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

Single fiber electromyography (SFEMG) was established by Stalberg and Eskedt in the 1960s, and is of proven value in the diagnosis of neuromuscular disorders, especially myasthenia gravis. It has proved to be the most sensitive technique in detecting a neuromuscular transmission defect in comparison with the tensilon test, repetitive stimulation, and acetyl choline receptor antibody estimation. Single fiber electromyography typically requires the use of a specially contracted single fiber EMG needle electrode or facial concentric needle electrode with a small recording surface (25 micrometers), which is exposed at a po on the side of the electrode, 3 mm from the tip. Ref Harrison20th edition pg 2456