Beneficial neurocognitive effects of transcranial laser in older adults

Abstract

Transcranial infrared laser stimulation (TILS) at 1064 nm, 250 mW/cm has been proven safe and effective for increasing neurocognitive functions in young adults in controlled studies using photobiomodulation of the right prefrontal cortex. The objective of this pilot study was to determine whether there is any effect from TILS on neurocognitive function in older adults with subjective memory complaint at risk for cognitive decline (e.g., increased carotid artery intima-media thickness or mild traumatic brain injury). We investigated the cognitive effects of TILS in older adults (ages 49-90, n = 12) using prefrontal cortex measures of attention (psychomotor vigilance task (PVT)) and memory (delayed match to sample (DMS)), carotid artery intima-media thickness (measured by ultrasound), and evaluated the potential neural mechanisms mediating the cognitive effects of TILS using exploratory brain studies of electroencephalography (EEG, n = 6) and functional magnetic resonance imaging (fMRI, n = 6). Cognitive performance, age, and carotid artery intima-media thickness were highly correlated, but all participants improved in all cognitive measures after TILS treatments. Baseline vs. chronic (five weekly sessions, 8 min each) comparisons of mean cognitive scores all showed improvements, significant for PVT reaction time (p < 0.001), PVT lapses (p < 0.001), and DMS correct responses (p < 0.05). The neural studies also showed for the first time that TILS increases resting-state EEG alpha, beta, and gamma power and promotes more efficient prefrontal blood-oxygen-level-dependent (BOLD)-fMRI response. Importantly, no adverse effects were found. These preliminary findings support the use of TILS for larger randomized clinical trials with this non-invasive approach to augment neurocognitive function in older people to combat aging-related and vascular disease-related cognitive decline.

Photobiomodulation improves the frontal cognitive function of older adults

“…72 Although previous studies using these transcranial brain stimulation approaches have also found beneficial effects on cognitive function in older adults, [73][74][75] week). 50 Therefore, it is plausible that a longer PBM treatment may produce a long-lasting and greater treatment effects on EF. Moreover, the present study evaluated only two components of EF, namely inhibition ability and mental flexibility.…”

“…44 Besides, Vargas et al has conducted a PBM study to 21 elderly with subjective memory complaint and reported a significant effect on some frontal cognitive function, such as sustained attention and short-term memory. 50 The major objective of the present study was to examine the effects of PBM on frontal executive function in older adults. We hypothesized that PBM would facilitate frontal executive function, which would be indicated by improved inhibition ability and greater mental flexibility in older adults.…”

“…,46 Apart from clinical patient populations, PBM has been applied to healthy college students, whereby 8 minutes of PBM treatment to the right prefrontal pole (FP2) successfully improved their memory, sustained attention, and emotional state 44. Besides, Vargas et al has conducted a PBM study to 21 elderly with subjective memory complaint and reported a significant effect on some frontal cognitive function, such as sustained attention and short-term memory 50. The major objective of the present study was to examine the effects of PBM on frontal executive function in older adults.…”

“…Furthermore, researchers have found greater effects after applying five 8 minutes of PBM intervention for 5 weeks (ie, one for eachweek) 50. While transcranial direct current stimulation and transcranial magnetic stimulation aim to induce very small electric currents in the cortex that facilitate the depolarization and hyperpolarization of neurons, PBM utilizes low-level light to generate cellular biochemistry and increase blood flow.…”

Effects of transcranial photobiomodulation with near‐infrared light on sexual dysfunction

“…Adult subjects (age 18-65 years) meeting the DSM-IV SCID criteria for MDD, with the degree of depression severity rated at least moderate (Hamilton Depression Rating Scale, HAM-D 17 total score ranging [14][15][16][17][18][19][20][21][22][23][24], were included in the study after providing written informed consent. During the current episode, subjects could have failed no more than one FDA-approved antidepressant medication (for at least 6 weeks) and no more than one course of structured psychotherapy for depression (for at least 8 weeks).…”