Muscle and Nerve Disease

Question 1

Muscle

Answer 1

An intricate machine designedd to convert chemical energy into mechanical energy

Question 2

What are components of the process that sees muscles converting chemical energy to mechanical?

Answer 2

• Excitation-contraction coupling
• The contractile mechanism
• Structural components
• The energy system

Question 3

What are symptoms of muscle disease?

Answer 3

• Poor suck/ feeding/ failure to thrive/ floppy
• Weakness of skeletal muscles
• Short of breath
• Poor swallow
• Cardiomyopathy
• Cramp/ pain/ myoglobinuria

Question 4

What are the signs of muscle disease?

Answer 4

• Wasting/ hypertrophy
• Normal or reduce tone and reflexes
• Motor weakness (not sensory)

Question 5

What investigations are there for muscle disease?

Answer 5

• History and examination
• Creatinine kinase
• EMG
• Muscle biopsy (structure, biochemistry, inflammation)
• Genetic testing

Question 6

What are the classifications of muscle disease?

Answer 6

• Muscular dystrophies
• Channelopathies
• Metabolic muscle disease
• Inflammatory muscle disease
• Congenital myopathies
• Iatrogenic

Question 7

What do muscular dystrophies affect?

Answer 7

The mechanics of the muscle and are usually genetic

Question 8

Give examples of muscular dystrophies.

Answer 8

• Duchenne’s MD
• Becker’s MD
• Facioscapulohumeral MD
• Myotonic dystrophy
• Limb-Girdle MD

Question 9

What does facioscapulohumeral MD tend to present with?

Answer 9

Facial, scapula and bicep weakness

Question 10

Who is normally affected by Duchenne’s MD?

Answer 10

Boys

Question 11

What is abnormal in Duchenne’s MD?

Answer 11

Dystrophin

Question 12

What are channelopathies disorders of?

Answer 12

Ca, Na and Cl channels

Question 13

Give 4 examples of channelopathies.

Answer 13

• Familial hypokalemic periodic paralysis
• Hyperkalemic periodic paralysis
• Paramyotonia congenital
• Myotonia congeniita

Question 14

What are metabolic muscle diseases?

Answer 14

Disorders of carbohydrate and/or lipid metabolism

Question 15

Give examples of metabolic muscle diseases

Answer 15

• Mitochondrial myopathies/cytopathies
• Endocrinopathy (thyroid, Cushings)
• Biochemical abnormalities

Question 16

Give examples of inflammatory muscle diseases.

Answer 16

• Polymyositis

- Dermatomyositis

Question 17

What does polymyositis affect?

Answer 17

The muscles

Question 18

What does dermatomyositis affect?

Answer 18

Muscle and skin

Question 19

When can inflammatory muscle diseases occur?

Answer 19

At any age

Question 20

Other than painful weak muscles, how can dermatomyositis present?

Answer 20

Characteristic rash

Question 21

What do polymositis and dermatomyositis result in?

Answer 21

Painful weak muscles

Question 22

What is the treatment for inflammatory muscle disease?

Answer 22

Immunosuppression

Question 23

What investigations should be carried out for inflammatory muscle disease?

Answer 23

-Creatinine kinase (will be increased)
-EMG, inflammation and myopathic
Biopsy

Question 24

What will be found on muscle biopsy in polymyositis?

Answer 24

CD8 cells

Question 25

What will be found on muscle biopsy of dermatomyositis?

Answer 25

Humeral mediated B cells and CD4 cells

Question 26

Give an example of a disorder of the NMJ.

Answer 26

Myasthenia gravis

Question 27

What is the clinical presentation of myasthenia gravis?

Answer 27

Fatiguable weakness of: - Limbs - Eyelids - Muscles of mastication (chewing) and swallow - Talking - SOB - Diplopia

Question 28

What are the investigations for myasthenia gravis?

Answer 28

- AChR ab - Anti MuSK ab - Neurophysiology (repetitive stimulation and jitter) - CT chest (thymoma)

Question 29

What symptomatic treatment for myasthenia gravis is there?

Answer 29

Acetylcholinesterase inhibitor

Question 30

What immunosuppression treatment is there for myasthenia gravis?

Answer 30

- Prednisolone | - Steroid saving agent azathioprine

Question 31

When is immunoglobulin/plasma exchange used as treatment in myasthenia gravis?

Answer 31

In critically ill patients who are struggling to breath. It is a temporary measure

Question 32

What surgical procedure is often performed on those with myasthenia gravis?

Answer 32

Thymectomy

Question 33

What do peripheral nerves consist of?

Answer 33

- Sensory axons | - Motor axons

Question 34

What do small sensory fibres carry?

Answer 34

Pain and temperature

Question 35

What do large sensory fibres carry?

Answer 35

Joint position sense and vibration

Question 36

Give examples of nerve root diseases.

Answer 36

- Degenerative spine disease - Inflammation - Infiltration

Question 37

What are the types of lesions of individual peripheral nerves?

Answer 37

- Compressive/ entrapment neuropathy | - Vasculitic (mononeuritis multiplex)

Question 38

How can generalised peripheral neuropathy present?

Answer 38

- Motor/ sensory or both | - +/- autonomic features

Question 39

What are the causes of generalised peripheral neuropathy?

Answer 39

- Metabolic: diabetes, alcohol, renal failure, B12 - Toxic: drugs - Hereditary - Infectious: Lyme, HIV, leprosy - Malignancy: paraneoplastic - Inflammatory demylineating

Question 40

What is an examples of an acute inflammatory demyelinating condition?

Answer 40

Guillain Barre syndrome

Question 41

What is an examples of a chronic inflammatory demyelinating condition?

Answer 41

Chronic inflammatory demyelinating polyneuropathy

Question 42

What are the signs and symptoms of nerve root disease?

Answer 42

- Myotomal wasting and weakness - Reflex change - Dermatomal sensory change

Question 43

What are the signs and symptoms of individual nerve disease?

Answer 43

- Wasting and weakness of innervated muscle | - Specific sensory change

Question 44

What are the signs and symptoms of generalised peripheral neuropathy?

Answer 44

Sensory and motor symptoms starting distally and moving proximally

Question 45

What investigations should be carried out for nerve disease?

Answer 45

- Blood tests - Genetic analysis - Nerve conduction studies - Lumbar puncture with CSF analysis - Nerve biopsy (nb sensory nerve)

Question 46

How does ALS progress?

Answer 46

- Usually limb onset | - Later bulbar and respiratory involvement

Question 47

What LMN signs are there in ALS?

Answer 47

- Muscle fasciculations - Wasting - Weakness

Question 48

What UMN signs are there in ALS?

Answer 48

- Increased tone | - Brisk reflexes

Question 49

What is the prognosis for ALS?

Answer 49

- 3-5 years from symptom onset - 2-3 years from diagnosis - 50% will die within 14 months of diagnosis

Question 50

How is a diagnosis of motor neurone disease made?

Answer 50

- Unique combination of UMN and LMN signs | - EMG

Question 51

What is the treatment for motor neurone disease?

Answer 51

- Supportive (PEG, NIV, physio, OT, care) | - Riluzole