Beginner's Guide to MS: Do I Have MS? What Does It Take To Get Diagnosed with MS?

§ One attack with objective clinical evidence of one lesion, plus dissemination in space shown on MRI or two or more MRI lesions consistent with MS plus positive CSF finding and dissemination in time shown on MRI or second clinical attack;
§ Insidious neurologic progression suggestive of MS plus one year of disease progression determined retrospectively or prospectively and two of the following: positive brain MRI result (nine T2 lesions or at least four T2 lesions with positive Visual Evoked Potential), positive spinal cord MRI result with two focal T2 lesions, and positive CSF findings.

For an explanation of how lesions develop and what it means that a lesion is active or enhances, see Beginner's Guide to MS: What is a Lesion?

Dissemination in time is shown by detection of gadolinium enhancement at least three months after the onset of the first clinical event or detection of a new T2 lesion appearing at any time compared with a reference scan done at least 30 days after the onset of the initial clinical event.  Dissemination in space is shown by three of the following: one or more gadolinium-enhancing lesions or nine T2 hyperintense lesions; one or more infratentorial lesions; one or more juxtacortical lesions; or three or more periventricular lesions.

For a history of the criteria used in the diagnosis of multiple sclerosis from 1965 to the present, see Beginner’s Guide to MS: The History of Diagnostic Criteria. 

TESTS USED TO DIAGNOSIS MULTIPLE SCLEROSIS

Complete Neurological Exam—This exam evaluates the nerves of the head and neck; muscle strength and movement; balance, ambulation, and reflexes; and sensation, memory, speech, language, and other cognitive abilities.

Magnetic Resonance Imaging—MRIs can show inflammation, demyelination, and permanent damage, in persons with MS.  They are one tool used to show dissemination in time and space, as required in the diagnostic criteria, and should be conducted with and without gadolinium contrast agent.

Evoked Potential Tests—These tests record the nervous system's electrical response to the stimulation of specific sensory pathways (e.g., visual, auditory, general sensory). A slowed response time can sometimes provide evidence of scarring along nerve pathways that does not show up during the neurological exam.  For a more detailed discussion of Evoked Potential Tests and their role in diagnosis MS in addition to other diseases, see Clinical Utility of Evoked Potentials.

Cerebrospinal Fluid Analysis—Obtained by lumbar puncture (ie. spinal tap), analysis of cerebrospinal fluid (CSF), detects the levels of certain immune system proteins and the presence of oligoclonal IgG bands (not found in blood serum) or elevated IgG antibodies. These bands indicate an immune response within the CNS and are found in the CSF of about 90-95% of people with MS. But because they are present in other diseases as well, oligoclonal bands cannot be relied upon as positive proof of MS.