CAREER: Developing Transcranial Magnetic Stimulation as a Precision Brain Circuit Tool for Stroke Rehabilitation

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation method with many applications in research and therapy. TMS uses magnetic fields to deliver pulses that create temporary electric fields in the brain. The magnetic pulses are delivered over the scalp and the created electric fields can stimulate nerve cells in the brain regions where the pulse is delivered. Stroke is a medical condition where a lack of blood supply of a specific brain region results in nerve cell death that can affect the brain connections that control movement. Stroke is one of the main causes of disability that impacts the quality of life of millions of people. Many studies have investigated the use of TMS to assess the human motor system and to develop therapies for stroke. TMS is ideal for this because it allows for the measurement of the connection and transfer of brain signals between the motor cortex in the brain and the muscles. Also, TMS is a promising therapeutic tool to improve recovery and re-learning of motor control after stroke. However, despite the possible advantages of TMS-based brain stimulation therapies, the treatment outcomes vary considerably and not all patients benefit. In this project, the investigators will develop improved methods to measure and analyze brain signals to better adjust the TMS procedure to each individual patient’s brain motor system for better and more precise assessments and therapies for stroke survivors. The investigator will develop new educational materials, 3-D printed models, and hold workshops to teach these methods to a wide range of individuals including local high school students. The PI proposes to develop individualized TMS applications for assessing the motor system in adult stroke patients and future rehabilitation efforts. This will be based on (i) individual anatomical characterization using structural MRI and (ii) individual functional characterization employing electroencephalography (EEG), combined with (iii) advanced computational modeling. Ongoing oscillatory brain states, highlighting local brain excitability, will be tracked in real-time by EEG and be used to apply TMS in a closed-loop fashion. The PI will leverage these technological developments to advance TMS technology to assess motor circuitry and advance the field’s understanding of brain pathologies in stroke, thus enabling future clinical trials for stroke rehabilitation. This project will result in next-generation technology that will allow principled TMS studies of brain circuits in stroke with high spatial and temporal resolution. This will be based on advances in image and signal processing initially established for healthy individuals and translation towards individuals with stroke. Through initial experimental testing, it will be ensured that technological advances will result in improved practical applications. Outcomes of this research will result in new approaches for closed-loop TMS in individuals with stroke. Success in these efforts will allow the design and execution of more precise brain stimulation protocols for the assessment of motor circuits and TMS stroke rehabilitation protocols. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.