Abstract
The promise of stem cell regeneration has been the hope of many neurologic patients with permanent damage to the central nervous system. There are hundreds of stem cell trials worldwide intending to test the regenerative capacity of stem cells in various neurological conditions from Parkinson’s disease to multiple sclerosis. Although no stem cell therapy is clinically approved for use in any human disease indication, patients are seeking out trials and asking clinicians for guidance. This review summarizes the current state of regenerative stem cell transplantation divided into seven conditions for which trials are currently active: demyelinating diseases/spinal cord injury, amyotrophic lateral sclerosis, stroke, Parkinson’s disease, Huntington’s disease, macular degeneration and peripheral nerve diseases.
Introduction
Unlike other organs, the central nervous system (CNS) has a limited intrinsic capacity to regenerate following most types of injury, often leading to permanent disability. Stem cell trials for a variety of neurologic diseases provide patients and physicians with regenerative stem cell treatments that can potentially restore neurologic function previously lost due to disease, maldevelopment or trauma. In this review, we provide the current state of clinical stem cell research for several neurologic diseases in which stem cell trials are promising.
Conclusions
It is difficult to compare the efficacy of different stem cells or compare them to small molecule-based therapy. However, this comprehensive review highlights that, while no single cellular source appears as a first choice for regenerative therapy, there are several potential sources that offer substantial promise.
For demyelinating diseases such as MS, the diffuse nature of the disease involving the entire CNS presents a challenge for delivery of regenerative stem cells. Perhaps a focal proof-ofconcept model such as transverse myelitis or optic neuritis can demonstrate the regenerative capacity of neural stem cells. However, work with human fetal oligodendrocytes appears very promising. In consideration of MSCs for their immunologic and supportive roles, we are excited about the potential use in MS given their safety record.
