Department of Biomedical Engineering
Mentor: Alexander Opitz, Ph.D., Department of Biomedical Engineering
Project: Modulation of motor excitability using phase-specific closed-loop paired-pulse TMS
Da Som's research investigates how the brain’s rhythms influence its responsiveness to external stimulation. She uses a technique called paired-pulse transcranial magnetic stimulation (ppTMS) to measure two fundamental mechanisms of the motor cortex: short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF). Using a closed-loop system, she delivers these pulses at four distinct phases of the brain's ongoing rhythms. Her goal is to determine how the balance between inhibition and facilitation changes across these phases to identify the optimal timing for more effective neuromodulation. This work is incredibly exciting because it provides further insights into the complex interplay between inhibition and facilitation of motor function in the context of ongoing brain rhythms. Ultimately, Da Som aims to establish new guidelines for more effective therapeutic approaches to neurological disorders such as stroke and Parkinson’s disease.
Minnesota has one of the highest Parkinson’s disease mortality rates in the U.S., a condition closely linked to disruptions in brain inhibition and facilitation. Da Som's research provides a foundation for "phase-specific" stimulation, which could lead to more reliable diagnostic tools and personalized treatments. By understanding the precise timing of brain stimulation, we can develop smarter therapies that significantly improve the quality of life for Minnesotans living with movement disorders.
One of the most fascinating aspects of her experiments is seeing how clearly the hand's movement changes based on the stimulation protocol. In paired-pulse TMS, we deliver two pulses: a small initial pulse followed by a second pulse of the same intensity used in single-pulse TMS. It’s amazing to observe how changing the timing of the first pulse by just a few milliseconds can make the hand movement visibly smaller (SICI) or significantly larger (ICF). She has just completed the data collection and is now in the analysis phase. Da Som is thrilled to dive into the data to uncover exactly what is happening inside the brain to create these distinct responses.
