Introduction

Abstract

There is as yet no specific diagnostic laboratory test for MS. However, a battery of cerebrospinal fluid (CSF) findings — mononuclear pleocytosis, normal or only slight to moderate elevation of total protein, but a pronounced increase of IgG — the demonstration using the formulas of Ganrot and Laurell, Link, or Tourtellotte that this is of CNS origin, and the appearance of subfractions, oligoclonal bands in the gamma range (Lowenthal and coworkers), represent a combination which is highly pathognomonic for MS and of decisive value in establishing clinical diagnosis in cases with atypical symptomatology and course. Mononuclear pleocytosis, with the appearance of plasmocytes, is the earliest alteration found by routine examination of CSF. In the majority of cases it is a transitory finding, followed within 6–12 weeks by an IgG increase of persistent nature. The IgG increase in CSF is found in 60–80% of all MS cases, and oligoclonal bands have been demonstrated in 70–90% of CSF specimens from MS patients.