[Value of electroneuromyography in the diagnosis and follow-up of myasthenia gravis].

The diagnosis of myasthenia gravis is above all clinical, however electroneuromyography (ENMG) and laboratory tests can be helpful. ENMG testing is readily available and with immediate results. Useful with emergent symptoms, it is equally so in the event of more acute pictures found in generalized motor deficit and bulbar findings of respiratory failure. It can be performed in out-patient clinics or at the bedside. ENMG is based on an assessment of repetitive nerve stimulations (RNS), which can be sensitized, and more rarely on jiter studies using single-fiber electromyography (SFEMG). RNS recordings from multiple sites, depending on symptoms, are preferable. The usefulness of these tests varies depending on the clinical situation, not only for diagnosis but also during follow-up, in order to obtain objective evidence of the effects of treatment.