low-level laser therapy applied transcranially to mice following traumatic brain injury significantly reduces long-term neurological deficits

J Neurotrauma. 2007 Apr;24(4):651-6. 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/cm(2) ) 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.

MeSH terms

  • Animals
  • Brain / pathology
  • Brain Injuries / complications
  • Brain Injuries / pathology
  • Brain Injuries / radiotherapy*
  • Cerebral Cortex / pathology
  • Head Injuries, Closed / complications
  • Head Injuries, Closed / pathology
  • Head Injuries, Closed / therapy*
  • Low-Level Light Therapy*
  • Male
  • Mice
  • Movement / physiology
  • Nervous System Diseases / pathology
  • Nervous System Diseases / prevention & control*
  • Postural Balance / physiology
  • Reflex / physiology
  • Walking / physiology