Application of photobiomodulation in post-stroke dysfunctions: a literature review of recent clinical studies

Stroke patients often experience varying degrees of dysfunctions after a stroke, including motor, cognitive, speech, and other functional impairments. These post-stroke dysfunctions seriously affect the daily life and quality of life of patients. For many years, researchers have devoted themselves to finding non-invasive treatment methods to improve these functional deficits and enhance patients' quality of life. Photobiomodulation (PBM) is a non-invasive phototherapy, and can be an adjuvant therapy for various neurological disorders by promoting neurogenesis and eliciting anti-apoptotic, anti-inflammatory, and antioxidative responses. Existing animal experimental evidence indicates that PBM may offer potential benefits for stroke patients. However, robust clinical evidence remains limited. Recent clinical studies provided new data supporting the efficacy of PBM in post-stroke dysfunctions, including motor, cognitive, and speech impairments. These studies used transcranial PBM (tPBM) for cognitive impairment and aphasia, or peripheral PBM directly to paretic limbs to yield positive outcomes for limb spasticity and pain. This mini-review summarizes key findings from these studies and discusses the associated challenges and prospects of PBM.