INTRODUCTION

Multiple sclerosis (MS) is the most common autoimmune inflammatory demyelinating disease of the central nervous system. This disease primarily affects women of Northern European descent who are of child-bearing age. MS is characterized pathologically by multifocal areas of demyelination with loss of oligodendrocytes and astroglial scarring. Axonal injury is increasingly recognized as a prominent pathologic feature of MS.

Certain clinical features are typical of MS, but the disease has a highly variable pace and many atypical forms. Investigative studies such as MRI, evoked potentials, and spinal fluid analysis are often needed to confirm the diagnosis and exclude other possibilities.

The diagnosis, differential diagnosis, and unusual presentations of MS are reviewed here. Other aspects of MS are discussed separately. (See "Epidemiology and clinical features of multiple sclerosis in adults" and "Treatment of relapsing-remitting multiple sclerosis in adults" and "Treatment of progressive multiple sclerosis in adults" and "Comorbid problems associated with multiple sclerosis in adults".)

DIAGNOSIS

Multiple sclerosis (MS) is a clinical diagnosis. The clinical manifestations of MS are reviewed here briefly and discussed in detail separately. (See "Epidemiology and clinical features of multiple sclerosis in adults", section on 'Clinical symptoms and signs'.)

There are no clinical findings that are unique to this MS, but some are highly characteristic (table 1). Common symptoms of MS are listed in the table (table 2). The typical patient presents as a young adult with two or more clinically distinct episodes of central nervous system dysfunction with at least partial resolution. Presenting symptoms and signs may be either monofocal (consistent with a single lesion) or multifocal (consistent with more than one lesion). (See "Epidemiology and clinical features of multiple sclerosis in adults".)