Deep brain stimulation shows immediate improvement in arm and hand function after brain injury, study finds

Deep brain stimulation can provide immediate improvement in the strength and function of arms and hands weakened by head trauma or stroke, researchers at the University of Pittsburgh School of Medicine report today. Natural communications.

Encouraging results from extensive testing in monkeys and humans pave the way for new clinical application of already widely used brain stimulation technology and provide insight into the neural mechanisms underlying movement deficits caused by brain injury .

“Paralysis of the arms and hands significantly impacts the quality of life of millions of people worldwide,” said lead and corresponding author Elvira Pirondini, Ph.D., assistant professor of physical medicine and rehabilitation. at Pitt. “Currently, we do not have effective solutions for patients with stroke or head trauma, but there is growing interest in using neurotechnologies that stimulate the brain to improve upper limb motor functions.”

Brain damage caused by severe traumatic brain injury or stroke can disrupt neural connections between the motor cortex, a key brain region essential for controlling voluntary movements, and muscles. Weakening these connections prevents effective muscle activation and leads to movement deficits, including partial or complete paralysis of the arms and hands.

To stimulate the activation of existing but weakened connections, researchers proposed using deep brain stimulation (DBS), a surgical procedure that involves placing tiny electrodes in specific areas of the brain to deliver electrical impulses that regulate brain function. abnormal brain activity. In recent decades, DBS has revolutionized the treatment of neurological diseases such as Parkinson’s disease by providing a way to control symptoms once difficult to manage with medication alone.

“DBS has changed the lives of many patients. Today, with continued advances in the safety and accuracy of these devices, DBS is being explored as a promising option to help stroke survivors regain motor function “, said the lead author and surgical lead. of the project, Jorge González-Martínez, MD, Ph.D., professor and vice chair of neurosurgery and director of the Epilepsy and Movement Disorders Program at Pitt. “This offers new hope to millions of people around the world.”

Drawing on another successful Pitt project that used electrical stimulation of the spinal cord to restore arm function in people affected by stroke, the scientists hypothesized that stimulation of the motor thalamus, a structure nestled deep in the brain that acts as a key relay for movement control – Using DBS could help restore movements essential to everyday tasks, such as grasping objects.

However, because the theory has not yet been tested, they first had to test it in monkeys, which are the only animals to have the same organization of connections between the motor cortex and muscles as humans.

To understand the mechanism by which DBS of the motor thalamus helps improve voluntary arm movement and fine-tune the specific implant location and optimal stimulation frequency, researchers implanted the FDA-approved stimulation device in monkeys with brain damage affecting their efficiency. use their hands.

Once the stimulation was activated, it significantly improved muscle activation and grip strength. Importantly, no involuntary movements were observed.

To verify that the procedure could benefit humans, the same stimulation parameters were used in a patient who was scheduled to undergo DBS implantation in the motor thalamus to relieve arm tremors caused by brain injury resulting from a serious motor vehicle accident. car leading to severe paralysis. both arms.

As soon as the stimulation was reactivated, the range and strength of arm movements were immediately improved. The participant was able to lift a moderately heavy weight and reach, grasp, and lift a cup more efficiently and easily than without stimulation.

To help bring this technology to more patients in the clinic, researchers are currently working to test the long-term effects of DBS and determine whether chronic stimulation could further improve arm and hand function in people affected by trauma cranial injury or stroke.

Other authors of this research are Jonathan Ho, BS, Erinn Grigsby, Ph.D., Arianna Damiani, MS, Lucy Liang, MS, Josep-Maria Balaguer, MS, Sridula Kallakuri, Lilly Tang, BS, Jessica Barrios-Martinez, MD. , Vahagn Karapetyan, MD, Ph.D., Daryl Fields, MD, Ph.D., Peter Gerszten, MD, T. Kevin Hitchens, Ph.D., MBA, Theodora Constantine, PA-C., Gregory Adams, BS , Donald Crammond, Ph.D., and Marco Capogrosso, Ph.D., all of Pitt.