It was just last month that we heard about a brain implant which dispenses a protein to stop seizures in epileptic rats. An unrelated British/Canadian study now suggests that a brain implant in humans, which delivers that same protein, could be used to treat and even reverse the effects of Parkinson's disease.
As part of the new research, a total of 41 test subjects – all of whom had Parkinson's – got a Convection Enhanced Delivery system installed in their brain. This involved utilizing robot-assisted neurosurgery to place four tubes within the organ. The open tip of each tube reached into a different area of the brain, in which the disease was causing dopamine cells to die.
All four tubes were also connected to a single skull-mounted external delivery port, protruding through the skin behind one ear.
In a subsequent double blind trial, all of the volunteers received infusions via that port, once every four weeks for nine months. And while half of the participants were unknowingly given a placebo, the other half got a growth-factor protein known as Glial Cell Line Derived Neurotrophic Factor (GDNF). Earlier research suggested that this protein could help regenerate dopamine brain cells.
PET scans subsequently revealed a 100-percent improvement in the treated areas of the GDNF group's brains – by contrast, there was no change in brain scans of the placebo group. Unfortunately, though, Parkinson's symptoms weren't reduced in any of the volunteers. This may have been due to a lag taking place between the occurrence of biological improvements, and the expected reduction in the severity of symptoms.
That said, all of the test subjects were then put on the GDNF for another nine months. After that treatment period was over, members of both groups showed a moderate to large improvement in symptoms. Additionally, there were few if any side effects, suggesting that the technique is safe.
Plans now call for a larger-scale study, in which higher doses of the protein will be administered.
"The spatial and relative magnitude of the improvement in the brain scans is beyond anything seen previously in trials of surgically delivered growth-factor treatments for Parkinson's," says principal investigator Dr. Alan L. Whone, of the University of Bristol. "This represents some of the most compelling evidence yet that we may have a means to possibly reawaken and restore the dopamine brain cells that are gradually destroyed in Parkinson's."
A paper on the research was recently published in the Journal of Parkinson's Disease.
Source: IOS Press
