Table 2 Health conditions, subjects, outcomes measured, and main reported results
From: Devices used for photobiomodulation of the brain—a comprehensive and systematic review
Condition | No. of articles | No. of subjects | Condition of subjects | Age | Sex | Sham controlled | Treatment time | Outcomes measured | Results |
|---|---|---|---|---|---|---|---|---|---|
Physiological characterisation [9,10,11,12,13, 39, 42, 43, 47, 52, 53, 65, 66, 69, 72, 76, 79, 86, 90, 91, 102] | 21 | 553 | 552 healthy volunteers. 1 patient | 18–85 years | 256 females. 79 not specified (3 articles) | 14 | 2, 2.5, 4, 5, 8, 10, 11, 15, 20, 30 min sessions | Brain imaging—EEG, NIRS, fMRI, transcranial doppler, DCS. Motor cortex excitability—TMS-evoked MEPs. Neuropsychological assessment tests—cognitive task (2-back) | Increased electrophysiological oscillations, neuromodulation of alpha and gamma powers, induced neuroplastic changes in the cortex. Increased cortical excitability and cerebral oxygen saturation. One article showed that PBM had no effect on the four major resting-state brain networks, relating to the fact that the subjects were young and healthy, as opposed to other studies. One article showed significant temperature increase |
Cognitive function [8, 29, 40, 41, 44, 48,49,50,51, 54, 70, 81, 85, 88, 93, 96, 100, 104] | 18 | 697 | 645 healthy volunteers. 52 patients | Mostly 18–35 years. 5 studies above 49 years | 286 females. 138 not specified (4 articles) | 16 | 2.5, 5.8, 6, 7.5, 8, 12, 20 min sessions | Neuropsychological assessment tests—ANAM, PGNG, KBIT, attention task, MEFT, CFT, simple RTT, PVT, DMS, WCST, category task, PANAS, HKLLT, REY-O. Brain imaging—EEG, NIRS, fMRI | Facilitates behavioural cognitive processing in adults at risk for cognitive decline and age-related memory deficits. Enhances visual working memory capacity, sustained attention, cognition, and emotion. Significant change in brain electrophysiological features. Improved performance and function. Clear influence on brain activity, but only in regions that were functionally active. Effective and safe |
Traumatic brain injury [15,16,17,18, 60, 61, 64, 95, 98, 103] | 10 | 142 | 111 patients. 31 healthy volunteers | 14–71 years | 11 females. 99 not specified (2 articles) | 2 | 10, 20, 25.8 to 64.5, 30, 42 to 60 min sessions | Brain imaging—SPECT scans, MRI, EEG, cerebral blood flow. Neuropsychological assessment tests—CVLT-II, WAISIV, TMT-B, DVT, r-CRS. Self-assessments | Self-assessments and test results showed improvement in cognitive function, concentration, reaction time, verbal memory, and overall symptoms. Affects myelin repair pathways and increases synapses after acute and chronic TBI |
7 | 92 | 82 patients. 10 healthy volunteers | 20–85 years | 43 females | 4 | 6, 20, and 25 min sessions | Neuropsychological assessment tests—MMSE, ADAS-Cog, MoCA, WMQ, AST, PSM, IADL, CDT, CPT, LMT-I and II, TMT-A and B. Brain imaging—EEG, MRI, DCS, biomarkers. Self-assessments | Positive improvements enhanced cognitive functions and reversed olfactory dysfunction, safe and well tolerated, potentiated fast oscillations. Delta waves power increase improved alertness and attention; alpha waves decrease caused less anxiety | |
4 | 125 | Patients | 19–64 year | 80 females | 4 | 8, 20 to 30 min sessions | Neuropsychological assessment tests—HDRS, T-SRQ, QIDS-C, CES-D, dot probe task, ABM & ABM Responsiveness | Reduction of depression symptoms, anti-depressant effects. 1 article established a threshold of inefficacy of t-PBM for MDD | |
4 | 58 | Patients | 50–80 years | 21 females | 1 | 2.8, 5.5, 10 to 15, 20, 30, 35 min sessions | Neuropsychological assessment tests—UPDRS, MoCA, TUG, cognition, fine motor skill and static balance tests. Self-assessments | Improvements in signs of PD in 2 studies. One noted minimal positive changes. One demonstrated that H2 water + PBM alleviated severe disease symptoms | |
4 | 1416 | Patients | 40–90 years | 339 females. 630 not specified (1 article) | 3 | 19.5 to 39, 40 min sessions | Neuropsychological assessment tests—NIHSS, BDAE, BNT, PNT, mRS, Letters FAS test. Brain imaging—fMRI | Different light locations caused different behavioural effects, may serve as a new treatment that can promote better neuromodulation poststroke. One study determined it was safe and effective. Two studies stated it had no significant outcomes | |
3 | 65 | Patients | 48–90 years | 27 females | 1 | 5.8, 6, 20, 25 min sessions | Neuropsychological assessment tests—MMSE, ADAS-Cog, CDR, FAQ, HKLLT, Rey-O, GAS-10, CGDS | Overall improvement in symptoms—cognitive, executive, mood swings, visual and verbal memory, independence. Less depressive and anxiety symptoms. Safe with no side effects reported | |
3 | 103 | Patients | 18–70 years | 12 females. 39 not specified (1 article) | 2 | 4 and 8 min session | Neuropsychological assessment tests—OCS, HDRS, HARS, LVFT, Timeline Follow back, PANAS, Wellbeing/Distress Scale, CTHEV. Drug screens. Reported improvements | Reduces opioid cravings and use, as well as depression and anxiety | |
2 | 32 | 22 healthy volunteers. 10 patients | 17–60 years | 23 females | 2 | 1.4 and 4 min sessions | Neuropsychological assessment tests—HADS, PANAS, SCID, HDRS, HARS, test faces, drawings, holding force and grip strength. Brain imaging—NIRS | Lower anxiety and depression scores. Comfortable and safe treatment. In one study, one test showed improvement the other did not | |
2 | 31 | Patients | 5–59 years | 9 females | 0 | 20 to 30 min sessions | Neuropsychological assessment tests—SRS-2, CGI-I, CGI-S, ASRS, BRIEF-A, Q-LES-Q, GAF, CARS, HSQ-ASD, APSI, SDAG, MERS-R, PSQI | Reduced symptoms and severity—improvement in executive functions, such as cognitive flexibility, emotional control, sleep quality, attention. Well tolerated and effective | |
2 | 232 | Healthy volunteers | 18–65 years | 96 females. 120 not specified (1 article) | 2 | 8 min session | Self-assessments | No improvement in exposure, but anxiolytic effects may be achieved. Combination of behavioural training with non-invasive brain stimulation may be a treatment | |
2 | 50 | Patients | 52.4 mean age | All male | 1 | 4, 10.7, 12.6, 20, 25, 28.2 min sessions | Neuropsychological assessment tests. Self-assessments | Improvement in symptoms, treatment should be continuous to continue the effects. Safe with no side effects. Treatments will likely need to be continued on a regular basis | |
ADHD [63] | 1 | 8 | Patients | 8–46 years | 3 females | 0 | 9 min session | Self-assessments | Positive improvement in symptoms |
Anxiety [92] | 1 | 15 | Patients | 18–64 years old | 10 females | 0 | 20 min sessions | Neuropsychological assessment tests—SIGH-A, CGI-S, CGI-I, PSQI | Treatment was effective and well tolerated. Reduction in anxiety symptoms |
Bipolar disorder [58] | 1 | 5 | Patients | 60–85 years | 3 females | 1 | 10 min session | Neuropsychological assessment tests—YMRS, TMT-B, PHQ9, DMS | Improvement in cognitive tasks (e.g., cognitive flexibility, impulsivity, and attention), except for verbal fluency |
Motor performance [70] | 1 | 56 | Healthy volunteers | 18–30 years | 42 females | 1 | 5 min session | Motor performance—finger tapping test | Transcranial light irradiation may improve the motor performance in healthy subjects. Safe with no physical tissue damage |
Schizophrenia [71] | 1 | 32 | Patients | 49.88 mean age | 32 not specified (1 article) | 1 | 15 min sessions | Neuropsychological assessment tests—MMES and PANAS | No significant improvements |
Severe disorder of consciousness [62] | 1 | 8 | Patients | 54.1 mean age | 5 females | 0 | 10 min sessions | Neuropsychological assessment tests—r-CRS | Increased alertness and awareness of the chronic DOC patients |
Sexual dysfunction [83] | 1 | 20 | Patients | 18–65 years | 11 females | 1 | 30 min | Self-assessments. Neuropsychological assessment tests—SAFTEE-SI | Demonstrated a significant therapeutic effect, with reversal of sexual dysfunction in patients with multifactorial causation |
Traumatic brain injury with depression [59] | 1 | 39 | Patients | 40.5 mean age | 20 females | 0 | 30 min sessions | Neurological assessment tests—HDRS, QIDS | Efficacy in depression symptoms. Some patients responded within 4 weeks, more rapid than the response typical of standard oral antidepressants |
Blood conditions [32] | 1 | 90 | Patients | 76.2 mean age | 41 females | 1 | 30 min sessions | Blood tests | Improvement in blood lipid and hemorheology behaviour of patients with vascular disease |
Vertebrobasilar insufficiency [68] | 1 | 25 | Patients | 64 mean age | 20 females | 0 | NR | Diagnostic test—De Klyn’s test, and balance test—Berg Balance Scale | Improvement in global stability and balance, along with reduction of VBI symptoms, better blood perfusion and an increased level of oxygen in brain tissue |