Peripheral Nervous System and Skeletal Muscle

Question 1

structures affected in demyelinating neuropathy

Answer 1

schwann cells and myelin sheath

Question 2

mononeuritis multiplex pattern of involvement can lead to ___ distribution of lesion

Answer 2

several nerves, asymmetric

Question 3

most common chronic acquired peripheral neuropathy

Answer 3

chronic inflammatory demyelinating polyradiculoneuropathy

Question 4

most common cause of peripheral neuropathy

Answer 4

DM

Question 5

one of the most common viral infections of PNS

Answer 5

VZV

Question 6

most common inherited peripheral neuropathy

Answer 6

charcot-marie tooth (CMT) disease

Question 7

[diagnosis]

symmetric ascending demyelinating polyradiculoneurpathy

Answer 7

GBS

Question 8

[diagnosis]

associated with camplylobacter jejuni, mycoplasma pneumoniae, CMV, EBV, prior vaccination

Answer 8

GBS

Question 9

[diagnosis]

CSF finding: albuminocytologic dissociateion, little pleocytosis, increased protein

Histology: lymphoplasmacytic perivenular and endoneural infiltrate

Demyelination: segmental (most prominent lesion); axonal damage if severe

Answer 9

GBS

Question 10

most common form of distal sensorimotor polyneuropathy; axonal neuropathy

Answer 10

diabetic neuropathy

Question 11

[diagnosis]

peroneal muscle atrophy (high arch and claw toe)

progressive, distal sensorimotor neuropathy

Answer 11

charcot-marie-tooth disease

Question 12

[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

Answer 12

lambert eaton myasthenic syndrome

Question 13

myasthenic syndrome associated with Type II antibody-mediated hypersensitivitity

Answer 13

MG, LEMS

Question 14

[diagnosis]

fatigable weakness with exertion, postsynaptic Ach receptor, muscle specific receptor tyrosine kinase

diplopia, ptosis, more focal involvement

Answer 14

MG

Question 15

[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

Answer 15

dermatomyositis

Question 16

[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

Answer 16

polymyositis

Question 17

[diagnosis: common inflammatory myopathies]

immunologic damage to small blood vessels (type I interferon response)

Answer 17

dermatomyositis

Question 18

[diagnosis: common inflammatory myopathies]

CD8 mediated damage to muscle; blood vessels NOT involved

Answer 18

polymyositis

Question 19

[diagnosis]

pelvic girdle weakness up to shoulder, pseudohypertrophy of lower leg, arrythmias, cardiomyopathy, mental retardation,

early onsent, more severe

Dystrophin gene: absent

Answer 19

duchenne

Question 20

[diagnosis]

pelvic girdle weakness up to shoulder, pseudohypertrophy of lower leg, arrythmias, cardiomyopathy, mental retardation,

late onsent, milder

Dystrophin gene: reduced

Answer 20

becker

Question 21

[diagnosis: schwannoma or neurofibroma]

NF2 (merlin)
intracranial cerebellopontine angle attached to CN VIII (vestibular)

Answer 21

schwannoma

Question 22

[diagnosis: schwannoma or neurofibroma]

NF1
plexiform

Answer 22

neurofibroma

Question 23

[schwannoma]

Antoni ___: cellular areas; spindle cells in fascicles

Answer 23

antoni A

Question 24

[schwannoma]

Antoni ___: hypocellular, spindle cells in myxoid stroma

Answer 24

antoni B

Question 25

[diagnosis] schwannoma on tje cerebellopontine angle attached to CN VIII

Answer 25

NF II

Question 26

[diagnosis] Presence of antoni A and B, palisading of nuclei with verocay bodies S100 (+)

Answer 26

Schwannoma

Question 27

[diagnosis] bland schwannoma cells with stromal cells CD34+ bag of worms in nerve fascicles Collagen bundles: shredded carrot

Answer 27

Neurofibroma Associated with NF1

Question 28

[type of NF] CD34+ bag of worms shredded carrot

Answer 28

NF1

Question 29

[diagnosis] patient is a known NF1 noted new tumor arising within a major nerve, continous with a neurofibroma highly malignant neurofibroma

Answer 29

Malignant Peripheral Nerve Sheath Tumors

Question 30

[diagnosis: type of NF] ``` pigmented iris nodules cafe au lait spots CN VIII gliomas pheochromocytoma glial tumors hamartomatous lesions ```

Answer 30

NF Type 1

Question 31

[diagnosis: type of NF] bilateral CN VIII schwannoma multiple meningiomas ependymomas (commonly intraspinal)

Answer 31

NF Type 2