Myasthenia gravis

Question 1

What is Myasthenia Gravis?

Answer 1

Autoimmune Neuromuscular disorder.
Loss of communication between nerve and muscle at neuromuscular junction.
Fluctuating weakness of VOLUNTARY skeletal muscles

Question 2

MG etiology

Answer 2

book
Antibodies attack (ACh) Acetylcholine rectors.
Results in decrease number of ACh receptors available at neuromuscular junction. ACh molecules can’t at attach to ACh receptors and stimulate muscle contraction. This leads to increase muscle weakness.

Question 3

Myasthenia Crisis

Answer 3

• LIFE TREATENING Acute exacerbation of muscle weakness
• triggered by Resp infection, pregnancy, stress, surgery, or beginning corticosteroids
• Affect swallowing and breathing
• RESPIRATORY FAILURE

Question 4

Cholinergic Crisis

Answer 4

• Rare
• Medication overdose
• D: Diaphoresis - B: Bronchial Secretions
• U: urination - E: Emesis
• M: MIOSIS( excessive constricts of pupils) - L: Lacrimation
• B: bradycardia - L: Loose stool

Question 5

MG clinical manifestations (part I)

Answer 5

• Ptosis: dropping eye or both
• Diplopia: double vision
• Blurred vision
• difficulty swallowing
• SOB
• change in facial expressions

Question 6

MG clinical manifestations (part II)

Answer 6

• voice impairment ( Selma Blair)
• impaired speech (Selma Blair)
• dysphasia
• generalized weakness
• increased salivation
• muscle wasting - fatigue - muscle atrophy

Question 7

Medical Management Goals

Answer 7

1. Relive symptoms
2. Improve function
3. Reduce & remove antibodies

TX depends on: Age, Severity of disease, Resp & bulbar involvement, and Pace of progression.

Question 8

Diagnosing MG

Answer 8

• PE & Neuromuscular exam
• Tensilon Test: Helps diagnose. Improves muscle contractility in ppl with MG. Also, helps diagnosis between Myasthenia crisis & Cholinergic Crisis.
• Ice Test: place ice pack on eye 2-5 min. When removed there is a decrease in ptosis. Patient able to move eye. Confirmed MG.

Question 9

Pharmacological management MG

Answer 9

• Anti- Cholinergic Inhibitors: Pyridostigmine Bromide
• 1 hr before meals same time DAILY*
• Immunosuppressant: Prednisone etc.
• Cytotoxic drugs: Azathioprine/Imuran)

Question 10

Surgical management MG

Answer 10

• Thymectomy: Removal of Thymus

Presence of thymus enhances ACh antibodies that are responsible for attacking ACh receptors

Question 11

Rapid Induction Therapy MG

Answer 11

• Plasmapheresis: removal of antibodies that are attacking. Used in acute exacerbations.
• IVIG (Intravenous Immunoglobulin): indicated for Myasthenia Crisis or for surgery when corticosteroids are contraindicated.