NCT07271524

Non-invasive Deep Brain Stimulation to Improve Spatial Navigation Abilities in Individuals Following Traumatic Brain Injury

Investigation of the Plasticity of Deep Brain Structures in Mild Cognitive Impairment and Healthy Aging (PlasMA)

• Status: Not Yet Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 25 (estimated)
• Sponsor: Friedhelm Hummel · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

Impairments in spatial memory and spatial navigation are commonly reported amongst patients presenting post-traumatic brain injury (TBI). In this study, the investigators examine the effect of non-invasive deep brain stimulation of the hippocampal-entorhinal complex (HC-EC), a key region supporting navigation abilities, on spatial navigation performance in TBI patients. Using a virtual reality task where participants must first encode and later recall the location of objects in a virtual arena, the investigators contrast performance while active versus control stimulation is applied to the HC-EC. The investigators additionally record brain activity using electroencephalography (EEG) prior to, during, and after task performance to characterize the neural correlates of spatial navigation abilities in TBI patients, and how they are affected by stimulation.

Detailed description

Patients will perform a virtual reality spatial navigation task comparable to that used previously by Beanato and colleagues (2024; DOI: 10.1126/sciadv.ado4103). Patients will perform 4 blocks of task, each lasting approximately 10 minutes; during the full duration of each block, either active or control transcranial temporal interference stimulation (tTIS) will be applied in an interleaved manner, and EEG recordings will be collected. Resting-state EEG recordings will also be collected prior to and following task performance. Structural, diffusion-weighted, and resting-state MRI scans will additionally be performed during a prior baseline session.

Conditions

• Traumatic Brain Injury

Interventions

Type	Name	Description
OTHER	Transcranial electric stimulation	Transcranial temporal interference stimulation (tTIS) is an innovative non-invasive brain stimulation approach, in which two or more independent stimulation channels deliver high-frequency currents in the kHz range (oscillating at f1 and f1 + Δf). These high-frequency currents are assumed to be too high to effectively modulate neuronal activity. Still, by applying a small shift in frequency, they result in a modulated electric field with the envelope oscillating at the low-frequency Δf (target frequency) where the two currents overlap. The peak of the modulated envelope amplitude can be steered towards specific areas located deep in the brain, by tuning the positions of the electrodes and the current ratio across stimulation channels. Here, the investigators apply tTIS via surface electrodes applying a low-intensity, sub-threshold protocol following the safety guidelines for low-intensity transcranial electric stimulation in humans.

Timeline

• Start date: 2025-12-01
• Primary completion: 2027-12-01
• Completion: 2027-12-01
• First posted: 2025-12-09
• Last updated: 2025-12-09

Locations

2 sites across 1 country: Switzerland