About Cerebral Palsy
- Are there stem cell therapies available for cerebral palsy?
- How close are we? What do we know about cerbral palsy?
- What research is underway?
- Further reading on cerebral palsy
Are there stem cell therapies available for cerebral palsy?
Currently, there are no Health Canada or U.S. Food and Drug Administration approved stem cell therapies for treating cerebral palsy. Patients researching their options may come across companies with Web sites that say otherwise and offer fee-based stem cell treatments. Many of these claims are not supported by sound scientific evidence and patients are encouraged to review some of the links below before making crucial decisions about their treatment plan.
For more about stem cell clinical trials for cerebral palsy click here. (For printed version: http://1.usa.gov/1BykIWH)
How close are we? What do we know about cerbral palsy?
- Cerebral palsy (CP) is actually a group of permanent disorders that cause a range of life-long motor and posture related impairments.
- CP is the most common childhood physical disability, affecting about 2.5 of every 1,000 live term births and 22 of every 1,000 live premature births. It affects boys more than girls.
- The causes are complex and not completely understood. Many risk factors may be present and interrelated. Common ones include preterm birth, multiple births, shortage of oxygen (hypoxia) or blood supply (ischemia) and gestational infections/inflammation. Other risk factors include genetics, diseases of the blood vessels or metabolism, head injuries, and higher maternal age.
- Symptoms typically begin to appear before the age of two and include lack of coordination, stiff, tight muscles or increased reflexes and stiff gait, dragging one foot or leg, walking on toes or floppy muscles.
- Rehabilitative strategies focus on exercise, occupational therapy, surgery and drugs. Only two treatments have been shown to minimize or prevent damage in newborns at risk for CP: therapeutic hypothermia (a controlled drop in temperature) to minimize damage due lack of oxygen or blood supply, and magnesium sulfate, which can stabilize oxygen supply.
- Most adults with CP have a normal life expectancy but may face worsening mobility or increased pain and discomfort. Very severe physical disabilities can contribute to a shortened lifespan.
- People with CP may require intensive, life-long access to health services, social services and rehabilitative interventions. With no cure in sight, the burden to the individual and caregivers is substantial.
How can stem cells play a part?
Researchers have many years of hard work ahead of them before they can mobilize stem cells into replacing or repairing the central nervous system cells that CP has injured. To get to that goal, they are investigating the use of embryonic, fetal and adult tissue/blood stem cells. Two types that show promise in preclinical lab models are mesenchymal stem/stromal cells (MSCs) and neural stem cells.
Are there lots of groups working on developing a stem cell therapy?
Many research teams around the globe are working on stem cell therapies for CP. They are trying to identify how stem cells work, how best to grow and direct stem cells in the laboratory, and how to stimulate the small number of stem cells that naturally reside in the brain. They are also investigating cell dosages and delivery methods.
Lessons have been learned from pre-clinical and early phase clinical studies on other neurological conditions, such as spinal cord injury, multiple sclerosis, eye diseases and Parkinson’s. This research suggests that stem cells have both protective and regenerative properties that could be harnessed to repair damaged brain tissue. Ongoing trials are testing the safety of stem cells for treating these neurological conditions in children and adults and scientists are waiting to see whether the findings are relevant to CP.
Stem cell research on CP is moving down a number of different avenues and some successes have yielded very small Phase 1/2 clinical trials using MSCs and neural stem cells.
What research is underway?
Before basic stem cell research can be translated into the clinic for patients, it must first be rigorously tested and validated. Studies transplanting stem cells into animals have shown some benefits, but exactly what the stem cells are doing is still somewhat unclear as not many of the transplanted cells actually go on to survive. Their ability to promote blood vessel formation, make support cells of the brain (astrocytes or oligodendrocytes), increase survival of brain cells, or block the spleen’s normally inflammatory response to injury may account for a stem cell effect.
Finding a stem cell therapy for CP will take time, but the wealth of information generated from labs around the globe is converging to help with the transition from basic research to the clinic. Overall, discoveries in the stem cell and CP fields are advancing. With the first clinical trials underway, real-world results might be seen in the next several years. Scientists, clinicians, policymakers, families and individuals with CP are working together to move CP research forward.
Current research using mesenchymal stem/stromal cells
Mesenchymal stem/stromal cells (MSCs) can be easily collected from bone marrow, fat and umbilical cords. In the lab, they can make a few different types of specialized cells. They can dampen the immune response, inhibit inflammation, stimulate blood vessel formation, and activate the small numbers of neural precursor cells in the brain. Years of doing bone marrow transplants (which also contain MSCs) for leukemia have proven that MSCs are relatively safe. Also, MSCs don’t seem to cause the kind of graft rejection typical with other donated stem cell transplants.
Researchers have shown that MSCs can stimulate neural precursors in the brain and provide physical scaffolding for nerves, but to date there is still little evidence that MSCs help repair neural damage. Nevertheless, a small collection of clinical trials are testing MSCs from bone marrow and umbilical cord blood in people with CP. Researchers find cord blood advantageous because it is easy to obtain and comes with little risk to the donor and little chance of transmitting infectious viruses. Researchers eagerly await the findings from these trials. In the meantime, there are lessons to be learned from the results pouring in from MSC trials for other diseases. This knowledge will help researchers design better clinical trials, taking into account many more known factors that could impact MSC performance.
Current research using neural stem cells
Scientists are still fine-tuning their pre-clinical stage studies using neural stem cells for CP. For example, they are trying to identify the best drugs to trigger expansion of neural stem cells in individuals, and find better ways to expand or treat the neural stem cells in the laboratory before re-implanting them. The method that works best in animals uses donor neural stem cells, expanding them and injecting them directly into the brain. Gene therapy is also being tested by investigators in the hope that inserting growth factors into neural stem cells will increase their capacity to protect damaged neurons.
Scientists are continuing to learn about neural stem cells from studying other diseases and, although they show much promise, their application to CP is not without challenges. First, scientists must prove the cells are safe for use in humans. And there are still concerns, though increasingly minimal, over potential tumour formation or transplant rejection. Once safety concerns are addressed, researchers will have to optimize timing, dosage, delivery, and survival of the transplanted stem cells. The transition from ‘bench’ to ‘bedside’ is challenging, yet the exciting work underway suggests that using stem cells as a therapy for CP is realistic.
Further reading on cerebral palsy
Readers may wish to peruse the recommended sites and below for more information about cerebral palsy and the possible future applications of stem cells to treat this disease.