Transcranial Near-infrared Laser Therapy in Improving Cognitive Recovery of Function Following Traumatic Brain Injury

Effects of intravascular photobiomodulation on cognitive impairment and crossed cerebellar diaschisis in patients with traumatic brain injury: a longitudinal study

The association between intravascular photobiomodulation (iPBM) and crossed cerebellar diaschisis (CCD) and cognitive dysfunction in patients with traumatic brain injury (TBI) remains unknown. We postulate that iPBM might enable greater neurologic improvements. The objective of this study was to evaluate the clinical impact of iPBM on the prognosis of patients with TBI. In this longitudinal study, patients who were diagnosed with TBI were recruited. CCD was identified from brain perfusion images when the uptake difference of both cerebella was > 20%. Thus, two groups were identified: CCD( +) and CCD( -). All patients received general traditional physical therapy and three courses of iPBM (helium-neon laser illuminator, 632.8 nm). Treatment assemblies were conducted on weekdays for 2 consecutive weeks as a solitary treatment course. Three courses of iPBM were performed over 2-3 months, with 1-3 weeks of rest between each course. The outcomes were measured using the Rancho Los Amigos Levels of Cognitive Functioning (LCF) tool. The chi-square test was used to compare categorical variables. Generalized estimating equations were used to verify the associations of various effects between the two groups. p < 0.05 indicated a statistically significant difference. Thirty patients were included and classified into the CCD( +) and CCD( -) groups (n = 15, each group). Statistics showed that before iPBM, CCD in the CCD( +) group was 2.74 (exp 1.0081) times higher than that of CCD( -) group (p = 0.1632). After iPBM, the CCD was 0.64 (exp-0.4436) times lower in the CCD( +) group than in the CCD( -) group (p < 0.0001). Cognitive assessment revealed that, before iPBM, the CCD( +) group had a non-significantly 0.1030 lower LCF score than that of CCD( -) group (p = 0.1632). Similarly, the CCD( +) group had a non-significantly 0.0013 higher score than that of CCD( -) after iPBM treatment (p = 0.7041), indicating no significant differences between the CCD( +) or CCD( -) following iPBM and general physical therapy. CCD was less likely to appear in iPBM-treated patients. Additionally, iPBM was not associated with LCF score. Administration of iPBM could be applied in TBI patients to reduce the occurrence of CCD. The study failed to show differences in cognitive function after iPBM, which still serves as an alternative non-pharmacological intervention.

Infrared neuromodulation:a neuroengineering perspective

Infrared neuromodulation (INM) is a branch of photobiomodulation that offers direct or indirect control of cellular activity through elevation of temperature in a spatially confined region of the target tissue. Research on INM started about 15 ago and is gradually attracting the attention of the neuroscience community, as numerous experimental studies have provided firm evidence on the safe and reproducible excitation and inhibition of neuronal firing in both in vitro and in vivo conditions. However, its biophysical mechanism is not fully understood and several engineered interfaces have been created to investigate infrared stimulation in both the peripheral and central nervous system. In this review, recent applications and present knowledge on the effects of INM on cellular activity are summarized, and an overview of the technical approaches to deliver infrared light to cells and to interrogate the optically evoked response is provided. The micro- and nanoengineered interfaces used to investigate the influence of INM are described in detail.

Photobiomodulation Therapy in Oral Medicine: A Guide for the Practitioner with Focus on New Possible Protocols

Photobiomodulation (PBM) is the term to define the wide range of laser applications using low-energy densities and based on photochemical mechanisms where the energy is transferred to the intracellular mitochondrial chromophores and respiratory chain components. In literature, a great number of works are reported showing the advantages of PBM use in many oral diseases such as recurrent aphthous stomatitis, herpes infections, mucositis, and burning mouth syndrome. Different factors may explain the increasing reported use of PBM in oral medicine: the absence of side effects, the possibility of safely treating compromised patients such as oncologic patients, the possibility of a noninvasive approach not associated with pain or discomfort, and the possibility of performing short sessions. The review's aim is to describe the possible applications of PBM in oral medicine, giving practitioners simple guide for practice together with the information of a new treatment possibility "at home" performed by the patient himself under supervision.