Table 2.
PBM1 application on human sample
| Authors | Age (Gender, model) | Total sample size / groups (n) | Neuropsychological assessment | Neuropsychological results | Brain results | PBM parameters (Wavelength nm / Wavelength type (frequency)/ intensity/irradiance) | Target | Duration | |
|---|---|---|---|---|---|---|---|---|---|
| Arakelyan (2005) | Mean: 73.1 years (37% men, AD 2) | N = 145/ AD control (n = 15); AD PBM (n = 25); AD MFT3 (n = 25); AD LCT4 (n = 17); AD LMLCT5 (n = 25); AD Pharmacotherapy (n = 38) | Cognitive function (ADAS-cog6) | PBM improved cognition in AD | - | 633 nm/NR7/ NR /4 mW | Intravenous application | 6 days over 18 months | |
| Bullock et al. (2021) | Mean: 67.7 years (60% men, PD8) | N = 20/ PD PBM protocol 1 (n = 10); PD PBM protocol 2 (n = 10) | Cognitive function (MoCA9) | PBM did not affect general cognition in PD | - | 904 nm/ Pulsed (50 Hz)/ 42 J/ 60 mW/diode | Transcranial application with 4 irradiation points (lateral cranial point, midline cranial point, parietal region point, and intranasal) |
Protocol 1: 1 month placebo (3 times per week) + 1 month washout + 1 month PBM/placebo (2 and 1 times per week, respectively) Protocol 2: 1 month PBM (3 times per week) + 1 month washout + 1 month PBM/placebo (1 and 2 times per week, respectively) |
|
| Chan et al. (2019) | Range: > 60 years (10% men, healthy) | N = 30/ Aged control (n = 15); Aged PBM (n = 15) |
Global cognitive function (CDRS10) Verbal learning (HKLLT11) Depressive symptoms (CGDS12) Anxiety symptoms (BAI13) |
PBM leads to a positive effect on cognitive inhibition and lexical/semantic access in healthy aging PBM leads to a faster reaction time and better fluency (generating total words) in healthy aging PBM did not result in depressive and anxiety symptoms amelioration |
- | 633 nm and 870 nm/ Continuos / NR/ 999 mW | Transcranial application with 3 irradiation points (right and left frontopolar regions [FP114, FP215, and Pz16]) | One day | |
| Chan et al. (2021) |
Mean: 66.3 years (50% men, MCI17) |
N = 18/ MCI control (n = 9); MCI PBM (n = 9) |
Visual memory (Computerized Corsi block test) |
PBM leads to improvements in visual memory in MCI | PBM reduced frontal lobe HbO18 in easier and difficult levels of a visual memory task, in MCI | 810 nm/ Continuous / 7 J/cm2/ 20 mW/cm2 | Transcranial application with 9 irradiation points in the frontal lobe (placed to F719, AF720, Fp1, FpZ21, Fp2, AFZ22 and FZ23) | One day | |
| Chao (2019) | Mean: 79.8 ± 5.8 years (37.5% men, AD or dementia) | N = 8/ AD control (n = 4); AD PBM (n = 4) |
Cognitive function (ADAS-cog; NPI24) |
PBM improved cognition and neuropsychiatric symptomatology in AD or dementia |
PBM increased cerebral perfusion and connectivity between posterior cingulate cortex and lateral parietal nodes in AD or dementia, increased CBF25 in parietal cortex, and did not alter the default-mode-network |
810 nm/ Pulsed (40 Hz)/ 720 J/ 100 mW | Transcranial application with 2 irradiation points (posterior and anterior) and intranasal application | 36 non-consecutive days (3 times per week) | |
| Fear et al. (2023) | Mean: 68 years (40% men, healthy) | N = 7 / Aged Pre and Post PBM | - | - | PBM increased ATP26 synthase flux | 670 nm/ NR/ NR/ NR | Transcranial application with 1 irradiation point (occipital lobes) | 4 consecutive days | |
| Hu et al. (2023) | Mean: 64.74 ± 5.73 years (16% men, healthy) | N = 61/ Aged Pre and Post PBM |
Working memory (N-back task) |
PBM (single and repeated) improved memory on day 1 and day 7, on healthy ageing. These results were maintained during the follow up at day 14, 21 and 28 | PBM (single) decreased HbO activity during the memory task in the right hemisphere, and PBM (repeated) decreased HbO activity in both hemispheres | 1064 nm/ NR/ 3.4 J/ 250 mW/cm2 | Transcranial application with 1 irradiation point (left DLPFC27) | 7 consecutive days | |
| Lee & Chan. (2023) | Range: 50–80 years (43% men, healthy) | N = 30/ Aged Pre and Post PBM | Visual memory (computerized visual span task) | PBM did not improved visual memory | PBM reduced HbO in a difficult level of visual memory task, but not in the easier level | 810 nm/ Continuous/ 7 J/cm2/ 20 mW/cm2 | Transcranial application with 9 irradiation points (F7, AF7, Fp1, Fpz, Fp2, AF8, F8, Fz and Cz) | One day | |
| Liebert et al. (2021) | Range: 60–80 years (41% men, PD) | N = 12/ PD PBM Protocol 1 (n = 6); PD PBM Protocol 2 (n = 6) |
Cognitive function (MoCA) |
PBM improved the cognitive function with both protocols | - |
Transcranial: 810 nm/ Pulsed (40 Hz) / 240 J/ 200 mW/cm2 Intranasal: NR/ NR/ 15 J/ NR Transdermal and Transabdominal: 904/ Pulsed (50 Hz)/ 3.6 J/ 47 mW/cm2 |
Transcranial, intranasal, transdermal and transabdominal |
Transcranial: Protocol 1: 144 non-consecutive days (3 times per week for 4 weeks + 2 times per week for 4 weeks + 1 time per week for 4 weeks + 3 per week for 40 weeks). Protocol 2: 99 non-consecutive days (3 times per week for 4 weeks + 2 times per week for 4 weeks + 1 time per week for 4 weeks + 3 per week for 24 weeks) Intranasal: NR Transdermal and transabdominal: Same protocol as transcranial |
|
| Nagy et al. (2021) | Range: 65–75 years (50% men, AD) | N = 60/ AD control (n = 30); AD PBM (n = 30) |
Cognitive function (MoCA) |
PBM improved the cognitive function in AD | - | 650 nm/ NR/ NR/ NR | Intranasal application | 36 non-consecutive days (3 times per week) | |
| Papi et al. (2022) | Mean: 64.13 ± 4.73 years (0% men, MCI) | N = 42/ MCI control (n = 21); MCI PBM (n = 21) |
Cognitive function (MMSE28) Attention (Go/No-Go task) |
PBM increased the cognitive function, and specifically attention | - | 850 nm/ NR/ 60 J/ 400 mW | Transcranial application with 1 irradiation point (Fp2) | One day | |
| Qu et al. (2022) | Mean: 65.6 ± 5.41 years (20% men, healthy) | N = 86/ Aged control (n = 25); Aged PBM (n = 61) |
Working memory (N-back tasks) |
PBM improved working memory in healthy ageing. There was a higher accuracy in two of the testing conditions and lower response time on the more difficult condition | - | 1064 nm/ Continuos / 120 J/ 250 mW/cm2 | Transcranial application with 1 irradiation point (left DLPFC) | 7 consecutive days | |
| Razzaghi et al. (2024) | Mean: 74.66 ± 14.4 in PBM groups, and 75.85 ± 7.19 years in control groups (77% men, AD and MCI) | N = 13/ AD and MCI control (n = 7); AD and MCI PBM (n = 6) |
Cognitive function (MoCA) Anxiety symptoms (HAM-A29) Depression symptoms (HDRS30) |
PBM improved the cognitive assessment in AD and MCI Both groups significantly improved depression levels, but not anxiety levels |
- | 810 nm/ Pulsed (40 Hz)/ 300 J/ 150 mW/cm2 | Transcranial application with 3 irradiation points (frontal, occipital and temporal lobe) | 72 non-consecutive days (6 times per week) | |
| Saucedo et al. (2021) | Range: 56–85 (23% men healthy) | N = 68/ Aged control (n = 33); Aged PBM (n = 35) | - | - | PBM increased oxidized CCO31 in right and left prefrontal cortex in healthy ageing, decreased HbR in right prefrontal cortex, and did not modified prefrontal HbO | 1064 nm/ Continuos / 120 J/cm2/ 250 mW/cm2 | Transcranial application with 1 irradiation point (right anterior prefrontal cortex [P2]) | One day |
1. PBM = photobiomodulation. 2. AD = Alzheimer’s disease. 3. MFT = magnetic field therapy. 4. LCT = light chromotherapy. 5. LMLCT = combined PBM, MFT and LCT. 6. ADAS-cog = Alzheimer’s disease assessment Scale- Cognitive subscale. 7. NR = not reported. 8. PD = Parkinson’s disease. 9. MoCA = Montreal Cognitive assessment. 10. CDRS = clinical dementia rating scale. 11. HKLLT = Hong Kong list learning test. 12. CGDS = geriatric depression scale. 13. BAI = Beck anxiety inventory. 14. FP1 = left frontopolar region. 15. FP2 = right frontopolar region. 16. Pz = peripherial zone. 17. MCI = mild cognitive impairment. 18. HbO = oxygenated hemoglobin. 19. F7 = frontal region 7. 20. AF7 = mastoid frontal region 7. 21. Fpz = prefrontal zero region. 22. AFz = mastoid frontal zero region. 23. Fz = frontal zero region. 24. NPI = neuropsyvhiatric inventory. 25. CBF = cerebral blood Flow. 26. ATP = adenosine triphosphate. 27. DLPFC = dorsolateral prefrontal cortex. 28. MMSE = mini-mental state examination. 29. HAM-A = Hamilton anxiety rating scale. 30. HDRS = Hamilton depression rating scale. 31. CCO = cytochrome C oxidase. 31. HbR = deoxygenated hemoglobin