Team – Sayenko Lab | Houston Methodist

Dimitry Sayenko, MD, PhD, Principal Investigator

Dimitry Sayenko, MD, PhD, graduated in 1996 from the Russian State Medical University with an MD degree. From 1996 to 2006 he was a researcher at the Institute for Biomedical Problems – the leading Russian research institute specializing in biomedical aspects of manned spaceflight. There he worked with a team of collaborators from NASA, as well as European, Japanese, and Canadian space agencies. In October 2005, he earned a PhD in aerospace medicine, with a thesis on the effect of microgravity on postural control in cosmonauts and astronauts. Sayenko completed his postdoctoral training at the National Rehabilitation Center in Japan (2006-2008), as well as at the Toronto Rehabilitation Institute in Canada (2008-2012). From 2012 to 2014, Sayenko held a faculty appointment at the University of Louisville, and he worked as a research assistant professor in the Frazier Rehab Institute, where he investigated the mechanisms of neuromodulation induced by epidural spinal stimulation. From 2014 to 2018, Sayenko performed research at the University of California-Los Angeles, where he utilized spinal stimulation after spinal cord injury to recover sensorimotor function in the upper and lower limbs, as well as to regain postural control during sitting and standing.

Sayenko’s current research focuses on the mechanisms and effects of spinal neuromodulation in the sensorimotor recovery after neurological disorders and injuries, including stroke and spinal cord injury. In his spare time, he enjoys spending time with his family, and cooking any kind of food and sharing it with friends. He also enjoys gardening, hiking and swimming.

Senior Research Staff

Postdoctoral Fellows

Jeonghoon Oh, PhDResearch Associate I

Jeonghoon completed his PhD in the Department of Kinesiology at the University of Miami, FL. Previously, his research has focused on gait and postural control in individual with neurological disorders or who have undergone gait impairment using core concepts from biomechanics and motor control. He joins the Dr. Sayenko’s Lab with the aim of uncovering the neural mechanisms associated with the functional recovery of upper and lower limb movements after exposure to spinal cord stimulation. In his spare time, he enjoys spending time with his wife, and cooking food (especially Korean) and sharing it with friends. He also enjoys hiking, swimming, and playing tennis.

Alexander Steele, PhD Research Engineer II

Alexander G. Steele completed his PhD in neuroengineering at the University of Houston and has a B.S. and M.S. in mechanical engineering. Previously, his research focused on using non-invasive methods for understanding spinal cord circuity, research which was acknowledged by DARPA when he was named a 2022 DARPA Riser. He joined the Neuromodulation and Recovery Laboratory at Houston Methodist Research Institute June of 2019 where his work focuses on elucidating the effects of spinal cord injury on spinal signaling and how spinal cord stimulation can aid in restoration of sensorimotor function using both non-invasive and invasive methods. His interests include prosthetics, solid modeling, control theory, and neuroscience.

Valerie Dietz, PhDPostdoctoral Fellow

Valerie completed her PhD in the Department of Biology at Texas A&M University in College Station, Tx. Her previous research experience focused on utilizing cellular and molecular- based approaches to understand the development of neuropathic pain after spinal cord injury. Additionally, she worked on projects investigating the use of neural progenitor cell transplantation and changes in neural circuitry after injury. During her PhD, Valerie was also passionate about teaching introduction biology courses and mentoring undergraduate students in research. As a Postdoctoral Research Fellow in the Neuromodulation and Recovery Laboratory, Valerie will work on investigating how two types of spinal stimulation, lumbosacral epidural spinal stimulation (ESS) and transcutaneous spinal stimulation (TSS) can help improve lower limb locomotion. Outside of research, Valerie enjoys spending time with her husband, family, and pets!

Clinical Research Therapists

Michelle Scheffler, OTR, MOT Senior Occupational Therapist

Michelle completed her PhD and master’s degree in occupational therapy at Texas Woman’s University. Her research focused on executive function in young women with stroke. She has been an occupational therapist since 2013 and has extensive clinical experience treating a variety of individuals, particularly those who are medically complex and those with neurologic impairments. She joined the Sayenko lab in 2022 and is the primary clinician for the upper limb studies. She is also responsible for rehabilitation program development and oversight within the lab’s ongoing studies. Outside of research, Michelle is a classically trained pianist and enjoys spending time with her family and baking.

Catherine Martin, PT, NCSSenior Physical Therapist

Catherine Martin PT, MS joined the Center of Neuromodulation and Recovery January of 2022 and has been with Houston Methodist Hospital since 2009. She focused her career promoting health, wellness, and independence to those with complex neurologic and medical conditions while working at HMH In-Patient Rehabilitation Department for 10 years. After passing her board examination to become a Neurologic Certified Specialist, she accepted a position as the physical therapy neurologic coordinator for the Acute Care Department in 2019 completing consults within the Neurology and Neuromuscular Department. In this role she was able to continue to foster her passion of assisting individuals with progressive neurologic conditions adapt within their home environment. When not at work, Catherine enjoys time with her husband, 2 sons, and dog camping, playing various outdoor activities, and visiting family.

Clinical Research Team

Rachel Markley, MPH, CCRPClinical Trials Manager

Rachel Markley graduated in 2013 with a BS in nutrition and community health from The Ohio State University. After graduation, she moved to Texas for the warmer winters. She completed her Master of Public Health in 2015 from the UT Health Science Center at Houston. Rachel joined Houston Methodist in January 2019 as a research coordinator to support the Sayenko lab growing research program. Rachel is currently the Clinical Trials Manager for the Department of Neurosurgery where she leads the coordinator staff and works on building and strengthening the clinical research infrastructure.

Jenny DinhResearch Coordinator

Jenny received a BS in Health and Human Performance from the University of Houston and joined the Neuromodulation and Recovery Laboratory in 2022. Jenny pursued a career in clinical research to understand how clinical research studies operate and to gain experience working in a lab. As a research coordinator, she provides interpersonal support and facilitates and coordinates the daily clinical trial activities, and is responsible for subject recruitment. Her interests include learning how to cook different cuisines, pilates, and spending time with her cat.

Amanda Howes-Keith, MSClinical Research Specialist

Amanda earned her M.S. in Clinical Exercise Physiology from the University of Houston-Clear Lake in 2022. She has hands-on experience as a Neuro-Deficient Exercise Specialist at Project Walk Houston Paralysis Recovery Center. She enjoyed working closely with clients, which sparked her interest to contribute to neurology research. As an avid athlete, Amanda currently works professionally as a dancer, circus artist, and choreographer. She’s excited to apply her knowledge of physiology and movement in the Neuromodulation and Recovery Laboratory. Outside of her professional life, Amanda enjoys spending time with her husband, two dogs, and is a theme park/roller coaster enthusiast!

Research Assistant

Shishira SiripuramResearch Assistant 1

Shishira Siripuram, from Houston, Texas, graduated from the University of Texas at Austin in 2023 with a BSA in Biology. She is currently a Research Assistant in Dr. Sayenko’s lab, focusing on spinal cord injury recovery through noninvasive neuromodulation. Aspiring to become a physician, she aims to combine compassionate care with medical innovation, especially for underserved populations. Outside of work, she enjoys going to the gym, experimenting with new recipes, diving into skincare, and spending quality time with her family.