The Brain Cell Transplant that Could Potentially Treat Parkinson’s Disease

Parkinson’s Disease is a degenerative condition of the patient’s central nervous system which affects, among other things, the person’s motor functions. The disease initially manifests as involuntary movements such as shaking and difficulties to keep steady limbs, and can eventually evolve to include rigidity, slowness of movement and, eventually, difficulty walking and getting around. It is common for patients who have struggled with the disease for long periods of time to also experience psychological symptoms, such as stress, anxiety, depression, and even dementia at some point. The symptoms themselves — especially the motor ones — are referred to as parkinsonism.

Unknown Variables

It is not known why this disease affects certain people over others, but it has been determined that certain factors, such as heritage, exposure to pesticides, and certain lifestyle choices can affect the onset of the condition. Once Parkinson’s begins to take hold, the affected person begins losing neurons in the substantia nigra, a region of the midbrain. Said loss leads to diminished levels of dopamine in this area, causing the aforementioned symptoms to begin progressively surfacing, and worsening with time. It is still unknown what triggers the brain cells in this area to begin dying in Parkinson’s patients, but it has been discovered that their cause of death is due to the build-up of proteins in their Lewy bodies.

As much as there is still a lot of unknown variables in Parkinson’s Disease, certain treatments have already surfaced which, while they do not help to cure the disease, can improve its symptoms and help the patient to live a normal life for as long as possible. Among these treatments, we can find the antiparkinson medication levodopa and dopamine agonists, which can ease the symptoms of the disease in its initial stages. Once the condition develops, and the medication begins to lose effectiveness, the patient can undergo changes in their diets as an alternative method to help relieve the symptoms. Furthermore, patients that suffer from advanced stages of the disease can undergo surgery to place microelectrodes for deep brain stimulation which can help relieve the motor symptoms once the medication loses effectiveness.

Brain Cell Transplants in the 80's and 90's

Our understanding of Parkinson’s has evolved to the point in which we already know the mechanism behind the disease, but we are no closer to curing than how we were a few years ago. All the treatments developed, so far, are designed to ease the symptoms and allow the victim to retain some semblance of functionality. However, this all may be about to change thanks to new experimental treatments aimed at replacing the dead neurons in the person’s substantia nigra which should, in theory, help him or her regain the functionality they had before the disease began to surface.

However, regardless of the theoretical improvements that this procedure could entail, this is not the first time it has been attempted, as it was done so decades ago with disappointing results after which the project was put on hold indefinitely. It was believed that the failure of the procedures in those occasions was due to the instability and effectiveness of the brain cells, or lack thereof. Said experiments were initially held in the 80's and 90's and the reasoning behind it was that, if the medication that increased the levels of dopamine in the person’s system helped to ease the symptom, then replacing the cells in the brain in charge of producing the substance should remove them entirely. So they set off to replace using the neurons taken from the brains of aborted fetuses and implanting them into the substantia nigra of Parkinson’s patients.

Results

At first, some patients showed significant improvements in the reduction of tremors, rigidity, and involuntary spasms. However, the vast majority didn’t show improvements, and some even manifested additional symptoms, the most important being the appearance of uncontrolled movements. In short, the cons far outweighed the pros, and the procedure was put on indefinite hold in 2003 to research exactly how, when, and where the method went wrong.

Despite several cons, it was clear that many patients managed to reap benefits from the procedure. With that in mind — and more than a decade later —, scientists have set out to give it another shot.

Modern Brain Cell Transplants

Certain groups in Asia and the US are surfacing in hopes of reviving the experimental treatment, this time using safer and more stable cells. In its initial phase, scientists and researchers of the Weill Cornell Medicine group located in New York have presented very promising results along with optimistic claims to which each and every Parkinson’s sufferer in the world rejoices.

After interviewing five patients who had received the experimental procedure more than a decade ago, it was impressive to observe how the symptoms had evolved, in that some of them had shown and still show improvements from their initial phase before they underwent the treatment.

Upon reflecting on the failure of the first project, it was determined that the most plausible reason revolved around the patient’s rejection of the implanted cells. Specifically, that since they were essentially implanted with parts of another person’s brain (in this case, the aborted fetuses’) which contained not only the dopamine neurons but also other types of cells, some of these could have grown within the recipient which, in turn, caused the unexpected side effects. Moreover, it was suspected that the patients who didn’t show either improvements or detriments simply didn’t take to the implanted cells.

What Does it Mean?

Using this knowledge, scientists have spent the best part of 12 years researching methods to create perfect neurons from stem cells to replace the ones damaged by Parkinson’s. In this sense, rejection of the implanted brain cells is virtually impossible given that they are perfect copies of the neurons which were destroyed by the disease. Furthermore, the other benefit of lab-produced brain cells is that the supply is unlimited since they no longer depend on aborted fetuses to harvest them. As of now, there are already over a thousand doses of brain cells produced and ready for implanting, sitting in a freezer.

The treatment is already fit for human testing; all that’s left is to receive permission from the Food and Drug Administration which, hopefully, will happen for 2018. It was already determined that the failure of the first treatments were due to the nature of the implanted cells. In this sense, there is an air of hope surrounding the new procedures: on one hand, there is fear that rushing into them might cause more harm than good. But on the other, this just might be the right opportunity for those who suffer from Parkinson’s to receive the cure they have needed for so long.