An interventional study of tDCS 8 channels and sham tDCS 8 channels in Patients With Persistent Post-concussion Symptoms, sponsored by University of Liege. Not yet recruiting at 1 site in Belgium. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-26.
Sponsored by University of Liege · Not applicable, Interventional, and Other
In this randomized, sham-controlled, two-group, parallel, single-session study, the investigators aim to identify EEG biomarkers associated with cerebellar transcranial direct current stimulation (tDCS) in patients with persistent post-concussion symptoms (PPCS). Cerebellar tDCS will be used to modulate brain network connectivity, which is known to be altered in PPCS. The study will include 38 participants, each completing a single session including EEG recordings before and after stimulation. Participants will be randomly assigned to one of two conditions: 1) active cerebellar tDCS, or 2) sham stimulation.By focusing on EEG functional connectivity and related signal metrics, this study aims to better understand the neural mechanisms of cerebellar tDCS and support the development of targeted interventions for patients with PPCS.
141 studies on the registry are indexed under Post-Concussion Syndrome; 34 are open to participants now.
This study's planned enrollment of 38 is below the median of 52 across 114 interventional studies indexed under Post-Concussion Syndrome.
Browse Post-Concussion Syndrome studies →University of Liege is the lead sponsor of 251 studies on the registry; 50 are open to participants now.
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Active tDCS participants will receive high-definition cerebellar transcranial direct current stimulation using a multi-electrode montage optimized to target bilateral cerebellar regions. The electrode configuration is identical across conditions and has been defined using computational modeling to maximize focality while limiting current spread to adjacent areas. The stimulation consists of a 30-second ramp-up phase, followed by 20 minutes of continuous stimulation, and a 30-second ramp-down phase.
Device: tDCS 8 channels
Sham tDCS participants will undergo the same high-definition cerebellar electrode montage as the active tDCS group, ensuring identical setup and participant experience. However, no sustained current is delivered to the scalp. The protocol includes brief ramp-up and ramp-down phases at the beginning and end of the session to mimic the sensations of real stimulation, while preventing any meaningful modulation of cortical excitability. This approach, established in previous studies, maintains blinding of participants to the stimulation condition. The investigator administering the stimulation will also be blinded, as the tDCS device allows double blinding, with identical screen displays in both sham and active conditions.
Device: sham tDCS 8 channels
Transcranial direct current stimulation is a non-invasive brain stimulation technique that delivers a weak direct electrical current through scalp electrodes to modulate neuronal excitability (\<2mA). Cerebellar tDCS will be administered using an 8-channel montage optimized with the Stimweaver software (Neuroelectrics, Barcelona, Spain) to maximize current density over the cerebellum while minimizing off-target effects. A constant direct current will be applied for 20 minutes, with a 30-second ramp-up at the beginning and a 30-second ramp-down at the end. Other Name:
Transcranial direct current stimulation is a non-invasive brain stimulation technique that delivers a weak direct electrical current through scalp electrodes to modulate neuronal excitability (\<2 mA). The device used has a sham setting that allows sham stimulation to be delivered while the interventionist remains blinded.Other Name:
EEG Functional Connectivity in the Alpha Band (dwPLI)
EEG functional connectivity will be assessed using the debiased weighted Phase Lag Index (dwPLI) in the alpha frequency band (8-12 Hz). This metric quantifies the consistency of phase relationships between EEG signals across brain regions while minimizing the effects of volume conduction. It will be used to evaluate changes in large-scale brain network connectivity associated with cerebellar transcranial direct current stimulation (tDCS) in patients with persistent post-concussion symptoms (PPCS). Differences in connectivity patterns between pre- and post-stimulation recordings, as well as between active and sham groups, will be analyzed.
Time frame: EEG functional connectivity will be assessed at two time points: immediately before and immediately after the stimulation session.
Signal entropy and complexity
Signal entropy and complexity refer to quantitative measures of the irregularity, unpredictability, and informational richness of EEG brain activity. These metrics capture the degree of order versus randomness in neural signals and are used to assess changes in brain dynamics induced by the intervention.
Time frame: Immediately before and immediately after the stimulation session
EEG microstate
EEG microstate analysis will be conducted to examine temporal dynamics of large-scale brain networks. Metrics will include microstate duration, coverage, and occurrence. These will be computed from resting-state EEG recordings acquired before and after stimulation to explore modulation of brain network organization.
Time frame: Immediately before and immediately after the stimulation session
EEG spectral analysis (alpha peak and spectral slope)
Spectral properties of EEG signals will be analyzed, including alpha peak frequency and spectral slope. These measures provide insight into oscillatory activity and excitation-inhibition balance. Analyses will be performed on resting-state EEG recordings collected pre- and post-intervention.
Time frame: Immediately before and immediately after the stimulation session
Phase-amplitude coupling
Analyses will assess phase-amplitude coupling and coherence to evaluate cross-frequency interactions and synchronization between brain regions. These measures will be derived from resting-state EEG recordings before and after stimulation.
Time frame: Immediately before and immediately after the stimulation session
Alpha band participation coefficient
The participation coefficient in the alpha band will be computed to assess the integration of brain regions within large-scale networks. This will be derived from resting-state EEG data collected pre- and post-intervention.
Time frame: Immediately before and immediately after the stimulation session
Rivermead Post-Concussion Symptoms Questionnaire
Post-concussion symptoms will be assessed using the French version of the Rivermead questionnaire. This self-reported measure evaluates the severity of common post-concussion symptoms and will be used to characterize baseline symptom burden.
Time frame: Pre-intervention (baseline)
Simple Reaction Time Task
Participants will complete a computerized simple reaction time task to assess processing speed and motor responsiveness. Performance will be compared before and after stimulation.
Time frame: Pre-intervention and immediately post-intervention
SCAT6 symptom evaluation
The SCAT6 symptom evaluation (Step 2) will be used to assess immediate concussion-related symptoms. This questionnaire will be administered before and after the intervention to explore changes in symptom severity.
Time frame: Pre-intervention and immediately post-intervention
Sustained Attention Task (TAP)
A computerized cognitive task assessing attention will be administered pre- and post-intervention. Performance metrics will be analyzed to evaluate potential cognitive effects of the stimulation.
Time frame: Pre-intervention and immediately post-intervention
Blinding assessment
A blinding questionnaire will be completed by both the participant and the interventionist to assess the effectiveness of blinding between active and sham stimulation conditions.
Time frame: Immediately post-intervention
Adverse events reporting
Adverse events will be assessed using a standardized questionnaire as described in Reckow et al. This will capture any discomfort or side effects associated with the intervention.
Time frame: Immediately post-intervention
Sociodemographic characteristics and medical history
Sociodemographic data will be collected to characterize the study population, including age, gender, level of education, employment status, physical activity level, and substance use (alcohol, tobacco, and drugs). Participants' medical history and current medication use will be recorded to characterize baseline health status and control for potential confounding factors in analyses.
Time frame: Pre-intervention (baseline)
Plan to share: Yes — De-identified individual participant data will be made available to qualified researchers whose requests are methodologically sound and for legitimate scientific purposes, following publication of the primary study results.
Supporting information: Study protocol
Time frame: IPD and supporting information will be made available after publication of the primary study results upon reasonable request and subject to approval. Data will be stored in Dataverse ULiège under restricted access for an indefinite period.
Access criteria: Access to the anonymized individual participant data (IPD) and supporting information, including the study protocol, data dictionary, and statistical analysis code, will be granted to qualified researchers upon reasonable request. Requests will be evaluated by the principal investigator based on scientific validity, methodological quality, and compliance with the original ethical approval and informed consent. Approved users will receive access through a secure institutional repository (e.g., ULiège Dataverse) Only de-identified data will be shared.
No publications or documents are linked to this record.
Start is estimated for Sep 2026; primary completion for Dec 2027, 15 months later.
Of 54 non-industry interventional studies with no phase under Post-Concussion Syndrome, half reached primary completion within 40 months of starting (the median), counting those still running; a quarter within 24 and three quarters within 58. This study's planned 15 months is below that.
Counting every sponsor, half of 56 studies reached it within 40 months; a quarter within 23 and three quarters within 69.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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