Traumatic Brain Injury (TBI) is a significant public health concern, often resulting in long-term cognitive deficits that affect individuals’ ability to engage in work, study, and social activities.
A groundbreaking pilot study, conducted by Dr. Jaimie Henderson and colleagues at Stanford Medicine in California, explores the potential benefits of deep brain stimulation (DBS) targeting the central lateral nucleus of the thalamus in individuals with moderate-to-severe TBI.
Study Participants and Design
The study enrolled six adults, aged 22 to 60, who had experienced moderate-to-severe TBI 3 to 18 years prior. Participants exhibited persistent cognitive impairment for over two years, hindering their return to pre-injury levels of functioning. Glasgow Coma Scale scores indicated the severity of their injuries, and pre-surgery Glasgow Outcome Scale-Extended scores reflected moderate disability. Most injuries resulted from motor vehicle accidents.
Researchers implanted electrodes guided by imaging and a virtual model of each participant’s brain. These electrodes targeted the central lateral nucleus and the associated medial dorsal tegmental tract. Wires from the electrodes were subcutaneously placed and connected to a battery pack and controller implanted in the upper chest. Following a 14-day titration phase to determine optimal stimulation parameters, participants received deep brain stimulation for 12 hours a day over 90 days.
The primary outcome measure was a 10% improvement in completion time on part B of the trail-making test (TMT-B), a tool assessing attentional control and information processing speed. All five participants who completed the trial exceeded this benchmark, with an average improvement of 31.75%. Notably, participants with the greatest initial deficits experienced the most significant improvements, exceeding 40%.
Secondary Outcome Measures
Participants were also evaluated for quality of life and fatigue. Two individuals met the pre-specified improvement benchmark, two remained stable, and one experienced a decline. The study demonstrated a positive impact on cognitive function, indicating the potential broader implications of DBS for TBI patients with chronic cognitive deficits.
Adverse Events and Long-term Effects
There were 14 adverse events, two of which were classified as serious. A participant with a postoperative scalp infection was withdrawn from the study, and another experienced symptoms attributed to aseptic meningitis. However, all adverse events resolved without lasting consequences. Remarkably, the five participants who completed the trial still retained their DBS implants years after its conclusion.
Dr. Henderson highlighted the significance of the findings, emphasizing the need for a phase II study to validate the effectiveness of the DBS technique. The goal is to expand the trial and explore the broader applicability of DBS in addressing chronic cognitive deficits in TBI patients.
This pilot study presents a promising avenue for alleviating cognitive deficits in individuals with long-term effects of traumatic brain injury. Deep brain stimulation targeting the central lateral nucleus of the thalamus demonstrated notable improvements in processing speed, with implications for enhancing the quality of life for TBI survivors. Further research through a phase II study will be pivotal in confirming these findings and expanding the potential applications of DBS in this patient population.
reference link : https://www.nature.com/articles/s41591-023-02638-4