Peripheral Nervous System and Skeletal Muscle Flashcards
structures affected in demyelinating neuropathy
schwann cells and myelin sheath
mononeuritis multiplex pattern of involvement can lead to ___ distribution of lesion
several nerves, asymmetric
most common chronic acquired peripheral neuropathy
chronic inflammatory demyelinating polyradiculoneuropathy
most common cause of peripheral neuropathy
DM
one of the most common viral infections of PNS
VZV
most common inherited peripheral neuropathy
charcot-marie tooth (CMT) disease
[diagnosis]
symmetric ascending demyelinating polyradiculoneurpathy
GBS
[diagnosis]
associated with camplylobacter jejuni, mycoplasma pneumoniae, CMV, EBV, prior vaccination
GBS
[diagnosis]
CSF finding: albuminocytologic dissociateion, little pleocytosis, increased protein
Histology: lymphoplasmacytic perivenular and endoneural infiltrate
Demyelination: segmental (most prominent lesion); axonal damage if severe
GBS
most common form of distal sensorimotor polyneuropathy; axonal neuropathy
diabetic neuropathy
[diagnosis]
peroneal muscle atrophy (high arch and claw toe)
progressive, distal sensorimotor neuropathy
charcot-marie-tooth disease
[diagnosis]
no weakness with exertion (response increases with repetitive exertion) affecting extremities, presynaptic Ca channel is affected resulting to blocked Ach release
associated with neuroendocrine carcinoma of the lung
lambert eaton myasthenic syndrome
myasthenic syndrome associated with Type II antibody-mediated hypersensitivitity
MG, LEMS
[diagnosis]
fatigable weakness with exertion, postsynaptic Ach receptor, muscle specific receptor tyrosine kinase
diplopia, ptosis, more focal involvement
MG
[diagnosis]
juvenile
myalgia progressing to proximal weakness then to distal weakness
with heliotrope rash, gottron papules
mononuclear infiltrate in the perimysial, perivascular
atrophy: perifascicular atrophy
dermatomyositis
[diagnosis]
usually seen among adults
myalgia progressing to proximal weakness then to distal weakness
no skin changes
mononuclear infiltrate in the endomysium, and pattern of atrophy is patchy
polymyositis
[diagnosis: common inflammatory myopathies]
immunologic damage to small blood vessels (type I interferon response)
dermatomyositis
[diagnosis: common inflammatory myopathies]
CD8 mediated damage to muscle; blood vessels NOT involved
polymyositis
[diagnosis]
pelvic girdle weakness up to shoulder, pseudohypertrophy of lower leg, arrythmias, cardiomyopathy, mental retardation,
early onsent, more severe
Dystrophin gene: absent
duchenne
[diagnosis]
pelvic girdle weakness up to shoulder, pseudohypertrophy of lower leg, arrythmias, cardiomyopathy, mental retardation,
late onsent, milder
Dystrophin gene: reduced
becker
[diagnosis: schwannoma or neurofibroma]
NF2 (merlin)
intracranial cerebellopontine angle attached to CN VIII (vestibular)
schwannoma
[diagnosis: schwannoma or neurofibroma]
NF1
plexiform
neurofibroma
[schwannoma]
Antoni ___: cellular areas; spindle cells in fascicles
antoni A
[schwannoma]
Antoni ___: hypocellular, spindle cells in myxoid stroma
antoni B
[diagnosis]
schwannoma on tje cerebellopontine angle attached to CN VIII
NF II
[diagnosis]
Presence of antoni A and B, palisading of nuclei with verocay bodies
S100 (+)
Schwannoma
[diagnosis]
bland schwannoma cells with stromal cells
CD34+
bag of worms in nerve fascicles
Collagen bundles: shredded carrot
Neurofibroma
Associated with NF1
[type of NF]
CD34+
bag of worms
shredded carrot
NF1
[diagnosis]
patient is a known NF1
noted new tumor arising within a major nerve, continous with a neurofibroma
highly malignant neurofibroma
Malignant Peripheral Nerve Sheath Tumors
[diagnosis: type of NF]
pigmented iris nodules cafe au lait spots CN VIII gliomas pheochromocytoma glial tumors hamartomatous lesions
NF Type 1
[diagnosis: type of NF]
bilateral CN VIII schwannoma
multiple meningiomas
ependymomas (commonly intraspinal)
NF Type 2
