The effects of transcranial LED therapy (TCLT) on cerebral blood flow in the elderly women

Abstract

During aging processes, there is a range of functional changes, where we can highlight the disease related to the central nervous system, such as Alzheimer disease and others forms of dementia. This study investigated the effects of transcranial light emitting diode (LED) on cerebral blood flow in healthy elderly women analyzed by transcranial Doppler ultrasound (TCD) of the right and left middle cerebral artery and basilar artery. Twenty-five noninstitutionalized elderly women (mean age 72 years old), with a cognitive status >24, were assessed using transcranial Doppler ultrasound on two separate occasions: pre-irradiation and post-transcranial LED therapy (TCLT). Prior to this, they answered two questionnaires: the perceived stress scale and the general health questionnaire. TCLT (627 nm, 70 mW/cm(2), 10 J/cm(2)) was performed at four points of the frontal and parietal region for 30 s each, totaling 120 s two times per week for 4 weeks. Paired t-test results showed that there was a significant improvement after TCLT with increase in the systolic and diastolic velocity of the left middle cerebral artery (25 and 30%, respectively) and basilar artery (up to 17 and 25%), as well as a decrease in the pulsatility index and resistance index values of the three cerebral arteries analyzed (p < 0.05). TCD parameters showed improvement in the blood flow on the arteries analyzed. TCLT promoted a blood and vasomotor behavior of the basilar and middle cerebral arteries in healthy elderly women.

Therapeutic effects of 10-HzPulsed wave lasers in rat depression model: A comparison between near-infrared and red wavelengths

“…In this study, using red and NIR lasers, an energy density of about 1.2 J/cm 2 was delivered on the prefrontal cortex. This optimal range of energy density received by the cortex was enough for effective photomodulation of neural cells, this fact was also reported by other studies . In addition, there has been an increased interest in using the PW mode lights (especially, at 10‐Hz) for tLLLT in recent years .…”

Photobiomodulation improves the frontal cognitive function of older adults

“…[28][29][30][31] Photon absorption increases oxygen consumption, 32 leading to increased oxidative phosphorylation and mitochondrial activity. 35 The increased adenosine triphosphate and cerebral blood flow work together to enhance brain function. 34 Cerebral blood flow is increased due to the vasodilation that occurs after the release of nitric oxide.…”

“…34 Cerebral blood flow is increased due to the vasodilation that occurs after the release of nitric oxide. 35 The increased adenosine triphosphate and cerebral blood flow work together to enhance brain function. [36][37][38] This mechanism is supported by previously reported animal experiments, which identified increases in cytochrome c oxidase and metabolic capacity following PBM.…”

Near-infrared photobiomodulation combined with coenzyme Q10 for depression in a mouse model of restraint stress: reduction in oxidative stress, neuroinflammation, and apoptosis

“…The mitochondrial electron transfer chain -primarily the cytochrome c oxidase (COX) enzyme- is the most likely site for the primary absorption of red (630–670 nm) and NIR (800–880 nm) photons (Karu and Kolyakov, 2005); COX excitation increases the synthesis of neuronal ATP and improves bioenergetic function (de Freitas and Hamblin, 2016; Mintzopoulos et al, 2017). Low levels of light at these wavelengths modulates the release of nitric oxide (NO) (Uozumi et al, 2010) and increases both cerebral oxygenation (Wang et al, 2017) and blood flow (Salgado et al, 2015). Besides these effects, transcranial PBM can stimulate neurogenesis (Tanaka et al, 2011) and provide neuroprotection via antioxidant, anti-neuroinflammatory, and anti-apoptotic activities (De Taboada et al, 2011; Hamblin, 2017; Lu et al, 2017; Salehpour et al, 2017; Salehpour et al, 2018a).…”