neuromuscular d/o Flashcards
what is the typical presentation for ALS?
asymmetric progressive weakness in one limb that progresses to other limbs
bulbar sx like dysphagia and dysarthria
late– eye and bowel/bladder difficulties
what clinical signs do you expect w/ ALS??
UMN– + babinski, Hoffaman’s sign, rigidity
LMN– muscle atrophy, fasciculations (esp tongue)
describe the pathophysiology of ALS
progressive neurodegenerative d/o of frontal lobe, corticospinal tract, brain stem, spinal cord
death of both UMN and LMN causing motor issues
who & why would you refer an ALS presenting patient?
neurologist
for diagnosis & EMG
what is definitive way to diagnose ALS
UMN & LMN signs in 3 of 4 body regions (bulbar, cervical, thoracic, and lumbar)
what is probably way to diagnose ALS?
LMN signs in 2 of 4 regions
how must LMN signs be diagnosed?
with an EMG
negative EMG does not rule it out bc it might be too early
how is ALS managed w/ medications?
riluzole for prolong time till resp. failure
edaravone to delay functional decline
supportive meds for spasticity and saliva control
what is the prognosis for ALS?
death 2-3 years after diagnosis (diagnosis typically is delayed by a year)
what are three variants of ALS?
primary lateral sclerosis (CNS or UMN only)
progressive muscular atrophy (PNS/LMN only)
progressive bulbar atrophy (brain stem)
how do you differentiate isolated bulbar sx from ALS?
get a head MRI to rule out brainstem pathology
what part of neuromuscular transmission is disrupted w/ spinal muscular atrophy (SMA)?
anterior horn cell/ LMN
what is SMA?
spinal muscular atrophy
autosomal recessive LMN disease d/t mutation in SMN1 gene
how does SMA present?
SYMMETRIC, proximal weakness, worse in LE
inability to sit unsupported, weak cry
hypotonia
less severe motor ability, longer survival
how is SMA diagnosed?
newborn screening
genetic testing
how is SMA treated
medications
IV med for gene replacement (Zolgensma)
intrathecal, antisense drug (spinraza)
list 3 disorders of the NMJ
myasthenia gravis
botulism
Lambert-eaton syndrome
what is Lambert-eaton myasthenic syndrome (LEMS)
autoimmune dz from antibodies going against PRESYNAPTIC calcium channels causing decrease in acetylcholine release= muscle weakness
often paraneoplastic syndrome– related to small cell lung cancer
what are typical LEMS symptoms?
SYMMETRIC proximal muscle weakness
areflexia
autonomic dysfx– dry mouth
LEMS vs Myasthenia gravis
with Myasthenia gravis, weakness worsens w/ movement while w/ LEMS it improves w/ movement!
w/ myasthenia, the POST synaptic is being blocked, w/ LEMS the PRE synaptic is being blocked
how is LEMS diagnosed?
diagnosed by EMG, confirmed w/ VGGC antibodies
get chest CT if negative PET to look for underlying malignancy
how is LEMS treated?
treat underlying malignancy/cancer
pyridostigmine
3,4-diaminopyridine
neonatal vs congenital myasthenia
neonatal is from mother; support and neostigmninie
congenital is from protein mutation; acetylcholinesterase inhibitors
define myopathy
proximal symmetric weakness
