How is multiple sclerosis diagnosed?

Due to the broad range and subtleties of symptoms, multiple sclerosis may not be diagnosed for months to years after the onset of symptoms. Physicians, particularly neurologists, take detailed histories and perform complete physical and neurological examinations.

• MRI (magnetic resonance imaging) scans with intravenous gadolinium helps to identify, describe, and in some instances date lesions in the brain (plaques).
• An electro-physiological test, evoked potentials, examines the impulses traveling through the nerves to determine if the impulses are moving normally or too slowly.
• Finally, examining the cerebro-spinal fluid that surrounds the brain and spinal cord may identify abnormal chemicals (antibodies) or cells that suggest the presence of multiple sclerosis.

Collectively, these three tests help the physician in confirming the diagnosis of multiple sclerosis. For a definite diagnosis of multiple sclerosis, dissemination in time (at least two separate symptomatic events or changes on MRI over time) and in anatomical space (at least two separate locations within the central nervous system, which can be demonstrated by MRI or neurological exam) must be demonstrated.