Multiple sclerosis--making the diagnosis.

Although intensive research into all aspects of MS in the past 50 years has led to a great deal of information about pathological processes that may relate to its causation and expression, the disease is still an enigma--one of the greatest unsolved problems in medicine. Recent advances in neuroimaging and the ability to measure conduction in CNS pathways (evoked potentials) reveal subclinical effects, complementing clinical examination and frequently enabling a firm diagnosis in earlier phases of the disease than hitherto. In some situations earlier conclusive diagnosis facilitates management. But this is by no means invariably so. Clinical criteria continue to be paramount; investigative findings are supportive rather than being primarily diagnostic in their own right. Integrating this information at any one time for the maximum benefit of the patient tests knowledge and judgement.