Skeletal muscles myopathies and dystrophies

Question 1

Which type of atrophy Involve type I and type II fibers ?

Answer 1

Denervation atrophy

Question 2

Complete loss of myofibrils – nuclei condense and aggregate -atrophy

Which type of atrophy?

Answer 2

Denervation atrophy

Question 3

End stage, muscle fibers disappear and replaced by adipose tissue

Which type of atrophy ?

Answer 3

Denervation atrophy

Question 4

Associated with prolonged immobilization

Which type of atrophy?

Answer 4

Disuse

Question 5

Involve type II fibers only

Which type of atrophy?

Answer 5

Disuse

Question 6

heterogeneous group of inherited disorders of muscle

Which type of dystrophy?

Answer 6

MUSCULAR DYSTROPHIES

Question 7

MUSCULAR DYSTROPHIEe begging ? Leads to?

Answer 7

beginning in childhood • It is lead to progressive weakness and muscle wasting.

Question 8

MUSCULAR DYSTROPHIES’s Histologically?

Answer 8

advanced cases muscle fibers undergo degeneration and are replaced by
fibrofatty tissue and collagen.

Question 9

Which feature distinguishes dystrophies from myopathies which also present with muscle
weakness.?

Answer 9

muscle fibers undergo degeneration and are replaced by

fibrofatty tissue and collagen.

Question 10

: X-linked Duchenne & Becker muscle dystrophy.

Mutation in?

Answer 10

Mutation in dystrophin

Question 11

autosomal limb-girdle muscular
dystrophy

Mutation in?

Answer 11

Mutation in Caveolin and Sacroglycan

Question 12

congenital muscular dystrophy.

Mutation in ?

Answer 12

Mutation in Laminin:

Question 13

two most common forms of muscular dystrophy are?|

Answer 13

Duchenne
muscular dystrophy (DMD) and Becker muscular dystrophy (BMD).

Question 14

most severe and common form of muscular dystrophy?

Answer 14

DMD

Question 15

clinically manifest by the age of 5 years. It leads to wheelchair
dependence by 10 to 12 years of age, and thereafter progresses persistently which type of dystrophy?

Answer 15

DMD

Question 16

is less common and much less
severe than DMD
?

Answer 16

BMD

Question 17

very large protein found in skeletal and cardiac muscle, brain, and
peripheral nerves ?

Answer 17

Dystrophin

Question 18

Muscle biopsy specimens from individuals with DMD show ?

Answer 18

little or no dystrophin

Question 19

Muscle biopsy specimens from individuals with BMB show?

Answer 19

, have diminished

amounts of dystrophin.

Question 20

This complex stabilizes
the muscle cell during contraction and may be involved in cell signaling through
interaction with other proteins. ?

Answer 20

dystrophin-glycoprotein complex .

Question 21

Dystrophin-glycoprotein complex defects are thought to make ?

Answer 21

muscle cells vulnerable to

transient membrane tears during contraction that lead to calcium influx.

Question 22

Dystrophin-glycoprotein complex defects are thought to make muscle cells vulnerable to
transient membrane tears during contraction that lead to calcium influx. • The result is ?

Answer 22

myofiber degeneration that with time outpaces the capacity for repair.

Question 23

important for cardiac muscle function; this
explains why cardiomyopathy eventually develops in many patients
?

Answer 23

dystrophin-glycoprotein complex

Question 24

X-Linked Muscular Dystrophy

Affected ? Carrier? Explain

Answer 24

In the affected families’ females are carriers; they are clinically
asymptomatic but often have elevated serum creatine kinase and show
minimal histologic abnormalities on muscle biopsy. • Female carriers and affected males who survive into adulthood are also at
risk for developing dilated cardiomyopathy

Question 25

histologic alterations in skeletal muscles affected by DMD and BMD are?

Answer 25

similar except that | the changes are milder in BMD

Question 26

Morphology of DMD and BMB? And later stages?

Answer 26

Variation in fiber size (2) Increased numbers of internalized nuclei (3) Degeneration, necrosis, and phagocytosis of muscle fibers (4) Regeneration of muscle fibers (5) Proliferation of endomysial connective tissue • In later stages the muscles eventually become almost totally replaced by fat and connective tissue. • Cardiac involvement, when present, consists of interstitial fibrosis

Question 27

symptomatic later in childhood or adolescence and progresses at a slower and more variable rate? Type of x-linked Muscular Dystrophy ?

Answer 27

BMB

Question 28

Many patients live well into adulthood and have a nearly normal life span. Type of x-linked muscular dystrophy?

Answer 28

BMD

Question 29

Cardiac involvement can be the dominant clinical feature and may result in death in the absence of significant skeletal muscle weakness. Type of x-linked muscular dystrophy?

Answer 29

BMD

Question 30

Duchenne MD clinically ?

Answer 30

Affect males, female are carrier. • Rapidly progressive skeletal muscle weakness (proximal more than distal) • Delayed developmental millstone • Frequent fall • Difficulty in walking, running and climbing stairs or hills. Cardiomyopathy • Mental retardation • Night blindness • Death 15-25 years due to respiratory or cardiac failure

Question 31

What is Gower sign and where does it occur ?

Answer 31

Difficulty in rising (Gower sign) standing up with the aid of hands pushing on knees • Characteristic gait shown by walking on their toes Duchenne MD:

Question 32

Calf pseudo dystrophy ( due to muscle fibrosis, not enlarged muscle fibers). • Serum CK very high Is shown in ?

Answer 32

Duchenne MD

Question 33

Investigations of MD?

Answer 33

• EMG: Myopathic pattern • Muscle biopsy • Genetic studies

Question 34

Muscle of shoulder and pelvic girdle or both with variable rates of progression Why type of MD?

Answer 34

Limb girdle MD

Question 35

Mutation Caveolin & Sacroglycan ? Type of MD?

Answer 35

Limb girdle MD

Question 36

Onset late first and second decade, sever disability within 20-30 years type of MD?

Answer 36

Limb girdle MD

Question 37

Diagnosis by exclusion | Type of MD?

Answer 37

Limb girdle MD

Question 38

Most common form of adult muscular dystrophy ?

Answer 38

Myotonic dystrophy

Question 39

AR (less frequently AD) type of MD?

Answer 39

Limb girdle MD

Question 40

AD which type of MD?

Answer 40

Myotonic dystrophy

Question 41

Slowing muscle relaxation once contracted | Type of MD/

Answer 41

Myotonic dystrophy

Question 42

bedside test of Myotonic dystrophy | ?

Answer 42

Difficulty in releasing hand grip

Question 43

Expansion of a CTG nucleic acid triplet | Type of MD?

Answer 43

Myotonic dystrophy

Question 44

``` Multisystem disease (smooth muscle, CNS, endocrine gland and eye) with major cardiac involvement. • Features: myotonia, muscle weakness, cataract, arrhythmias, diabetes and testicular atrophy ``` Type of MD?

Answer 44

Myotonic dystrophy

Question 45

Congenital myopathy | Onset?

Answer 45

Progressive, early onset

Question 46

Characterized by Floppy infant syndrome ( marked generalized hypotonia at birth). ?

Answer 46

Congenital myopathy

Question 47

Congenital myopathy | Characteristics?

Answer 47

CNS abnormality can occur. • Absent mitochondria • Normal serum CK

Question 48

Caused by Immune mediated antibodies (commonest) ?

Answer 48

Neuromuscular junction disorder: NMJ

Question 49

autoantibody to NMJ postsynaptic acetyle-choline receptors (Acho) Type ?

Answer 49

Mysthenia gravis

Question 50

autoantibody to NMJ presynaptic type?

Answer 50

Lembert Eaton syndrome

Question 51

Neuromuscular junction disorder: NMJ | Causes: ?

Answer 51

Immune mediated antibodies (commonest)  Mysthenia gravis: autoantibody to NMJ postsynaptic acetyle-choline receptors (Acho)  Lembert Eaton syndrome: autoantibody to NMJ presynaptic • Genetic defect in neuromuscular junction protein • Infections: bacterial toxins (clostridium tetani, Clostridium botulinum)

Question 52

Risk: • Mythenia gravis? Lambert Eaton syndrome:?

Answer 52

Mythenia gravis: associated with thymic abnormality • Lambert Eaton syndrome: associated with small cell lung cancer

Question 53

Autoimmune disorder • Age less than 40 years • Female more than male ?

Answer 53

Myasthenia gravis MG

Question 54

Pathophysiology: • Autoantibody against Ach. Receptor post synaptic – degradation , depletion and destruction of receptor – insufficient muscle contraction Type?

Answer 54

Myasthenia gravis MG

Question 55

Clinical feature: • Weakness involving the extraocular and facial muscles, muscles of extremities and other muscle groups • Ptosis or diplopia, difficulty in chewing, speaking or swallowing. ? Type?

Answer 55

Myasthenia gravis MG

Question 56

Complication of Myasthenia gravis MG | ?

Answer 56

respiratory failure.

Question 57

Investigation of Myasthenia gravis MG | ?

Answer 57

acetylcholine receptor antibody level

Question 58

Dramatic improvement with drugs? Myasthenia gravis MG

Answer 58

anticholinesterase activity

Question 59

Infectious myositis?

Answer 59

granulomatous myositis

Question 60

Non infectious myositis:?

Answer 60

autoimmune): 1. Polymyositis (PM) 2. Dermatomyositis (DM) 3. Inclusion body myositis (IBM)

Question 61

Patient with sarcoidosis will have ?

Answer 61

granulomatous myositis ( giant cell 0

Question 62

Mononuclear inflammatory cell infiltrate and many basophils regenerating fibers ?

Answer 62

Polymyositis

Question 63

Skin erthematous rash characteristics manifestation of ?

Answer 63

Dermatomyositis

Question 64

? Occurs in childhood as a for of fermatomyosis ?

Answer 64

Vasculitis