The common language

A clinical database requires standardization through the use of a common language, based on an agreement upon the nomenclature, the definitions and the classifications to be used. With such a tool, medical practice is made easier because the relevant features of the record are easily identified. This also facilitates the exchange of data between investigators.

Thus, classical definitions have been adopted for relapses, remissions and progression. Specific definitions have been set up for the characterisation of the relapses and the onset of progression, and for the categories of symptoms.

The Kurtzke EDSS scale has been incorporated in EDMUS since it is presently the gold standard and in wide usage for MS clinical practice and research. However, the unsatisfactory consistency in the scoring between several examiners is a well-known phenomenon. Among the reasons for it is the ambiguous nature of some definitions.

Consequently, a special EDMUS Grading Scale has been derived from the DSS scale with precise and concise definitions of the grades and no mixing of functional systems with walking abilities. This scale is quick and easy to assess, even retrospectively. The EGS scale has been validated by the EVALUED study.

The diagnostic classification is made according to Poser's criteria and, more recently, to McDonald's criteria.