Myasthenia Gravis Flashcards
Myasthenia Gravis is a(n)…
acquired, autoimmune, progressive disease
Myasthenia Gravis is characterized by?
Muscle weakness
Myasthenia Gravis has remissions and exacerbations? True or false?
True
What causes flares in MG?
Emotional stress, pregnancy, illness, heat
MG peaks within ____ years of diagnosis?
2 years
Is a result of…
reduction of acetylcholine receptors
Severity varies from what to what?
Mild motor neuron disturbances to respiratory failure
MG typically originates where?
Face, jaw, and neck
What parts of the body are later affected?
Arms and legs
What are the two types of MG?
Ocular
Generalized
What are the ocular symptoms of MG?
Ptosis
Diplopia
What is ptosis?
Droopy eyes, can be uni/bilateral, can switch eyes
What is diplopia?
Double vision
What are bulbar symptoms of MG?
Dysarthria
Dysphagia
Fatigable chewing
What is dysarthria?
“Marbled” speech
Diagnosis of MG depends on….
ocular or general symptoms
What are the tests to diagnose MG?
Tensilon Test
Ice Pack Test
Serologic Test- Autoantibodies
Nerve conduction test (EMG)
Explain tensilon test…
Tensilon is an acetylcholinesterase inhibitor that is given IV; onset is 30-45 seconds, duration of action is 5-10 minutes; watch the eyelids, ptosis will improve if MG
Explain ice pack test…
surgical glove filled with ice is placed on eyelid(s) for 2 minutes; when ice is removed, ptosis will immediately improve if MG
Which antibodies does the serologic test show?
Acetylcholine receptor (AChR-Ab) antibodies Muscle-specific tyramine kinase (MuSK) antibodies
Drug therapy for MG
Acetylcholinesterase inhibitors
>first line treatment
>pyridostigmine bromide
Immunotherapeutics
>predisone
>azathioprine
>cyclosporineShort term treatments are used…
until other medications take effect
prior to surgery
for myasthenic crisis
What are the short term treatments for MG?
Intravenous immunoglobulin (IVIG) Plasmapheresis (plasma exchange)
What is intravenous immunoglobulin (IVIG)?
Injection of nonspecific antibody (immunoglobulin) that dials down the immune system’s production of its own antibodies
What is plasmapheresis?
Plasma exchange; antibodies are removed from plasma to decrease symptoms; 6 exchanges over a 2-week period
MG Surgical Management
Thymectomy- removal of thymus (thymus enhances AChR antibodies); done early in diagnosis
Hospital admissions for MG are related to…
respiratory tract infection
acute myasthenic crisis
Teach:
Balanced diet (semi-solid is best) What causes flairs Medicine regimen Complications of MG Complications of therapy Support groups available
Difference between myasthenic crisis and cholinergic crisis?
Myasthenic crisis:
> Caused by NOT ENOUGH anticholinesterase drugs or some type of infection
Cholinergic Crisis
> Caused by TOO MANY anticholinesterase drugs
Features common to both myasthenic crisis and cholinergic crisis?
Apprehension Restlessness Dyspnea Dysphagia Generalized weakness Respiratory failure
Unique features of myasthenic crisis?
Increase in VS
Bowel/ bladder incontinence
Absence of cough/ swallow reflex
Improvement of symptoms with tensilon test
Unique features of cholinergic crisis?
Flaccid paralysis Hypersecretions (saliva, sweat, tears) N/V/D Abdominal cramps Worsening symptoms with tensilon test
