Until the beginning of the 1980s, evoked potentials (EPs) were considered a unique diagnostic tool for multiple sclerosis (MS), particularly because of their capacity to reveal the presence of clinically hidden dysfunction in a sensory system when MS was suspected owing to clinically evident dysfunction in another brain or spinal cord area. Since the advent of magnetic resonance imaging (MRI), multiple lesions can be detected much more easily and reliably, which led some clinicians to consider that EPs had lost their place in the workup of MS patients. This holds not true as EPs remain of utmost importance in two indications:

– as a method to objectivize ill-specific symptoms: provided that the stimulus should be adapted to the precise sensory sub-modality in which a deficit has been suspected, EPs may be used to decide whether or not the patient should be orientated toward MRI, less accessible and more expensive;

– as a follow-up tool: based on some observations over time periods exceeding 30years, we know that EPs remain remarkably stable in the absence of lesion appearance or evolution; therefore, we frequently use them to reliably reassure patients fearing relapses, based on non-specific symptoms. Consequently, we consider it both medically and economically justified getting a baseline recording of multimodality-evoked potentials in any patient in whom MS has been diagnosed. While the classical stimulus modalities (pattern visual, brainstem auditory, electrical somatosensory and motor EPs) should be preferred, other less-classical modalities (laser, vestibular myogenic, blink reflex) may prove useful in some specific cases.