INTRODUCTION

The multitude of symptoms and the variable course of MS often cause difficulties in its differential diagnosis, even for the most experienced clinicians. It is part of the confirmation of this serious diagnosis to exclude other diseases whose symptoms may be confused with those of MS.

The correct diagnosis is based on factors gleaned from various sources (see Chapter 8): clinical aspects – indications from the case history as to onset and course of the symptoms, findings of clinical examinations, therapeutic influences, etc.; electrophysiology – delay of latencies in various central tract systems; laboratory investigations – changes in CSF and serum; and imaging procedures. Each of these aspects has to be considered in the differential diagnosis before being accepted as part of the diagnosis.

In specialized MS centers (Murray and Murray 1984; Hemdon and Brooks 1985), misdiagnosis of referrals occurs at a rate of 10% to 15%. It is a particular danger that during the initial period of observation, a diagnosis which is only under consideration becomes established and distracts the attention of the examiner from the differential diagnostic possibilities. When a diagnosis is established, almost all symptoms and signs should be explained by it, and further aspects of the differential diagnosis may be ignored. For this reason it is particularly important to reevaluate the established diagnosis at regular intervals and, in particular, the probable and possible ones. The most important diagnostic parameter in MS is the observation of the disease course.