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. 2018 Jan 8;19(1):17.
doi: 10.1186/s13063-017-2414-5.

Photobiomodulation Using Low-Level Laser Therapy (LLLT) for Patients With Chronic Traumatic Brain Injury: A Randomized Controlled Trial Study Protocol

Free PMC article

Photobiomodulation Using Low-Level Laser Therapy (LLLT) for Patients With Chronic Traumatic Brain Injury: A Randomized Controlled Trial Study Protocol

Guilherme da Cruz Ribeiro Poiani et al. Trials. .
Free PMC article


Background: Photobiomodulation using low-level laser therapy (LLLT) has been tested as a new technique to optimize recovery of patients with traumatic brain injury (TBI). The aim of this study is to evaluate inhibitory attentional control after 18 sessions of active LLLT and compare with the placebo group (sham LLLT). Our exploratory analysis will evaluate the efficacy of the active LLLT on verbal and visuospatial episodic memory, executive functions (working memory, verbal and visuospatial fluency, attentional processes), and anxiety and depressive symptoms compared to the sham group.

Methods/design: A randomized double-blinded trial will be made in 36 patients with moderate and severe TBI. The active LLLT will use an optical device composed of LEDs emitting 632 nm of radiation at the site with full potency of 830 mW. The cranial region with an area of 400 cm2 will be irradiated for 30 min, giving a total dose per session of 3.74 J/cm2. The sham LLLT group contains only an LED device with power < 1 mW, only serving to simulate the irradiation. Each patient will be irradiated three times per week for six weeks, totaling 18 sessions. Neuropsychological assessments will be held one week before the beginning of the sessions, after one week, and three months after the end of LLLT sessions. Memory domain, attention, executive functioning, and visual construction will be evaluated, in addition to symptoms of depression, anxiety, and social demographics.

Discussion: LLLT has been demonstrated as a safe and effective technique in significantly improving the memory, attention, and mood performance in healthy and neurologic patients. We expect that our trial can complement previous finds, as an effective low-cost therapy to improve cognitive sequel after TBI.

Trial registration:, NCT02393079 . Registered on 20 February 2015.

Keywords: Anxiety; Cognition; Depression; Memory; Photobiomodulation; Rehabilitation; Traumatic brain injury.

Conflict of interest statement

Ethics approval and consent to participate

This study was approved by Committee for Ethics in Research of Psychology HC-FMUSP (COSEPE), number 15/2014; and the Ethics Committee of Project Research Analysis of the Faculty of Medicine HC-FMUSP, process number 42092815.9.0000.0068. All patients were clearly informed about the procedures and were required to sign consent form before inclusion in the study.

Consent for publication

Approved by all co-authors.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.


Fig. 1
Fig. 1
Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT): enrollment, assessment, interventions, and data collection. BDI-II: Beck Depression Inventory, 2nd edition; BAI: Beck Anxiety Inventory; TMT A and B: Test Trail Making form A and B; COWAT: Controlled Oral Word Association Test; SNL: Sequence of Numbers and Letters; DSST: Digit Symbol Substitution Test; RAVLT: Rey Auditory Verbal Learning Test
Fig. 2
Fig. 2
Flowchart of the LLLT study
Fig. 3
Fig. 3
a Two identical helmets, active and sham stimulation. b The inside view of the active LLLT helmet

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