Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neurology > Neuromuscular Disorders > Flashcards

Neuromuscular Disorders Flashcards

1
Q

Describe the pathway that occurs over the neuromuscular junction

A
  1. AP
  2. Opening of voltage gated calcium channels
  3. Calcium influx
  4. Vesicles of ACh are released
  5. ACh diffuses across
  6. Binds to ACh receptors
  7. Permeable to sodium and potassium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the name of the enzyme that breaks down ACh

A

Acetylcholinesterase

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

How does curare work?

A

Occupies the same position as ACh receptor but does not open ion channel - no muscle contraction leads to no respiration

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

How does novichok work?

A

Inhibits cholinesterase

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

Name two presynapic disorders

A
  • Clostridium botulinum

- Lambert Eaton Myasthenic Syndrome

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

Describe clostridium botulinum

A

Organism present in soil and food that can infect wounds. Exotoxin inhibits ACh release by cleavage of pre-synaptic proteins involved in vesicle formation and blocks vesicle docking on presynaptic membrane - rapid onset weakness without sensory loss

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

What can botox be used for medically?

A

To relax muscles

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

Describe Lambert Eaton Myasthenic syndrome

A

Antibodies to presynaptic Ca2+ channels leads to less vesicle release

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

What is Lambert Eaton associated with?

A

Small cell carcinoma

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

State the treatment for Lambert Eaton syndrome?

A

Pyridostigmine

3.4- diaminopyridine

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

What is Myasthenia Gravis?

A

Autoimmune disorder where antibodies to acetyl choline receptors are produced, reducing the number of functioning receptors leading to muscle weakness and fatigue

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

Describe the pathophysiology of Myasthenia Gravis

A
  1. T cells are activated by unfolded AChR subunits
  2. B cells are stimulated to produce anti-AChR IgG antibodies
  3. Thymic cells are attacked by these antibodies and release anti-AChR immune complexes
  4. These activate antigen presenting cells
  5. Antibodies block the binding of ACh
  6. Ultimately causing destruction of muscle end plate folds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When do females tend to present with MG?

A

20s

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

When do males tend to present with MG?

A

70/80s

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

State the clinical features of MG

A

Weakness typically fluctuating and worse through the day

Most common - extraocular, facial, bulbar and proximal limb weakness

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

What is the acute treatment of MG?

A

Acetylcholinesterase inhibitor (pyridostigmine)
IV immunoglobulin
Thymectomy

17
Q

What is the chronic treatment of MG?

A

Steroids
Steroid sparing agents - azathioprine and mycophenolate
Immunomodulation
Plasma exchange/immunoglobulin

18
Q

What do people with MG die of?

A

Respiratory failure
Aspiration pneumonia
Side effects of immunosuppression

19
Q

Define fasciculations

A

Visible, fast, fine spontaneous twitch. May occur in healthy muscle - stress/caffeine/fatigue or in denervated muscle that becomes hyper-excitable

20
Q

Define myotonia

A

Failure of muscle relaxation after use due to defect in chloride channel - delay in release of grip

21
Q

What are the signs/symptoms of muscle disease?

A

Myalgia
Muscle weakness
Wasting
Hyporeflexia

22
Q

Give an example of immune mediated muscle disease

A

Dermatomyositis and polymyositis

23
Q

How is degenerative muscle disease characterised?

A

Thumb sparing

24
Q

What are muscular dystrophies?

A

Inherited, non-inflammatory progressive disease that have no central or peripheral nerve abnormality

25
Q

What is myotonic dystrophy?

A

Autosomal dominant, multisystem involvement, trinucleotide repeat disorder

26
Q

How does myotonic dystrophy present?

A

Myotonia, weakness, cataracts, ptosis, frontal balding, cardiac defects

27
Q

Name the infective causes of muscular dystrophies

A

Coxsacchie, uncooked pork (cistercercosis), borrelia

28
Q

What is rhabdomyolysis?

A

Dissolution of muscles, damage to skeletal muscle causes leakage of large quantities of toxic intraceullar contents into plasma

29
Q

In what circumstances can rhabdomyolysis occur?

A

Crush injuries, toxins, post convulsions, extreme exercise, alcoholic collapse, acute renal failure, DIC

30
Q

What is the triad of symptoms in rhabdomyolysis?

A
  1. Myalgia
  2. Muscle weakness
  3. Myoglobinuria
31
Q

What is sarcopenia?

A

Loss of skeletal muscle mass and function, primarily a disease of the elderly

32
Q

Describe the muscle power grading

A

0 - no movement
1 - flicker when attempting to contract
2 - some movement if gravity removed
3 - movement against gravity but not resistance
4 - movement against resistance but not full strength
5 - normal strength

Neurology (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions