Multiple Sclerosis: Diagnosis and Differential Diagnosis.

The diagnostic criteria for multiple sclerosis (MS) have been continuously evolved since 1950's, and gained speed parallel to the development of detailed laboratory methods. The common aim for all the defined criteria up to now, is to establish the dissemination in space and time of the clinical picture caused by the lesions in the central nervous system (CNS), and to rule out other diseases which might mimic MS. There is no definite measure or laboratory marker for the diagnosis of MS, yet. Both the clinical features of the disease, and laboratory investigations such as magnetic resonance imaging (MRI), and cerebrospinal fluid (CSF) analyses are being used. Clinical and imaging findings that may be seen in MS, can also be mimicked by some infectious, neoplastic, genetic, metabolic, vascular and other idiopathic inflammatory demyelinating disorders (IIDD). In the earlier stages of the disease, especially IIDD's such as neuromyelitis optica spectrum disorders (NMOs) and acute disseminated encephalomyelitis (ADEM) can cause diagnostic difficulty, however, these disorders which have both distinct pathogeneses and clinical courses than MS, should also be treated differently. Therefore, to identify MS-related attacks and determine the final diagnosis is vital for the correct treatment choice and longterm disability prevention. In this manuscript the principal approach for the diagnosis and differential diagnosis of MS has been reviewed regarding the recent guidelines.