Motor Neuron Diseases Flashcards
associated symptoms of motor neuron lesions
table 3
t/f on PE look for both umn and lmn lesion signs aside from weakness (atrophy, fasciculations, abnormal reflexes)
true
common mnd mimics
myasthenia gravis
neurosyphilis
post-polio syndrome
thyroroxicosis
lesions in als
umn and lmn
lesions in pma
purely lmn
lesions in pls
purely umn
lesions in pbp
umn and lmn
familial mutation in als
superoxide dismutase type 1 or sod 1
t/f death occurs in als after 6 years of diagnosis
false, 2-5 years
pathophysiology of als
unknown
motor neuron susceptibility factors can lead no mni
glutamate toxicity can lead to cell death
el esocorial federation for diagnosis of als
signs of lmn and umn degeneration
progressive spread of signs with absence of ecg and imaging evidence
revised el esocorial criteria
table 5
awaji shima categories
table 6
mri findings in als
used to exclude mnd mimics
hyperintensities or atrophy in precentral gyrus
what is ncv
examines sensory and motor nerve action potentials
can distinguish axonal and demyelinating lesions
results of axonal vs demyelinating lesions
axonal: abnormal or reduced amplitude of sensory or motor aps
demyelinating: abnormal latencies and/or conduction velocities
ncv results of patient with als
sensory: normal
motor: normal conduction velocity, reduced amplitude
what is emg
examines motor unit action potentials
discriminates neuropathic and myopathic source
emg results in als
spontaneous activities (fasciculation, fibrillation, sharp waves)
motor unit aps are large
recruitment pattern is reduced
pls vs pma
table 7
pathophysiology of spinal muscular atrophy
autosomal recessive disorder caused by mutations in spinal motor neuron gene
clinical manifestations of sma
weakness of varied severity depending on type and age of onset
proximal muscles more affected
types of sma
1: werdnig-hoffman
2: dubowitz
3: wohlfart-kugelberg-welander
4: after 50
pathophysiology of kennedy’s disease
adult onset sma
x linked recessive
clinical features of kennedy’s disease
slowly progressive bulbar weakness and atrophy
proximal > distal
eom sparing
gynecomastia and testicular atrophy
pathophysiology of hirayama disease
focal ischemic changes in anterior horn cells of lower cervical cord
clinical features of hirayama disease
progressive wasting of muscles in hand and forearm
brachioradialis sparing
progresses then stabilizes
pathophysio of acute poliomyelitis
due to poliovirus going through oral route to cns
- spinal cord (lumbosacral > cervical > thoracic)
- nucleus ambiguus, cn 5, 7, 12
clinical features of acture poliomyelitis
minor: nonspecific
major: headache, fever, vomiting, malaise, neck and back stiffness, asymmetric weakness, hypo/areflexia
clinical features of post-poliomyelitis syndrome
new onset 20-30 years after infection
fatigue, joint pains, muscle pain, weakness, atrophy
associated cancer with paraneoplastic motor neuron disorder
subacute motor neuronopathy: lymphoma
paraneoplastic encephalomyelitis: sclc and (+) anti-hu antibodies
anti-glutamate drug that can improve als prognosis
riluzole
new drug to treat als
edavarone
signs of poor prognosis in als
older short interval between symptoms onset and diagnosis weight loss reduced pulmo function muscle weakness bulbar onset of disease
