Brainscape's Knowledge GenomeTM

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


See full index

Nervous System > Muscle and Nerve Disease > Flashcards

Muscle and Nerve Disease Flashcards

1
Q

What is the change in energy that occurs in muscle?

A

Chemical energy -> mechanical energy

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

What are the four factors responsible for the transformation of energy in muscles?

A
  • Structural
  • Contractile mechanism
  • Excitation-contraction coupling (ion channels)
  • Energy system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the general symptoms for muscle disease?

A 
• Weakness of skeletal muscle 
• Short of breath (respiratory muscles)
• Poor swallow (aspiration)
• Cardiomyopathy
• Cramp, pain, stiffness, myoglobinuria 
(Babies: poor suck / feed / failure to thrive / floppy)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the investigations used for muscle diseases?

A 
• History and examination 
• Creatine kinase (CK)
• Electromyography (EMG)
• Muscle biopsy;
o Structure 
o Biochemistry 
o Inflammation
• Genetic testing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is an Elcetromyography (EMG)?

A

Measures muscle response or electrical activity in response to a nerve’s stimulation of the muscle. The test is used to help detect neuromuscular abnormalities.

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

What are the general signs of muscle diseases?

A
  • Wasting / hypertrophy
  • Normal or reduced tone and reflexes
  • Motor weakness (NOT sensory)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the two classification of muscles diseases?

A

Congenital or acquired

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

What are the causes of congenital muscle diseases

A 
Attack components of muscle responsible for energy transformation 
• Structural -> muscular dystrophies 
• Contractile -> congenital myopathies 
• Coupling -> channelopathies
• Energy -> enzymes / mitochondria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the causes of acquired muscles diseases?

A
  • Metabolic (Ca, K)
  • Endocrine (thyroid, adrenal, vit D)
  • Inflammatory muscle disease
  • Iatrogenic: medication (steroids / statins)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is responsible for the stability of the sarcolemma (membrane) in Myocytes?

A

Dystrophin protein links intracellular (myocyte) actin to sarcoglycan complex in the membrane, which is anchored to the extracellular matrix around the myocyte.

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

What occurs in muscular dystrophy?

A

No support from dystrophin protein, so the sarcolemma wilts and becomes unstable. Over time, cellular proteins like creatine kinase (CK) escape the damaged cell, and Ca enters. This leads to cell death.

In the short term, muscle regeneration occurs creating muscle fibres of different lengths. In the long term, it leads to muscle atrophy and infiltrates by fat and fibrotic tissue, leaving muscles very weak.

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

Name five different types of muscular dystrophies

A
  • Duchenne’s MD (no dystrophin)
  • Becker’s MD (dystrophin abnormality)
  • Faciosacpulohumeral MD
  • Myotonic dystrophy (cataracts)
  • Limb-Girdle MD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What occurs in channelopathies?

A

Disorders of Ca, Na, K and Cl channels.

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

Name four different types of channelopathies

A
  • Familial hypokalemic periodic paralysis (all Ca, Na, K)
  • Hyperkalemic periodic paralysis (Na)
  • Paramyotonia congenita (Na)
  • Myotonia congenita (Cl)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the types of metabolic muscle diseases?

A
  • Disorders of carbohydrate metabolism (glycogenosis)
  • Disorders of lipid (fatty acid) metabolism
  • Mitochondrial myopathies / cytopathies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are two types of inflammatory muscle diseases (myositis)?

A
  • Polymyositis

* Dermatomyositis

17
Q

What are the clinical features of myositis?

A
  • Acute or subacute
  • Painful weak muscles
  • Characteristic rash of derma.
  • Any age
18
Q

What are the investigations used to myositis?

A 
• High CK
• EMG, inflammation and myopathic 
• Biopsy:
- Polymyo.: CD8 cells
- Dermato: humeral-mefiated, B cells and CD4 cells
19
Q

Name a disorder of the neuromuscular junction?

A

Myasthenia gravis

20
Q

What is myasthenia gravis?

A

Chronic autoimmune (Type II Hypersensitivity) neuromuscular disease that causes weakness in the skeletal muscle.

B cells produce antibodies which bind to the nicotinic ACh receptors on the sarcolemma, which blocks ACh and so don’t respond to contract signal from CNS.

21
Q

What is the clinical presentation of myasthenia gravis?

A 
Fatigue:
• Limbs
• Eyelids (ptosis)
• Muscle of mastication, swallow
• Talking 
• SOB
• Dipolopia (double vision)
22
Q

What is the investigation of myasthenia gravis?

A 
• ACh receptor antibodies 
• Anti-muscarinic antibodies 
• Neurophysiology:
   - Repetitive stimulation
   - Jitter 
• CT chest (thymoma)
23
Q

What is the treatment of myasthenia gravis?

A

• Symptomatic: acetylcholinesterase inhibitor (pyridostigmine)
• Immunosuppression (reduce production of autoantibodies)
- Prednisolone
- Steroid saving agent (azathioprine)
• Immunoglobulin / plasma exchange
• Thymectomy (reduces muscle weakness)

24
Q

What types of autoantibodies are produces in myasthenia gravis?

A

Complement pathway:
Enzymatic cascade to fight bacterial infection -> inflammation -> muscle cell destruction and reduction of ACh receptor on sarcolemma

Muscle specific receptor tyrosine kinase antibodies:
Targets proteins in muscle cells

25
Q

What is another way myesthina gravis can present (secondarily)?

A

As a paraneoplastic syndrome, so an underlying cancer, like a thymoma, generate an immune response generating autoantibodies.

26
Q

What are the different components of a peripheral nerve?

A 
• Sensory axons
   - Small fibres (pain and temperature)
   - Large fibres (joint position sense and vibration)
• Motor axons 
• Autonomic axons 
• Nerve sheath (myelin)
27
Q

What is the aetiology for peripheral neuropathy?

A 
• Hereditary 
• Metabolic: diabetes, alcohol, renal, B12
• Toxic: drugs
• Infectious: Lyme, HIV, leprosy 
• Malignancy: paraneoplastic 
• Inflammatory demyelinating 
   - Acute – Guillain Barre Syndrome 
   - Chronic – chronic inflammatory demyelinating polyneuropathy
28
Q

What is the clinical presentation of nerve roots disease?

A
  • Myotomal wasting and weakness
  • Reflex change
  • Dermatomal sensory change
29
Q

What is the clinical picture of individual nerve disease?

A
  • Wasting and weakness of innervated muscle

* Specific sensory change

30
Q

What is the clinical picture of generalised peripheral neuropathy?

A

Sensory and motor symptoms, usually starting distally and moving proximally

31
Q

What investigations are carried out for peripheral nerve diseases?

A
  • Blood tests
  • Genetic tests
  • Nerve conduction studies
  • Lumbar puncture (CSF analysis)
  • Nerve biopsy
32
Q

What are the UMN and LMN signs of amyotrophic lateral sclerosis?

A 
Degeneration of motor neurone 
• LMN = muscle fasciculations, wasting, weakness 
• UMN = increased tone, brisk reflexes  
• No sensory involvement 
• 10% have cognitive decline
33
Q

Give an example of an anterior horn cell/motor disease

A

Amyotrophic lateral sclerosis (ALS)

34
Q

What is the prognosis of ALS?

A
  • 3-5yrs from symptom onset
  • 2-3yrs from diagnosis
  • 50% die within 14 months of diagnosis
35
Q

What is the diagnosis of ALS?

A
  • Unique combination of UMN + LMN signs

* EMG

36
Q

What is the management of ALS?

A
  • Supportive: PEG feed, non-invasive ventilation, physio, OT, SALT, care
  • Riluzole (delays the onset of ventilator-dependence or tracheostomy)
  • Anticipatory / palliative care

Nervous System (47 decks)

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