Epidural Electrical Stimulation Can Restore Walking

In a recent revolutionary clinical trial, researchers determined that they could restore walking in individuals paralyzed due to a spinal cord injury. According to the Nature publication, the lumbar spinal cord contains the neurons required for walking. Epidural electrical stimulation (EES) in this area of the spinal cord can restore walking in some individuals.

In the neuronal pathway required for walking, the brain activates these neurons by sending signals that cascade down descending pathways from the brainstem to the lumbar spinal cord. Researchers in the publication provided context for the study: “Isolated case studies have reported that EES can immediately reactivate nonfunctional neurons in the lumbar spinal cord, enabling people with paralysis to walk. Application of EES during neurorehabilitation (EESREHAB) further improved the recovery of walking, even when the stimulation was turned off.”

This study, published by Claudia Kathe and her colleagues, explored EES in human and mouse models. Six of the nine participants recruited and enrolled in this clinical trial had motor paralysis with some sensation in their legs, and three had complete sensorimotor paralysis.

In the human participants, EES was delivered through a paddle lead surgically implanted over the epidural surface of the lumbar spinal cord. Immediate results were seen across all nine participants, which had improved or regained the ability to walk while supported by the robotic interface.

Researchers also found that weight-bearing capacities were improved after five months of EESREHAB. Additionally, “participants who exhibited residual function before EESREHAB displayed a pronounced increase in lower limb motor scores that restored walking even in the absence of EES in four participants. These results support the primary and secondary endpoints of the clinical trial.”

According to the article, sustained walking recovery implies that this treatment helps remodel the spinal cord.

Kathe and her colleagues concluded, “understanding the contributions of each neuronal subpopulation to complex behaviors such as walking is a fundamental challenge in neuroscience. Here, we describe unbiased methodologies that leverage comparative single-cell genomics to circumscribe the cellular and spatial origin of perturbation responses. The application of Augur and Magellan to single-nucleus and spatial transcriptomes provides a generalizable framework to prioritize cellular subpopulations in any biological tissue in response to any biological stimulus.”

While the results of this study are promising, it is just the beginning. Researchers will need to reiterate the research and demonstrate that the results can be replicated before it is incorporated into clinical practices.