University of Calgary
Parkinson Canada/University of Calgary Partnership
Graduate Student Award
$30,000 over 2 years
Use of cortical perfusion to develop closed-loop DBS system for PD
Deep brain stimulation (DBS), which delivers electrical pulses to key regions of the brain affected by Parkinson’s disease, can generate dramatic improvements and even eliminate some people’s symptoms. In DBS, the amplitude, duration and frequency of these pulses – the parameters – are critical to DBS’s therapeutic effects.
Despite the high-profile treatment’s success, this therapy still faces some challenges. The biggest challenge is that a clinician determines the parameters of DBS and programming may take months to obtain the best results. Yet Parkinson’s is a dynamic condition with hour-to-hour changes.
That’s why University of Calgary PhD student Sohail Noor has been developing optical imaging techniques that assess the specific effect this therapy has on the brain and provide this information back to the stimulator to adjust the parameters of stimulation automatically. Noor’s approach is based on a type of green light that is absorbed by haemoglobin, the protein that carries oxygen through the bloodstream.
“When there’s neural activity in the brain, it needs fuel, and that fuel is blood,” Noor explains. “Changes in the light levels give you a measure of the blood volume, and changes in blood volume tell you about neural activity.”
By reviewing the information Noor receives from examining the differences in light levels that server as markers for blood volume, he’s concluded that the changes deep brain stimulation cause are not just around the electrode tip, deep in the brain. This procedure also affects neural activity in the cortical region, the top layer of the brain, and these effects can be monitored with optical imaging.
Noor is developing this new technology in collaboration with biomedical engineering professor Dr. Kartikeya Murari, the co-supervisor of his doctoral work. Murari and his colleagues have developed miniaturized, self-contained imaging equipment that can be implanted in rodents’ skulls. The equipment collects this kind of light-based information about blood flow while leaving the animal free to move around normally. This way, they can monitor normal brain activity in real time, providing a new window on this physiological frontier.
Noor hopes this new technology will help to refine the effectiveness of DBS. “These are novel methods,” says Noor. “Our ultimate goal is to create a feedback signal for DBS, which would become part of a system for all Parkinson’s patients receiving this procedure.”