[Diagnostic tests in myasthenia gravis. Creation of a standard for diagnosis using a method of consensus]

Nowadays the best test for the diagnosis of myasthenia gravis (MG) is the single fiber electromyography (SFEMG). Due to the cost of the test it has not become routine in most part of the hospitals to confirm the diagnosis of MG.

To identify an acceptable gold standard for hospitals which do not have access to SFEMG, but have access to some other classical test through the use of a consensus methodology.

The study was realized in three stages. The first two stages were done through a prolective survey and the third stage through a Delfos methodology. During the first stage 59 general neurologist were interviewed, applying an instrument in which they were asked which were the best test and the best group of tests to diagnose MG without using the SFEMG. During a second stage, a second collection instrument was applied to 15 experts in motoneuron diseases to identify the best isolated test and the best test scheme with and without using the SFEMG in four frequent clinical situations in clinical practice (typical clinical case of generalized MG, patient with ocular myasthenia, patient with generalized MG of medium and low probability). Finally four flowcharts were created of the four analyzed clinical situations and were approved through a Delfos methodology with 8 neurologist motoneuron disease.

We identified an acceptable gold standard for hospitals which do not have access to SFEMG through the use of a consensus methodology. We have also completed four diagnostic flowcharts about the most frequent clinical situations that we have faced in the ordinary practice.

We have found a series of important results for the diagnosis of MG available to general physicians, internists and neurologist that do not have all the test for the diagnosis of MG.