Transcranial PBM
Chapter 2

2 - Treatment Parameter Analysis

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Standard Dosing Parameters

Clinical protocols for transcranial brain photobiomodulation typically employ wavelengths between 810-1070 nm with power densities (irradiance) ranging from 50-400 mW/cm². Energy density (fluence) delivered per session ranges from 13-185 J/cm², with treatment durations of 6-24 minutes per session. Most successful protocols utilize pulsed wave delivery rather than continuous wave, with pulse frequencies of either 10 Hz (alpha band) or 40 Hz (gamma band).​

The 10 Hz pulsing frequency aligns with brain alpha oscillations and has demonstrated effectiveness in promoting skin wound healing, reducing inflammation and brain damage in TBI, enhancing mitochondrial function and neurogenesis, and mitigating amyloid-beta accumulation and cognitive impairment in AD models. The 40 Hz gamma frequency has shown particular promise for activating microglia to reduce amyloid burden, improving cognitive function with more pronounced changes in brain electrical activity, and enhancing glymphatic clearance through multisensory stimulation.​

Treatment frequency typically ranges from 3-7 sessions per week, with total treatment durations of 8-12 weeks for optimal results. Many protocols combine transcranial placement targeting frontal, parietal, and temporal regions with intranasal delivery to reach deeper brain structures including the ventromedial prefrontal cortex, orbitofrontal cortex, and hippocampus.

Low Power vs Class IV

Recent findings challenge current practices using low-power LED devices and suggest a need to revise treatment protocols to ensure adequate power delivery for therapeutic effects. The demonstrated safety and efficacy of high-powered PBM, particularly in treating complex neurological conditions, positions it as a promising non-invasive therapeutic option.

Future development of this technology should focus on optimizing delivery systems while maintaining necessary power levels for effective tissue penetration. Additional controlled clinical trials are warranted to further validate these findings and establish standardized treatment protocols. The potential of PBM as both a primary and adjunctive therapy merits continued investigation, particularly given its favorable risk-benefit profile and the growing need for effective treatments for neurological conditions.

The evidence suggests that when properly implemented with adequate power and appropriate parameters, PBM represents a valuable therapeutic tool that could significantly impact the treatment of various neurological conditions, offering new hope for patients with limited treatment options.

Parameter Published Optimal Range/Value

Irradiance (mW/cm²) 22–285 (most studies for cognitive effects)

Fluence (J/cm²) 15–60 common: 20–30 for neuro, 12–84 for psych, max 60)

Max Dose/Session ≤60 J/cm² (per site/session, with most studies using 15–30)

Sessions/Week 3 (e.g., Mon/Wed/Fri)

Total Sessions 18–24 (over 6–8 weeks); some protocols up to 40–72

Source

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