Cognitive Enhancement Through Transcranial Laser Therapy

Phase 2

Completed

Brief Summary: This is a mechanism-driven translational project to test the efficacy of transcranial low-level light/laser therapy (LLLT), for enhancing cognitive function in middle-aged and older adults and participants with Mild Cognitive Impairment.

Detailed Description: The goal of this project is to test the efficacy of LLLT to enhance neurocognitive function in middle-aged adults and examine the modulating influences of carotid atherosclerosis. The specific aims will be accomplished in a randomized controlled trial (RCT) by examining cognitive test performance and blood oxygen level-dependent (BOLD) response to a working memory task in middle-aged and older adults and participants with Mild Cognitive Impairment pre- and post- six-week long intervention of LLLT or placebo. In addition, the investigators will examine if carotid artery intima-media thickness (IMT) moderates the therapeutic effects of LLLT.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

neurological disease (e.g., large vessel stroke, seizure disorder, Parkinson's disease, Alzheimer's disease, clinically significant traumatic brain injury with loss of consciousness > 30 minutes, multiple sclerosis, or brain infection/meningitis
baseline IQ < 85 placing them below the average range of intellectual functioning
major psychiatric illness (e.g., schizophrenia, bipolar disorder) or substance abuse (diagnosed abuse and/or previous hospitalization for substance abuse)
severe cardiovascular disease (e.g., pacemaker), chronic obstructive pulmonary disease, liver or kidney disease, inflammatory illness

Arm && Interventions

Group	Intervention	Description
LLLT	LLLT	Six weekly sessions of LLLT. The treatment will consist of applying light of a specific wavelength (1064 nm) using a laser diode supplied by Cell Gen Therapeutics, LLC (CG-5000 laser, HD Laser Center, Dallas, TX, USA). Each laser stimulation session will consist of total 8 min, with eight 1 min/cycle treatments alternating between two locations on the right forehead.
Placebo	Placebo	The control group will undergo the same procedure as the treatment group, but will receive brief (5-s) stimulation to the intended site on the forehead, followed by 55 s of no stimulation, for each 1-min cycle. Thus the control group will receive approximately 1/12th of the cumulative energy density as the treatment group. This is sufficient to provide a brief sensation of slight heat (as active placebo) at the onset of each one-minute cycle, using a fraction of the energy received by the experimental group.

Primary Outcome Measures

Name	Time	Method
Psychomotor Vigilance Task (PVT)	Time 1 represents PVT performance (reaction time in msec) at baseline, Time 2 represents PVT performance (reaction time in msec) six weeks later.	The psychomotor vigilance task (PVT) is a sustained-attention, reaction-timed task that measures the consistency with which subjects respond to a visual stimulus.

Secondary Outcome Measures

Name	Time	Method
Working Memory (2 Back Task)	T1 represents 2back Reaction Time (RT) in msec at baseline; T2 represents Reaction Time (RT) in msec 6 weeks later	2Back task performance (Reaction Time in msec)
Brain Blood Oxygen Level Dependent Response to Working Memory (2Back) Task	T1 represents score at baseline; T2 represents follow-up score, 6 weeks later	The outcome represents a score on a scale - brain activation in response to a working memory task (t-statistic). The range is approximately -15 to +15. Positive scores reflect greater engagement of working memory brain regions and better performance.