1050nm 810nm 660nm Photobiomodulation Mechanisms Part B

III. Parkinson‘s Disease

NIA Workshop Consensus

The 2025 PBM workshop hosted by the US National Institute on Aging (NIA) explicitly noted the potential value of PBM in treating Parkinson‘s Disease (PD) . Experts agreed that PBM is a safe and potentially effective treatment modality warranting further research in age-related diseases.

810nm: Primary Therapeutic WavelengthAccrding to systematic reviews, the potential therapeutic mechanisms of PBM in PD include:

Protection of dopaminergic neurons: By improving mitochondrial function and reducing oxidative stress.

Anti-inflammatory effects: Inhibiting microglial activation, reducing neuroinflammation.

Enhanced cerebral blood flow: Improving perfusion to the basal ganglia.

660nm and 1065nm: Adjunctive and Theoretical Applications

660nm: Can be used for peripheral irradiation or in combination therapies to improve local circulation.

1065nm: Based on its penetration advantage, it could theoretically act on deeper basal ganglia structures.

IV. Traumatic Brain Injury (TBI)

810nm: Preferred Wavelength

FDA-Registered Clinical Trial (NCT06956404) explicitly uses an 808nm laser directed at the forehead to improve CBF and executive function in older adults with chronic TBI.

Key Research from the University of Birmingham:
A research team at the University of Birmingham, UK, found:

810nm near-infrared light (2 minutes daily for 3 days) significantly improved functional recovery after TBI.

Significantly reduced activation of astrocytes and microglia: These cells are closely linked to the inflammatory processes following brain injury.

Significantly lowered biochemical markers of cell death (apoptosis) .

After 4 weeks, performance on balance and cognitive function tests was significantly improved.

810nm was more effective than 660nm.

660nm: Combined Application for Sleep Improvement

Another clinical trial (NCT05072743) evaluated PBM for sleep disturbances in patients post-concussion:

Used a combination of 660nm red light and 830-840nm near-infrared light applied to the cervical spine (neck).

Treatment was twice weekly for 6 weeks.

Outcome measures included the Epworth Sleepiness Scale (ESS) and Insomnia Severity Index (ISI).

Preliminary results showed significant improvements in subjective sleep quality, with some patients describing it as “the best sleep of their lives.”

1065nm: Potential Application

Based on its deep tissue penetration, 1065nm could theoretically aid in repairing deep brain structures after TBI, though direct evidence is lacking.

V. Brain Tumors

Current Research Status and Limitations:

Based on existing literature, PBM is NOT suitable for treating brain tumors, for the following primary reasons:

Safety Concerns: The primary mechanisms of PBM involve promoting cell survival and proliferation, which could potentially have adverse effects on tumor cells.

Clinical Trial Exclusion Criteria: All reviewed欧美 clinical trials (including NCT06956404, NCT05072743, etc.) explicitly list a history of brain tumors as an exclusion criterion.

NIA Workshop Consensus: Brain tumors were not identified as a PBM indication.

Conclusion: Brain tumors are an absolute contraindication for PBM. PBM devices of any wavelength should not be used to irradiate areas with brain tumors.

VI. Brain Atrophy

Therapeutic Principles and Evidence:

Brain atrophy is a common pathological feature of various neurodegenerative diseases (AD, PD, etc.). Based on evidence from AD research, PBM may counteract brain atrophy through the following mechanisms:

Promoting Neurogenesis: Stimulating hippocampal neural stem cells to differentiate into functional neurons.

Reducing Neuronal Apoptosis: Inhibiting caspase-3 mediated apoptosis.

Enhancing Synaptic Plasticity: Improving connections between neurons.

Increasing Cerebral Blood Flow: Improving nutrient supply to atrophic regions.

Wavelength Selection Recommendations:

810nm: Primary therapeutic wavelength for transcranial irradiation of atrophy-related brain regions (e.g., hippocampus, prefrontal cortex).

660nm: Can be used in combination therapies.

1065nm: Based on its penetration advantage, may potentially aid nutrient supply to deep brain structures.

VII. Cerebral Arteriosclerosis

Therapeutic Principles and Evidence:

Vasodilation Effect (Unique Advantage of 1065nm) :
Based on the general mechanisms of photobiomodulation:

Nitric Oxide Release: Absorbed by vascular endothelial cells, promoting NO release and causing vasodilation.

Increased Cerebral Blood Flow: Improving perfusion distal to narrowed arteries.

Reduced Vascular Resistance: Potentially achieved by improving microcirculation.

Penetration Depth Advantage:
The longer 1065nm wavelength penetrates deeper than 810nm, allowing it to reach deeper cerebral blood vessels, making it potentially more effective for deep vasodilation.

Synergistic Role of 810nm:
810nm may indirectly improve symptoms related to arteriosclerosis through:

Regulating Vascular Endothelial Function: Improving endothelium-dependent relaxation.

Anti-inflammatory Effects: Reducing vascular wall inflammation.

Antioxidant Effects: Reducing LDL oxidation.

Wavelength Selection Recommendations:

1065nm: Targets deep cerebral vessels for vasodilation and increased blood flow.

810nm: Targets cortical vessels, improves endothelial function.

Index of FDA-Registered Clinical Trials

Index of Top-Tier Journal Literature