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Question 1

Antibodies in Myasthenia Gravis

Answer 1

1. Anti-AChR-> found in 85% patients
   - > only in 50% patients with only ocular type
2. Anti-MuSK (muscle specific kinase) in 10% patients, but in 40% in those without Anti-AChR Ab
   - >they predispose to generalized type of MG
3. Anti-LRP4 ([Low-density] Lipoprotein receptor-related protein 4)

Question 2

Diagnosis of Myasthenia Gravis

Answer 2

1. Antibodies
2. Repetetive nerve stimulation -> decrement of >10%
3. EMG single fiber -> blocking and jitter (drganie)
4. Edrophonium chloride test
5. Ice pack test
6. Thymus’ abnormalities

Question 3

Condition that can mimic Myasthenia gravis

Answer 3

1. Congenital myasthenia
2. Drug induced myasthenia ex. Penicillamine
3. Lambert-Eaton Myasthenic Syndrome
4. Neurasthenia
5. Hyperthyroidism (Graves disease)
6. Botulism

Question 4

Lambert-Eaton Myasthenic Syndrome causes

Answer 4

• > anti P/Q-type calcium channels (85% patients with LEMS)
  1. Small-cell lung cancer

-> 33% of LAMS are not assossiated with cancer ->with HLA-B8 or -DR4 haplotypes

Question 5

Treatment of LAMS

Answer 5

1. Look for a tumor
2. AChE, especially Piridostygmine
3. 3,4-diaminopyridine -> blocks potassium channel efflux in nerve terminals -> increases action potential duration
4. Plasmapheresis
5. Immunosupresants or IVIG

Question 6

Myasthenia Gravis treatment

Answer 6

1. Anticholinesterase
2. Immunosupression
3. Plasmapheresis
4. IVIG
5. Thymectomy

Question 7

Anticholinesterase Myasthenia Gravis treatment

Answer 7

1. Piridostigmine
2. Ambenonium
3. Neostigmine (Prostigmin)

Question 8

Immunosupression Myasthenia Gravis treatment

Answer 8

1. Prednisone -> I treatment
2. Azathioprine
3. Mycophenolate mofetil
4. Rituximab

Question 9

Oculomotor Nerve (III) Palsy symptoms

Answer 9

1. Dilated fixed pupil
2. Inability to look up or medialy
3. Lateral ocular deviation or “down and out” look
4. Diplopia
5. Absent accomodation
6. Ptosis (of upper lid)

Question 10

Oculomotor Nerve (III) Palsy causes

Answer 10

4xI 3xH

1. Ischemia
2. Intracranial aneurysm
3. Head trauma
4. Intracranial tumor
5. Hemorrhage
6. Hereditary (congenital)
7. Idiopathic

Question 11

Trochlear Nerve Palsy symptoms

Answer 11

1. Hypertropia -> upward deviation of the eye (ill eye is higher than opposite eye)-> increases when patient looks down and to opposite side
2. Reduced ability to look downward when looking medialy
3. Diplopia -> especially when looking down (ex. walking downstairs, reading)

Question 12

Trochlear Nerve Palsy causes

Answer 12

1. Head trauma
2. Congenital
3. Ischemic (microvascular)
4. Secondary to posterior fossa surgery
5. Posterior fossa tumor (rarely)

Question 13

Abducens Nerve (CN VI) Palsy symptoms

Answer 13

1. Reduced or absent abduction of the eye
2. Esotropia -> a form of strabismus in which one or both eyes turns inward
3. Diplopia

Question 14

Abducens Nerve (CN VI) Palsy causes

Answer 14

1. Ischemia (arteriosclerosis, DM, hypertension)
2. Increased ICP - intercranial pressure
3. Intracranial tumor
4. Trauma
5. Meningitis
6. Demyelination
7. Intracranial hypotension (ex. after lumbar puncture)