Stem Cell Research
Stem cells are undifferentiated cells that have the remarkable potential to grow into any kind of cell, and under specific conditions can be induced to become tissue or organ specific cells. Therefore it is widely believed that they may be able to help reverse paralysis. Several studies are looking at specific ways to use stem cells to restore lost functionality.
Geron, a biotechnology company based in California is investigating ways in which stem cells can be used to restore spinal cord function by injecting stem cells into the site of damage. This company’s clinical trial began in 2010 and is the first to use human embryonic stem cells in people. The multi-phase trial is testing the safety of the treatment in patients with recent spinal cord injuries. Geron is one of two companies that is close to meeting FDA approval for treatment options that use human embryonic stem cells. Massachusetts-based Advanced Cell Technology (ACT) is the other company.
Preliminary results presented by Geron at an international conference in June 2011 revealed that no significant adverse affects were experienced by the first two trial patients.
The ability to grow new nerve cells is present with us from birth, however it declines as we grow older. Therefore If nerve cells become diseased or damaged, the human body cannot repair them. This factor has been the overwhelming barrier to treating paralysis. Scientific findings may shed some light on how to overcome this seemingly intractable obstacle.
Regeneration of nerve cells offers new hope for treatments for paralysis.
Research by Harvard University, University of California-San Diego and University of California-Irvine, published in the August 2010 issue of Nature Neuroscience, revealed a possible solution. Researchers were able to regenerate spinal cord nerves in mice by manipulating an enzyme involved in cell growth.
They were able to do this by knocking out a gene called PTEN which normally inhibits new nerve growth. In so doing substantial regrowth in nerve cells controlling voluntary movement occurred. The next stage of the research will look at whether spinal cord function can be restored.
Paralysis can involve other parts of the body. Each form requires a customized approach to finding a cure. Paralysis of the vocal cords, for example, relies heavily on therapy as the first option for dealing with this condition. There are several possible causes of vocal paralysis, including complications from surgery, chest trauma or viral infections. Other times, the cause is unknown.
The difference in treating this type of paralysis is that it can reverse itself spontaneously in some cases. Treatment begins with voice therapy. A procedure called arytenoid adduction can be performed to improve voice quality. It involves rotating the affected vocal cord and is often performed with another procedure called thyroplasty to change the structure of the vocal cords. It is an effective approach for paralysis caused by injury from airway instrumentation during surgery.
The 2011 Triological Society’s Combined Sections Meeting explained that a customized treatment plan for vocal cord paralysis is the best form of treatment. While procedures such as reinnervation have been successful, medical experts now believe this procedure is a better option for younger patients. As more is learned, other recommendations for existing options may emerge, illustrating how the field continues to evolve.
Another therapeutic approach that has shown promise is deep-brain stimulation. Stroke patients are good candidates for this approach to overcome weakness or paralysis. Researchers at Kyoto University in Japan used high-frequency transcranial magnetic stimulation over the affected part of the brain in stroke patients with moderate to severe paralysis.
Participants also received physical therapy in conjunction with magnetic stimulation. Magnetic stimulation, in effect, re-taught lost motor skills when combined with physical therapy. After the six-week trial, researchers reported that the patients regained some motor control and reversed paralysis temporarily by reducing abnormal muscle tension that inhibited movement.
Researchers concluded that the human brain can adapt to stimulation, opening the potential for using this method to treat paralysis in stroke patients and those with other movement disorders. Magnetic stimulation is non-invasive, offering a distinct advantage to other forms of treatment.
The research into a cure for paralysis has opened up new areas of understanding of how the human body functions. Knowledge of the genetics affecting nerve cell regeneration and how the brain adapts have uncovered novel methods to treating specific causes of paralysis. While controversial, stem cell research opens doors to re-programming unspecialized cells to repair damaged tissue. With continued research, the cure for paralysis may be within the grasp of science.
Christopher & Dana Reeve Foundation: Paralysis Facts & Figures
Medline Plus: Paralysis
Stem Cell Information: Stem Cell Basics
Kai Kiu et al. PTEN deletion enhances the regenerative ability of adult corticospinal neurons. Nature Neuroscience, August 2010; 13:1075-1081.
Society for Neuroscience: Brain-machine interfaces offer improved options for prosthetics and treatments after injury