The Effect of Transcranial Photobiomodulation for Motor Performance Improvement in Patients with Brain Disorders

Transcranial photobiomodulation (PBM) therapy has emerged as a promising alternative therapeutic option for the management of neurological and psychiatric disorders. However, the underlying mechanisms of PBM therapy and its effects on motor performance in brain disorders are not yet fully understood. The aim of this literature review is to provide a more detailed and evidence-based explanation of the rationale and intent behind the correlation between PBM therapy and its effects on motor performance in brain disorders. A literature search was performed in the databases "PubMed/Medline", "Scopus," and "Google Scholar" for all relevant English language papers. A combination of different keywords was used for the database search. Video articles, patents, review articles, book chapters, articles using other transcranial methods, non-transcranial PBM, and case reports were excluded. Out of the 2174 papers, 18 addressed the effect of PBM on motor performance. Among these, four studies were on ischemic stroke models and individuals with stroke, six studies on models associated with traumatic brain injury (TBI), five studies on models associated with neurodegenerative diseases and Parkinson's disease, and four studies related to models and patients with central nervous system inflammation. All studies have shown that motor parameters improve with PBM. In two studies on healthy individuals, 65 showed improvement in motor function and 16 showed improvement in motor evoked potential. In most studies (n=10), the wavelength used was between 800 and 900 nm. Near-infrared or LED continuous light was used in most studies. However, two studies compared the effects of pulsed and continuous waves and found the superiority of pulsed over continuous waves. PBM therapy appears to be useful in brain injury, inducing changes at the behavioral, motor, cellular, and chemical levels. Recent studies suggest that PBM therapy may have potential benefits in improving motor performance in brain disorders, including stroke, traumatic brain injury, Parkinson's disease, and demyelination. However, further research is needed to determine the optimal parameters for PBM therapy and to investigate its effects on motor function in different brain disorders. Overall, PBM therapy appears to be a promising therapeutic option for brain injury and warrants further investigation.