(A422) Photobiomodulation Therapy Following Decompressive Craniectomy Improves Motor Function Recovery in a Rat TBI Model

Introduction: Traumatic brain injury (TBI) is a major cause of morbidity and mortality. Decompressive craniectomy (DC) alleviates intracranial pressure but can result in long-term motor deficits known as Syndrome of the Trephined (SoT). Photobiomodulation (PBM), using red (660 nm) and near-infrared (850 nm) light, has shown potential to enhance motor recovery. This study evaluates whether PBM improves functional outcomes after DC in a rodent TBI model.

Methods: Long-Evans rats were randomized into five groups: sham (n=13), hemicraniectomy only (n=11), TBI + hemicraniectomy (n=11), TBI + 660 nm PBM (n=8), and TBI + 850 nm PBM (n=6). Rats were trained on the Beam Walk task before injury. Moderate-to-severe TBI was induced via controlled cortical impact, followed by DC. PBM therapy was administered twice daily for five days following injury. Motor function recovery was assessed using the Beam Walk Test, measuring forelimb and hindlimb slips, time to traverse, and near falls. Statistical analysis included two-way ANOVA and Tukey’s HSD test.

Results: Two-way ANOVA revealed a significant interaction between time point and treatment cohort (p=0.0437), with significant main effects for cohort and time from baseline to Week 3 (p < 0.0001). No significant baseline differences were observed among groups. By 3 days post-treatment, the TBI + 850 nm PBM group showed significant improvement compared to the hemicraniectomy (p=0.0182) and TBI craniectomy groups (p < 0.0001), with recovery approaching sham levels by Week 3 (p>0.9999). Both PBM groups exhibited significant recovery at 3 days (660 nm: p=0.0157; 850 nm: p=0.0005), while untreated groups showed persistent deficits (p < 0.0001). No significant differences were found between the TBI craniectomy and hemicraniectomy groups at 3 days (p=0.1972), indicating similar early impairments. PBM therapy produced sustained motor function benefits compared to untreated groups (p < 0.0001).

Conclusions: PBM therapy enhances motor recovery following DC in a rodent TBI model, supporting its potential as an adjunct therapy in TBI rehabilitation.