ABSTRACT
Low-level laser (light) therapy (LLLT) for traumatic events that
cause brain damage is currently an experimental concept. The
broad goals for clinical utilization are the prevention of brain
damage, relief of symptoms, and stimulation of the repair process.
Experimental studies have tested and continue to test these goals
by investigating LLLT in animal models of stroke and traumatic
brain injury (TBI). Animal studies of tLLLT for ischemic stroke
have been summarized in this chapter. Studies by other groups
on LLLT in mouse TBI models have been discussed. Four studies
from our laboratory have been described. The first study looked at
pulsed versus continuouswave (CW) laser irradiation in a controlled
cortical impact (CCI)-TBI model and found pulsed 810 nm laser at
10 Hz to be superior. The second study looked at four different
laser wavelengths (660, 730, 810, and 980 nm) in a closed-head
TBI model; only 660 nm and 810 nm were effective. The third study
looked at different treatment repetition regimens (1, 3, and 14 daily
laser treatments). The last study used immunofluorescence tech-
niques to show that neurogenesis, brain-derived neurotrophic factor
(BDNF), and synaptogenesis were upregulated after transcranial
LLLT (tLLLT) for TBI. Limitations in knowledge are still apparent,
such as the optimal wavelength, light source, doses, pulsed or
CW, polarization state, treatment timing, and repetition frequency.
Collaborative efforts between clinicians and basic researchers will
likely increase the usage and understanding of effective laser-based
therapies in the central nervous system (CNS).
