8/24/2026
A Pitt study found that adjusting deep brain stimulation frequency helped restore speech and swallowing control after traumatic brain injury.
PITTSBURGH — Deep brain stimulation, or DBS, improved speech and swallowing problems caused by traumatic brain injury, according to a University of Pittsburgh School of Medicine study published in Nature Communications on Aug. 24, 2026. The proof-of-concept study found that low-frequency electrical stimulation of a deep brain region called the motor thalamus improved control of facial and tongue muscles used for speaking and swallowing.
Key Takeaways
- A University of Pittsburgh School of Medicine study published in Nature Communications found low-frequency deep brain stimulation (DBS) of the motor thalamus improved speech and swallowing after traumatic brain injury (TBI).
- The proof-of-concept study, led by Elvira Pirondini, Ph.D., and Jorge A. Gonzalez-Martinez, M.D., Ph.D., of Pitt, tested stimulation at 50 to 80 Hz, nearly three times lower than the 130 Hz used in standard high-frequency DBS.
- Researchers tested low-frequency DBS in eight participants with intact speech and swallowing who were undergoing DBS implantation for essential tremor, and in one participant with TBI who had chronic moderate dysphagia and severe dysarthria.
- In the TBI participant, word intelligibility improved by 8%, 20% and 16% across three testing sessions when stimulation was on versus off, exceeding the 15% threshold considered a large clinically significant change.
- The study was not a clinical trial and involved one TBI participant; the research team, which also included collaborators from the University at Buffalo and Carnegie Mellon University, says larger studies are needed to test safety and effectiveness across more patients and injury types, including stroke.
Deep brain stimulation study builds on Pitt's neuromodulation research for brain injury recovery
The study was led by Elvira Pirondini, Ph.D., assistant professor of physical medicine and rehabilitation at Pitt's Rehab Neural Engineering Laboratory, and Jorge A. Gonzalez-Martinez, M.D., Ph.D., professor of neurological surgery at Pitt. It builds on the group's earlier work using neuromodulation to improve arm and hand movement after brain injury.
"Rehabilitating speech deficits after an injury is a top priority for many people, often even more than mobility," said Pirondini, co-senior and corresponding author of the study. "For many people, losing speech affects work, independence and relationships. It can have a profound effect on a person's life."
How many people are affected by speech and swallowing problems after traumatic brain injury?
Speech and swallowing depend on coordinated signals between the brain and the muscles of the face, tongue, throat and respiratory system. Brain injuries can disrupt those pathways, causing dysarthria — impaired speech — and dysphagia — difficulty swallowing. More than 5 million people in the United States live with dysphagia or dysarthria, according to the study.
Current treatments often rely on speech-language therapy and compensatory techniques. Outcomes vary, and external communication devices do not restore natural speech production.
Low-frequency deep brain stimulation targeted the motor thalamus in two participant groups
Researchers tested stimulation in eight participants with intact speech and swallowing pathways who were undergoing DBS implantation for essential tremor, and separately in one participant with chronic TBI who had moderate dysphagia and severe dysarthria.
DBS has long been used for conditions such as Parkinson's disease tremor, typically using high-frequency stimulation around 130 Hz. Other research groups have shown that high-frequency stimulation can suppress speech. The Pitt team instead used low-frequency stimulation, cutting the frequency almost threefold to the 50 to 80 Hz range.
In the eight essential tremor participants, low-frequency DBS increased activation of face and throat muscles without worsening speech. In the TBI participant, low-frequency DBS improved facial muscle movement, swallowing and speech control.
How much did the TBI participant's speech intelligibility improve during stimulation?
The TBI participant's word intelligibility improved by 8%, 20% and 16% across three testing sessions when stimulation was on, compared with stimulation off. A 7% change is considered a small clinically significant improvement, and a 15% change is considered large, according to the study.
"This study shows that stimulation parameters matter," said Gonzalez-Martinez, co-senior author of the study. "By targeting the correct brain circuit with low-frequency stimulation, we may be able to support the remaining pathways that help patients speak and swallow after brain injury."
Larger studies needed before deep brain stimulation becomes a treatment for TBI-related speech loss
The study was not a clinical trial and involved one participant with TBI and speech and swallowing deficits. The research team says larger studies are needed to test safety, effectiveness and long-term effects across more patients and injury types, including stroke.
The study reflects collaboration across Pitt's physical medicine and rehabilitation and neurological surgery departments, along with co-authors from the University at Buffalo and Carnegie Mellon University. In a clinical trial recruiting participants this year, researchers are testing whether DBS can produce lasting improvements in speech and in hand and arm motor function over a four-week stimulation period.
Frequently Asked Questions
Q: What did the Pitt study find about deep brain stimulation for speech and swallowing after traumatic brain injury?
A: Low-frequency DBS of the motor thalamus improved facial and tongue muscle control in participants with essential tremor and improved swallowing and speech control in one participant with chronic TBI, without worsening speech.
Q: How does this low-frequency approach differ from standard deep brain stimulation?
A: The Pitt team used stimulation in the 50 to 80 Hz range, nearly three times lower than the 130 Hz typically used in high-frequency DBS, which other research groups have shown can suppress speech.
Q: Is deep brain stimulation an approved treatment for speech and swallowing problems after traumatic brain injury?
A: No. This was a proof-of-concept study involving one participant with TBI, not a clinical trial, and researchers say larger studies are needed to confirm safety and effectiveness.
Additional Resources
- Published study: Frequency-dependent effects of motor thalamus deep brain stimulation on speech and swallowing | Nature Communications
- EurekAlert! release: Low-frequency deep brain stimulation improves speech and swallowing after traumatic brain injury, Pitt study shows | EurekAlert!
- Press contact: Liz Reid | UPMC Media Relations
- Related Pitt coverage: "DBS May Improve Hand, Arm Strength in TBI Patients" — https://www.neurosurgery.pitt.edu/news/dbs-may-improve-hand-arm-strength-tbi-patients
- Swallowing Disorders Center | UPMC Deep Brain Stimulation (DBS) for Movement Disorders and OCD | UPMC
- Center for Brain Injury Rehabilitation | UPMC
- Speech Therapy | UPMC Rehabilitation Institute
- Clinical trial registration: Deep Brain Stimulation Motor Ventral Thalamus (VOP/VIM) for Restoration of Speech and Upper-limb Function in People With Subcortical Stroke | ClinicalTrials.gov
- Elvira Pirondini, Ph.D.
- Jorge A. Gonzalez-Martinez, M.D., Ph.D.
- Study participant with PI
- Braden Pritts, study participant
Authors and Funding
Authors: Lilly Tang, Erinn Grigsby, Ph.D., Arianna Damiani, M.Sc., Jonathan Ho, M.D., Isabella Montanaro, Sirisha Nouduri, Scott Ensel, Ph.D., Sara Trant, M.A., Theodora Constantine, P.A.-C., Gregory Adams, Denise Balason, Tracey Thomas, M.S., Jordyn Ting, Ph.D., George Wittenberg, M.D., Ph.D., Kevin Franzese, D.O., Julie Fiez, Ph.D., Donald Crammond, Ph.D., and Kaila Stipancic, Ph.D., all of Pitt; Kelly Zdrowak, M.A., of the University at Buffalo; and Bradford Mahon, Ph.D., of Carnegie Mellon University.
Funding and Disclosures: The study was executed through the support of internal funding from the Department of Physical Medicine and Rehabilitation and the Department of Neurological Surgery at Pitt. The study was also supported by the University of Pittsburgh Hunter Family Foundation Traumatic Brain Injury Translational Research Program.
