MSK path II Flashcards
What is most common form paraneopkastic caused neuropathy
sensorimotor neuronopathy
paraneoplastic sensorimotor neuronopathy is most commonly assoc with what tumor
SCC, oat cell of lung
What tumors secrete IgM that could demyelinate nerves
waldenstrom macroglobulinemia
what other condition secretes Ig that could damage nerves
multiple myeloma
where are SCC located inlungs typically
central
perinuclear clearing
waldenstrom macroglobulinemia
what is it called when hurts between 2nd and 3rd digit toes
morton neuroma
traumatic nerve injury
What is name for hereditary motor and sensory neuropathie
charcot-marie-tooth disease
most common inherited peripheral neuropathy
CMT
clincal signs CMT
distal mm atrophy
sensory loss– lots of bruises and scrapes
foot deformities– pes cavus foot
damage to schwanna cells is called
demyelinating neuropathy
damage to axons is called what
axonal neuropathy
damage to central neurons is called what
neuronopathy
painless weakness in eyes
myasthenia gravis
autoAb in myasthenia
Ab against ACh R
what tumor is myasthenia assoc with
thymoma
hassels corpuscles
thymic gland
young myasthenic patient with thyroid abrnomality
thymic hyperplasia> thymoma
presentation myasthenia patient with Ab against muscle specific R tyrosine kinase
focal muscle involvement
neck, shoulder, facial, respiratory and bulbar
Dx myasthenia
Hx
PE
autoAb
electrophysiologic studies
Tx myasthenia
ACHE Inhibitors
Tx thymoma in myasthenia patient
thymectomy
Lambert Eaton Myasthenic Syndrome
autoimmune caused by Ab that block Ach release by inhibiting presynaptic Ca channel
clinical difference myasthenia gravis and LEMS
LEMS gets better with time
myasthenia gets worse with time
why does LEMS get better with time
because more stimulation will get enough Ca out to cause action
LEMS assocaited with
neuroendocrine carcinoma of lung– looks like ALL in child
usually SCC
what microbe produces botulinum toxin
clostridium botulinum
gram +
curare
blcok ACh R and cause flaccid paralysis
Sx botulism
double vision, blurred vision, droopy eyelids slurred speech difficulty swallowing dry mouth muscle weakness
genetic defects in NMJ lead to what
congenital myasthenic syndromes
characteristics of type I skel mm fibers
slow, high lipid content, red color from myoglobin,
high oxidative capacity (low glycolytic)
checkerboard pattern of skel mm fibers. darker are what type
II
clusters of atrophic muscle fibers
neurogenic
perifascicular atrophy in muscle fibers
dermatomyositis
type II mm fiber atrophy
normal type I fibers
prolonged corticosteroid therapy or disuse
disorders skel muscle happen how
myopathic injury or disrupting the muscle innervation
increased CK MM in blood
degeneration releasing cytoplasmic enzymes (part of myofiber necrosis)
segmental myofiber degeneration and regneration
when is myofiber hypertophy seen
physiologic adaptation to exercise or in assoc with chronic myopathic conditions
cytoplasmic inclusions in mm
vacuoles, aggregates protesins, clustered organelles
all suggest myopathy
3 main primary inflammatory myopathies
polymyositis, dermatomyositis and inclusion body myositis
what immune mediated disorders can cause myositis
SLE, systemic sclerosis, sarcoidosis
muscle fiber surrounded by blue cells
lymphocytes = inflammatory myopathy
dermatomyositis
systemic autoimmune disease presents with proximal muscle weakness and skin changes (swollen hands and feet)
what occurs in dermatomyositis that leads to muscle injury
vasculitis small vessels
anti Mi2 Ab
Gottron papules and heliotrope rash, dermatomyositis
anti Jo1 Ab
interstitial lung disease, nonerosive arthritis and skin rash called “mechanics hands”
Ab against histidyl t-RNA synthetase
anti P155/P140 Ab
against transcriptional regulators
assoc with paraneoplastic and juvenile dermatomyositis
myofiber atrophy accentuated at edges of fascicles
perifascicular atrophy
infiltrate rich in CD4 and C’5-9 in muscle fascicles
dermatomyositis
what movements are hardest in begining of dermatomyositis
getting up from chair and climbing because affect proximal muscles first
heliotrope rash
lilac colored discoloration of upper eyelids with periorbital edema and scaling erythematous eruption dusky red patches over knucles, elbows and knees (gottron papules)
associated conditions with dermatomyositis
dysphagia from esophageal mm
interstitial lung disease which can lead to death
