Invasive Strategies as Therapeutic Approaches for Central Nervous System Diseases

The main goal of experimental therapies for the treatment of degenerative neurological diseases ranges from the prevention of molecular events underlying neuronal death to the replacement of concrete damaged neuronal populations. Invasive therapeutic strategies such as grafting of embryonic neural cells or of adult bone marrow stem cells, the induction of trophic factor synthesis in brain cells by virus-mediated genetic transfer, and the electrical stimulation of the brain by the placement of electrodes into concrete brain circuits have accrued in the past decades. However, successful results obtained in experimental animals do not necessarily correlated with similar clinical advances. The rationale of these different invasive therapeutic strategies to treat brain damage and neurodegenerative processes is reviewed in this chapter. The discussion is focused on some noticeable discrepancies between experimental advances represented by the proposed therapies and their actual clinical benefits.