Myasthenia Gravis

PATIENT PRESENTATION:
62 yr old female, K.W. with an insignificant PMHx, presents to the to the ED with complaints of progressive weakness/fatigue for 6 weeks that is worse in the afternoon, difficulty keeping eyes open, trouble with her gait, and now complains of difficulty breathing. She is intubated for airway protection and is admitted to the Neuro Surgical Intensive Care Unit.

DIFFERENTIAL LIST:
Guillian-Barre, botulism, myasthenia gravis

LABS & TESTS:
Labs: Na+ 136, K+ 3.8, WBC 10, HCT 38, HGB 13
Vital Signs: HR 73, BP 132/67, SpO2 90% on 6L NC, RR 31

Diagnostic Tests:
AChR Antibody blood test – positive
Nerve Conduction Study – decreased

Physical Exam:
Admitting Exam: K.W. is AAOx3, follows commands x4, has 3/5 strength in all extremities, and has bilateral ptosis. After 3 weeks on your unit, K.W. is now 1/5 strength in all extremities, cannot open her eyes, and now has a tracheostomy.

DIAGNOSIS:
Myasthenia gravis.

TREATMENT:
Treatment will include IVIG, prednisone PO, and Mestinon® PO.

OUTCOME:
Although there is no cure, symptoms can be reduced. K.W. will need long term steroids and physical therapy. She will need to be educated to avoid stressful situations, wear an eye patch if she experiences double vision d/t eye muscle weakness, and call 911 if she experiences any respiratory difficulties as this could be a sign of myasthenic crisis.

Case created by Kelley Wicheta, 2011.