Effects of QEEG-guided low-intensity transcranial magnetic stimulation on executive network function in an athlete with chronic traumatic brain injury

Traumatic brain injury (TBI) may result in persistent executive dysfunction, adversely affecting cognitive control, attention, and decision-making in athletes. Quantitative electroencephalography (QEEG)-guided personalized neuromodulation has emerged as a potential approach for targeting neurophysiological abnormalities associated with chronic TBI. This single-case study investigated a 33-year-old male athlete with chronic TBI who underwent a 12-session individualized low-intensity transcranial magnetic stimulation (Li-TMS) intervention guided by baseline QEEG findings. Stimulation was sequentially applied to Pz, F3, and F4 using frequency-specific protocols selected according to the participant’s individualized neurophysiological profile. Resting-state QEEG and cognitive flexibility were assessed before and after the intervention using QEEG and the Cambridge Neuropsychological Test Automated Battery (CANTAB) Intra–Extra Dimensional Set Shift (IED) task. Descriptive pre- to post-intervention comparisons demonstrated reductions in excessive slow-wave activity together with alterations in alpha-, beta-, and sensorimotor rhythm-related oscillatory patterns within frontal and central regions. QEEG-derived connectivity measures showed reduced deviations from age-adjusted normative values across selected cortical networks. Concurrent reductions in Total Errors Adjusted and Total Trials Adjusted were also observed in the CANTAB IED task. Given the single-case design, these findings should be interpreted as intervention-associated neurophysiological and behavioral observations. This case provides preliminary evidence that individualized, QEEG-guided Li-TMS was associated with neurophysiological changes and concurrent changes in cognitive flexibility-related task performance following chronic TBI. Further controlled studies are needed to confirm the clinical significance of these findings.