A man was given treatment last week (May 18, 2015) to try and reverse his Parkinson's disease: a treatment that hasn't been tried for nearly 20 years. Fetal cells were injected into his brain in the hope that they will integrate with his brain tissue and repair the damage done by the disease.

Parkinson's disease is when some of the nerve cells that produce dopamine in the brain die. The trials that took place in the past had varying success. In the patients that had successful treatment, the fetal cells wired themselves in the brain correctly and began producing dopamine. In some cases, the injected cells produced so much dopamine that the patients didn't need to take their Parkinson's medication anymore.

This result seems to be so jaw-droppingly successful that you might wonder why the treatment was abandoned. One of the reasons was that the original scientists conducting the research underestimated how long it would take for the fetal cells to integrate into the brain. It took at least three years for the cells to integrate and start showing symptoms; this was long after the trials had ended. Another reason was that success seemed to be fickle and not all patients integrated the new cells equally well. In fact, scientists still aren't sure what causes the selectivity of success.

In the future, there is hope that stems cells will take over the role of fetal cells in replacing the missing dopamine in the brain, making the treatment less controversial. Currently, the embryonic stem cells come from the fetuses of terminated pregnancies. Stem cells could also be made as needed so there wouldn't be a shortage problem.

In fact, the man who received treatment first mentioned in the article only had half of his brain injected with the embryonic cells due to a lack of supply. The team had tried to go ahead with the surgery four times before but the operation had to be canceled due to a lack of available cells. At least three fetuses are required to have enough cells to treat only half the brain.

Roger Barker, who is leading the new study at the University of Cambridge, says: "We would expect that if we do both sides, he will see an improvement in around six months to a year." The maximum benefits will start to be apparent within three to five years.

Scientists have hopes for the future role that stem cells will play in this treatment. Stem cells have the capacity to multiply indefinitely and produce a technically infinite supply of cells for a patient, unlike fetal cells. These stem cells could make neurons and repair the damage done by Parkinson's.

The teams that are working on this research hope to begin testing their new stem cell techniques in 2017.

[Via New Scientist]