Spinal Cord Stimulation Lead May Be Safe for Use in MRI
A new spinal cord stimulation (SCS) lead designed to be compatible with MRI in various clinical scenarios may be heat-safe, scientific investigators reported. The results of their study may improve patient safety and access to MRI.
The radio frequency field in an MRI causes an increase in temperature at the electrode of an implanted medical lead. Ensuring heating safety during MRI is complex and requires a complete understanding of the MRI system, lead behavior, and individual patient characteristics, said the investigators. The study confirmed the ability of the researchers’ model to predict radio frequency electrode heating (ie, temperature changes) accurately in animals. The results thus provide confidence that the model can predict heating in patients, said the authors.
The research team implanted leads and temperature probes in the spinal canals of anesthetized pigs and scanned them in a 1.5-T MRI system at multiple landmarks. The animal model simulations were then compared with animal electrode temperature measurements to confirm the model’s accuracy.
Researchers subsequently used several MRI coils to simulate the electromagnetic effects that result from variations in human morphology. The study authors performed simulations for hundreds of clinical lead paths in each human model and combined the results with lead characterization analyses to predict the temperature increase at the electrodes in the spinal cord for each patient situation.
Although the increases in temperature varied significantly among the 10,000 patients, device scenarios, and MRI scenarios, the resulting temperature predictions demonstrated that a lead designed for reduced radio frequency heating produced temperatures below 43 °C for the full range of implant scenarios during 30 minutes of active scanning.
Stem Cell Transplant Could Improve Treatment of Degenerative Disc Disease
Stem cell transplant is viable and effectively halts or reverses degenerative disc disease of the spine in animals, according to a meta-analysis of several studies. The meta-analysis may encourage the performance of future research in humans. Recent developments in stem cell research have made it possible to assess the treatment’s effect on intervertebral disc (IVD) height, said researchers.
“This landmark study draws the conclusion in preclinical animal studies that stem cell therapy for disc degenerative disease might be a potentially effective treatment for the common condition that affects people’s quality of life and productivity,” said Wenchun Qu, MD, PhD, a physician at the Mayo Clinic in Rochester, Minnesota.
Stem cell transplant not only increased disc height, but it also increased disc water content and improved appropriate gene expression. “These developments place us in a position to prepare for translation of stem cell therapy for degenerative disc disease into clinical trials,” said Dr. Qu. The increase in disc height in patients who received transplants resulted from restoration of the nucleus pulposus structure and an increased amount of water content, said the researchers.
The investigators searched for original, randomized controlled trials on animals that examined the association between IVD stem cell transplant and change of disc height. Six studies met inclusion criteria.
The researchers found that the disc height index increased by more than 23.6% in the transplant group, compared with the placebo group. None of the six studies showed a decrease of the disc height index in the transplant group. Increases in the disc height index were statistically significant in all individual studies.