Photobiomodulation Promotes Motor Recovery Following Decompressive Craniectomy for Traumatic Brain Injury.

Area of Science:

• Neuroscience
• Biomedical Engineering
• Regenerative Medicine

Background:

• Photobiomodulation (PBM) utilizes red and near-infrared light for therapeutic benefits in neuropathology.
• The transmission of PBM through the scalp and skull to the central nervous system remains unclear.
• Decompressive craniectomy (DC) for traumatic brain injury (TBI) may enhance PBM penetrance and neurorehabilitation.

Purpose of the Study:

• To evaluate PBM tissue penetrance in the context of TBI and DC.
• To assess the efficacy of PBM on motor deficit recovery following TBI and DC.
• To investigate the impact of scalp and cranial bone on PBM light transmission.

Main Methods:

• Adult rats underwent TBI induction using a closed-head model.
• PBM transmittance was measured ex vivo through scalp and hemicranium samples.
• Motor recovery was assessed using the beam walk test to quantify limb deficits.

Main Results:

• PBM intensity was attenuated by scalp and cranial bone, but sufficient penetration was achieved post-DC.
• PBM-treated rats showed significantly fewer hindlimb slips compared to untreated TBI controls.
• Both 660 nm and 850 nm PBM demonstrated efficacy in improving motor recovery.

Conclusions:

• PBM light penetrates sufficiently through the skull after DC in TBI models.
• PBM therapy enhances neurorehabilitation and motor recovery in TBI rats.
• DC may be a viable strategy to improve PBM efficacy for TBI treatment.