Patho - NMDs Flashcards
GBS what it is and causative organisms
autoimmune disease; acute + rapid peripheral nervous system disorder/polyneuropathy characterized by ascending paralysis lower limbs –> head where they can only blink
organisms: campylobacter jejuni, CMV
- used to be associated with post-vax but decreased incidence now
GBS pathology
Demyelination along peripheral nerves, roots and cranial nerves by macrophages and lymphocytes; elicited in response to the causative organism antigen exposure
GBS S&S
ascending skeletal muscle paralysis, paresthesia (tingling), loss of deep tendon reflexes (knee), peripheral facial weakness
resp: vent failure due to diaphragm + intercostals affected, atelectasis and secretion retention, weak/absent cough, decreased gag reflex, dysphagia, resp failure; will eventually require MV support
20/30/40 rule
helps diagnose weakened insp muscle strength for NMDs such as myasthenia gravis, GBS
VC<20ml/kg, MIP < 30ml/kg, MEP < 40ml/kg = critical values and means they need MV support
How to Dx GBS
CSF findings via lumbar puncture = increased protein level could indicate GBS due to demyelination; insp muscle strength trending (VC/MIP/MEP 20/30/40 rule), EMG/electromyography measures nerve conduction + muscle strength, clinical Hx and S&S
GBS 2 primary treatments and other supportive therapy
IVIG = provides health IgG via IV to replace the damaged IgG and dilute the antibodies responsible for GBS autoimmune response; OR
Plasmapheresis/plasma exchange = removes damaged IgG + inflammatory components and transfuse back health blood products (harder to access tho)
supportive therapies: CS in combi with IVIG, O2 therapy, bronchial hygiene, MV, tracheostomy, physiotherapy
Describe ALS and the progression
aka Lou Gehrig’s disease; progressive degeneration of upper and lower motor neurons within brain + SC
progression is slower and can begin in limbs –> central (face/cough/swallow) or have bulbar onset central –> limbs
T/F ALS can be definitively diagnosed
false… ALS is diagnosed via exclusion (ruling out viruses/GBS; tumours with MRI)
ALS treatment
Riluzole - inhibits glutamate release and delays nerve damage;
G-tube feeding, BiPAP/CPAP, bronchial hygiene, tracheostomy;
depends what type of palliative care they want
describe SMA and the types (brief)
SMA = spinal muscular atrophy
autosomal recessive disorder involving progressive motor neuron disease
4 types; type 1 most severe, type 4 least severe
SMA Tx
Spinraza ($$$ - targets the SMA protein to make it more complete/functional); BiPAP, Trach tube, MV, bronchial hygiene
describe myasthenia gravis pathology
NMJ NMD!!!
- autoimmune response involving IgG attacking ACh receptors at neuromuscular junction
- results in ACh blocked and receptors destroyed = muscles receive less signal
- results in motor neuron dysfunction (sensory intact)
- episodic muscle weakness (rather than continuous/progressive)
- improves with rest
S&S of myasthenia gravis
ocular symptoms ptosis, diplopia = unique to MG;
facial muscle weakness, dysphagia, limbs weak
myasthenia gravis Dx
ocular symptoms, serum AChR antibodies!! most specific test; insp muscle strength, tensilon test where tensilon/AChEsterase inhibitor should restore muscle function (! unique), ice pack test (cold reduces AChE action)
myasthenia gravis tx
Pyridostigmine or Neostigmine = AChE inhibitors; CS and other immunosuppressants, plasmpheresis
