The main messages contained within this review are firstly that any advance in the management of patients with neurological disability must come from improved understanding of the mechanisms underlying that disability and secondly that the only way to demonstrate real benefit is by a process of evaluation which must incorporate appropriate measuring tools. In other words, to emphasise the crucial role of the basic sciences (be it cellular biology, immunology, physiology, or imaging) in elucidating the mechanisms underlying disability and similarly to underline the importance of the scientific principles which underpin the outcome measures used to evaluate disease management.

The three great challenges currently facing the field of neurological rehabilitation are firstly to elucidate these mechanisms, secondly to ensure that this knowledge transfers speedily to the clinical arena, and thirdly to identify scientifically sound outcome measures with which to evaluate clinical intervention.

There have been several recent advances in our understanding of the mechanisms underlying disability in neurological disorders, and multiple sclerosis provides an excellent example. This is one of the main causes of neurological disability in young adults and recent work in this area has shown the value of scientific investigation which is driven by addressing important clinical questions. There have also been encouraging advances in measuring outcome in the field of neurological rehabilitation and these will be discussed with particular reference to their application to the evaluation of therapy and rehabilitation.

Multiple sclerosis is a complex neurological disorder perhaps best exemplified by its diverse patterns of disease activity, incorporating relapses and progression.1 The development of MRI has provided an invaluable diagnostic tool which may also be used to monitor and predict disease activity2 and evaluate therapeutic interventions.3 However, once the initial flush of enthusiasm passed, it became clear that there was a major discrepancy between …