"Identifying and Targeting Potential Biomarkers of Motor Dysfunction after Stroke using Non-invasive Neurostimulation and Neuroimaging"

Michael Borich, Ph.D.
Assistant Professor, Rehabilitation Medicine
Program Faculty, Biomedical Engineering, Georgia Tech
Training Faculty, Neuroscience Program, Emory University
Faculty Member, Parker H. Petit Institute for Bioengineering and Bioscience
Emory University/Georgia Tech

Up to 80% of stroke survivors have persistent motor impairment of the paretic arm that interferes with performing functional activities and limits activity participation. Stroke can trigger maladaptive changes in the strength and organization of structural and functional connections between brain regions. During paretic arm movement, there is exaggerated interhemispheric inhibition (IHI) from the contralesional hemisphere to the ipsilesional hemisphere. Exaggerated IHI creates an abnormal activity imbalance between brain hemispheres and this imbalance seems to be a primary contributor to motor impairment of the paretic arm after stroke. Although restoring the balance of activity between brain hemispheres has been a primary target of many novel rehabilitation strategies, limited progress has been made to improve arm motor function and reduce persistent disability for stroke survivors.

In this talk, I will describe work in our lab using transcranial magnetic stimulation (TMS), a form of non-invasive brain stimulation, to both characterize and modulate cortical activity and connectivity in the brain after stroke. In the first part of my talk, I will describe how abnormal cortical excitability after stroke has been traditionally characterized using standalone TMS techniques. In the second part of my talk, I will discuss current findings from our lab using concurrent EEG recordings of TMS-evoked cortical activity that demonstrate abnormal interhemispheric interactions are present in the human brain after stroke and these abnormal interactions are related to arm motor impairment. Finally, I will introduce an upcoming project in our lab investigating the use of bifocal TMS to transiently modulate local cortical excitability and IHI in the human brain in an effort to restore the balance of activity between the hemispheres and improve arm motor function after stroke.

Biography

Dr. Michael Borich is an assistant professor in the Division of Physical Therapy, Department of Rehabilitation Medicine in the Emory University School of Medicine. He has a secondary appointment in the Wallace H. Coulter Department of Biomedical Engineering a joint Emory/Georgia Tech department and also in the Parker H. Petit Institute for Bioengineering and Bioscience at Georgia Tech. Dr. Borich is keenly interested in understanding and harnessing the plastic capacity of the human nervous system in

health and disease in an effort to improve rehabilitation outcomes for individuals with neurologic injury and disease.

He received his bachelor’s degree in physiology and his doctor of physical therapy both from the University of Minnesota. After finishing his PhD training in rehabilitation science and neuroscience at the University of Minnesota, Dr. Borich competed a postdoctoral research training using neurostimulation and neuroimaging techniques to elucidate biomarkers of recovery after stroke and mild traumatic brain injury at the University of British Columbia. He joined the Division of Physical Therapy at Emory in 2014. His previous clinical experience centers on rehabilitation from acute neurologic insult and major multiple trauma.

Dr. Borich currently directs the Neural Plasticity Research Lab at Emory, a trans-disciplinary research and training environment generously supported by multiple funding agencies. His research team utilizes multimodal neuroimaging and neurostimulation techniques to characterize and modulate the structural and functional neuroplastic correlates of learning and recovery of function following neurologic insult.