Diagnosis and differential diagnosis of multiple sclerosis

Purpose of Review: When a patient presents with symptoms or imaging suggestive of multiple sclerosis (MS), making the correct diagnosis may at times be straightforward but in many cases is quite challenging. Symptoms may be difficult for patients to characterize and for clinicians to interpret; findings on examination may be subtle; imaging is not always specific; and the differential diagnosis of possible demyelinating disease is quite broad. Making a correct diagnosis of MS early in the disease course is likely to become even more important over time as new disease-modifying therapies, particularly those with potential neuroprotective benefits, are introduced. This article reviews the current diagnostic criteria for MS and illustrates their application as well as reviews the differential diagnosis for patients presenting with symptoms or imaging suggestive of demyelinating disease. Recent Findings: The diagnostic criteria for MS were revised by the International Panel on Diagnosis of Multiple Sclerosis in 2010. Summary: The diagnostic criteria for MS have been revised several times over the years, most recently giving rise to the McDonald 2010 criteria. The diagnosis of MS begins with a patient who presents with symptoms typical for the disease, termed the "clinically isolated syndrome," which most commonly affects the optic nerves, brainstem, or spinal cord. If the patient's symptoms and imaging are typical for MS, the clinician can then apply the appropriate diagnostic criteria. If atypical clinical or imaging findings are present, alternative etiologies must be pursued as appropriate.