Diagnosis of multiple sclerosis.

The diagnosis of multiple sclerosis (MS) remains clinically determined, based on evidence for lesions disseminated over time and space. Evidence of multifocal disease can now be obtained through paraclinical tests, such as magnetic resonance imaging and evoked responses. Cerebrospinal fluid abnormalities may facilitate diagnosis. The disease is extremely protean in its manifestations, although early in the course, sensory symptoms, motor weakness, and optic neuritis occur most frequently. Once a diagnosis is established, patients should be so informed by their physician, so that they will be prepared to engage in dialogue about available treatment options. The diagnosis is not difficult in straightforward cases, but a large differential exists, which varies depending on the temporal and spatial profile of disease with which the patient presents.