Muscle Flashcards
1
Q
What is the clinical picture of Trichinosis?
A
Puffy face with tender muscles. There is ocular muscle weakness, tongue weakness, masseter and pharyngeal muscle weakness
2
Q
What is the most realiable confirmatory test for a diagnosis of Trichinosis?
A
Biopsy of about 500mg of muscle demonstrating, encysted larvae, eosinophilia and inflammatory myopathy
3
Q
What is the treatment for Trichinosis?
A
Albendazole/Thiabendazole + Prednisone
4
Q
What parasite causes the pseudohypertrophy of thigh and calf muscles?
A
Cysticercosis
5
Q
What is the main differential for HIV myopathy and how to distinguish between the 2?
A
Zidovudine induced myopathy showing ragged red fibers on biopsy. HIV myopathy is also associated with severe generalized muscle weakness that characterizes advanced cachectic AIDS
6
Q
T or F. HIV myopathy has NORMAL CK enzymes
A
T
7
Q
What factors favor IBM over polymyositis?
A
- Onset more than 50
- Normal CK
- Aberrant pattern: early wrist, finger flexor, quad, ankle dorsiflexion involvement
8
Q
In polymyositis what percentage of patients have sparing of facial and distal muscles?
A
75%
9
Q
What are the skin changes that precede muscle weakness in Dermatomyositis?
A
Erythema, maculopapular eruption, scaling eczematoid dermatitis, exfoliative dermatitis
10
Q
Where the the ff manifestations of DM located?
- V sign
- Heliotrope rash
- Gottron papules
- Shawl sign
A
- neck and upper shoulders
- eyelids, bridge of nose, cheeks, forehead
- papules on elboes, knuckles, IP joints
- shoulders and upper arms
11
Q
What tumors are most associated with PM and DM?
A
Men: Lung and colon
Women: Breast and ovarian
12
Q
What treatment for RA increases the incidence of or precipitates a myositis?
A
d-penicillamine
13
Q
20 percent of PM and DM have concomittant: arthritis, Raynaud syndrome, mechanic’s hands– what is the antibody associated with these synthetase syndrome
A
anti Jo1
14
Q
What are the typical myopathic findings in EMG?
A
- brief action potentials of low voltage
- fibs
- polyphasic units
- trains of positive sharp waves
- myotonic activity
15
Q
How to differentiate between the pathologic findings in DM vs PM
A
DM is characterized by perifascicular atrophy in contrast to evident necrosis of single fibers of PM
DM microvascular changes are also seen
PM inflammatory infiltrates by mononuclear cells are found scattered throughout the muscle unlike DM perimysial connective tissure only
16
Q
Which one PM or DM is mediated by humoral response? cytotoxic response?
A
PM Cytotoxic
DM Humoral
17
Q
What is thetreatment for DM and PM?
1st line
2nd line
Acute and severe cases
A
1st line: 1g per kg of prednisone. Taper when Cks are normal and weakness has subsided
2nd line: Methotrexate and Azathioprine
Acute and severe: MPPT and IVIG
18
Q
What is the most common inflammatory myopathy in patients older than 50 years old?
A
Inclusion body myositis
NOT INCLUSION BODY MYOPATHY!!!!
19
Q
What is the pattern of weakness in inclusion body myositis?
A
Distal in the arms, proximal and distal in the legs
MORE FOCAL compared to DM/PM
Selective weakness of the flexor pollicis longus
20
Q
Which has depressed reflexes at the onset? PM/DM/IBM
A
IBM
21
Q
What is the characteristic histopathologic findings in inclusion body myositis?
A
Intracytoplasmic, subsarcolemmal vacuoles and eosinophilic inclusions in both the cytoplasm and nuclei of degenerating muscle fibers
Save from this the muscle looks like less severe PM with CD8 T cells
22
Q
T or F CKs can be high in muscular dystrophy
A
T! In some…
23
Q
How to differentiate polymyalgia rheumatica with PM DM?
A
NORMAL CK and biopsy
Rapid response to prednisone WITHIN 48 HOURS!
HIGH sedimentation rate more than 65
Related to temporal arteritis
24
Q
Which among these are characteristic of Duchenne/Becker OR Emery Dreifuss OR both
- Onset at the 1st decade
- X linked RECESSIVE
- Proximal muscles
- Cardiac arrhythmias
- Greated CK elevation
A
- DB
- BOTH
- BOTH
- ED>DB
- DB
25
What muscular dystrophy has its onset on the 2nd to 3rd decade, with a dysferlin pathology and begins in the DISTAL MUSCLES
Miyoshi myopathy
26
What percentage of Duchenne muscular dystrophy HAVE NO HISTORY OF THE DISEASE?
30%
27
In duchenne what is affected first? Pelvicrural OR pectoral girdle OR bulbar?
Pelvicrural then pectoral girdle
The ocular facial and bulbar muscles are spared
28
Becker muscular dystrophy patients have normal mentation and may walk into adulthood. T or F?
T
29
What is the histopathologic picture of duchenne and becker?
Segmental degeneration and phagocytosis of single muscle fibers and evidence of regenerative activity --> advanced; loss of muscle fibers, residual fibers of larger and smaller size, fibrosis and increase in lipocytes
30
T or F dystrophin is absent in patients with becker and duchenne
F. Present to some extent in Becker
31
What is dystrophin attached to inside and outside?
Attached to F actin of cytoskeleton inside and outside attached to dystrophin associated proteins and glycoproteins that link the sarcolemmal membrane to the extracellular matrix
32
What protein is deficient in emery dreifuss and what is its function?
Emerin-- part of the nuclear membrane
33
Which of the ff are true of the Landouzy Dejerin Muscular Dystrophy?
1. May be associated with congenital muscle absence
2. Frequent cardiac involvement
3. Caused by deletions at the tip of chromosome 6p interfering with chromatin structure
4. Popeye arms
1. T
2. F
3. F. gene 4q
4. T
AKA Fascioscapulohumeral dystrophy
34
In Kearns-Sayre syndrome what is the first muscle to be affected
AKA as progressive external ophthalmoplegia
The eyelid levators are the first to be affected causing ptosis followed by EOM paralysis
Other features of KS syndrome include pigmentary retinopathy-- less commonly, bilateral sensorineural deafness, heart involvement (cardiomyopathy, cardiac conduction defect), central nervous system involvement (cerebellar ataxia, dysarthria, bilateral facial weakness, intellectual deficit), skeletal muscle myopathy, intestinal disorders, endocrine disorders (delayed puberty, hypoparathyroidism, diabetes), and renal failure.
35
In the Kearns Sayre syndrome hutchinsonian facies seen because of?
In an attempt to raise the eyelids, the forehead is wrinkled and the head is thrown back
36
What genes are involved int he developement of the Kearns Sayre syndrome?
POLG
ANT1
Twinkle
37
At what age do the ff present?
1. Oculopharyngeal dystrophy
2. Progressive extrenal ophthalmoplegia
3. Fascioscapulohumeral MD
4. Emery dreifuss
5. Becker MD
6. Duchenne MD
1. 6th to 7th decade
2. Usually in adolescence
3. 6-20 years old
4. VARIES: Childhood, late adol, adulthood
5. usually at 12 years old
6. 3-6 years old
38
What is the trinucleotide repeat sequence at chromosome 19q causes myotonic dytrophy?
CTG in the DMPK gene chromosome 19q-- intron therefore not coding for proteins
Normal: 5-30 CTG repeats
MD: 50-20,000
39
What are the first muscles affected in the myotonic dystrophy type 1?
The small muscles of the hands along with extensor muscles of the hands along with the extensor muscles of the forearms
BUT in some ptosis of the eyelids and thinness and slackness of the facial muscles may be the earliest signs
RECALL THAT IBM ALSO PRESENTS WITH INITIAL ATROPHY OF HAND MUSCLES--both conditions present with distal weakness that is "atypical" of myopathies.
40
What non muscular tissues are affected in myotonic dystrophy type 1?
Lens of the eye-- 90% OF PATIENTS WILL HAVE LENTICULAR OPACITIES
brain--mild to moderate degrees of developmental cognitive delay
testicle atrophy
frontal alopecia
esophagus
heart
skin
41
Define myotonia
Prolonged idiomuscular contraction following brief percussion or electrical stimulation and in the delay of relaxation after strong voluntary contraction
42
What muscles show myotonia at best in MD1?
Tongue and flexors of fingers
43
What are the pathologic features of MD1?
1. Hypertrophy of type 1 fibers
2. Peripherally placed sarcoplasmic masses and circular bundles of myofibrils (ringbiden)
3. Central nuclei much like myotubular myopathy
44
What protein is missing in miyoshi dystrophy?
Dysferlin responsible for calcium mediated membrane repair
45
What is the pattern of miyoshi myopathy?
Distal myopathy
46
Polymyositis can be distinguished from dystrophy on the basis of CK elevation except in which dystrophies that also present with elevated CKs
Duchenne and Miyoshi
47
T or F Prednisone trial for 6 months can distinguish between polymyositis and dystrophy
T. If it improves then PM!
48
How to distinguish between SMA and myositis?
EMG
49
What is the dose of prednisone for muscular dystrophy?
0.75mg per kg
50
What drug has been shown to reduce myotonia?
Mexiletine
51
ALL THE GLYCOGENOSES ARE INHERITED AS AUTOSOMAL RECESSIVE TRAITS EXCEPT FOR?
X linked phosphoglycerate kinase deficiency
52
What is the enzyome missing in patients with
1. Pompe disease
2. McArdle Disease
3. Tarui
4. Cori forbes
5. Andersen disease
1. Acid maltase
2. Myophosphorylase
3. Phosphofructokinase
4. Debranching enzyme
5. Branching enzyme
53
What is the treatment for Pompe disase?
What are the 3 kinds of acid maltase deficiency?
Recombinant acid alpha-glucosidase
1. Infant (Pompe) MOST SERIOUS
2. Child
3. Adult
54
What are the similarities in McArdle and Tarui disease in terms of clinical manifestations?
What are the deficient enymes in McArdle and Tarui?
Development of muscle cramps AFTER EXERCISE and second wind after increasing cardiac output and substituting fatty acids for glucose.
There is a physiologic contracture during exercise-- myoglobinuria can also occur
McArdle myophosphorylase aka known as glycogen phosphorylase
Tarui Phosphofructokinase
55
What type of Carnitine Palmitoyltransferase Deficiency causes necrosis of muscle fibers?
Type 1 causes necrosis of muscle fibers
IIa lipid bodies accumulate in the liver
IIb excess lipid in the heart liver kidneys muscle
56
What are the most weakened muscles in Chronic Thyrotoxic myopathy?
Basedow paraplegia: Pelvic girdle and thighs
NB: This can be present in patients with NO OVERT signs of thyrotoxicosis
57
What treatments are available for thyrotoxic hypokalemic periodic paralysis?
1. Potassium chloride 100-200mg to terminate the disease
| 2. Propanolol 160mg daily in divided doses
58
What percentage of MG patients have Hyperthyroidism?
5%
Those with hyperthyroidism is 20-30x more likely to develop MG
59
What parts become weak with corticosteroid induced myopathies?
Limb and girdle musculature
60
What muscle fibers are affected with steroid myopathy?
2b
61
What drug is most associated with critical illness polyneuropathy?
Neuromuscular blocking agents
Steroids are also associated with acute myopathy
62
What mushroom causes acute necrotizing myopathy?
Amanita phalloides
63
What acute necrotizing myopathy is PAINLESS?
Hypervitaminosis of vitamin E
64
What drugs cause amphiphilic cationic drug myopathy?
1. Chloroquine
2. Amiodarone
3. Perhexiline
Also cause sensoriumotor neuropathy
65
What two drugs cause antimicrotubular myopathy and peripheral neuropathy?
Vincristine and Colchicine
66
Among the toxin induced myopathies almost all have increased creatinine EXCEPT FOR?
Chronic steroid myopathy
| Mitochondrial myopathy
67
What drugs can cause mitochondrial myopathy?
Zidovudine and Germanium
68
What treatment can be given for patients wiy myoglobinuria?
1. Alkalinization of urine
| 2. Diuresis with mannitol or loop diuretics
69
What gene confers a risk for statin induced myopathy?
SLCO1B1 that codes for an organic anion-transporting polypeptide
70
What drug for gout causes an acute necrotizing myopathy?
Colchicine
Interferes with the polymerization of micrtotubules in muscle and nerve
71
Central core disease, Nemaline rod myopathy and Myotubular myopathy all present in what decade of life?
1st
72
What is the level of CKs in congenital myopathies?
Normal or slightly elevated
73
All central core myopathy patients have a tendency to develop what disease?
Malignant hyperthermia
74
How to differentiate central core myopathy and nemaline rod myopathy clinically?
Facial, lingual and pharyngeal muscles are involved in Nemaline but spared in central core
75
What disease make a person more prone to cramping?
Motor system disease
Hypothyroidism
Chronic polyneuropathy
Nerve or root injury
76
What are treatments for cramping?
Quinine sulfate
Diphenhydramine
Procainamide
77
What composes the Satoyoshi syndrome?
```
Widespread cramping
Alopecia
Amenorrhea
Malabsorption
Epiphyseal destructoin
```
YOUNGER THAN 20 YEARS OLD
78
What is the characteristic pattern of weakness in IBM?
Usually more focal than PM and DM (may present as isolated weakness of the flexor policies longus, quads and neck extensors)-- distal in the UE BOTH distal and proximal in the LE
79
What limb girdle muscular dystrophy type mimics:
1. Emery Dreifuss
2. Becker/Duchenne MD
1. LGMD 1B
| 2. LGMD 2C-F
80
What LGMD has a common gene/ protein deficiency affected with Miyoshi myopathy? What is this protein?
LGMD 2b, Dysferlin
81
Which among the dystrophies has onset at 6th to the 7th decades?
Oculopharyngeal dystrophy
82
Which of the dystrophies has massive CK elevation up to 50x?
Miyoshi myopathy and Becker/Duchenne
83
Identify mode of inheritance
1. LGMD 1
2. LGMD 2
3. Duchenne
4. Emery dreifuss
5. Becker
1. LGMD 1 AD
2. LGMD 2 AR
3. Duchenne XRec
4. Emery dreifuss XRec
5. Becker XRec
84
What muscles are weak in a patient with a waddling gait?
Bilateral gluteus medius
85
What are the ECG features of Duchenne muscular dystrophy?
Prominent on the right precordial leads and deep Q waves in the left precordial and lim leads
86
How does one distinguish limb girdle muscular dystrophy 2c-F from Duchenne muscular dystrophy?
Mode of inheritance: X linked recessive for Duchenne while autosomal recessive from LGMD 2. LGMD2 resembles a severe Duchenne muscular dystrophy.
87
What type of limb girdle muscular dystrophy has its defect in the dystrophin associated glycoproteins? alpha beta gamma delta
LGMD 2C-F aka severe childhood autosomal recessive muscular dystrophy
(Maybe that's why they mimic each other?)
88
What is the inheritance pattern of PEO?
a. AR
b. AD
c. Maternal mitochondrial pattern
A and C are the most common but all can occur depending on the gene effected
89
What 3 conditions come to mind in a patient with difficulty in both eye opening and closure?
1. Progressive external ophthalmoplegia
2. MG
3. Myotonic dystrophy
90
The facial muscles masters, SCMs, deltoids and the peronei are variable weak and wasted in 25% of cases of PEO. How can be PEO be distinguished from other entities that involve eye movement and other muscles?
Ptosis and ocular paralysis precede involvement of other muscles by many years
91
What muscular dystrophy presents with bilateral ptosis and dysphagia?
Oculopharyngeal dystrophy
92
Identify the inheritance pattern:
6. Myotonic dystrophy
7. Miyoshi myopathy
8. Oculopharyngeal dystrophy
9. Progressive external ophthalmoplegia
10. Limb girdle muscular dystrophy
6. Myotonic dystrophy AD
7. Miyoshi myopathy AR
8. Oculopharyngeal dystrophy AD
9. Progressive external ophthalmoplegia AD/AR/Mitochondrial
10. LGMD: Type 1 is AD Type 2 is AR
93
Describe MD facies of hatchet face with a swan neck.
Ptosis, frontal baldness, wrinkled forehead with exaggerated forward curvature of the neck
94
Why do MD patients have:
1. Nasal voice
2. Megacolon
3. Problems giving birth
4. Chronic bronchitis
5. Prolonged PR interval
1. Pharyngeal muscle weakness
2. Loss of smooth muscles
3. Uterine muscle weakness
4. Diaphragmatic weakness and alveolar hypoventilation
5. Myocardium involvement
95
How does one differentiate MD from emery dreifuss if cardiac involvement is found in both? Bases: Contractors and inheritance
ED: + Contractures X rec
MD: - Contractures AD
But of course the myotonia of MD will set it apart
96
What are the 4 striking features of MD?
1. Ptosis with limb weakness
2. Cardia-autoimmune features
3. Myotonia
4. Dystrophic change in non muscular tissues
97
What percentage of MD patients have lenticular opacities?
90% on slit lamp
98
What feature of MD is not present in congenital MD?
Myotonia.
There is profound hypotonia, drooping eyelids, carp mouth, open jaw
99
What is the inheritance pattern of the distal muscular dystrophy Welander? How does the disease progress?
Autosomal dominant!
VERY SLOWLY. After 10 years weakness of proximal muscles may also be seen
100
What type of LGMD mimics Miyoshi myopathy in terms of gene and protein affected?
LGMD 2B-- BUT THE distribution of weakness is DIFFERENT
101
What 3 points, taken together can distinguish polymyositis from dystrophy?
1. Course: PM is much faster
2. Level of CK and aldolase: Only Duchenne and Miyoshi have high CKs among the dystrophies
3. Trial of prednisone will improve PM but not dystrophy: do for SIX MONTHS
102
What are the 3 avenues for treatment of dystrophy?
1. Steroids
2. Injection of human myoblasts
3. Injection of an antisense oligonucleotide to accomplish exon skipping resulting in functional dystrophin
103
What are the findings in the adult acid maltase deficiency?
CKs
EMG
CKs normal or slightly increased
EMG brief motor unti potentials, high frequency discharges, occasional myotonic discharges WITHOUT CLINICAL evidence of myotonia
104
What form of acid maltase deficiency is worst? Infant, Childhood, Adult?
Infant! Pompe Disease
105
What is the biochemical basis of second wind in Tarui and McArdle disease?
Increase in cardiac output and substituting free fatty acids and blood borne glucose for muscle glycogen
106
Which one? Tarui or McArdle
| Prevention of the conversion of glycogen to glucose 6 phosphate
McArdle
Enzyme: Myophosphorylase
Tarui: G6P to G1P by phosphofructokinase
107
How does the forearm ischemic test identify patients with Tarui or McArdle?
1 min vigorous hand exercise then BE at 1 min and another at 3 min-- if lactate does not increase then +
108
What drink are given to patients with McArdle and Tarui?
Sucrose 75g drink
109
What are the 2 functions of carnitine in the metabolism of fatty acids?
1. Transport long chain fatty acylcoenzyme A from the cytosol compartment of the muscle fibers into the mitochondria where they undergo beta oxidation
2. Prevent the intramitochondrial accumulation of acyl-CoAs protecting the muscle cells from the membrane destabilizing effects of theses substances
110
Differentiate the inheritance pattern and treatment for:
1. Primary systemic carnitine deficiency
2. Carnitine palmitoyltransferase deficiency
1. l-carinitine for cardiomyopathy, AR
2. high carbohydrate low fat diet ingestion of frequent meals and additional carbs before and during exercise, AR
Carnitine is linked to the fatty acid by CPT1 so they can have cross the outer membrane of the mitochondria. Once inside they are linked by to CoA for beta oxidation. Carnitine is recycled back to the outer membrane.
111
What are the 3 manifestations of fatty acid metabolic pathway deficiencies?
1. Encephalopathic syndrome in infancy or childhood, SIDS
2. Myopathic syndrome, infancy to adulthood, with or without cardiomyopathy
3. Rhabdomyolysis after an episode of sustained physical activity and fasting-- begins in the second decade of life
112
What are the usual muscles that show atrophy in chronic thyrotoxic myopathy?
Shoulder and hands
113
T or F: The diagnosis of chronic thyrotoxic myopathy is mainly clinical, classic signs of hyperthyroidism are a requirement for diagnosis.
F
114
What is the most important muscle abnormality in hypoparathyroidism?
Tetany
115
What congenital myopathy presents in the 1st decade with proximal and distal weakness with ophthalmoparesis and ptosis?
Myotubular myopathy-- X-linked condition
116
What is special about these muscular dystrohpies?
1. LGMD1A
2. LGMD1B
3. LGMD2B
4. LGMD2C-F
5. LGMD2A
1. LGMD1A: AD Distal more than proximal; Allelic with myofibrillar myopathy
2. LGMD1B: AD Similar to emery dreifuss
3. LGMD2B: Allelic to Miyoshi myopathy-- dysferlin is affected
4. LGMD2C-F: Same phenotype as Becker dystrophy
5. LGMD2A: Accounts for 40% of LGMD patients-- calpainopathy
117
What is atypical about Miyoshi myopathy, Welander myopathy, TIbial muscular dystrophy?
Distal weakness first before proximal
118
What is the second common muscular dystrophy in Japan?
Fukutin Congenital muscular dystrophy: severe mental retardaiton and developmental anomalies of the cortex
119
What Congenial muscular dystrophy?
1. Presents with hypotonia, diffuse weakness, mental retardation, cataracts, retinal dysplasia, retinitis, glaucoma (2); Elevated CKs
2. No elevatin in CK; restricted flexion of the neck and spine, multiple contractures, spared cognition.
1. Muscle eye brain disease OR Walker Warburg disease
| 2. Rigid spine syndrome
120
Dfx polymyositis from musucular dystrophy.
1. Polymyositis is faster
2. Immunostaining
3. Trial of prednisone for 6 months-- if there is imporvement then this is PM
121
What is the treatment for muscular dystrophies?
1. Prednisone 0.75mg per kg daily may retard progression for duchenne
2. Mexiletene for myotonic dystrophy
122
What do patients with primary systemic carinitine deficiency die of?
Cardiomyopathy
123
What is the treatment for carnitine palmitoyltransferase deficiency?
High carbohydrate
Low fat diet
Additional carbs before and during exercise
Bezafibrate for CPT II
124
What percentage of patients with myasthenia gravis also have hyperthyroidism?
5%
125
What are the muscle fiber types that atrophy during corticosteroid myopathy?
Type 2b
126
What part of muscle is depleted in steroid induced myopathy?
Myosin
127
What electrolyte should be checked for patients with solitary bone cysts who present with acute myopathic weakness?
Phosphorous
128
What is the most common cause of arthrogryposis?
What are other causes?
Werdnig Hoffman Disease
(SMA type 1)
```
Myotonic dystrophy
Congenital myasthenia
Congenital myopathy
Congenital muscular dystrophy
Neonatal neuropathy
Prader Willi syndrome
Amyoplasia
```
129
What is the key differentiating feature of congenital structural myopathies compared to muscular dystrophy?
Lack of progression or VERY SLOW progression
130
What gene or chromosome is defective in central core disease?
This makes the patient susceptible to?
Ryanodine receptor
Malignant hyperthermia from anesthetics later in life.
131
Treatment for myositis ossificans?
EHDP
| Ethane 1 hydroxy 1,1-diphosphonate to inhibit deposition of calcium phosphate
