Integrating fetal neural transplants into a therapeutic strategy: the example of Huntington's disease

Fetal neural transplants have become clinically relevant over the past 15 years for two major neurodegenerative diseases, namely Parkinson's disease and Huntington's disease. It is therefore timely to consider how this neurosurgical procedure can integrate the therapeutic armamentarium, what can be expected of it, and what cannot. We use here the example of Huntington's disease to show what fetal neural transplants may uniquely offer for that disease. Up to very recent times, Huntington's disease has been one special example of those neurodegenerative diseases against which neurologists feel totally helpless. This has all changed today and, although results are essentially still to come, one can foresee the mobilization of very large scientific and medical forces against this disease, with definite steps forward in terms of physiopathology and a better view of the therapeutic challenges. While defining the role that fetal neural transplantation may play in meeting these challenges, we also try to show rationales and developments for all types of treatments attempted or suggested so far, as well as their limits and, when relevant, informative failures. The date of writing this review needs to be noted, because the rapid accumulation of data on molecular mechanisms of Huntington's disease pathogenesis and the increasing numbers of clinical trials do not allow much time for the ink of a review to dry.