Diagnostic challenge: Myasthenia gravis in the emergency department.

PURPOSE: To describe an instructive case of neurological disease encountered by a nurse practitioner (NP) student in the emergency department (ED). Characteristics, epidemiology, pathophysiology, diagnostic considerations, and appropriate testing options for myasthenia gravis (MG) are included.

DATA SOURCES: Findings from the history, physical examination, and diagnostic testing of a 41-year-old male with neck weakness and pain. Review of published literature about MG.

CONCLUSIONS

MG is a pure motor syndrome characterized by fluctuating muscle weakness and fatigue and is exacerbated by sustained muscle use. It is usually caused by an autoimmune process that is chronic and progressive. Multiple patient encounters with the healthcare system often occur prior to diagnosis. Many viable treatment options now exist that can enhance quality of life and improve function.

IMPLICATIONS FOR PRACTICE: The NP must include MG in the differential diagnosis with any report of fluctuating muscle weakness or other neurological, upper gastrointestinal, respiratory, or ophthalmic complaint. The key diagnostic finding is a specific muscle weakness that can be reproduced and exacerbated with sustained muscle use. These considerations will lead to earlier diagnosis and treatment.