2.9 Neurological and Sensory MYASTHENIA GRAVIS

Question 1

Myasthenia Gravis

what is it

Answer 1

Receptors:
Chemicals messengers, called neurotransmitters, fit precisely into receptor sites on your muscle cells. in myasthenia gravis, certain receptors sites are blocked or destroyed, causing muscle weakness

Question 2

Myasthenia Gravis

Pathophysiology

Answer 2

Pathophysiology
Chronic autoimmune neuromuscular disorder of PNS
Destroys acetylcholine receptors → muscle contraction impaired, especially with repetition

Question 3

Myasthenia Gravis

Causes:

Answer 3

Causes:
Thymus gland hyperplasia or tumors produce antibodies –most

Other causes: hyperthyroid, RA, lupus

Question 4

Myasthenia Gravis
Complications
MYASTHENIC CRISIS

Answer 4

MYASTHENIC CRISIS
Sudden exacerbation
Motor weakness
Risk of respiratory failure

S/S:
Tachycardia, tachypnea, respiratory distress, dysphagia, restlessness, speech impairments, anxiety
Causes:
Undermedication
Missed med doses
Infection/stress

Question 5

Myasthenia Gravis
Complications
CHOLINERGIC CRISIS

Answer 5

CHOLINERGIC CRISIS
Life-threatening
Motor weakness
Risk of respiratory failure

S/S:
GI, muscle weakness, vertigo, respiratory distress
Cause:
overdose of anticholinesterase meds

Question 6

Myasthenia Gravis

Manifestations

Answer 6

Manifestations

Dependent on the muscles involved

Initially eye muscles (diplopia, ptosis)

Facial muscles (speech, chewing, dysarthria, dysphagia)

Fatigue & weakness

Dysphagia & PNA –respiratory muscles often involved

Exac: stress, fever, infection, overexertion, heat

Relief: rest, better in the ams

Question 7

Myasthenia Gravis
Diagnosis
Complications

Answer 7

Diagnosis

Careful history and physical S/S (ocular, respiratory, facial, respiratory)

Testing:
Nerve stimulation tests
Antiacetylcholine receptor antibodies in serum
Anticholinesterase (Tensilon) testing

Complications:
Aspiration
pneumonia

Question 8

Myasthenia Gravis

Treatments

Answer 8

Treatments

Medications:

Anticholinesterases (prevent breakdown of acetylcholine)

Immunosuppressants

Surgery: thymectomy

Plasma exchange (plasmapheresis)- temporary

Question 9

Myasthenia Gravis

Nursing Care

Answer 9

Nursing Care
Teach energy conservation & scheduling activity
Strict med scheduling
Teach crisis prevention
Swallow safety/aspiration risk –teach family Heimlich
Many medications are contraindicated- check with provider, no OTCs
Airway management with surgery
Avoid temperature extremes
Avoid respiratory infections