Peripheral Neuropathy Flashcards
features of large motor fibre damage?
weakness unsteadiness wasting reduced power normal sensation absent reflexes
features of large sensory fibre damage?
numbness paraesthesia unsteadiness normal power vibration and JPS reduced absent reflexes
features of small fibre damage?
pain dyesthesia normal power pin prick and temperature sensation reduced reflexes present
features of autonomic nerve damage?
dizziness impotence nausea and vomiting normal power normal sensation reflexes present
types of motor fibre?
myelinated A alpha
sensory fibres?
myelinated A alpha/beta (touch, vibration, proprioception) thinly myelinated A delta (cold, pain) unmyelinated C (heat, pain)
autonomic fibres?
thinly myelinated A delta
unmyelinated C fibres
pseudoathetosis?
due to loss of proprioception (A alpha/beta fibres)
causes writhing hand motion when eyes are closed
radiculopathy?
nerve root is damaged
- most common cause = disc prolapse but can be an inflammatory cause
plexopathy?
damage in plexus
peripheral neuropathy?
damage to peripheral nerve
3 examples of types of peripheral neuropathy?
mononeuropathy (e.g wrist drop) mononeuritis multiplex (lost of nerves picked off) length dependant peripheral neuropathy
length dependant peripheral neuropathy?
weakness/sensory loss in length dependant pattern
classic glove and stocking pattern but can be more severe and spread to more central areas
symmetrical vs asymmetrical wasting in muscle?
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
what is mononeuritis multiplex?
associated with vasculitis
asymmetrical patchy neuropathy in context of other illness
lots of nerve affected
radiculopathy follows what pattern?
spinal nerve dermatomes and myotomes
most common plexopathy?
traction injury in arm (e.g erbs palsy)
presentation of plexopathy?
often have a lot of pain widespread symptoms (e.g whole limb)
old people vs young people with nerve damage?
old = axonal loss young = demyelination (e.g guillan barre)
neurophysiology?
testing which can determine whether axonal loss of demyelination
features of demyelinating neuropathy?
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)
what is GBS?
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
how is GBS managed?
IV immunoglobulin infusion and/or plasma exchange
cause of death in GBS?
autonomic failure (cardiac arrhythmia)
what is hereditary neuropathy?
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)
types of axonal neuropathy?
idiopathic
vasculitis (likely to cause disability?)
paraneoplastic
infections (HIV, syphilis, lyme, hepatitis)
drugs/toxins (alcohol, amiodarone, phenytoin, chemo)
metabolic (diabetes, hypothyroid)
chronic autonomic neuropathy?
diabetes (gastroparesis)
amyloidosis
hereditary
acute autonomic neuropathy?
GBS
porphyria
treatment of axonal peripheral neuropathy?
treat cause symptomatic treatment (physio, orthotics, neuropathic pain relief)
how can radiculopathy and peripheral nerve compression be differentiated?
radiculopathy = shooting pains
