30

what results from a demyelinating neuropathy

Answer 30

conduction is slowed

Question 31

what causes an acute (days to weeks) demyelinating neuropathy

Answer 31

guillaine barre syndrome

Question 32

what causes a chronic (months to years) demyelinating neuropathy

Answer 32

chronic inflammatory demyelinating polyradiculopathy

hereditary sensory motor neuropathy (used to be called charcot marie tooth disease)

Question 33

what is the presentation and duration of GBS like

Answer 33

progressive paraplegia over days lasts up to four weeks
peak symptoms at 10-14 days
associated sensory symptoms (pain very common) proceed weakness

Question 34

what infection is associated with GBS

Answer 34

campylobacter

-inflammation of axon- stripped myelin

Question 35

what is the prognosis of GBS

Answer 35

25% require ventilation

10% die form autonomic failure (cardiac arrythmia)

Question 36

what is the treatment for GBS

Answer 36

immunoglobulin infusion and/ or plasma exchange

Question 37

what is exam like in GBS

Answer 37

initially reflexes will be normal, as they ‘ go off legs’ may loose them

Question 38

what are the hereditary neuropathies

Answer 38

pure motor, sensory, sensorimotor, small fibre and autononmic variants
can be demyelinating or axonal
AD, AR, X linked types

Question 39

what happens in the HMSN type 1 hereditary neuropathy

Answer 39

longstanding loss of muscle, pes cavus, thin distal musculature

Question 40

what are the types of axonal neuropathies

Answer 40

idiopathic (age related)
vasculitis (mononeuritis multiplex)
paraneoplastic
infectious (HIV, syphillis, lyme, hepatitis)
drugs/ toxins
metabolic (diabetes, B12/ folate, hypothyroidism)

Question 41

what are the causes of chronic autonomic neuropathy

Answer 41

diabetes (gastroparesis)
amyloidosis
hereditary

Question 42

what are the acute causes of autonomic neuropathy

Answer 42

GBS
porphyria (unexplained abdo pain in the young)

Question 43

what is the treatment for axonal peripheral neuropathy

Answer 43

treat cause e.g. infection 
symptomatic relief (physio, orthotics, neuropathic pain relief)

if vasculitic
pulsed IV meythlprednisolone + cyclophosphamide

Question 44

what is the treatment for demyelinating peripheral neurpathies

Answer 44

IV immunoglobulins
steroids
azathioprine, mycophenalate, cyclophosphamide