On Dec. 3, the Burke Medical Research Institute welcomed Alexander Rotenberg, M.D., Ph.D., assistant professor of neurology at Boston Children’s Hospital and Harvard Medical School, to deliver BMRI’s Weekly Seminar. Rotenberg discussed some of the latest translational research on transcranial magnetic stimulation (TMS).
TMS is a noninvasive brain stimulation technique that uses a rapidly changing magnetic field to induce weak electric currents in targeted areas of the brain. Already, several TMS devices have been approved by the FDA for motor and language mapping and for treatment of major depression. TMS motor mapping approaches the spatial resolutions achieved by fMRI and research suggests that, in cases of discrepancy between the two techniques, absence of TMS response is a better predictor of the absence of motor function.
A major focus of Rotenberg’s work is using TMS to diagnose and manage epilepsy. Epilepsy has been linked to the loss of inhibition in cortical neurons; although pharmacological interventions are available, one-third of patients don’t respond to these treatments, explained Rotenberg. TMS can evaluate whether a pharmacological intervention is working by measuring the ratio of cortical excitation and inhibition.
Moreover, TMS has shown some success in disrupting and preventing epileptic seizures. To better understand the underlying mechanisms and improve on possible therapeutic applications, Rotenberg’s laboratory has been studying TMS in rodent models. They overcame a significant limitation of these models—that the animals had be anesthetized while undergoing TMS—by developing a setup to restrain unanesthetized rats during TMS. This enables a closer approximation of the procedure in humans and eliminates any effects from general anesthesia. In their study of post-traumatic epilepsy (the most common form of acquired epilepsy in young adults) in rodents, Rotenberg’s lab has found that cortical inhibitory neurons may be especially vulnerable to the oxidative stress caused by injury.
Since 2003, the BMRI Weekly Seminar has invited renowned scientists from across the country to share their research with the Burke community. Seminar speakers also have the opportunity to meet one-on-one with the BMRI investigators. Check out upcoming speakers here.