Dd&t3 Diseases Of The Muscle

Front 1

Neurogenic atrophy: 2 causes

Back 1

Loss of anterior horn cells
Loss of axons

Front 2

Neurogenic atrophy: pathologic changes of denervation?

Back 2

Small angular fibers
Group Atrophy
Fiber type grouping

Front 3

What causes type 2 fiber atrophy?

Back 3

Disuse
Corticosteroids
Debilitating disease

Front 4

Define muscular dystrophy. What is it characterized by?

Back 4

Progressive hereditary degenerative disease of muscle.

Degeneration of muscle fibers

Front 5

Duchenne muscular dystrophy: define.

Back 5

Severe, generalized muscular dystrophy with a rapid progression, strong familial pattern, and occurrence predominantly in males.

Front 6

DMD: general heredity.

Back 6

Strong familial pattern, but one third of cases may result from spontaneous mutation.

Front 7

Specific heredity of DMD

Back 7

X-linked recessive

Front 8

DMD: affect on muscles.

Back 8

Proximal weakness
Pseudohypertrophy of calf muscles
Myocardial involvement, CPK elevated

Front 9

DMD: lifespan? cause of death?

Back 9

Death in ealry 20s

Death due to respiratory or cardiac failure

Front 10

DMD: age of onset? muscles affected first?

Back 10

Symptoms generally appear before age 4

Pelvic muscles affected first

Front 11

DMD: initial symptoms?

Back 11

Difficult walking, running, rising from sitting position

Front 12

DMD: movement sign?

Back 12

Gower's sign

Front 13

Muscular dystrophy: pathology

Back 13

Atrophic rounded fibers
Degeneration
Hypertrophic fibers
Central nuclei/fiber splitting
Increased CT

Front 14

Cause of DMD

Back 14

Absence of dystrophin, a protein

Front 15

Myotonia: define. What are the 3 types?

Back 15

Disorder characterized by an impaired ability to relax a previously-contracted muscle.

Myotonia congenita
Myotonic dystrophy
Paramyotonia

Front 16

Myotonic muscular dystrophy: inheritance? onset?

Back 16

Autosomal dominant

20-40 yo

Front 17

Myotonic muscular dystrophy: other abnormalities?

Back 17

Cataracts/endocrine abnormalities
Cardiomyopathy
Frontal alopecia/gonadal atrophy
Abnormal glucose tolerance

Front 18

Defect in myotonic muscular dystrophy

Back 18

cAMP dependent protein kinase, resulting in abnormal phosphorylation of ion channels

Front 19

Myotonic muscular dystrophy: clinical features?

Back 19

Myotonia
Distal weakness

Front 20

Myotonic muscular dystrophy: pathology?

Back 20

Dystrophic features
Central nuclei

Front 21

What is the name of the inflammatory myopathies with unknown etiology?

Back 21

Polymyositis

Front 22

Polymyositis: age of onset? muscle changes?

Back 22

20-50 yo

Proximal weakness

Front 23

Polymyositis: course? other involvement of the body?

Back 23

Course variable

Can have skin involvement (rash)
May be associated with collagen vascular diseases and paraneoplastic syndromes

Front 24

Polymyositis: lab changes?

Back 24

CPK, ESR elevated

Front 25

Polymyositis: treatment?

Back 25

Steroids

Front 26

Polymyositis: pathology?

Back 26

Degeneration/regeneration
Inflammation
Atrophy
Skin involvement: nonspecific chronic inflammation

Front 27

Example of metabolic myopathy (general)

Back 27

Glycogen storage diseases

Front 28

McArdle's disease: defect?

Back 28

Myophosphorylase absent

Front 29

McArdle's disease: inheritance? age of onset?

Back 29

Autosomal recessive

Usually begins in childhood

Front 30

McArdle's disease: symptoms? lab changes?

Back 30

Pain/cramps/stiffness
Weakness
Symptoms related to exercise

Myoglobinuria

Front 31

McArdle's disease: pathology?

Back 31

Vacuolar myopathy

Front 32

Myasthenia gravis: cause?

Back 32

Autoimmune - antibodies to acetylcholine receptor

Front 33

Myasthenia gravis: diagnosis? treatment?

Back 33

Anticholinesterase drugs used for both

Front 34

Myasthenia gravis: symptoms?

Back 34

Weakness/fatigue after sustained muscle activity

Abnormal muscle rigidity

Front 35

Myasthenia gravis: age of onset? course?

Back 35

3rd-6th decades

Course variable; death from respiratory failure or aspiration pneumonia

Front 36

Myasthenia gravis: associated abnormalities? molecular biology associated with that?

Back 36

75% have thymic abnormalities

Thymic T cells may activate B cells to produce antireceptor antibodies

Front 37

Myasthenia gravis: pathology?

Back 37

Focal lymphocytic infiltrates
Focal type 2 fiber atrophy
Generalized atrophy (late)

Front 38

Staining of muscle fibers

Back 38

Type 1 - low ATPase
Type 2 - high ATPase