The Tensilon (intravenous edrophonium chloride) test is a frequently used and frequently useful office test for myasthenia gravis (MG). The main controversies concerning the test are the reasons for administering it and the style in which it is administered.
Tensilon testing is useful as a diagnostic test for ocular MG but not as a means of adjusting medical treatment for this condition. Myasthenic extraocular muscles, especially the eyelids, usually respond dramatically in the untreated patient. Similarly, ocular movement, although often not restored completely to normal, is generally improved with the administration of Tensilon. In contrast, Tensilon administration as a means of judging drug dosage is far less useful. The real question with therapy in ocular MG is not whether the eyes will wiggle a little bit more with an intravenous cholinesterase inhibitor but whether a satisfactory (to the patient) response to oral cholinesterase inhibitors can be achieved. This determination