When Should I get DBS or Can I Wait for Stem Cell Therapy?
Parkinson’s patients all want to know when they should get DBS (deep brain stimulation) therapy. When will stem cell or gene therapy become available? And finally, should they wait?
“Years ago such treatments were the stuff of science fiction and Hollywood horror movies, but deep brain stimulation as a treatment for Parkinson’s disease is real and effective when patients are properly chosen.”
When will Stem Cells become available?
There have been many stem cell studies done on animal models of Parkinson’s disease. Although the results are very encouraging, there are obstacles to this technology, which must be cleared before governing bodies, like the FDA, will approve a stem cell trial in humans.
Through hard work in the laboratory, animal and human studies now show that fetal and embryonic stem cells can be directed toward the formation of dopamine cells and can form synapses that can connect with a host’s brain tissues, restoring dopamine and function (Freed, 2001, Mendez, 2002, Lindval, 2002, Isacson, 2003, Bjorklund, 2003). But these advances are slow and the processes of understanding the biology and optimizing dopamine stem cell function are likely to take many additional years in the laboratory. If animal studies are satisfactory, there will be a move to human trials. As stated, these advances are measured in years, not weeks or months.
Should I have DBS now?
DBS has been proven to be the best treatment to come along for Parkinson’s patients since the 1960s when L-Dopa was discovered. Several studies have shown that DBS can increase and sustain “on” time in Parkinson’s patients (Kleiner-Fishman & Lozano, 2003).
DBS can relieve many symptoms of Parkinson’s such as tremor, dystonia (muscle cramping) and dyskinesia (impairment of voluntary movement). Therefore, it can increase “on” time and improve quality of life in many patients. DBS cannot, however, improve postural instability, voice or speech, memory problems or dementia. Most important, DBS does not cure or halt the progression of Parkinson’s disease and cannot make a patient any better than his/her best medicated “on” time. I can’t help but repeat this in every consultation as I set realistic expectations of this therapy for my patients.
Parkinson’s patients can be helped by DBS if patients experience “on” and “off” times during the day (motor fluctuations), despite the best medical therapy available. It gives patients more “on” time and relieves tremors, dyskinesia and dystonia. In other words, if medicines are no longer effective for high quality of life, it may be time to consider DBS.
In the office, I can help determine patients’ needs and how well they may respond to DBS through a series of evaluations, which include an interview, physical exam and standardized testing. The evaluation helps me determine what type and at which stage a patient’s Parkinson’s disease is when on and off medications. If there is a substantial difference between “on” and “off” times with medications (>35%), then DBS can most likely give more “on” time. If there is little or no difference, then DBS is not the proper treatment.
If I have a DBS can I still have stem cells or gene therapy later in life?
If the use of stem cells for Parkinson’s disease is shown to be effective, then the cells will become available for patients even though they had DBS therapy. So, if you are a candidate for DBS, have your DBS therapy and enjoy your quality of life. Then, when and if other therapies become available, you may still be a candidate for them because DBS does not destroy brain tissue, as did earlier operations of the brain.
From the past to the future
We live in exciting times. Twenty-five years ago none of us could have imagined the treatments for Parkinson’s disease that are available today. Years ago such treatments were the stuff of science fiction and Hollywood horror movies, but deep brain stimulation as a treatment for Parkinson’s disease is real and effective when patients are properly chosen. Years back it wasn’t even a concept when L-Dopa was discovered in the late 1960s, but now DBS is one of our Gold standard in the treatment of Parkinson.
Patients should consider having DBS now if their disabilities are impairing their activities of daily living, despite best medical management. Stem cells may be coming but are not available now. DBS can help bridge the time gap between today and the future when stem cell transplants may become available.
By Bruno V. Gallo, MD