Neuroprevention: a new challenge?

Neurodegenerative disease (NDD) has become the leading cause of disability and dependency in Western and European societies. Treatments, when available, are symptomatic, and their efficacy is usually poor or decreases with disease progression. So far, no treatment can effectively modify NDD, partly because of the inevitable delay between the onset of the pathological process and therapeutic intervention. The ideal strategy would be to stop the pathological process before neurons degenerate - in other words, before symptoms. However, to do this, the populations at high risk of developing NDD need to be identified. Predicting the appearance of NDD encounters two main issues. The first is to accurately determine the very beginning of the neurodegenerative process and to follow its course; the second is to determine those populations at high risk of developing NDD. Several approaches have been proposed to identify presymptomatic markers, including the refinement of the semiology in the early stages of the disease and/or the prospective follow-up of asymptomatic carriers of the genetic form of NDD in particular. To predict the onset of NDD at the asymptomatic stage, however, raises ethical issues at a time when no preventative medication is as yet available.