Other Causes of Positive EdrophoniumTest

Improvement after edrophonium is not unique to MG, and also seen in
congenital myasthenic syndromes (CMS),
the Lambert–Eaton syndrome (LES),
intracranial aneurysms,
brainstem lesions,
cavernous sinus tumors,
end-stage renal disease, and
muscle diseases affecting the ocular muscles