Muscle disorders Flashcards

1
Q

what is muscle supplied with and how

A

acetylcholine
by the lower motor neuron via the neuromuscular juction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what does acetylcholine do

A

causes depolarisation of the muscle cells leading to contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the definition of myopathy

A

disease of muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does myositis mean

A

inflammation of muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is myalgia

A

pain arising from muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is muscular dystrophy

A

a large group of hereditary disorders featuring abnormal muscle development of function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the clinical features of muscular dystrophy

A

vary depending on whether the condition is congenital or acquired and the distribution of the affected muscles
in general proximal weakness is experienced
gait can become waddling
pain may be present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are typical features of proximal weakness

A

issues when rising from sitting, climbing stairs, lifting arms above head
weakness is not fatigable
reflexes may still be present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is Gower’s sign

A

use of arms to provide support when standing
indicates weakness of pelvic girdle
typical in congenital muscular dystrophies such as Duchenne’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is Duchenne’s muscular dystrophy

A

x-linked condition where there is a mutation in dystrophin gene
manifestations typically emerge at 3-6yrs old

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the characteristics of Duchenne’s

A

initial pelvic girdle weakness, then shoulder, trunk, arms
eventual development of scoliosis
characteristic calf pseudohypertrophy (muscle infiltration by fat)
associated with cardiac respiratory failure
typically wheelchair dependent by teens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is scapular winging

A

sign of proximal weakness
seen when arms are outstretched forward

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is polymyositis

A

acquired inflammatory muscle disorder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the features of polymyositis

A

progressive proximal weakness
arises over weeks (subacute)
associated muscles pain
may be association with autoimmune disorder or cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the investigation results of polymyositis

A

creatine kinase is elevated
inflammatory pattern on muscle biopsy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is myalgia

A

aches and pains in muscles
pain is not accompanied by serious muscle damage
may be associated difficulty with movements (distinguish limitation due to pain from true weakness)

17
Q

What are the causes of myalgia

A

statins are a common cause, may lead to discontinuation
can be seen due to drug, infection, inflammatory disorders, after strenuous exertion

18
Q

what is rhabdomyolysis

A

severe complication of muscle disease
massive breakdown of muscle fibres, with leakage of myoglobin
accumulation of myoglobin in renal tubules leading to acute renal failure, which may require dialysis and become permanent

19
Q

what are the causes of rhabdomyolysis

A

drug toxicity, infection, crush injuries, burns, genetic muscle disorders, and sustained exertion in healthy people

20
Q

what are the diagnostic tests for muscular dystrophy

A

blood tests - creatine kinase elevated, lactate elevated in some conditions, genetics
electromyography can show specific features suggesting myopathy
MRI
muscle biopsy

21
Q

management of muscular dystrophy

A

multidisciplinary approach
focus on mobility, orthotics, nutrition, contractures, swallowing, cardiac and respiratory function

22
Q

management for acquired conditions due to muscular dystrophy

A

treat underlying causes where possible
supportive mobility, swallow and respiratory, management of complications