Low-Level Laser Therapy Applied Transcranially to Mice following Traumatic Brain Injury Significantly Reduces Long-term Neurological Deficits

Amir Oron Department of Orthopedics, Assaf Harofeh Medical Center, Zerifin, Israel.
Uri Oron Photothera Inc., Carlsbad, California.
Jackson Streeter Photothera Inc., Carlsbad, California.
Luis De Taboada Photothera Inc., Carlsbad, California.
Alexander Alexandrovich Department of Pharmacology, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel.
Victoria Trembovler Department of Pharmacology, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel.
Esther Shohami Department of Pharmacology, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel.

To cite this paper: Amir Oron, Uri Oron, Jackson Streeter, Luis De Taboada, Alexander Alexandrovich, Victoria Trembovler, Esther Shohami. Journal of Neurotrauma. April 1, 2007, 24(4): 651-656. doi:10.1089/neu.2006.0198.

Low-level laser therapy (LLLT) has been evaluated in this study as a potential therapy for traumatic brain injury (TBI). LLLT has been found to modulate various biological processes. Following TBI in mice, we assessed the hypothesis that LLLT might have a beneficial effect on their neurobehavioral and histological outcome. TBI was induced by a weight-drop device, and motor function was assessed 1 h post-trauma using a neurological severity score (NSS). Mice were then divided into three groups of eight mice each: one control group that received a sham LLLT procedure and was not irradiated; and two groups that received LLLT at two different doses (10 and 20 mW/cm2 ) transcranially. An 808-nm Ga-As diode laser was employed transcranially 4 h post-trauma to illuminate the entire cortex of the brain. Motor function was assessed up to 4 weeks, and lesion volume was measured. There were no significant changes in NSS at 24 and 48 h between the laser-treated and non-treated mice. Yet, from 5 days and up to 28 days, the NSS of the laser-treated mice were significantly lower (p < 0.05) than the traumatized control mice that were not treated with the laser. The lesion volume of the laser treated mice was significantly lower (1.4%) than the non-treated group (12.1%). Our data suggest that a non-invasive transcranial application of LLLT given 4 h following TBI provides a significant long-term functional neurological benefit. Further confirmatory trials are warranted.