GBS Flashcards
what is GBS
most common form of autoimmune inflammatory demyelinating polyradiculoneuropathies
what is the etiology of 75% of GBS cases
preceded by acute infection 2wks prior
- URI, campylobacter jejuni, epstein barr, mycoplasma pneumonia, cytomegalovirus
- vax
- strong association w zika virus
what is the pathophys of GBS
auto-immune attack on schwann cells of peripheral nerves:
antigens trigger mobilization of macrophages and lymphocytes -> migration to nodes of ranvier, attack schwann cells and strip myelin away -> slow conduction velocity
- axon may degen
progressive demyelination phase limited to 4wks**
- remyelination usually begins w/i 2-3wks as long as axons are good and haven’t died off
what is the typical age of onset
30s-50s
- can occur anywhere in the lifespan
is there any geographic clustering of GBS
no - except for recent cases w Zika virus outbreaks
what are 4 methods of dx
lumbar puncture
EMG
NCV
presence of clinical features w course <4wks
how can a lumbar puncture dx GBS
presence of excess protein in CSF d/t demyelination but no inc in WBCs
if clinical features of GBS last >4wks, what does this indicate
different health condition than GBS
- CIDP likely
how can an EMG dx GBS and what is a limitation
(+) for fibrillation potentials
- as axon degen, leads to loss of innervation and can see fibrillation
if mild case, may be w/i normal limits
how can a NCV dx GBS
shows slow nerve conduction velocity and/or conduction block
- myelin is what inc conduction speed to jump b/w nodes
what are clinical sx present for <4wks that may dx GBS
progressive, relatively symmetrical weakness w areflexia and exclusion of other causes
- starts distal -> prox
- recovery starts prox -> distal
what are 6 differential dx for GBS
CIDP
lyme dz/tick paralysis
MG
neuropathy
cord compression/cauda equine syndrome
FND
how do you distinguish CIDP from GBS
chronic inflammatory demyelinating polyneuropathy sx last >4wks
how do you distinguish lyme dz or tick paralysis from GBS
biomarkers to indicate lyme dz
how do you distinguish myasthenia gravis (MG) from GBS
path of MG is in NMJ
- pattern of onset is different
how do you distinguish a neuropathy from GBS
causes of neuropathy like HIV, DM, ETOH, toxic, metabolic
how do you distinguish FND from GBS
similar onset of weakness (symmetrical), but not attributed to any path as FND is psychosomatic/genic in nature
what is nadir
when sx reach maximal severity and plateau and stabilize
- once reach nadir, go into recovery phase
what is the prognosis for GBS
most reach nadir w/i 1wk
most regain amb function
1/2 have minor residual deficits (ie dec DTR and strength)
few have permanent severe disability or develop CIDP
what can contribute to different prognoses in GBS
remyelination starts at cell body of axons
- shorter nerves innervating prox ms regain function sooner
- longer axons in peripheral ms take longer
if axon degen/dies off
what are reasons for a permanent severe disability prognosis
axons degen/die off - recovery from axon sprouting or nearby axon reinnervating
- limited
dec amb d/t pretibial ms weakness
what are reasons for mortality in GBS
respiratory failure
cardiac issues
organ failure
what are 6 poor prognostic indicators
need for vent support
CN involvement (ie swallowing)
axonal damage
advanced age
preceding GI or CMV infection
rapid progress to quad w/i 1wk of onset
what are 5 clinical features of GBS
- rapid progression of symmetrical weakness or varying severity
- diminished or absent DTRs
- joint pain & myalgia
- stocking & glove pattern of sensory disturbances
- autonomic dysregulation
when does recovery typically begin
2-4wks after plateau
what are 3 motor sx of GBS
- progressive rapid development of weakness
- limbs, face, eyes, trunk, and/or oropharyngeal ms - (B) symmetrical distal->prox
- mild to total paralysis/quadriplegia w respiratory and CN involvement
what are 5 characteristics of sensory disturbances often seen in GBS
- typically before ms weakness
- distal-> prox loss in “stocking glove” pattern
- return occurs prox to distal pattern
- hyperesthesia, paresthesias
- dec vibratory sense and proprioception
what is hyperesthesia and why is this seen in GBS
every sensory input is perceived as pain
- super difficult to manage
axons that carry pain, pressure, light touch are demyelinated
pain from C fibers don’t have myelin and are the only nerves that aren’t really impacted
what are 5 qualities of pain in GBS
- associated w pressure areas and lengthening/stretching long, myelinated axons
- worse at night
- aching, burning, radicular pain
- symmetrical, often in large ms groups (ie gluts, quads, hamstrings)
- soft tissue stiffness at late stage contributes to pain
what are qualities of autonomic dysfunction seen in GBS
cardiac arrhythmias **
dec cardiac outputs, abnormal EKG, BP fluctuations, sweating abnormalities (problems w thermoregulation), pupillary dysfunction
why do more than 50% have OH as autonomic dysfunction clinical feature
likely d/t dec ms tone in LEs
- no ms contraction/tone to get venous return to maintain BP
if someone w suspected GBS has intact reflexes what does this indicate
suggestive of an alternative dx
- 70% of people w GBS have dec or absent reflexes
what cranial nerve involvement can be seen in GBS
facial weakness
opthalmoparesis
- eye mvmts
oropharyngeal weakness
- difficulty speaking, swallowing
what are the 2 gold standards for treatment of GBS and how would you choose b/w them
plasmaphoresis
IV immunoglobulin
same benefit, IVIg is less invasive
plasmaphoresis: how does it work, when is it most effective, and benefits
5-10day course of treatment removing immunoglobulins and cytokines and replacing them w albumin (a neutral protein) via a large catheter in arm
w/i 1wk of sx for optimal effect
- can benefit pts up to 30 days after dx (tho likely not same effect on recovery)
shortens recovery time by 1/2 for (I) respiratory function and return to amb
IV immunoglobulin: how does it work, and benefits
5 daily infusions that neutralize autoantibodies and dec level of inflammatory cytokines
- dilutes concentration of immune cells in bloodstream thus dec impact of inflammatory cells
dec recovery time by 1/2 if initiated early in dz process
what are 5 components of medical management outside of the gold standard treatments
corticosteroids
vent support/pulm hygiene
autonomic dysregulation
pain meds
DVT/PE prophylaxis
what does evidence say about the use of corticosteroids
lacks evidence, but still widely prescribed
what medical management might autonomic dysregulation need
may need meds for transient HTN or HoTN
pacer for severe bradycardia or tachycardia (less common)
why are pain meds prescribed and what does evidence say
neuropathic pain and hyperesthesia common
poor response to most pain meds
why do we want to do aggressive DVT/PE prophylaxis
high risk d/t weakness
what are 3 examples of DVT/PE prophylaxis
heparin
compression stockings
PROM -> A/AROM
what are 6 interventions in the progressive phase of the dz
supportive care
promote pulm hygiene
skin protection
pain management
OH mgmt & monitor VS
psychosocial support
how can ROM be used to manage pain
w widely distributed force w open hands and cradle w arms
- may inc pain in short term but dec pain (ms aching, cramping, and discomfort) after
how can TENS be used for pain management
jam signals from C fibers to be transmitted to SC and perceived in sensory cortex
how can ice packs be used for pain management
slow nerve conduction velocity, slow C fiber input and dec pain input
how can ace wrapping be used for pain management
prolonged widespread contact tends to dec pain w other sensory inputs if person was then to move leg after
what are examples of OH management options
abdominal corsets, anti-embolism stockings to maintain BP
what are 5 interventions during the early recovery phase
- pulm hygiene, respiratory ms training
- pain management
- stretching
- prevention of secondary complications
- active ther-ex
what must be avoided when doing interventions in the early recovery phase
avoid overuse damage
- can set back recovery
what are parameters for stretching in the early recovery phase
gentle, avoid end-range for joint protection and pain management
- avoid traction on nerves that are recovering
what are secondary complications to prevent in the early recovery phase
pressure ulcers
joint subluxations
disuse atrophy
respiratory infection
DVT
what are parameters for active ther-ex in the early recovery phase
GM, A/AROM in ms 2/5 or less
- powder boards, no resistance
- few reps
what is overuse damage in GBS and what is this d/t
prolonged weakness in the absolute strength and endurance of a ms d/t excessive activity
d/t repetitive recruitment of same motor units bc other motor units are unavailable
what phase does overuse damage occur in
in early and/or late phase
what are 3 sx of overuse damage
DOMS (1-5 days)
dec max isometric force
dec in function and strength
sx: ms aches, soreness, paresthesia
what should a pt do if they recognize sx of overuse damage
rest until back to baseline
how can muscle fatigue and overuse damage be avoided
low reps and resistance
frequent rests
monitor response to activity
rotate ms groups
non-fatiguing activity/exercise
aerobic training w mod intensity 60% target HR or RPE 13/20
what education should you provide a pt w GBS on nerve regen
nothing you can do to make nerves regen faster
- no benefit to aggressive ther-ex programs
what exercise is overuse damage and fatigue more commonly seen from
eccentric contractions
when and how do you progress exercise in GBS
if pt improves or shows no decline after one week
- slow progression
- monitor 3-7days before
what are 3 key PT interventions for during the recovery phase
- functional mobility training
- CV endurance training
- graduated strength training
what is criteria to graduate strength training from the recovery phase
should have >2/5 strength before AG activity, otherwise keep GM
should have >3/5 strength before eccentric activity
activity pacing and precautions to prevent overwork damage
CIDP vs GBS
similar pathophys and clinical sx
CIDP has a different course w slow progressive weakness, sensory loss, areflexia
- chronic
what is required for a CIDP dx
at least 2 months progressive onset of sx
what is the etiology of CIDP
unknown
cluster cases seen following tetanus and flu vax
what are the gold standards for medical management of CIDP
IVIg, plasmapheresis, and prednisone (corticosteroids)
what are alternative agents for CIDP medical management outside of the gold standards
similar treatments to GBS
- immune modulators that dampen immune response
ex: interferons, rituximab, methotrexate, other chemo
what are the 3 course variants for CIDP
monophasic
relapsing
progressive
what is the lifespan of someone w CIDP impacted and not impacted by
not by clinical course
by functional capabilities
what is a monophasic course CIDP variant
one episode of deterioration for >4wks followed by sustained improvement
what is a relapsing course CIDP variant
at least 2 separate deteriorations and at least one improvement b/w episodes
- plateau and be okay for awhile and then deteriorate
what is a progressive course CIDP variant
gradual deterioration w no episodes of improvement
what CIDP course variant has the poorest prognosis
progressive
what are 3 good prognostic indicators in CIDP
symmetrical sx
distal nerve abnormalities
favorable response to initial steroid treatment
what is the general prognosis of CIDP
normal lifespan typically achieved
- long term disability rate of 13-20% –> more common in progressive variant
PT in CIDP vs GBS
really similar w similar avoidance of fatigue and overuse
what is the focus of PT in CIDP
functional training and aerobic conditioning
