pathology 1227-1246 (peripheral nerves)

Question 1

what are the 2 main components of peripheral nerves

Answer 1

axons and myelin sheaths

Question 2

what is the name for the spherical structures that occur within a day of axonal injury

Answer 2

myelin ovoids

Question 3

what is the term for a non-neoplastic haphazard whorled proliferation of axonal processes and associated schwann cells that result in a painful nodule

Answer 3

traumatic neuroma

Question 4

what are some insults that may lead to neuronopathies

Answer 4

herpes zoster and toxins like platinum compounds

Question 5

what do peripheral axonopathies preferentially affect

Answer 5

distal extremities

Question 6

what are neuronopathies likely to affect

Answer 6

equally proximal and distal parts of the body

Question 7

what are common causes of mononeuropathy

Answer 7

trauma, entrapment, and infections

Question 8

what is a common cause of mono neuritis multiplex

Answer 8

vasculitis

Question 9

does guillain-barre occur in the PNS or CNS

Answer 9

PNS

Question 10

what is guillain barre characterized by

Answer 10

weakness beginning in the distal limbs that rapidly advances to affect proximal muscle functions

Question 11

what is the dominant histological finding in guillain barre syndrome

Answer 11

inflammation of peripheral nerves, manifested as perivenular and endoneurial infiltration by lymphocytes, macrophages, and a few plasma cells

Question 12

what is the most common chronic acquired inflammatory peripheral neuropathy

Answer 12

chronic inflammatory demyelinating poly(radical)neuropathy

Question 13

what is chronic inflammatory demyelinating poly(radicalo) neuropathy characterized by

Answer 13

symmetrical mixed sensorimotor polyneuropathy that persists for 2 months or more

Question 14

what is the term for a noninfectious inflammation of blood vessels that can involve and damage peripheral nerves

Answer 14

vasculitis

Question 15

what are some of the neurologic manifestations caused by lyme disease in the 3rd and 4th stages of disease

Answer 15

polyradiculoneuropathy and unilateral or bilateral facial nerve palsies

Question 16

what is the most common cause of peripheral neuropathy

Answer 16

diabetes

Question 17

what is the predominant pathologic finding in individuals with symmetric sensorimotor neuropathy

Answer 17

axonal neuropathy

Question 18

what is the primary event in uremic neuropathy

Answer 18

axonal degeneration

Question 19

what is paraneoplastic sensorimotor neuronopathy most commonly associated with

Answer 19

small cell lung cancer

Question 20

what is morton neuroma marked by

Answer 20

perineurial fibrosis

Question 21

what is CMT1A caused by

Answer 21

duplication of a region on chromosome 17 that includes PMP22 gene

Question 22

what is CMT1B caused by

Answer 22

mutations in myelin protein zero gene

Question 23

what is CMT1X caused by

Answer 23

mutations in the GJB2 gene

Question 24

what does GJB2 gene encode

Answer 24

connexin32, which is a gap junction component that is expressed in schwann cells

Question 25

what is CMT2A caused by

Answer 25

mutations in the MFN2 gene

Question 26

what gene causes hereditary neuropathy with pressure palsy

Answer 26

PMP22

Question 27

what is lambert-eaton syndrome caused by

Answer 27

antibodies that block ACh release by inhibiting a presynaptic calcium channel

Question 28

what is the most common loss of function mutation in congenital myasthenia syndromes

Answer 28

gene encoding the epsilon-subunit of the ACh receptor

Question 29

how does botox act

Answer 29

by blocking the release of ACh from presynaptic neurons

Question 30

what does Curare block

Answer 30

Each receptors

Question 31

what does curare use result in

Answer 31

flaccid paralysis

Question 32

what is type 2 fiber atrophy with sparing of type 1 fibers seen with

Answer 32

prolonged corticosteroid therapy or disuse

Question 33

when is segmental myofiber degeneration and generation seen

Answer 33

when only part of a myofiber undergoes necrosis

Question 34

what is an immunologic disease in which damage to small blood vessels contributes to muscle injury

Answer 34

dermatomyositis

Question 35

what is another name for the dilated capillary looks seems in dermatomyositis

Answer 35

telangiectasias

Question 36

what do anti-Mi2 antibodies direct against

Answer 36

helicase implicated in nucleosome remodeling

Question 37

what do anti-Mi2 antibodies show a strong prominent associated with

Answer 37

prominent gottron papules and heliotrope rash

Question 38

what are anti-Jo1 antibodies associated with

Answer 38

interstitial lung disease, non erosive arthritis, and skin rash (mechanics hands)

Question 39

what are anti-Jo1 antibodies direct against

Answer 39

the enzyme histidyl t-RNA synthetase

Question 40

what are anti-P155/P140 antibodies associated with

Answer 40

paraneoplastic and juvenile cases of dermatomyositis

Question 41

what is the most common inflammatory myopathy in children

Answer 41

dermatomyositis

Question 42

what is the name for an adult-onset inflammatory myopathy that shares myalgia and weakness with dermatomyositis but lacks its distinctive cutaneous features

Answer 42

polymyositis

Question 43

what is a prominent part of the inflammatory infiltrate of the affected muscle in polymyositis

Answer 43

CD8-positive cytotoxic T cells

Question 44

where are mononuclear inflammatory cell infiltrates usually located with polymyositis

Answer 44

endomysial in location

Question 45

what is the most common inflammatory myopathy in patients older than 65 years

Answer 45

inclusion body myositis

Question 46

what is the first line of defense for polymyositis and dermatomyositis

Answer 46

corticosteroids

Question 47

what are the leading culprit for toxic myopathies

Answer 47

statins

Question 48

what are some common examples of conditions with defects in ECM surrounding myofibers

Answer 48

ullrich congenital muscular dystrophy and merosin deficiency

Question 49

what is UCMD characterized by

Answer 49

hypotonia, proximal contractors and distal hyperextensibility

Question 50

what is emery-dreifuss muscular dystrophy caused by

Answer 50

mutations in genes that encode nuclear lamina proteins

Question 51

what is the triad the EMD is marked by

Answer 51

slowly progressive humeroperoneal weakness, cardiomyopathy associated with conduction defects, and early contractures of the achilles tendon, spine and elbows

Question 52

what gene is over expressed in fascioscapulohumeral dystrophy

Answer 52

DUX4

Question 53

what is the most common disorder of lipid metabolism to cause episodic muscle damage with exercise or fasting

Answer 53

carnitine palmitoyltranferase II deficiency

Question 54

what does the carnitine palmitoyltranferase II deficiency cause impairment of

Answer 54

transport of free fatty acids into mitochondria

Question 55

what does myophosphorylase deficiency/ mcArdle disease result in

Answer 55

episodic muscle damage with exercise

Question 56

what does acid maltase deficiency impair

Answer 56

lysosomal conversion of glycogen to glucose

Question 57

what do mutations affecting KCJN (potassium channel) cause

Answer 57

anderson-twail syndrome

Question 58

describe anderson-twail syndrome

Answer 58

autosomal dominant disorder associated with periodic paralysis, heart arrhythmia, and skeletal abnormalities

Question 59

what do mutations affecting SCN4A (sodium channel) cause

Answer 59

several autosomal disorders with presentations ranging from myotonia to periodic paralysis

Question 60

what is the most common cause of hypokalemic paralysis

Answer 60

missense mutations in CACNA1S

Question 61

what do mutations of CLC1 cause

Answer 61

myotonia congenita