MG

Question 1

Microscopy of MG at NMJ

Answer 1

Flattening of synaptic folds

Increase in size of synaptic clefts

Question 2

Mechanism of AchR antibodies

Answer 2

Destroy (mc)
Block
Endocytosis

Question 3

Myoid cell function

Answer 3

Muscle tissue in thymus
Attached to extra thymic AchR
Antibodies against myoid cell criss react with AchR

Question 4

Thymus abnormality in how many pt of MG

Answer 4

75%

60%- Hyperplasia
10%- Thymoma

Question 5

Thymoma c/f

Answer 5

Local- Sup mediastinum structures compression

PARANEOPLASTIC SYNDROMES

• Pure RBC aplasia
• Hypo-Gamma-globulinemia
• Pernicious anemia
• Dermatomyositosis
• Pan hypopituitarism
• SLE
• CUSHING SYNDROME**

Question 6

Thymoma + hypogammaglobulinemia syndrome

Answer 6

Goods syndrome

Question 7

Extra tests must for MG

Answer 7

MRI - Thymoma

TSH- 3-7% have HYPERTHYROIDISM

Question 8

C/f of MG

In order of severity

Answer 8

EASY FATIGUE (Prox muscle—High AchR)

OCULAR

FACIAL

SKELETAL

Question 9

Ocular features of MG

UNILATERAL*****

Answer 9

Lid fatigue (ptosis on upward)

Lid twitch (up-down- ptosis with twitchin)

Curtain sign (raise ptotic eyelid-other falls down)

Peek sign** (cannot close eyes tightly)

Question 10

Facial features of MG

Answer 10

Snarling app (vertical smile)

Mushy voice + nasal timbre

PHARYNGEAL MUSCLE DYSTROPHY
(progressive dysphagia + asp pneumonia)

Question 11

Normal in MG?

DSBCP

Answer 11

DTR
Sensory system
Bladder
Cognition
Pupillary reflex

Least common nerve involved = 9th

Question 12

Age and sex of MG

Answer 12

F»M (3:2)

F= 20-30
M= 50-60

Question 13

Ix in MG

EIAMLS

Answer 13

Edrophonium Test
(2mg—-f/b—8mg—- if improves MG+)
S/E= Cholinergic crisis —MH-ve

ICE PACK TEST (screening)
(Cold—inhibits AchE)

AchR Ab (85% + in MG. 50% + in Ocular Mg)

MUSK Ab

LRP-4 Ab

RNS (Rapid nerve stimulation)
—DECREMENTAL RESPONSE WITH INCREASED FREQ OF STIMULATION by 10% minimum

SFEMG (best test)
Jitter +

Question 14

Musk enzyme Ab cf

Answer 14

Decreased clustering

+ in BULBAR MG (Dysarthria and Dysphagia only)

No effect of Cholinergic drugs and thymectomy

Question 15

Rx MG

Answer 15

1) Ach INHIBITORS-

DOC = Pyridostigmine (oral/weak)—acts on NMJ

Neostigmine (inj/strong/chol crisis+)

NEVER PHYSOSTIGMINE (centrally acting)

2) IMMUNOSUPRESSANTS
3) THYMECTOMY (compulsory)

Question 16

Immunosuppressive in MG

Answer 16

Immediate- Plasmapheresis/IVIG

Short term- Gluco/Tacro/Cyclosporine

Delayed- MycoMof/Azathioprine

Question 17

Different MG Tx

BULBAR, OCULAR

Answer 17

B= Rituximab+pyrido

O= Pyrido+/- Immunosuppressives

Question 18

LEMS C/f

Exactly opposite to MG

Answer 18

Skeletal> Facial> Ocular

DTR reduced
Bladder involved
Dry mouth
NO easy fatiguability
Prox muscles+ trunk muscles

Question 19

Ix LEMS

Answer 19

Edrophonium NEGATIVE

RNS- INCREMENTAL RESPONSE (50Hz @ higher freq)

Decremental at lower freq

Question 20

Rx LEMS

Answer 20

2,3 DAP (Diaminopyridine)

Pyridostigmine

Question 21

Drugs C/I in MG

Answer 21

BB
dTC
FQ and Aminoglycosides

Question 22

Scoring for MG migraine SAH

Answer 22

OSSERMAN GRADING

MIDAS scale

hunt and hess scale