Therapeutic effects of photobiomodulation for traumatic brain injury

Abstract

Traumatic brain injury (TBI) is a leading cause of mortality. A key outcome determinant is edema, resulting from impaired cerebrospinal fluid dynamics, metabolite accumulation, and secondary brain injury. Existing edema therapies are invasive, limited, and risky. Meningeal lymphatic system maintains brain fluid homeostasis and metabolite clearance, and its drainage is impaired in TBI, worsening injury. Photobiomodulation (PBM) is noninvasive low-intensity light that reduces inflammation, activates neuroprotection, and increases lymph flow. We studied PBM efficacy in mice with TBI.
Mild closed head injury was induced in 6-month-old male C57BL/6 mice. Groups: Sham, TBI, TBI+PBM (n=8). Transcranial PBM: 10 days, 17 min illumination, 5-min pause, three times, LED 1050 nm, 30 J/cm². Brain water was assessed by wet-dry weight and histology; neurological deficit by Beam-walking; cognition by Morris water test.
Edema developed on day 1 and persisted 10 days; PBM reduced it. Perivascular spaces increased from day 1 to day 10; PBM reduced vasogenic edema toward Sham values. PBM decreased ventricular enlargement, approaching Sham. Beam-walking time increased on day 10 in TBI; PBM decreased it. In Morris water test, TBI mice showed longer latency and less target-quadrant time; PBM improved both.
Thus, mild closed TBI causes brain edema, impaired cerebrospinal fluid dynamics, and motor/cognitive deficits persisting up to 10 days. PBM (LED, 1050 nm, 30 J/cm²) reduces vasogenic edema, ventricular enlargement, and improves neurological and cognitive functions. PBM is promising noninvasive approach for TBI consequences, including impaired meningeal lymphatic drainage and metabolite accumulation.
Supported by Russian Science Foundation (24-45-00010).

Speaker

Arina Evsiukova
1. Department of Biology, Saratov State University, Astrakhanskaya 83, 410012 Saratov, Russia.
Russia

Discussion

Ask question