Brain transplants. A new approach to the therapy of neurodegenerative disease.

There is now a wealth of experimental evidence to suggest that transplantation to the brain may ameliorate a variety of neurologic and endocrine disorders. Many unanswered questions remain. Chief among these questions are the duration of any salutary effects and the potential long-term risks to the host CNS. Answers to these questions will only come with carefully controlled long-term clinical studies. Given the high incidence and devastating nature of many of these diseases, such studies will have enormous scientific and social impact. Regardless of the outcome, there is the potential for a greater understanding of the pathologic mechanisms underlying neurodegenerative diseases and, thus, the possibility that definitive therapies will be found as a result.