Fred Lublin

New evidence and consensus has led to further revision of the McDonald Criteria for diagnosis of multiple sclerosis. The use of imaging for demonstration of dissemination of central nervous system lesions in space and time has been simplified, and in some circumstances dissemination in space and time can be established by a single scan. These revisions simplify the Criteria, preserve their diagnostic sensitivity and specificity, address their applicability across populations, and may allow earlier diagnosis and more uniform and widespread use.

The International Panel on MS Diagnosis presents revised diagnostic criteria for multiple sclerosis (MS). The focus remains on the objective demonstration of dissemination of lesions in both time and space. Magnetic resonance imaging is integrated with dinical and other paraclinical diagnostic methods. The revised criteria facilitate the diagnosis of MS in patients with a variety of presentations, including "monosymptomatic" disease suggestive of MS, disease with a typical relapsing-remitting course, and disease with insidious progression, without clear attacks and remissions. Previously used terms such as "clinically definite" and "probable MS" are no longer recommended. The outcome of a diagnostic evaluation is either MS, "possible MS" (for those at risk for MS, but for whom diagnostic evaluation is equivocal), or "not MS."

New diagnostic criteria for multiple sclerosis integrating magnetic resonance image assessment with clinical and other paraclinical methods were introduced in 2001. The "McDonald Criteria" have been extensively assessed and used since 2001. New evidence and consensus now strengthen the role of these criteria in the multiple sclerosis diagnostic workup to demonstrate dissemination of lesions in time, to clarify the use of spinal cord lesions, and to simplify diagnosis of primary progressive disease. The 2005 Revisions to the McDonald Diagnostic Criteria for MS should simplify and speed diagnosis, whereas maintaining adequate sensitivity and specificity.

BACKGROUND: In 1996, the clinical course of multiple sclerosis (MS) was characterized as relapsing-remitting, primary progressive, secondary progressive or progressive relapsing. Since then, an increased understanding of MS and its pathology prompted a re-examination of these clinical phenotypes. Main recommendations of the 2013 revisions are provided herein. SUMMARY: Clinically isolated syndrome has been added, and progressive relapsing MS has been eliminated, from the clinical course descriptions. All forms of MS should be further subcategorized as either active or non-active. Active MS is defined as the occurrence of clinical relapse or the presence of new T2 or gadolinium-enhancing lesions over a specified period of time, preferably at least one year. An additional subcategory for patients with progressive MS differentiates between those who have shown signs of disability progression over a given time period and those who have remained stable. The term 'worsening' is recommended to describe patients whose disease is advancing for any reason, whereas 'disease progression' should be reserved for those with progressive disease who are truly progressing (as opposed to worsening from a relapse). The term 'benign' should be used with caution as the course of MS can worsen at any time, even after many years of apparent stability. Key Messages: Newer characterizations of MS phenotypes include a consideration of disease activity (based on the clinical relapse rate and imaging findings) and disease progression. Accurate clinical course descriptions are useful for communication, prognostication, clinical trial design and to guide everyday clinical decision-making.