Nerve and Muscle Disease

Question 1

which enzyme is deficient in McArdle’s disease?

Answer 1

myophosphorylase

Question 2

when does McArdles usally present?

Answer 2

first decade of life

Question 3

how does McArdles usally present?

Answer 3

severe and cramping muscle pain shortly after starting exercise

Question 4

levels of which enzyme are raised in the majority of people with McArdles?

Answer 4

Creatinine Kinase

Question 5

vigourous exercise if you have McArdles increases risk of which complications?

Answer 5

rhabdomyolysis with myoglobinuria

subsequent AKI

Question 6

how does myotonic dystrophy affect you muscles?

Answer 6

delayed muscular relaxtion and muscle wasting

Question 7

myotonic dystrophy is due to a tri-nucleotide repeat on which chromosome?

Answer 7

chromosome 19

Question 8

myotonic dystrophy follows which mode of inheritance?

Answer 8

autosomal dominant

Question 9

the sternocleidomastoid and distal limb muscles are usually affected in first in myotonic dystrophy- this results in what?

Answer 9

grip myotonia

foot drop

(porximal limbs muscles affected later)

Question 10

what kind of cataracts can be seen in myotonic dystrophy?

Answer 10

christmas-tree like cataracts

Question 11

facial weakness (‘haggard’), early frontal balding, temporalis muscle wasting and jaw muscle atrophy are seen in which muscle disease?

Answer 11

myotonic dystrophy

Question 12

which muscle disease is caused by impaired release of acetylcholine by the pre-synaptic terminal?

Answer 12

Lambert-eaton Myasthenic syndrome

Question 13

lambert Eaton syndrome is assoc w which cancer?

Answer 13

small cell lung

Question 14

what clinical features are seen in lambert eaton syndrome?

Answer 14

proximal muscle weakness- waddling gait

diminshed/absent deep tendon reflexes

Question 15

what autonomic features are present in lambert eaton syndrome?

Answer 15

constipation

postural hypotension

impotence

dry mouth

Question 16

presence of which antibodies confirm a diagnosis of lambert eaton?

Answer 16

anti-VGCC antibodies

Question 17

why is CT used when investigating lambert eaton?

Answer 17

rule out malignancy

Question 18

how is lambert eaton treated?

Answer 18

3,4- diaminopyridine (amifampridine)

blocks presynaptic Ca²⁺ channels and increases quantity of ACh released

Question 19

which autoimmune disease affects the post-synaptic nicotonic acetylcholine receptors at the NM junction?

Answer 19

myasthenia gravis

Question 20

who is affected by myasthenis gravis men/women?

Answer 20

women more so,

common in 2nd/3rd decade

Question 21

muscle fatigue seen in myasthenis gravis improves upon rest/exercise?

Answer 21

improves on rest

Question 22

are the facial muscles affected in myasthenia gravis?

Answer 22

yes- jaw, facial muscles, speech/swallow and resp muscles affected

Question 23

what complications can occur with myasthenis gravis?

Answer 23

myasthenia crisis

cholinergic crisis

Question 24

describe myasthenia crisis?

Answer 24

weakness of respiratory muscles causing ventilator failure

Question 25

in myasthenia crisis urgent elective tracheal intubation should be considered when vital capacity falls below what threshold?

Answer 25

below 15mL/kg

Question 26

what commonly precipitates cholinergic crisis?

Answer 26

high dose anticholinesterase medication symtpoms include: sweating, hypersalivation and miosis→can lead to resp failure

Question 27

which drugs can induce or exacerbate myasthenia?

Answer 27

gentamicin B blockers verapimil lithum phenytoin chloroquine

Question 28

which antibodies are present in myasthenia?

Answer 28

anti-AChR if this is negative check anti-MuSK

Question 29

how is myasthenia managed?

Answer 29

symptomatic control w acetylcholinesterase inhibiton using **pyridostigmine**

Question 30

if thymoma is present in myasthneia what procedure can be performed?

Answer 30

thymectomy

Question 31

schwann cell proliferation in an 'onion bulb' appearnace is classically seen in which disease?

Answer 31

charcot-marie-tooth disease

Question 32

distal muscles in the lower limb are commonly affected in charcot-marie-tooth disease what is this apearance termed?

Answer 32

inverted champagne bottles appearance

Question 33

many patients with guillian-barre syndrome have histroy of which preceding infections?

Answer 33

capylobacter EBV CMV HIV

Question 34

how are the nerves affected in Guiliian-Barre syndrome?

Answer 34

demyelination and axonal injury

Question 35

how do pateints with guillian-baree present?

Answer 35

symmetrical, progressive ascending paralysis w absent reflexes

Question 36

is guillian barre an acute or chronic condition?

Answer 36

acute- people can fully recover however this varies from weeks to months to years

Question 37

what is CIDP?

Answer 37

Chronic Inflammatory Demyelinating Polyradiculoneuropathy (proximal and distal muscle weakness with hypo/areflexia and distal numbness)

Question 38

how can CIDP be treated?

Answer 38

oral steroids IV immunoglobulins

Question 39

what is spinal muscular atrophy sometimes termed?

Answer 39

Werdnig-Hoffmann disease

Question 40

what aspect of the spinal cord is affected in spinal muscular atrophy (werdnig-Hoffman)?

Answer 40

degeneration of anterior horns (LMN) leads to progressive muscular wasting and often early death

Question 41

what is the mode of inheritance in spinal muscle atrophy?

Answer 41

autosomal recessive

Question 42

the severe form of which disease causes 'floppy baby syndrome' wihtin first month of life?

Answer 42

spinal muscle atrophy (werdnig-hoffmann) marked hypotonia and tongue fasciculations

Question 43

poliovirus causes which nerve disease?

Answer 43

poliomyelitis

Question 44

how is polio virus transmitted?

Answer 44

faecal-oral transmission

Question 45

how does polio virus cause disease?

Answer 45

destruction of cells in the anterior horn of the spinal cord (LMN death)

Question 46

what are the signs and symtpoms of poliomyelitis?

Answer 46

same as that of LMN disease: weakness, hypotonia, flaccid paralysis, fasciculations, hyporeflexia, muscle atrophy