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Year 2 Clinical Pathology > Diseases of muscle > Flashcards

Flashcards in Diseases of muscle Deck (43):
1

Give the 5 limited symptoms of muscle disease?

1) Wasting
2) Pain
3) Cramping
4) Fasciculations
5) Weakness

2

What are the 5 clinical muscle investigations?

1) Clinical examination (neurological)
2) Electromyograph
3) Nerve conduction studies
4) MRI
5) Serum/ Blood investigations

3

Give 3 common sights of muscle biopsy?

1) Deltoid
2) Biceps
3) Quadriceps

4

What does the term limb-girdle muscular dystrophy refer to?

Group of rare inherited disorders which predominantly affect the muscles around the shoulder girdle and hip girdle causing progressive muscle weakness eg. Duchenne muscular dystrophy

5

What is the pattern of inheritance of Duchenne muscular dystrophy?

X linked recessive

6

What are the 4 clinical features of Duchenne muscular dystrophy?

1) Relentlessly progressive muscle wasting
2) Chair-bound by 12 years
3) Proximal muscle weakness
4) Hypertrophy of calves

7

What is the pattern of inheritance of Emery-Dreifuss Muscular dystrophy?

X linked recessive

8

What are the 3 clinical features of emery-dreifuss muscle dystrophy?

1) Weakness of proximal arm and distal leg muscles
2) Early contractures
3) Cardiomyopathy

9

What is the pattern of inheritance of core disease?

Autosomal dominance

10

Core disease is a defect of what kind of protein?

Myofribilar and internal cytoskeletal proteins

11

Duchenne muscular dystrophy is a disease of which part of the muscle?

Plasma membrane

12

When is core disease usually detected?

When the child starts walking

13

How is core disease defined?

The central core is a well demarcated zone in the center of a muscle fibre, devoid of normal histochemical activity.

14

In core disease, cores only occur in what type of fibres?

Type 1 fibres

15

Nemaline myopathy is a disease of what proteins?

Myofibrillar and internal cytoskeletal proteins

16

Nemaline myopathy has what kind of inheritance pattern?

Autosomal recessive

17

What are the 4 clinical features of nemaline myopathy?

1) Generalised neonatal hypotonia
2) Resp insufficiency
3) High arched palate
4) Kyphoscolioisis

18

Malignant hyperthermia is a disorder of what part of the muscle?

Ion channels and ion transporters

19

What is malignant hyperthermia?

Abnormal susceptibility to certain inhalational anaesthetics which leads to a prolonged rise in intracellular calcium ions leading to rigid contractions and elevation in body temp

20

What are the muscle biopsy changes in malignant hyperthermia?

Mild and non specific

21

Myotonic dystrophies are due to what kind of genetic defect?

Repeat expansion

22

What is the pattern of inheritance of myotonic dystrophy?

Autosomal dominant

23

What is the age of onset of myotonic dystrophy?

20-30 years

24

What are the 2 clinical features of myotonic dystrophy?

1) Myotonia and progressive weakness of facial muscles
2) Cardiac conduction defects

25

Fascioscapulohumeral dystrophy has what kind of inheritance pattern?

Autosomal domiant

26

When does fascioscapulohumeral dystrophy present?

In early adult life

27

In addition to the skeletal muscle effects, what are the 3 other clinical features of fascioscapulohumeral dystrophy?

1) Myocardium affected
2) Progressive deafness
3) Retinal vasculopathy

28

What is the pathology of myasthenia gravis?

Autoimmune disease with Ab usually IgG, against the acetylcholine receptor

29

Is muscle biopsy an appropriate diagnostic test for myasthenia gravis? What changes may be seen on biopsy?

NOT an appropriate diagnostic test
May see mild changes of denervation atrophy

30

What is Eaton-Lambert Myasthenic Syndrome?

Rare, non metastatic manifestation of malignancy - usually oat cell carcinoma of the bronchus

31

Are any changes seen on biopsy in Eaton-lambert Myasthenic Syndrome?

No specific changes seen

32

Mitochondrial myopathies are related to what defect?

Respiratory chain defects

33

What are the 3 histological changes in mitochondrial myopathy?

1) Ragged red fibres
2) Accumulation of lipid on Oil red O stain
3) Biopsy may be relatively normal

34

What is dermatomyositis?

Inflammatory myopathy responsible for chronic debilitating disease, associated with a scaly rash

35

What is the most common type of drug-induced myopathy?

Steroid induced myopathy

36

Steroid induced myopathy leads to what 2 histological changes?

1) type 2 fibre atrophy
2) Increase in lipid droplets

37

What is the most serious drug induced myopathy caused by?

Heroin and ecstasy

38

What are the 3 clinical features of heroin and ecstasy induced myopathies?

1) Necrotising myopathy causing: rhabdomyolysis
2) Myoglobinuria
3) Renal failure

39

In addition to steroids, heroin and ecstasy what other drug can cause myopathy?

Statins

40

What is motor neuron disease characterised by?

Progressive disease of middle to old age which is characterised by widespread degeneration of motor neurons

41

What cells are involved in MND? 3

1) Anterior horn cells
2) Brain stem nuclei
3) Betz cells

42

What are the clinical features of MND?

Upper and lower motor neuron signs with wasting associated with spasticity and brisk reflexes

43

Which 3 endocrine disorders can lead to myopathies?

1) Glucocorticoid
2) Thyroid
3) Parathyroid
4) Growth hormone
5) Insulin

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