Paresis

Vagus nerve stimulation (VNS) is thought to activate neural pathways that release chemicals which promote plasticity and learning. Previous work has shown that the auricular branch of the vagus nerve innervates landmarks on the external ear. Work from the PI's laboratory has shown that electrical current applied to the external ear modulates physiological indexes of brain states implicated in the therapeutic effects of VNS. The broad objective of this project is to better understand physiological mechanisms modulated by auricular stimulation to support possible therapeutic effects in the form of motor learning.

This is an early feasibility trial to determine whether transcutaneous neuromuscular electrical stimulation, with or without transcutaneous spinal cord stimulation, using an investigational neurostimulation device improves functional arm/hand movements in individuals with paralysis or paresis due to a spinal cord injury or stroke and improves functional arm/hand or leg/foot movements in individuals with paralysis or paresis due to other brain or nerve injuries. In this study, eligible individuals that agree to participate will be asked to attend up to 5 study sessions a week for 1 year (depending on participant availability), with each session lasting up to 4 hours. At the first study session, participants will have their demographic information collected, vital signs assessed, and have measurements performed of their limbs and torso, as appropriate. They will also undergo clinical evaluations and tests to assess their current functional movement and sensation capabilities. During subsequent study sessions, participants will undergo many tasks designed to improve functional movements in paralyzed limbs. Specifically, participants will receive neuromuscular electrical stimulation to the limb(s) and/or electrical stimulation to the spinal cord to evoke specified movements. The stimulation parameters and locations on the spinal column and/or limb(s) that evoke specific movements will be noted. The movements will be assessed with visual inspection, electromyography, and/or sensors. The clinical evaluations and tests to assess functional movement and sensation capabilities will be repeated throughout the study and at the last study session to assess for functional improvements compared to the first study session. Upon completion of these study sessions, the individual's participation in the study is considered complete.

Lumbar disc herniations may result in lower limb weakness. In such cases, there is a strong indication for surgical intervention through microdiscectomy. This clinical study aims to investigate preoperative factors that may influence the postoperative outcomes of patients undergoing this procedure.

Following a stroke, the function of the distal upper limb, especially hand and finger movements, is often severely compromised, significantly restricting the ability to carry out daily activities. It is estimated that 55-75% of stroke survivors suffer from motor dysfunction, with upper limb impairments affecting up to 85% of them (Tang et al., 2024). Current rehabilitation approaches, while beneficial, often produce limited gains in hand function, particularly in patients with chronic stroke. Virtual reality (VR) training has emerged as a promising tool in neurorehabilitation, providing repetitive, task-specific, and engaging practice environments that can promote motor learning (Cameirão et al., 2012). tDCS has also shown potential to enhance motor recovery when combined with motor practice (Kang et al., 2016). To date, no studies have directly compared the effectiveness of Bi-tDCS with VR for improving upper limb function after stroke.