The International Neuromodulation Society (INS) has announced winners of its inaugural best abstract competition at the 12th World Congress (6–11 June, Montreal, Canada).
The scientific programme committee selected the five winning abstracts, out of more than 350 received, for their quality, originality and ingenuity.
“We felt it was important to acknowledge the full range of basic and clinical science in this honour,” said scientific programme chair and INS president-elect Timothy Deer. “Our field is evolving so rapidly that not only is it helping patients who are living with chronic disease today, but also shedding light on underlying mechanisms. Together, this growing understanding can spur advances in emerging bioelectronic medicine and current neuromodulation therapies.”
The top five abstracts represent a range of conditions addressed by neuromodulation; neural prosthesis and restoration for central nervous system injury, symptom management for incurable and progressive neurological disorder, and drug-free analgesia for neuropathic pain.
The five winning submissions are:
Neural bypass – A collaboration by Chad Bouton and team members at Battelle in Columbus, USA, with physicians at The Ohio State University Wexner Medical Center. A tetraplegic patient demonstrated the ability to use a neuroprosthetic brain implant system to intentionally move his hand and wrist. The implant, a 96-electrode array, was surgically placed on his motor cortex by OSU’s Ali Rezai. A Battelle-built multichannel stimulator relayed signals to nerves in his arm governing muscle control. Neural activity detected by the cortical array was processed by Battelle’s algorithms and encoded patterns sent to the stimulator to activate muscles. The demonstration showed the system could bypass the injury in the spinal cord and link brain activity in his motor cortex to voluntary muscle activity in his arm, hand and wrist, so that he was able to make voluntary motions in real time with high accuracy. The patient has spent seven months with the research team, who collected 300 hours of data in developing their custom algorithm. The study protocol has been approved for up to five participants.
‘Biometric’ movement disorder index – Stephanie Tran, a neuroscience undergraduate who participated in a project at the Movement Disorders Centre of Western University in London, Canada, presented findings of a research team that quantified the effects of deep brain stimulation in Parkinson’s disease patients. The team used a motion-capture suit to assess the slow, stiff movements of bradykinesia, which is commonly experienced by all Parkinson’s disease patients. Seven patients were assessed while performing a simple clinical test of their voluntary movement. For comparison, seven healthy control subjects were recorded performing the same exercise. Each patient was assessed at three pre-defined device settings used in common practice. The team defined a “B-Index” for bradykinesia based on range of motion, angular velocity, and variability in time and amplitude. The group found that at six months post-implant, patients’ bradykinesia was reduced to the point that their B-Index was not statistically different from healthy controls under a stimulation setting that involved decreasing pulse width while using medium frequency and voltage.
Stroke damage repair – A preclinical investigation lead by Andre Machado, at the Cleveland Clinic, that suggests deep brain stimulation may aid the brain’s plasticity and ability to form new neural connections during recovery from stroke. The team’s research in rats showed that DBS promoted growth of neurons that specialize in release of the neurotransmitter glutamate, which aids learning and memory. The group had previously shown that deep brain stimulation enhanced motor recovery after stroke. This abstract built on that earlier work by showing the effect was linked to enhanced formation of new neural connections and blood vessels in the damaged area. They believe this is the first time that a deep brain stimulation therapy has shown the potential for selective nerve growth after focal injury, implying there may be a neurorestorative potential. As with any new finding, the research remains preliminary and the team would need to replicate these findings before expanding further on the research.
Picturing pain therapy impact on the brain – Imaging studies were conducted by Quinn Hogan, of the Department of Anesthesiology at the Medical College of Wisconsin, USA, and colleagues. The research team used functional magnetic resonance imaging (fMRI) to show that parts of the brain’s so-called “pain network” are less activated when rats receive pain-relieving stimulation of the dorsal root ganglion (DRG), a structure at the edge of the spine. The researchers said the fMRI findings validate DRG stimulation as analgesic in rats, providing a model for future mechanistic research.
Preferred stimulation modes compared – Nadia Kriek and colleagues at the Center for Pain Medicine at the Erasmus University Medical Center in Rotterdam, the Netherlands, planned to present a comparison of five different spinal cord stimulation (SCS) modes, with the final data collected just prior to the meeting. They studied 43 patients who have a rare chronic pain condition, complex regional pain syndrome (CRPS), which is a leading indication for SCS since the therapy is highly effective in most CRPS patients. However, in some CRPS patients the therapeutic effect of SCS can diminish over time resulting in the loss of pain control, as shown by past studies. Some of these patients that have lost the therapeutic benefit of SCS can regain pain control if the stimulation frequency is increased to more than 250Hz. There is growing interest in new stimulation modes of SCS such as burst and high frequency. These new modes of stimulation along with conventional and sham stimulation were compared during the clinical trial. The patients began with conventional SCS of 40Hz, and after three months, were crossed over randomly into treatment groups. Each patient randomly received 40Hz, 500Hz, 1,200Hz, burst and sham stimulation, with two-day “washout” intervals between each stimulation mode. After 10 weeks each patient decided which mode was preferred, and continued on that mode for another three months, with an assessment taken again at the end of that period.
“This final abstract was selected on the basis of its sound clinical trial design and solid patient enrolment,” commented INS president Simon Thomson. “Developing an evidence base and disseminating knowledge about best practices are among key objectives that our society advocates. With the advent of several new modes of stimulation for practitioners to choose between, these recent findings were expected to be of particular interest.”
All abstracts submissions accepted for presentation at the congress will be published online in the INS journal Neuromodulation: Technology at the Neural Interface.