Skeletal Muscle Pathology Flashcards
1
Q
Part of muscle that envelopes single muscles
A
Epimysium
2
Q
Part of muscle that surrounds groups of muscle fibers
A
Perimysium
3
Q
Part of muscle that surrounds individual muscle fibers
A
Endomysium
4
Q
Molecule involved in muscle energy metabolism, has two monomers and three types of dimers
A
Creatine kinase
5
Q
Elevated total CK suggests this type of injury
A
Skeletal muscle
6
Q
Molecule involved in muscle oxygen use that is released with muscle damage - also elevated with cardiac injury
A
Myoglobin
7
Q
Molecule involved in muscle glycolysis that is released with muscle damage
A
Aldolase
8
Q
This molecule released with muscle damage is sometimes elevated when CK is normal
A
Aldolase
9
Q
Condition of skeletal muscle weakness due to autoantibodies against muscle acetylcholine receptor complex
A
Myasthenia Gravis
10
Q
Myasthenia Gravis is due to autoantibodies against this
A
Muscle acetylcholine receptor complex
(or anti-MUSK - muscle specific kinase)
11
Q
Two age peaks of Myasthenia Gravis
A
20’s and 60’s
12
Q
Skeletal muscle condition associated with thymic tumors (Thymoma, thymic hyperplasia)
A
Myasthenia Gravis
13
Q
Myasthenia Gravis is associated with tumors of this organ
A
Thymus
14
Q
Who is more likely to have Myasthenia Gravis, female or male?
A
Female
15
Q
Condition involving muscle weakness which worsens with repetition/duration
A
Myasthenia Gravis
16
Q
Condition that commonly affects eye muscles, so patients can have ptosis and diplopia
A
Myasthenia Gravis
17
Q
Are deep tendon reflexes preserved in Myasthenia Gravis?
A
Yes
18
Q
ACHesterase inhibitors results in improved symptoms in this condition
A
Myasthenia Gravis
19
Q
Condition of weakness due to antibodies against calcium channels
A
Lambert-Eaton Myasthenic Syndrome
20
Q
Lambert-Eaton Myasthenic Syndrome is due to antibodies against this
A
Calcium channels
21
Q
Condition where muscle strength increases with repetition/duration
A
Lambert-Eaton Myasthenic Syndrome
22
Q
Half of Lambert-Eaton Myasthenic Syndrome cases are due to paraneoplastic syndrome, and this is the most common
A
Small cell carcinoma of lung
23
Q
Small cell carcinoma of lung is the most often paraneoplastic syndrome that can cause this condition
A
Lambert-Eaton Myasthenic Syndrome
24
Q
Are deep tendon reflexes preserved in Lambert-Eaton Myasthenic Syndrome?
A
No, are decreased
May have autonomic effects
25
Do ACHesterase inhibitors improve symptoms in Lambert-Eaton Myasthenic Syndrome?
No
26
Condition that leads to impaired acetylcholine release, because there is dysfunction in firing of presynaptic calcium channels
Lambert-Eaton Myasthenic Syndrome
27
Clostridium botulinum can block release of this, causing myasthenic syndrome
ACH
28
Does this describe neuropathic or myopathic muscle atrophy:
End result is clustering of atrophy and hypertrophy
Neuropathic
29
Type II fiber atrophy is associated with prolonged use of these
Corticosteroids
30
What is pathognomonic of muscle denervation/reinnervation?
Clusters of type I myocytes and clusters of type II myocytes
31
Does steroid use result in type I or type II atrophy?
Type II atrophy
Type I preservation
32
Acute necrosis of skeletal muscle
Rhabdomyolysis
33
Levels of creatine kinase and aldolase in Rhabdomyolysis
Both high due to release of cytosolic proteins
34
In Rhabdomyolysis, regeneration may occur via these cells
Satellite cells (muscle stem cells)
Remember that part of healing response/regeneration is central nuclei
35
Central nuclei in muscle indicate this process has occurred
Regeneration
36
In Rhabdomyolysis, this molecule may be released into the urine and damage the kidneys, causing acute renal failure
Myoglobin
37
Autoimmune disease with proximal muscle weakness and skin changes
Dermatomyositis
38
Two age groups that may have Dermatomyositis
Peds (7 years) and adults (60's)
39
Dermatomyositis is an autoimmune disorder mediated by this type of cell
B cell
IgG, IgM and complement deposit in microvascular beds
40
Condition where IgG, IgM and complement deposit in microvascular beds, and results in microangiopathic ischemia in muscle and skin (rash, telangiectasias)
Dermatomyositis
41
Does Dermatomyositis affect proximal or distal muscle first?
Proximal
42
Condition with muscle aches and weakness with gross motor activities affected first (standing from chair, raising arms above head, climbing stairs)
Dermatomyositis
43
Condition with heliotrope rash on upper eyelids
Dermatomyositis
44
Condition with Gottron's papules on dorsal knuckles
Dermatomyositis
45
Condition with characteristic skin changes including malar erythema, mechanics hands, periungual telangiectasias, and periorbital edema
Dermatomyositis
46
Perivascular perimysial lymphoid infiltrate is pathognomonic of this condition
Dermatomyositis
47
Microvascular immune complexes and perifascicular atrophy are morphologically seen in this condition
Dermatomyositis
48
Level of CK in Dermatomyositis
Elevated
49
Anti-Jo1 antibodies are against this
Histidyl tRNA synthetase
50
Type of antibodies seen in Dermatomyositis that target histidyl tRNA synthetase
Anti-Jo1
51
Anti-Mi2 antibodies target this
DNA helicase
52
Type of antibodies seen in Dermatomyositis that target DNA helicase
Anti-Mi2
53
Type of antibodies that are most common in paraneoplastic Dermatomyositis
Anti-p140
54
Anti-Jo1 and Anti-Mi2 antibodies are seen in this condition
Dermatomyositis
55
Inflammatory myopathy mediated by cytotoxic T cells
Polymyositis
56
Polymyositis is inflammatory myopathy mediated by this type of cell
Cytotoxic T cells
57
What is the age of onset of Polymyositis?
Adult
58
Are there skin changes in Polymyositis?
No
59
What part of the muscle is Polymyositis located in?
Endomysium
60
Does Polymyositis involve angiopathy?
No
61
Condition involving muscle fatigue and cramps, proximal weakness initially - especially shoulder girdle
Polymyositis
62
Does Polymyositis affect proximal or distal muscles first?
Proximal
Especially shoulder girdle
63
Levels of CK and aldolase in Polymyositis
Both elevated
64
Anti-Jo1 and Anti-SRP antibodies are seen in this condition
Polymyositis
65
Raynauds, interstitial lung disease, and arthralgias are associated with this condition
Polymyositis
66
Inflammatory myopathy with cytoplasmic amyloid inclusions
Inclusion body myositis
67
Age of patients with Inclusion body myositis
Older adults, >50 years
68
Level of CK in Inclusion body myositis
Modest elevation
69
Condition associated with anti-CN1a antibodies
Inclusion body myositis
70
Inclusion body myositis is associated with this antibodies
Anti-CN1a
71
Condition with amyloid deposition in muscle fibers with CD8+ T cell response
Inclusion body myositis
72
Inclusion body myositis involves deposition of this in muscle fibers with CD8+ T cell response
Amyloid
73
Inclusion body myositis involves amyloid deposition in muscle fibers with response of this type of cell
CD8 T cells
74
Beta amyloid, Tau protein, and Synuclein can accumulate and deposit in muscle fibers in this condition
Inclusion body myositis
75
Condition with cytoplasmic inclusions of amyloid material, rimmed vacuoles, and endomysial T cell infiltrate
Inclusion body myositis
76
Condition with morphology of "rimmed vacuoles"
Inclusion body myositis
77
Autoimmune disease against skeletal muscle fibers
Immune-mediated necrotizing myopathy
78
Condition that produces subacute symmetric proximal weakness
Immune-mediated necrotizing myopathy
79
Condition that is associated with other autoimmune disorders and HMG-CoA reductase inhibitors (statins)
Immune-mediated necrotizing myopathy
80
Anti-SRP and anti-HMGCR (HMG CoA reductase) autoantibodies are seen in this condition
Immune-mediated necrotizing myopathy
81
Level of CK in Immune-mediated necrotizing myopathy
Significantly elevated
82
Condition with myocyte necrosis and regeneration, with minimal inflammatory infiltrate (macrophages present but not pathogenic)
Immune-mediated necrotizing myopathy
83
Two types of drugs that can cause Toxin mediated myopathy
Statins and Hydroxychloroquine
84
Drugs that cause proximal muscle weakness and type II fiber atrophy
Steroids
85
Binge drinking may result in this condition as well as myoglobinuria and acute renal failure
Rhabdomyolysis
86
Toxin mediated myopathy involving proximal muscle weakness with atrophy, myalgias, CK usually normal
Thyrotoxic myopathy
87
Level of CK in Thyrotoxic myopathy
Normal usually
88
Toxin mediated myopathy that can cause increased metabolic rate, weight loss, moist skin, diarrhea, palpitations, increased DTRs
Thyrotoxic myopathy
89
Toxin mediated myopathy involving proximal muscle weakness and CK elevation
Hypothyroid myopathy
90
Level of CK in hypothryoid myopathy
Elevated
91
Toxin mediated myopathy that can cause decreased metabolic rate, weight gain, dry skin, dry brittle hair, constipation, cold interolance, malaise, fatigue, decreased DTRs
Hypothryoid myopathy
92
Effect of Thyrotoxic myopathy on deep tendon reflexes
Increased
93
Effect of Hypothyroid myopathy on deep tendon reflexes
Decreased
94
Progressive muscle weakness due to nucleotide repeat disorder
Myotonic dystrophy
95
Inheritance pattern of Myotonic dystrophy
Autosomal dominant
96
Two main genes associated with Myotonic dystrophy
CTG repeats in DMPK gene
CCTG repeats in ZNF9 gene
97
Myotonic dystrophy may be caused by CTG repeats in this gene
DMPK (Myotonic dystrophy protein kinase)
98
Myotonic dystrophy may be caused by CCTG repeats in this gene
ZNF9 gene (Zn finger protein)
99
Condition characterized by slow relaxation of muscles after contraction and muscle degeneration
Myotonic dystrophy
100
Level of CK in Myotonic dystrophy
Not elevated (or minimal)
101
What age does Myotonic dystrophy present?
Any age, most patients normal at birth
102
Does Myotonic dystrophy show genetic anticipation?
Yes, is due to nucleotide repeat disorder
103
Does Myotonic dystrophy favor proximal or distal musculature?
Distal: forearms, hands, facial
104
Inherited form of muscle degeneration with fatty replacement
Muscular dystrophy
105
What is the inheritance pattern of Muscular dystrophy?
X linked recessive
106
Muscular dystrophy involves this gene
Dystrophin (anchoring protein to cytoplasmic structures to sarcolemma)
107
Dystrophin is an anchoring protein to cytoplasmic structures to sarcolemma, and is associated with this condition
Muscular dystrophy
108
Condition involving membrane destabilization and muscle fiber atrophy
Muscular dystrophy
109
Form of Muscular dystrophy involving an absence of dystrophin due to gene deletion
Duchenne MD
110
Form of Muscular dystrophy involving truncation of dystrophin
Becker MD
111
Condition with an abnormal sarcolemma-basal lamina interaction
Muscular dystrophy
112
Condition where dead muscle is replaced with fibroadipose tissue
Muscular dystrophy
113
In Duchenne Muscular dystrophy, what is the level of CK in the mother?
May be elevated
114
In Duchenne Muscular dystrophy, how does the child present at birth?
Normal - achieves early gross motor skills normally (sitting, rolling, standing)
115
Condition characterized by lordotic posture to stand, waddling gait, and Gower's sign (using arms to stand)
Duchenne Muscular dystrophy
116
Level of CK in Duchenne Muscular dystrophy
Very high
117
Condition of progressive muscular weakness that also effects cardiac and respiratory muscles
Death from respiratory compromise; pneumonia
Duchenne Muscular dystrophy
118
Life span of Duchenne Muscular dystrophy
25-30 years
119
Condition where muscle fibers degenerate, leading to increased fiber diameter variation, increased internal nuclei, and atrophy and death of fibers
Duchenne Muscular dystrophy
120
Condition with eventual replacement of dead muscle fibers with fat and fibrous tissue
Formerly enlarged muscles show "pseudohypertrophy" as they are fatty infiltrated
Duchenne Muscular dystrophy
121
Life span of Becker Muscular dystrophy
Death may be 40's or normal life span
122
Group of lower motor neuron diseases with muscle atrophy
Spinal muscular atrophy
123
Inheritance pattern of Spinal muscular atrophy
Autosomal recessive
124
Spinal muscular atrophy involves a mutation in this gene
Survival motor neuron gene (SMN1)
125
Mutation of Survival motor neuron gene (SMN1) is associated with this condition
Spinal muscular atrophy
126
This condition is the most common cause of infant mortality
Spinal muscular atrophy
127
Is SMA type 1 or 4 the least severe form of Spinal muscular atrophy?
Type 4 is least severe (1>2>3>4)
128
Allelic form of Spinal muscular atrophy that is the most common and most severe type
Werdnig-Hoffman disease (SMA1)
129
Werdnig-Hoffman disease is a form of this condition
Spinal muscular atrophy
(specifically involves SMA1)
130
In Spinal muscular atrophy, SMN1 mutation causes death of these cells
Anterior horn cells
131
Does Spinal muscular atrophy affect cranial nerves?
No, cranial nerves are spared
132
Flaccid paralysis, fascicultations, hyporeflexia and atrophy are clinical patterns of disease of this
Lower motor neurons
133
Morphology of this condition shows groups of atrophic muscle fibers, groups of normal or hypertrophic muscle fibers, and spinal cord shows loss of anterior horn neurons
Spinal muscular atrophy
134
What age does a patient with Werdnig-Hoffman disease (SMA1) present?
Begins soon after birth
Never learn to roll or sit
135
Spinal muscular atrophy form that begins soon after birth, never learn to roll or sit, and death by age 2 from respiratory compromise
Werdnig-Hoffman disease (SMA1)
136
Spinal muscular atrophy form with onset in infancy, patients do learn to sit
SMA2
137
Spinal muscular atrophy form with childhood onset, patients learn to walk
SMA3
138
Spinal muscular atrophy form with adulthood onset and normal milestones
SMA4
