Neuro Dz 1 Flashcards
most freq. cause of acute flaccid paralysis
GBS
GBS
immune mediated disorder directed against myelin or Schwann cells
variants of GBS
AIDP
MFS
AMAN
AMSAN
common antecedent illnesses of GBS
campylobacter infection
preceded by URI or GI infection
other potential causes of GBS
HIV, Zika, influenza, EBV, CMV etc
vaccinations
PCN, OCs, TNFs
epitropic mimicry
found in GBS
following illness, immune system goes into overdrive and begins attacking the myelin sheath and/or Schwann cells on peripheral n.
Pathophys of GBS
following epitropic mimicry,
demyelination of the nerve and axon degeneration
unable to pass on nerve impulses
all myelinated nerves are affected + protein movement to CSF = edema
GBS epidemiology
Bimodal presentation (50-79 y/o, 15-35 y/o)
Men > Women (pregnant women have increased incidence)
GBS presentation
symmetric paresthesias
early loss of DTRs
affecting lower extremities first
ascending weakness (can get to muscles of respiration)
severe pain
sensory changes
what is a significant source of mortality in GBS pts
autonomic changes + decreased Lung expansion/respiratory failure
autonomic changes in GBS
tachycardia –> bradycardia
paroxysmal HTN/HoTN
Urinary retention, ileum, loss sweating, flushing
cranial nerves affected by GBS
facial weakness (VII)
impaired EOMs, dysphagia and dysarthria (VI, III, XII, V, IX, X)
natural progression of GBS
rapidly progressive weakness and others peak 14-30 days
plateau phase 2-4 weeks (persistent, non progressive)
recovery time is 7 months
steps in diagnosis of GBS
- CBC/Chem panel
- Imaging
- LP
- Conduction studies
- NIP/FEV (staging)
LP of GBS
albuminocytologic findings
high protein levels, normal WBCs
tx of GBS
hospitalized +/- intubation, supportive care
plasmapheresis OR IVIG (no steroids)
plasmapheresis
HD catheter to filter out and remove Ags attacking the myelin
replace plasma with donor plasma so they don’t attack myelin
6-10 tx
IVIG
gives pts donor IVIG to decrease body’s production of bad IG cells
“tames immune system”
caution for renal failure, thrombosis
which tx for unstable GBS pt?
`IVIG
CIDP
chronic (over 8weeks) demyelination and demyelination of nerves + axon degeneration
CIDP s/s
fairly symmetric motor and sensory loss
motor > sensory
large and small muscles affected
diminished DTRs globally
CIDP work up
Lab work up
LP
imaging
EMG
CIDP tx
glucocorticoids
plasmapheresis
IVIG
distinguishing features of CIPD
Chronic onset motor > sensory old men not as commonly cranial nerves Tx with steroids
distinguishing features of GBS
acute onset all nerves equally affected bimodal presentation EOM issues steroids don't work
myasthenia Gravis
autoimmune destruction of nicotinic acetylcholine post synaptic receptors of skeletal muscle
abnormality of T cells and thymic function
pathophys of MG
- autoAbs block and destroy Ach Receptors
- deep folds of motor endplate are flattened = widened gap
THEREFORE: normal Ach release but insufficient number of receptors on muscle is triggered so contraction is weak or non existent
muscles affected by MG
skeletal muscles ONLY
no smooth/cardiac muscles
symptoms of MG
most commonly affected areas of small skeletal muscle that are used repeatedly
muscle fatigue with REPEATED use due to less contractile force
symptoms and staging of MG
at beginning - symptoms occur intermittently
eventually = fluctuate in severity, persistent
cardinal symptoms of MG
- ocular
- bulbar
- facial weakness (snear/snarl)
- head drooping
- limb weakness
ocular MG manifestations
ptosis/diplopia are first manifestation
pupils are always spared
what factors worsen MG symptoms?
end of the day feel more tired
sunlight, surgery, immunizations, emotional stress, heat, menstruation, illness
alleviating MG symptoms?
rest and relaxation
good self care
medications that exacerbate MG
- Abx
- BB
- Mg
- Prednisone
- Anti-cholinergics
- Verapamil
- lithium
PE findings of MG
bulbar weakness
weakness of facial muscle
weakness of limbs
which part of exam are unaffected by MG?
DTRs
Pupillary reflexes
Intact sensation
diagnostic tests for MG
- curtain sign
- ice pack test
- tensilon test
- AcH Ab lab testing
- MuskAb testing
- repetitive nerve stimulation/fiber MG
disease associated with MG
thymic hyperplasia/thymoma
must rule out via contrast CT scan of chest or MRI –> locally invasive and removed surgically
associated with other autoimmune dz
tensilon test
edrophonium (short acting actylcholinestersase inhibitor) given so that they can move the eye and open eye fully
diagnose MG
tx of MG
- Cholinesterase inhibitor
- Immunosuppressants
- Surgical
cholinesterase inhibitors we use MG
pyridostigmine (mestinon)
slow down degradation of ACh
mestinon
MOA, brand name, dosing
Pyridostigmine
individualized dosing
blocks acetocholinesterase, so that it allows Ach to remain in the NMJ for longer
mestinon
ADR
bradycardia, respiratory suppression, diarrhea, diaphoresis, abdominal cramps/pain
immunosuppressants used in MG
high dose prednisone
mychophenolate mofetil
azitharoprine
high dose prednisone MG
begun in hospital bc can exacerbate dz
80% of people are helped while they are on the steroids
slowly taper up
Mycophenolate mofetil (Myfortic)
alternative to pred, long term EBM data lacking
Azathiprine (Imuran)
non glucocorticoid drug of choice
interferes with T and B cell production and sustained improvement
slowly working, blood dyscrasia, BBW for malignancy risk
surgical thymectomy
standard of care 10-55 y/o
thymoma removed (transiently post op period)
may induce remission in some patients
general MG care
avoid drugs that worsen
considered immunocompromised
pregnancy can worsen (can cross fetus - neonatal)
myasthenia crisis
severe exacerbation of MG
causes acute respiratory insufficiency due to weakened diaphragmatic and intercostal muscles
should be suspected with a cold, recent medication
admit to ICU
tx of myasthenic crisis
- plasmapheresis
2. IV IG
essential tremor
MC involuntary movement dz
familial tremor that peaks at age 70
autosomal dominant
describe the tremor of essential tremor
high frequency, bilateral, symmetric
upper extremities and head
postural and kinetic (pronator drift)
tremor will improve with ___ worsen with ___-
improve with Alcohol
worsen with stress, strong emotion, fatigue, hunger, temperature extremes
treatment of ET
most cases pharm doesn’t work
primidone (mysoline)
Propanol (inderal)
primidone
mysoline
metabolized to phenobarbital but more active
ADRs common on initiation
propanolol
inderal
younger pts, MOA for tremor unknown,
Pseudotumor Cerebri
aka idiopathic intracranial hypertension
NOT benign, intractable, disabling, HA, risk of severe, permanent vision loss
S/s of Pseudotumor Cerebri
Elevated ICP (HA, papilledema, seizures, AMS)
worsened with bearing down or bend over
elevated ICP without (pseudo tumor cerebra)
- space occupying lesions on imaging
2. abnormalities of cerebrospinal fluid composition
etiology of Pseudotumor Cerebri
obese young women
often idiopathic, but may be vascular, otitis media/chronic mastoiditis, endocrine disturbances, medications)
symptoms of Pseudotumor Cerebri
HA, visual disturbances, intracranial noise, papilledema, vision loss, sixth cranial nerve palsy
work up of Pseudotumor Cerebri
CT of head, LP opening pressure
try to eliminate hydrocephalus, mass lesion
tx of Pseudotumor Cerebri
dc of associated meds, weight loss for pts, evaluation for other dz, pharm tx, serial LP, surgery
pharm tx of Pseudotumor Cerebri
Acetazolamide (Diamox)
Furosemide
Prednisone
surgery options for Pseudotumor Cerebri
VP shunt
optic nerve sheath fenestration (vision only, no HA relief)
Huntington’s chorea
autosomal dominant dz
affects lg motor movements
onset between 30-50, live 20 yrs
abnormal movements, intellectual changes, subtle but progress to severe
tx of Huntington’s chorea
purely symptomatic
progression can’t be halted
typically Haldol and reserpine to control dyskinesia and behavior
Huntington’s chorea workup
genetic formation of inclusion bodies in neuron
MRI atrophy of caudate nuclei and putamen
