A Clinical Approach to the Differential Diagnosis of Multiple Sclerosis.

The diagnostic criteria for multiple sclerosis (MS) rely on clinical, paraclinical, and radiographic findings of limited specificity. Many disorders mimic MS, and the decision of when to investigate an alternative diagnosis can be challenging. Reliance on extensive ancillary testing to exclude potential mimics, however, is unnecessary in most cases. Rather, recognition and rigorous interpretation of "classic" clinical and radiographic features of MS are often sufficient to establish the diagnosis. Misinterpretation of the clinical and radiographic diagnostic criteria for MS in the setting of more common diseases and syndromes and a lack of vigilance for "red flags" are important contributors to misdiagnosis. A clinical framework for the differential diagnosis of MS that emphasizes phenotypes atypical for MS and suggests diseases or syndromes in which they more commonly occur may be an important diagnostic guide for clinicians in contemporary practice.