My first Tensilon test

He came in with a few pages printed out from the Internet and started talking even before he had sat down.

“I feel tired all the time, but especially in the evenings. And my face has gone droopy. I looked it up on the Internet — I think it might be myasthenia gravis. I think I need to have a test called the Tensilon test. Am I right?”

My initial thought was that this patient had Internet Print-out Syndrome. But the history did reveal symptoms typical of myasthenia. The physical examination was also convincing: he tired quickly with exercise, and even though he spoke in short bursts, his voice faded toward the end of them. So I phoned the pharmacy to get some edrophonium.

As we were waiting, I explained to the patient what the test was all about. I explained that edrophonium — Tensilon — was used to diagnose myasthenia gravis and that patients with the disease improve after administration of the drug. I also explained the cholinergic side-effects, such as abdominal cramping and diarrhea. I put in an iv, attached the patient to a cardiac monitor and put some intravenous atropine on top of the resuscitation trolley. I had read up on the test recently and was ready for all eventualities.

I called in the other junior doctors and the medical students and slowly injected the placebo: nothing happened. Then I pushed in the Tensilon: the response was dramatic. My patient's face lit up, and his eyes opened wide. Then he started to cry. The hairs stood up on the back of my neck and I could feel my eyes fill up, too. Was this my first brilliant diagnosis as a neurology trainee? I called my boss into the room.

“Prof, his facial muscles improved dramatically — it was incredible — he even started to cry.”

His dry response:

“You are probably right in your diagnosis. But don't get too excited about the tears. Lacrimation is an invariable response to the cholinergic stimulation of the tear glands.”

All our hearts sank, and even the patient was looking more glum. Or maybe it was just the Tensilon wearing off.