Low-Level Light Therapy Effect on Metabolites Measured by MR Spectroscopy in Patients with Moderate Traumatic Brain...

Area of Science:

• Neuroscience
• Biomedical Engineering

Background:

• Traumatic brain injury (TBI) can lead to long-term neurological deficits.
• Low-level light therapy (LLLT) is being investigated for its potential to modulate recovery in TBI patients.
• The longitudinal metabolic changes following LLLT in TBI patients remain understudied.

Purpose of the Study:

• To assess the longitudinal metabolic response to LLLT in moderate TBI patients.
• To investigate metabolic changes in the corpus callosum (CC) using magnetic resonance spectroscopic imaging (MRSI).
• To evaluate the ratio of myo-inositol to N-acetyl aspartate (mI/NAA) as an indicator of neuroinflammation and neuronal health.

Main Methods:

• Secondary analysis of a prospective, double-blinded, sham-controlled study.
• Three Tesla two-dimensional MRSI was used to scan participants at acute, subacute, and late-subacute recovery phases.
• Linear mixed-effects modeling quantified the association between mI/NAA ratio, treatment, and time.

Main Results:

• Thirty-four participants (15 LLLT, 19 sham) were included.
• The mI/NAA ratio in the CC significantly increased over time in sham-treated participants.
• LLLT treatment maintained a stable mI/NAA ratio, resulting in significantly lower levels compared to sham treatment in the late subacute phase.

Conclusions:

• MRSI indicated a metabolic response to LLLT in TBI patients compared to sham treatment.
• LLLT may exert neuroprotective and anti-inflammatory effects when administered acutely after moderate TBI.
• These findings warrant further investigation into LLLT as a therapeutic intervention for TBI recovery.