Nerve damage Flashcards
where is an UMN
what does it do
brain/brain stem/ventral cord of spinal cord
supplies input to LMN
where is an LMN
what does it do
outside spinal cord
commands muscle contraction, supplied by UMNs
aetiology of LMN lesion (3)
MND
nerve compression
diabetic neuropathy
aetiology of UMN lesion
stroke
brain tumour
spinal cord problem
do UMNs supply the face bilaterally or unilaterally
bilaterally
do LMNs supply the face bilaterally or unilaterally
unilaterally
how does UMN lesion present in face
bilaterally with forehead sparing (bc forehead has bilateral supply)
how does LMN lesion present in face
unilaterally (incl forehead)
what is the nerve supply to the forehead(where do the UMNs come from)
bilateral - has UMNs from both sides
tone in UMN lesion
increased
tone in LMN lesion
decreased
atrophy in LMN lesion
increased (presents as wasted muscles and weakness)
atrophy in UMN lesion
no
reflexes in UMn lesion
hyperreflexia eg babinskis sign
reflexes in LMN lesion
diminished (problem at the last part of reflex)
is ‘fingers feel like a bunch of bananas’ an UMn or LMN lesion sign
UMN - increased tone in fingers (LMN would have wasting)
what do the toes do in babinskis
what is the normal plantar response
fanning - up and down
usually curl down
is bells palsy UMn or LMN
hence how does it present in face
LMN
unilateral motor and sensory loss including forehead (drooping of face)
which nerve is damaged in bells palsy
CN VII (facial)
radiculopathy definition
damage to anterior and posterior rami of one spinal nerve
= probs sensory and motor dysfunction in that myotome/dermatome
cervical disc prolapse causes problems where
arms
lumbar disc prolapse causes problems where
legs
what do you want to find out once you’ve figure out its a radiculopathy (nerve problem)
use dermatomes/myotomes to figure our which nerves
if several ?named nerve problem
treatment of lateral disc prolapse
treatment of central disc prolapse
lateral - nothing, just symptomatic, more hassle than its worth
central - surgery bc irreversible, patients choice (risks of surgery)
aetiology of brown sequard syndrome (2)
trauma - knife injury
demyelination
how does brown sequard syndrome present
ipsilateral paralysis
ipsilateral loss of vibration and fine touch
contralateral loss of pain and temp
why is paralysis and loss of vibration and fine touch ipsilateral in brownsequard syndrome
corticospinal tract and dorsal column cross fibres at the medulla (above the lesion)
what part of the spine is affected in brown sequard syndrome
half of it (spinal cord hemisection) L or R
why is pain and temp loss contralateral in brown sequards syndrome
spinothalamic tract crosses fibres below the lesion (as the enter the spinal cord)
aetiology of central cord syndrome
syringomyelia
trauma - old person with fall and hit head
pathophysiology of central cord syndrome
reduced blood supply to centre of spinal cord
which spinal tract is completely fine in central cord syndrome
dorsal column
how is the corticospinal tract affected in central cord syndrome
lateral fibres (leg) are fine medial fibres (arm) are affected
is fine touch normal or affected in central cord syndrome
normal
what motor supply is affected in central cord syndrome
arms - bc they are more medial than legs
how is the spinothalamic tract affected in central cord syndrome
it is lateral so not affected
BUT fibres that enter at that level cross over in the spinal cord here so they are affected
eg if central cord syndrome at C5-6 = loss of pain and temp sensation to badge patch and thumb
what type of weakness occurs in central cord syndrome
upper limb weakness
presentation of central cord syndrome (2)
upper limb weakness (from medial corticospinal tract)
pain and temp loss at nerves that enter spine at level of damage (cape like ST loss)
NO loss of fine touch (dorsal column fine)
lower limbs fine
treatment of bone mets to spine
dexamethasone high dose
radiotherapy
treatment of primary bone cancer
surgical excision
where does osteomyelitis (infection) usually occur in the spin
epidural abscess
what type of spine problem gets worse walking up hills
spinal claudication
loss of bladder/bowel control
saddle anaesthesia
erectile dysfunction
loss of motor function in legs (paralysis)
cauda equina
SURGICAL EMERGENCY
treatment of cauda equina
emergency surgical decompression
plexopathy definition
nerve damage to a plexus
peripheral neuropathy definition
damage to a peripheral nerve
what is mononeuritis multiplex
damage to more than one peripheral nerve
what is guillain barre syndrome
acutee motor demyelinating neuropathy
usually post infectious
presentation of guillian barre syndrome
pain
progressive paraplegia (lower limbs)
diarrhea (from infectious cause)
treatment of guillian barre syndrome
IVIg or plasma exchange
what is a rare genetic neuropathy
hereditary sensory motor neuropathy - range of presentations
is bells UMN or LMN
who does this present
LMN = unilateral face drooping INCLUDING forehead
is hyperreflexia UMN or LMN
UMN
