Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

NMSP Exam 2 > Peripheral Nervous System and Skeletal Muscle Path > Flashcards

Peripheral Nervous System and Skeletal Muscle Path Flashcards

1
Q

segmental demyelination

A

schwann cell dysfunction secondary to damage of the myelin sheath

no primary abnormality of axons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is a histo sign of demyelination?

A

onion bulbs = concentric layers of schwann cytoplasm and redundant basement membrane surrounding thinly myelinated axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

traumatic neuroma

A

failure of the outgrowing axons to find their distal target can produce a pseudo-tumor

painful nodule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

axonal degeneration

A

primary destruction of axon with secondary disintegration of myelin sheath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

axon damage

A

focal or generalized trauma or ischemia affecting the whole neuron body or its axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

describe the process of axonal degeneration

A
  1. myelin ovoids form due to engulfed axon fragments
  2. macrophages clean up
  3. proximal stump of severed nerve shows degenerative changes in distal 2-3 internodes
  4. axon undergoes regeneration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what happens to muscle fibers during axon degeneration?

A

lose neural input and undergo denervation atrophy resulting in angulated and target fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what reactions occur within the muscle fiber with damage?

A

segmental necrosis
vacuolization
regeneration
hypertrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the different anatomical patterns of peripheral neuropathies?

A

mononeuropathy - single nerve

polyneuropathy - multiple nerves

mononeuritis multiplex - multiple nerves in a haphazard fashion

polyradiculopathy - nerve roots + peripheral nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Bell’s palsy

A

mononeuropathy of CN VII causing facial muscle paralysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the clinical presentation of bell’s palsy?

A

one sided facial droop
associated with URI or DM
facial tingling
headache

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the ddx for facial droop?

A 
Bell's palsy
stroke
brain tumor
Ramsay hunt syndrome
Lyme dz
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the causes of neurogenic bladder?

A

nerve damage secondary to MS, Parkinsons or DM

infection of the brain or spinal cord

heavy metal poisoning

stroke

spinal cord injury

spina bifida

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Guillain-Barre

A

acute inflammatory demyelinating polyneuropathy

ascending paralysis

inflammation of demyelination of spinal nerve roots and peripheral nerves

immune-mediated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what organisms can cause GB?

A

C. jejuni
CMV
Ebstein Barr
Mycoplasma pneumoniae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the etiology of GB?

A

inflammation of peripheral nerves by lymphocytes, macrophages and plasma cells

macrophages penetrate Schwann cells at the nodes of Ravier and strip myelin away from axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what lab results can support GB?

A

increased CSF protein

anti-myelin antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

treatment of GB

A

plasmapheresis and IV Ig

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

chronic inflammatory demyelinating polyradiculopathy

A

most common acquired inflammatory peripheral neuropathy

symmetrical mixed sensorimotor polyneuropathy > 2 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what distinguishes chronic inflammatory demyelinating polyradiculopathy from GB?

A

time of course

response to steroids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

chronic inflammatory demyelinating polyradiculopathy diagnostic tools

A

sural nerve biopsy showing onion bulbs

complement-fixing IgG and IgM on myelin sheath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Leprosy/Hansen disease

A

schwann cells invaded by mycobacterium leprae

bacteria proliferates and infects other cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is the pathology underlying the symptomatology of leprosy

A

segmental demyelination
endoneurial fibrosis and thickened perineural sheaths
symmetric polyneuropathy affecting cool ext

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the presentation of leprosy?

A

loss of sensation

large traumatic ulcers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
diptheria neuropathy
Diptheria exotoxin damage to peripheral nerves
26
what is the presentation of Diptheria neuropathy?
``` paraesthesias weakness loss of vibratory sense loss of proprioception loss of respiratory muscle function if untreated ```
27
what is the most common viral infection of the PNS?
varicella zoster virus
28
shingles
reactivation of latent infection causing painful vesicular skin eruption in the distribution of sensory dermatomes
29
what is the pathology of shingles?
neuronal destruction and loss of affected ganglia regional necrosis and hemorrhage axonal degeneration of peripheral nerves after death of sensory neurons focal destruction of large motor neurons in anterior horns or cranial nerve motor nuclei
30
lyme dz neuropathy
unilateral or bilateral facial nerve palsies
31
HIV neuropathy
mononeuritis multiplex demyelinating disorder resembling GB later stages associated with distal sensory neuropathy
32
what is the most common cause of peripheral neuropathy?
DM
33
presentation of diabetic neuropathy
symmetric neuropathy involving distal sensory and motor nerves: ``` numbness loss of pain sensation difficulty with balance diffuse vascular injury autonomic dysfunction ```
34
what is the etiology of diabetic neuropathy?
segmental demyelination | thickened endoneurial arterioles
35
what else can cause neuropathy?
``` uremia thyroid dysfunction vitamin deficiency EtOH heavy metals chemotherapy ```
36
what causes neuropathy associated with malignancy?
direct infiltration or compression of peripheral nerve
37
what are the signs of neuropathies associated with monoclonal gammopathies?
``` POEMS: polyneuropathy organomegaly endocrinopathy monoclonal gammopathy skin changes ```
38
what are some examples of compression/entrapment neuropathy?
carpel tunnel - median nerve saturday night palsy - radial nerve morton neuroma - interdigital nerve
39
what is the most common inherited PN?
Charcot-Marie-Tooth
40
what are the subtypes of CMT?
CMT1 CMTX CMT2
41
CMT1
AD mutation on chrom 17 PMP22 gene second decade of life slowly progressive demyelinating motor and sensory
42
CMTX
X-linked form of Charcot-Marie-Tooth
43
CMT2
AD mutation on MDN2 gene | early childhood
44
familial amyloid polyneuropathies
amyloid deposition within the peripheral nerves
45
what inherited metabolic disorders can cause neuropathy?
leukodystrophies porphyria Refsum dz
46
what toxins block ACh release from the neuromuscular junction?
Clostridium botulinum | Curare
47
myasthenia gravis
autoantibodies to AChR at the neuromuscular junction
48
what is frequently associated with MG?
thymoma | thymic hyperplasia
49
what is the presentation of MG?
fluctuating generalized weakness that worsens with exertion and over the course of the day diminished response after repeated stimulation
50
what is usually the first sign of MG?
extraocular muscle weakness - ptosis and diplopia
51
MG tx
AChE inhibitors plasmapheresis immunosuppressives thymectomy
52
Lambert Eaton Myasthenic Syndrome
antibodies block ACh release by inhibiting presynaptic calcium channel 50% paraneoplastic process due to small cell carcinoma of the lung
53
what is the presentation of LEMS?
proximal muscle weakness and autonomic dysfunction repetitive stimulation increases muscle response
54
dermatomyositis
autoantibodies anti-Mi2 anti-Jo1 anti-P155/P140
55
what is the presentation of dermatomyositis?
``` lilac or heliotrope rash with periorbital edema telangiectasias Grotton lesions proximal muscle weakness dysphasia ```
56
dermatomyositis puts you at an increased risk to develop what?
visceral cancer
57
what is seen on histo in dermatomyositis?
perifascicular atrophy | perimysial mononuclear infiltrates
58
what is the common presentation of juvenile dermatomyositis?
onset at 7 y/o involves GI tract calcinosis and lipodystrophy
59
polymyositis
adult-onset myalgia and weakness due to CD8 Tcells in endomysium symmetrical proximal muscle involvement No cutaneous involvement
60
what is seen on histo with polymyositis?
endomysial mononuclear infiltrates | random distribution of affected fibers
61
inclusion body myositis
dz of late adulthood slowly progressive muscle weakness most severe in quads and distal upper extremities dysphagia common
62
what is on histo in Inclusion Body Myositis?
rimmed vacuoles
63
what is the treatment for inflammatory myopathies?
steroids | immunosuppressives if steroid-resistant
64
what toxins can cause myopathy?
``` statins chloroquine/hydroxychloroquine critical illness thyrotoxic alcohol ```
65
Duchenne MD
X linked mutation in Xp21 NO dystrophin production sx before 5 y/o wheelchair by 10-12 y/o
66
Becker MD
X linked mutation in Xp21 | reduced dystrophin production
67
what is pseudohypertrophy?
enlargement of muscles of LE associated with weakness increased bulk due to increased size of muscle fibers replaced by fat and CT as MD progresses
68
what is seen on histo in both DMD and BMD?
variation in fiber size increased internalized nuclei degeneration, necrosis and phagocytosis of fibers regeneration of fibers proliferation of endomysium fibers replaced by fat and CT (late stages)
69
what is seen in DMD histo but not BMD?
enlarged, rounded hyaline fibers that have lost their cross striations
70
myotonic dystrophy
AD mutation in DMPK gene due to CTG trinucleotide repeats *anticipation
71
what is the presentation of myotonic dystrophy?
``` myotonia muscle weakness "hatchet face" cataracts endocrinopathy cardiomyopathy ```
72
what is seen on histo with myotonic dystrophy?
ring fiber | sarcoplasmic mass
73
Emery-Dreifuss MD
X linked EMD1 or AD EMD1 mutations in gene encoding lamina proteins
74
EMD triad of symptoms
humeroperoneal weakness cardiomyopathy early contractures of Achilles, spine and elbow
75
Limb-Girdle MD
AD or AR disease | muscle weakness that involves proximal muscle groups
76
carnitine palmitoyltransferase II def
episodic muscle damage with exercise and fasting
77
McArdle Dz/myophosphorylase def
episodic muscle damage with exercise
78
Pompe dz/acid maltase def
infancy: generalized glycogenesis adult: respiratory and trunk muscle weakness
79
what are the mitochondrial myopathies?
Leber Leigh Barth Kearns-Sayre
80
Leber syndrome
point mutation in mtDNA optic neuropathy
81
Leigh syndrome
nuclear DNA gene mutation subacute necrotizing encephalopathy
82
Barth syndrome
nuclear DNA gene mutation infantile x-linked cardioskeletal myopathy
83
Kearns-Sayre syndrome
deletion of duplication in mtDNA ophthalmoplegia pigmentary degeneration of retina complete heart block
84
what can be seen in histo for mitochondrial myopathies?
ragged red fibers
85
spinal muscular atrophy
AR mutation in SMN1 on Ch. 5 causing destruction of anterior horn cells loss of motor neurons leading to muscle weakness and atrophy
86
what is the presentation for SMA?
generalized hypotonia/"floppy infant"
87
what is on the ddx for infantile hypotonia?
``` congential masthenic syndrome congenital myotonia congenital myopathies congenital MD encephalopathy neuronopathies (SMA) ```
88
what is the most common type of SMA?
Wernig-Hoffman disease onset at birth death < 3 y/o
89
what is the presentation of Wernig-Hoffman disease?
truncal and extremity weakness | chewing, swallowing and breathing difficulties
90
malignant hyperthermia
AD mutation in RYR1 gene causing channelopathy hypermetabolic state causing tachycardia, tachypnea, muscle spasm, and hyperreflexia triggered by anesthetics

NMSP Exam 2 (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions