Brain Brightening for Elderly Using QEEG-Guided tPBM

EEG Frequency and Blood Perfusion

Transcranial photobiomodulation (tPBM) is known to increase blood perfusion by stimulating cytochrome c-oxidase in mitochondria. Blood perfusion can be measured with H₂O PET, and studies have shown that blood perfusion and EEG frequency are closely correlated (Cook, O'Hara, Uijtdehaage, Mandelkern, & Leuchter, 1998).

• Sleep & High Stress:

  • High delta waves during sleep correspond with significant blood perfusion, reflecting increased metabolic demand.

  • High beta waves under stress also correlate with high perfusion levels.

• Theta & Alpha and Aging:

  • Theta and alpha waves are associated with reduced perfusion and decreased metabolism.

  • The aging process is marked by a slowing of alpha frequency and an increase in theta waves in EEG.

From this perspective, tPBM may counteract aging by enhancing blood perfusion and supporting metabolic function in the brain.

Entrainment of EEG Rhythm with Pulsed Noninvasive Brain Stimulation (NiBS)

Noninvasive brain stimulation (NiBS) includes techniques like rTMS, tDCS/tACS, and tPBM. These modalities have been shown to entrain brain rhythms and modify neuronal excitability:

• Repetitive Transcranial Magnetic Stimulation (rTMS):

  • Standard protocols:

    • 10 Hz rTMS = activation

    • 1 Hz rTMS = inhibition (Lefaucheur et al., 2020).

  • Individualized alpha frequency (+1 Hz) yields optimal activation (Roelofs et al., 2021).

• Transcranial Alternating Current Stimulation (tACS):

  • Theta-frequency tACS is used in individuals with a strong beta EEG pattern, and beta-frequency tACS is used in individuals with strong theta (Del Felice et al., 2019).

• Transcranial Photobiomodulation (tPBM):

  • Pulsed tPBM produces different effects compared to continuous tPBM (Yao et al., 2021).

  • 1 Hz tPBM improves tremors in Parkinson’s and irritability in autism (associated with excessive beta).

  • Low/mid-beta frequencies are optimal for cerebral blood perfusion and are utilized in pulsed tPBM (Bouny et al., 2022; Campos da Paz et al., 2018).

Pulsed tPBM is believed to synchronize neuronal firing and enhance EEG rhythms due to light-activated ion channels in neurons receiving the pulsed stimulation (Hamblin, 2016).

QEEG Patterns of Aging and Alzheimer's Disease (AD) / Mild Cognitive Impairment (MCI)

• Normal aging:

  • Cerebral blood flow slightly declines.

  • Theta power increases, while alpha power decreases slightly.

  • Beta frequency remains stable due to compensatory activity.

  • Reduced 40 Hz gamma power may be a marker of aging (Budzynski, 2007).

• MCI EEG Patterns:

  • Increased low-frequency amplitude (theta/delta) and decreased high-frequency amplitude (alpha/beta) (Şeker & Özerdem, 2024).

  • The theta/beta ratio is a useful biomarker for tracking neurodegeneration (Azami et al., 2023).

• Alpha Rhythm and Cognitive Function:

  • Alpha-band oscillations play a key role in memory and cognitive processing (Klimesch, 2012).

  • A slower alpha peak frequency is linked to cognitive decline (Klimesch, 1999).

These findings suggest that reversing age-related EEG changes using tPBM could improve cognitive function and brain connectivity.

QEEG-Guided tPBM for AD & MCI: Pilot Study Results

A brain-brightening protocol using QEEG-guided tPBM aims to:
✅ Decrease theta power
✅ Increase alpha and beta power
✅ Enhance alpha peak frequency

Pilot Study Findings

• Theta/Beta ratio significantly reduced after tPBM.

• Alpha peak frequency increased in the intervention group.

• Cognitive function improved, as seen in clinical measures.

Figure 1:

Analysis of 53 subjects with MCI receiving personalized near-infrared tPBM (10 min/session, 3x per week, for 8 weeks).

• TBR2 showed normalization of EEG balance in the frontal and parietal lobes after intervention.

Figure 2:

CDR & CDR-SB changes in 23 participants (8-week intervention + 4-week maintenance).

• Significant cognitive improvements were observed in the maintenance group.

Figure 3:

18 elderly participants (control vs. PBM group).

• Alpha peak frequency decreased in the control group but increased in the PBM group.

• This suggests tPBM counteracts typical age-related cognitive decline.

A Candidate Personalized tPBM Protocol Used in the Pilot Study

EEG Phenotype tPBM Protocol Time If alpha is weakened: Global Alpha + Global SMR + Gamma4 min + 4 min + 2 min
If alpha power is normal but slow: Occipital Alpha speed-up + Global SMR + Gamma4 min + 4 min + 2 min

If theta is strong (frontal, temporal)Global Alpha + Global SMR + Beta in the affected regions3 min + 3 min + 4 min

• Alpha (9-10 Hz), SMR (13-15 Hz), Beta (16-18 Hz), and Gamma (38-42 Hz) frequencies were used.

• Frequencies were adjusted based on age, individual power distribution, and response to tPBM.

References

Azami, H., et al. (2023). Beta to theta power ratio in EEG periodic components as a potential biomarker in mild cognitive impairment and Alzheimer's dementia. Alzheimers Res Ther, 15(1), 133. doi:10.1186/s13195-023-01280-z

Bouny, P., et al. (2022). A Single Session of SMR-Neurofeedback Training Improves Selective Attention. Brain Sci, 12(6). doi:10.3390/brainsci12060794

Budzynski, T., et al. (2007). Brain brightening: Restoring the aging mind. In Handbook of Neurofeedback.

Campos da Paz, V. K., et al. (2018). SMR Neurofeedback Training Facilitates Working Memory Performance in Older Adults. Frontiers in Behavioral Neuroscience, 12. doi:10.3389/fnbeh.2018.00321

Cook, I. A., et al. (1998). Assessing the accuracy of topographic EEG mapping for determining local brain function. Electroencephalogr Clin Neurophysiol, 107(6), 408-414.

Del Felice, A., et al. (2019). Personalized tACS and physical therapy for Parkinson’s disease. NeuroImage: Clinical, 22, 101768.

Hamblin, M. R. (2016). Shining light on the head: Photobiomodulation for brain disorders. BBA Clin, 6, 113-124.

Klimesch, W. (1999). EEG alpha and theta oscillations reflect cognitive and memory performance. Brain Research Reviews, 29(2), 169-195.

Klimesch, W. (2012). Alpha-band oscillations, attention, and stored information access. Trends in Cognitive Sciences, 16(12), 606-617.

Lefaucheur, J. P., et al. (2020). Evidence-based guidelines on rTMS: Clin Neurophysiol, 131(2), 474-528.

Roelofs, C. L., et al. (2021). Individual alpha frequency proximity and rTMS outcome. Clin Neurophysiol, 132(2), 643-649.

Şeker, M., & Özerdem, M. S. (2024). Dementia rhythms: EEG neuromarkers for MCI detection. Journal of Neuroscience Methods, 409, 110216.

Yao, L., et al. (2021). Effects of stimulating frequency of NIR LEDs light irradiation on EEG. Journal of Innovative Optical Health Sciences, 14(02), 2050025.