A 65-year-old previously healthy man presented to the emergency
department for several months of progressive upper extremity weakness and
blurry vision. He reports that over the past 3 months, playing the violin and
mowing the lawn have become more difficult because the longer he does these
activities, the weaker his arms become. His hands and forearms still feel
strong. His brother accompanies him and has noticed that in the evenings his
eyelids seem to droop more. The drooping worsens the more he blinks. He
also feels short of breath when lying flat. He was admitted to the neurology
service for further workup. Respiratory parameters were monitored
throughout his hospital course and remained stable. Neurologic exam was
significant for asymmetric, right greater than left ptosis, significant eye
closure and cheek puff weakness, and fatigable weakness of proximal upper
and lower extremities. On electromyography, repeti Right Ans -
myasthenia gravis
He was treated with intravenous immunoglobulins for presumed myasthenia
gravis with improvement in his ptosis and proximal muscle weakness. Chest
computerized tomography (CT) did not reveal a thymoma or thymic
hyperplasia. He was started on prednisone and pyridostigmine. He presented
to clinic 1 month later in follow-up at which point his acetylcholine receptor
antibodies had returned to positive. His prednisone dose was increased due to
continued symptoms and he was started on a steroid-sparing
immunosuppressive therapy with mycophenolate mofetil Right Ans -
myasthenia gravis
Autoantibodies directed against components of the Postsynaptic
Neuromuscular Junction (NMJ) Right Ans - myasthenia gravis
This leads to Functional Muscle Weakness Right Ans - Etiology and
Pathophysiology - Myasthenia Gravis
Weakness that worsens with exertion and often over the course of the day
, Diplopia and ptosis due to involvement of extraocular muscles are common
and distinguish myasthenia gravis from myopathies, in which involvement of
extraocular muscles is unusual
In some patients, symptoms are confined to ocular muscles, while others
develop generalized weakness that can be so severe as to require mechanical
ventilation
If bulbar or generalized weakness does not develop during the first 2 years,
further progression to generalized MG is significantly less likely, and these
patients are classified as having ocular MG (OMG)
The hallmark of MG is fluctuating and fatigable weakness that is worse at the
end of the day and during or following exercise. Patients will improve with
rest, and symptoms often worsen throughout the day Right Ans -
myasthenia gravis
A 35-year-old African American woman presented to the clinic for a second
opinion regarding her long-standing history of dysarthria and diplopia. Her
symptoms first began in her 20s and fluctuate throughout the day but are
primarily worse in the evening hours. Her speech has developed a nasal tone
and she often develops blurry or double vision later in the day.
She had negative acetylcholine receptor antibody testing but repetitive nerve
stimulation testing of the ulnar nerve demonstrated a compound muscle
action potential amplitude decrement greater than 10%. Her neurologic exam
is significant for fatigable ptosis, diplopia after prolonged lateral gaze,
primarily lower facial weakness, and neck flexion weakness Right Ans -
myasthenia gravis
Over the course of several years, she has been admitted to the hospital for
worsening respiratory distress and dysarthria, consistent with myasthenia
gravis (MG) crisis
She was treated with plasma exchange with good response. Prednisone was
initially very effective but had to be discontinued due to side effects of
worsening anxiety and suicidal ideations
Muscle-specific tyrosine kinase (MuSK) antibody testing was eventually
performed and confirmed the diagnosis of MuSK-positive MG
Given her MuSK positivity, she was started on rituximab with excellent
response Right Ans - myasthenia gravis
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Studyhall. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.99. You're not tied to anything after your purchase.