Most patients first seek medical help after an initial attack of symptoms called a clinically isolated syndrome (CIS). Not all patients who have a CIS go on to develop MS, and it is difficult to predict which patients will or will not.
Multiple sclerosis can be challenging to diagnose as there is no one test for it, and a number of other conditions may mimic its symptoms. To confirm a diagnosis of multiple sclerosis the doctor needs to find:
- Evidence of nerve damage in at least two different areas of the central nervous system (brain, spinal cord, and optic nerves)
- Evidence that the damage occurred in episodes that happened at least one month apart
- No evidence that the damage is caused by other conditions
A diagnosis of multiple sclerosis is based on results from a combination of various tests. These include the patient’s medical history, neurological exam, magnetic resonance imaging (MRI) scans, evoked potential tests, and possibly a spinal fluid test.
The doctor will ask about the patient’s personal and family medical history, including lifestyle factors, prescription or other drug use, and other medical conditions that the patient or relatives may have had. The doctor will ask the patient to describe the symptoms experienced, when they occurred, and how long they lasted.
In a neurological exam, the doctor will test the patient’s vision and reflexes and evaluate balance, coordination, and muscle strength.
Evoked Potential (EP) Tests
This is a simple and painless electrical test of nerve function that assesses how long it takes nerve impulses from the eye, ear, or skin to reach the brain. It involves having electrodes placed on the scalp over specific areas of the brain that process sensory information. Evoked potential tests can be used to evaluate nerve transmission for vision, sound, or muscle responses in the legs or arms.
Magnetic Resonance Imaging
Review Date: 06/17/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.