Muscular dystrophies Flashcards Preview

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Flashcards in Muscular dystrophies Deck (18):
1

DMD

X-linked recessive

2

Becker

X-linked recessive

3

Limb girdle MD

Autosomal recessive

4

Fascioscapular humeral

Dominant

5

Scapulohumeral

Autosomal recessive

6

Occulopharyngeal

Dominant

7

Myotonic dystrophy

Dominant (face, resp, limbs)

8

Muscle weakness, myotonia, non-muscle features

Autosomal dominant – Ch19 and Ch3

Adolescence – face, distal limbs

Later – respiratory muscles

Myotonic dystrophy (type 1 and type 2)

9

Mutations in dystrophin gene on long arm chromosome X

Alterations in anchorage of actin cytoskeleton to basement membrane

Fibres liable to tearing

Uncontrolled Ca2+ entry into cells

DMD
-alteration in achorage of actin cytoskeleton to basement membrane

10

Atrophy of type 1 fibres

Central nuclei

Ring fibres

Fibre necrosis

Fibrofatty replacement

Myotonic dystrophy

11

Muscle fibre necrosis & phagocytosis
Regeneration
Chronic inflammation and fibrosis
Hypertrophy

DMD

12

Endomysial lymphocytic infiltrate, invasion of muscle by CD8 + T lymphocytes

Segmental fibre necrosis

Polymyositis

13

Immune complex and complement deposition within and around capillaries within muscle

Perifascicular muscle fibre injury

B-lymphocytes and CD4 + T cells > cf polymyositis

Dermatomyositis

14

Neurogenic disorders of muscle

Small, angulated muscle fibres (adults)
Small, round muscle fibres (infants)
Target fibres
Fibre type grouping
Grouped atrophy

15

Progressive degeneration of anterior horn cells

Denervation atrophy, fasciculation and weakness

Motor neuron disease

16

Inherited; autosomal recessive – Ch5

Degeneration of anterior horn cells in spinal cord

Denervation of muscle

Types 1 - 4

Spinal muscular atrophy

17

Biopsy; fibrinoid necrosis of vessels
Serum contains pANCA (perinuclear antineutrophil cytoplasmic autoantibody)

PAN

18

Death in scleroderma?

Renal failure secondary to malignant hypertension
Severe respiratory compromise
Cor pulmonale
Cardiac failure or arrhythmias secondary to myocardial fibrosis