Neuromodulation to Improve Grasping Function After Spinal Cord Injury
Neuromodulation to Improve Grasping Function After Spinal Cord Injury
Lead Principal Investigator: Hang Jin Jo, PT, PhD
Funding Agency: NYS Department of Health
Awarded: July 2025
Abstract: The main goal of rehabilitation strategies in humans with spinal cord injury (SCI) is to strengthen transmission in spared neural networks to restore functional movements. However, current treatments in SCI result in limited behavioral improvements, highlighting the need to develop new methodologies to restore motor function. Recent evidence showed that transmission in cortical networks interacting with corticospinal neurons (i.e., late corticospinal descending volleys) in humans with SCI plays a crucial role in the recruitment of spinal motoneurons and functional outcomes (Cirillo et al., 2016; Jo et al., 2018). Therefore, this proposal has two main goals: 1) Target late corticospinal descending volleys using neuromodulation after cervical SCI and 2) Examine the effect of neuromodulation targeting late corticospinal descending volleys in combination with hand motor training after cervical SCI. In Aim 1, we will use paired corticospinal-motoneuronal stimulation (PCMS) in combination with intermittent theta burst stimulation (iTBS). During PCMS (Jo and Perez, 2020), we will use paired stimulation of the primary motor cortex by transcranial magnetic stimulation to elicit late corticospinal descending volleys (Di Lazzaro et al., 1998, 2014) and the peripheral nerve by electrical stimulation to improve corticospinal transmission and functional recovery in humans with cervical incomplete SCI. In addition, we will investigate how priming iTBS affects neuroplasticity of late corticospinal descending volleys. We will apply iTBS on primary motor cortex prior to paired stimulation with PCMS to facilitate late corticospinal volleys and potentiate the effect of PCMS. In Aim 2, we propose to combine our neuromodulation in Aim 1 with long-term motor training focused on hand grasping to strengthen spared connections and promote functional improvement in humans with cervical incomplete SCI. The primary significance of our proposal is that we develop a novel neuromodulatory strategy to target those impaired late descending corticospinal volleys. The results from this proposal may result in the development of more effective neuromodulation techniques that could benefit the rehabilitation of individuals with SCI.
