 Therefore, the concept of "clinical MS", for an MS that can be diagnosed, has been developed.Until MS diagnosis has been established, nobody can tell whether the disease one is dealing with is MS.

Cases of MS before the CIS are sometimes found during other neurological inspections and are referred to as subclinical MS. Preclinical MS refers to cases after the CIS but before the confirming second attack.After the second confirming attack the situation is referred to as CDMS (clinically defined multiple sclerosis).