A thiy five year old female has proximal weakness of muscles, ptosis and easy fatigability. The most sensitive test to suggest the diagnosis is.

Tensilon test (edrophonium test) is a pharmacological test used for the diagnosis of ceain neural diseases, especially myasthenia gravis. It is also used to distinguish a myasthenic crisis from a cholinergic crisis in individuals undergoing treatment for myasthenia gravis 10 mg edrophonium hydrochloride syringe and a 2 mg atropine syringe are prepared. Atropine is prepared for immediate use in case cholinergic crisis occurs. After a neurologic examination and recording of vital signs, first 2 mg edrophonium is injected intravenously. After waiting 30 seconds and ensuring that no adverse reactions occurred, the remaining 8 mg of edrophonium is also injected. A patient suffering from myasthenia gravis experiences improvement in muscle strength and endurance with repetitive movements, while normal persons do not feel any difference. The effects of edrophonium lasts around 10 minutes. The edrophonium allows accumulation of acetylcholine (ACh) in the neuromuscular junctions, and makes more ACh available to the muscle receptors, thereby increasing muscle strength in myasthenia gravis. In newborns, a 0.15 mg/kg edrophonium administered subcutaneously produces a response within 10 minutes. In infants, the drug is administered intravenously at a dose of 0.2 mg/kg. Improvement of diplopia is often used as an evaluation item because in this case, placebo effect can be excluded Ref Harrison20th edition pg 2456