I was diagnosed by a Tensilon test. my antibodies are all negative and my CT scan was negative for a thymoma, but my neuro opthamologist strongly suspected MG as my diagnosis. I then was referred to a neurologist who performed the test. He was able to do so because he sees his myasthenic patients in his office in the hospital.

The reason for extra caution in administering a Tensilon test is that the drug can slow your heart rate. Resuscitation equipment and drugs must be on hand for immediate use if needed.

In my case the test was strongly positive, it is amazing really, but the results are very short in duration. Tensilon lasts only a minute or so.

Hope this info helps