Myasthenia Gravis (Exam 4)

Question 1

Myasthenia Gravis

Answer 1

-Acquired - autoimmune - progressive disease characterized by muscle weakness

-Remissions and Exacerbations

Question 2

Myasthenia Gravis results from

Answer 2

A reduction of acetylcholine receptors

Question 3

Myasthenia Gravis Exacerbations are associated with

Answer 3

Emotional stress

Pregnancy

Illness

Heat

Question 4

Myasthenia Gravis typically peaks within

Answer 4

2 years of onset

Question 5

Severity of Myasthenia Gravis

Answer 5

Depends:

Mild motor neuron disturbances to respiratory failure

Question 6

Types of MG

Answer 6

Ocular (face) and Generalized

1/2 patines present with reports about vision problems

Question 7

What is the most common type of myasthenia gravis?

Answer 7

Ocular (around face) type

Question 8

MG typically originates in

Answer 8

Face
Neck
Jaw

Arm + Leg are affected later in disease process

Question 9

Myasthenia Gravis: Presenting Symptoms

Answer 9

50% Ocular Symptoms

15% Bulbar symptoms

<5% present proximal limb weakness alone

Question 10

MG Ocular Symptoms

Answer 10

Ptosis (droopy eyelid)
-fluctuates throughout any given day
-may be unilateral / bilateral (even switch eyes)

Diplopia (double vision)
-initially sense of blurred vision

Question 11

What is the name for a droopy eyelid?

Answer 11

Ptosis

Question 12

MG Bulbar symptoms

Answer 12

-Dysarthria (marbles in mouth)

-Dysphagia (swallowing)

-Fatigable chewing

Question 13

Diagnosis of MG depends on

Answer 13

If it is ocular or general symptoms

1. Bedside Test
2. Serologic Test
3. Nerver conduction test (EMG)

Question 14

Diagnosis of MG: Bedside Test

Answer 14

Sentives , but many false-postives

Use only with a patient with ptosis (improvement can be seen)

Tensilon Test

Ice Pack Test

Question 15

Tensilon Test

Answer 15

Bedside test done for ptosis MG

Tensilon - acetylcholinesterase inhibitor; onset 30-45 secs; duration 5-10 min

Given IV - watch eyelids:

ptosis will improves if MG

Question 16

Ice Pack Test

Answer 16

Bedside Test done for ptosis MG

Based on principle of improving neuromuscular transmission at lower muscle temperatures

Surgical glove of ice on lid x 2 minutes; remove ice; immediately assess potois

Will improves if MG

Question 17

What lab values helps asses for the presences of autoantibodies in MG?

Answer 17

Acetylcholine receptors antibodies
(AChR-Ab)

Muscle specific tryamine kinase antibodies (MuSK)

Question 18

MG: Drug Therapy

Answer 18

Acetylcholinesterase inhibitors (anticholinesterase)

-pyridostigmine bromide (common) / neostigmine

Question 19

MG: Acetylcholinesterase inhibitors

Answer 19

First line treatment

Can produces relief in minutes

May require day-to-day variation in dosing

Question 20

When is short term treatment usually ordered?

Answer 20

Ordered until medication take effect

Prior to surgery

Myasthenic crisis

Question 21

MG: Short Term Treatment

Answer 21

1. Intravenous immunoglobulin (IVIG)
2. Plasmapheresis (plasma exchange)

Question 22

Intravenous immunoglobulin (IVIG)

Answer 22

Short Term Treatment

An injection of nonspecific antibody (immunoglobulin) that works by dialing down the immune systems production of its own antibodies, much as warm air tells a thermostat to stop pumping out heat

Question 23

Plasmapheresis

Answer 23

Short Term Treatment

-IV line used to remove antibodies from plasma to decrease symptoms

Question 24

Plasmapheresis Changes timeline

Answer 24

6 exchanges over a 2-week period w/ weekly or monthly follow ups prn

Question 25

MG: Surgical Management

Answer 25

Thymectomy Thymus gland enhances acetylcholinesterase antibodies

Question 26

Thymectomy

Answer 26

Removal of thymus because the gland seems to enhance AChR antibodies Done early in diagnosis (2 years within onset of symptoms)

Question 27

MG Patient: Hospital Admission Typically r/t

Answer 27

-Respiratory tract infection -Acute myasthenic crisis

Question 28

Care of MG is focused on

Answer 28

Neurologic deficits and their impact on ADLS

Question 29

MG Patient: Teaching

Answer 29

Balanced diet that can be easily chewed / swallowed (semi-solid best) -What causes flares -Complication of disease -Complication of therapy -Support groups avaiable

Question 30

What diet is a patient with MG on?

Answer 30

Semi-solid is best because it helps with dysphagia

Question 31

MG: Medication schedules

Answer 31

Schedule so peak action during mealtime

Question 32

Myasthenic VS Cholinergic crisis

Answer 32

Myasthenic Crisis: -Caused by not enough Anticholinesterase Drugs (too little ACH) Cholinergic Crisis: -Caused by too many anticholinesterase drugs (too much ACH)

Question 33

Features common to both Myasthenic and Cholinergic Crisis

Answer 33

-Apprehension -Restlessness -Dyspnea -Dysphagia -Generalized weakness -Respiratory failure

Question 34

Unique Features of Myasthenic Crisis

Answer 34

Increased V.S Bowel / Bladder incontinence Absence of cough / swallow reflex Improvement of symptoms with Tensilon test

Question 35

Unique Features of Cholinergic Crisis

Answer 35

Flaccid paralysis Hypersecretions (saliva - sweat - tears) Abdominal cramps Worsening symptoms with Tensilon Test

Question 36

Tensilon test with myasthenic crisis

Answer 36

Improvement of symptoms

Question 37

Tensilon test with cholinergic crisis

Answer 37

Symptoms will worsen