Transcranial near-infrared light in treatment of neurodegenerative diseases

Abstract

Light is a natural agent consisting of a range of visible and invisible electromagnetic spectrum travels in waves. Near-infrared (NIR) light refers to wavelengths from 800 to 2,500 nm. It is an invisible spectrum to naked eyes and can penetrate through soft and hard tissues into deep structures of the human body at specific wavelengths. NIR light may carry different energy levels depending on the intensity of emitted light and therapeutic spectrum (wavelength). Stimulation with NIR light can activate intracellular cascades of biochemical reactions with local short- and long-term positive effects. These properties of NIR light are employed in photobiomodulation (PBM) therapy, have been linked to treating several brain pathologies, and are attracting more scientific attention in biomedicine. Transcranial brain stimulations with NIR light PBM in recent animal and human studies revealed a positive impact of treatment on the progression and improvement of neurodegenerative processes, management of brain energy metabolism, and regulation of chronic brain inflammation associated with various conditions, including traumatic brain injury. This scientific overview incorporates the most recent cellular and functional findings in PBM with NIR light in treating neurodegenerative diseases, presents the discussion of the proposed mechanisms of action, and describes the benefits of this treatment in neuroprotection, cell preservation/detoxification, anti-inflammatory properties, and regulation of brain energy metabolism. This review will also discuss the novel aspects and pathophysiological role of the glymphatic and brain lymphatics system in treating neurodegenerative diseases with NIR light stimulations. Scientific evidence presented in this overview will support a combined effort in the scientific community to increase attention to the understudied NIR light area of research as a natural agent in the treatment of neurodegenerative diseases to promote more research and raise awareness of PBM in the treatment of brain disorders.

Photobiomodulation in Alzheimer’s Disease—A Complementary Method to State-of-the-Art Pharmaceutical Formulations and Nanomedicine?

“…Transcranial or intranasal PBM for brain stimulation with R and NIR light has focused attention on positive outcomes on cognitive functions, the repair of neurodegenerative processes, control of energy metabolism, and adjustment of chronic brain inflammatory processes in AD subjects. Publications of experimental and clinical studies on tPBM in AD and other neurodegenerative disorders and ischemic brain injuries have demonstrated that this modality of therapy stimulates metabolic processes in brain tissue, increases intracellular ATP production and revives neuronal mitochondrial activity; modulates local oxidative stress; favors angiogenesis, capillary and lymphatic revascularization; restores destroyed synapses and generates new synapses; revitalizes the growth of new neural cells and acts as a neuroprotector, thus improving cognitive function and memory [ 282 , 283 , 284 , 285 , 286 , 287 , 288 , 289 , 290 ].…”

Design and validation of EEG biomarkers for transcranial photobiomodulation

“…Transcranial photobiomodulation (tPBM) has emerged as a promising neurotherapeutic intervention, particularly for cognitive impairments caused by injury, infection and neurodegeneration [1][2][3][4] . Despite its potential, a significant gap exists in understanding the immediate electrophysiological effects of tPBM, particularly regarding optimal dosage parameters for effective treatment.…”

Transcranial Irradiation Mitigates Paradoxical Sleep Deprivation Effect in an Age-Dependent Manner: Role of BDNF and GLP-1

“…NIR transcranial treatment, also known as photobiomodulation (PBM) therapy, uses non-ionizing light sources such as lasers, LEDs, and broadband light in the visible and infrared range emitting NIR light (wavelengths between 800 and 2500 nm). If an optical window between 650 and 1200 nm is employed, the produced light can pass through the physical barriers of the skin and skull and reach the brain parenchyma [ 26 ]. It is a nonthermal process in which endogenous chromophores cause events at different biological scales.…”