Myasthenia Gravis
Patient Presentation:
A.F., a 55 year old male presents to the ER with multiple complaints,
including ptosis, dysarthria, shortness of breath, and muscle weakness of
his lower extremities. BP is 149/88, HR is 92, SaO2 is 93% on room air, RR
is 19, and temperature is 99.3. The ptosis has been a recurrent problem
for the last two years and has not been resolved after two visits to the
optometrist. Within the past several months he reports increased muscle
weakness and difficulty chewing and swallowing properly. Last month he was
treated in the ER for aspiration pneumonia and discharged. Patient reports
that he has recently been under a lot of stress.
Differential list:
Stroke, multiple sclerosis, brain tumor, pneumonia, myasthenia gravis
Diagnosis:
In the ER a chest x-ray was performed that revealed bilateral infiltrates.
CBC showed an elevated WBC of 13,000. BMP revealed mild hyponatremia with
a sodium level of 130. All other electrolytes were within normal limits.
CT scan does not reveal infarct or hemorrhage. MRI is ordered which is also
negative for infarct or hemorrhage. EKG is normal sinus rhythm. 500 mg of
IV Levaquin® is started in the ER to treat the pneumonia along with a bolus
of 0.9% Normal Saline. Patient is admitted from ER for pneumonia and a
neurology referral is placed. Neurology sees the patient after he is
admitted to the hospital and orders an AChR antibody test. Elevated serum
antibodies to the acetylcholine receptors confirm a diagnosis of myasthenia
gravis.
Treatment:
The neurologist treats the patient with pyridostigmine 60 mg three times a
day and prednisone 5 mg everyday.
Outcome:
The prognosis for those with myasthenia gravis is good and it is possible
that symptoms may go into remission with medication therapy. It is
important to be aware that muscle weakness can cause respiratory distress
and needs to be attended to urgently.