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Completed

NCT Number: NCT05015478

Rhythmic Light Therapy for Alzheimer's Disease Patients

The investigator will investigate how light delivering 40 hertz (Hz) affects subjective sleep and cognition in a controlled laboratory study. A lab study will allow the collection of electroencephalogram (EEG) data, perform cognitive tests, and observe the response in those with mild cognitive impairment (MCI) compared to a healthy control group (HC).

Participants will attend two study sessions over the course of two weeks. During both sessions, all participants will experience 10 minutes of a low-level light, followed by a data collection period which involves a sleepiness rating, an electroencephalogram (EEG) recording, and a computerized memory test. Participants will then experience either a RL or a placebo RL condition for one hour, after which there will be a second data collection.

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Key information

Conditions

Mild Cognitive Impairment Cognition Disorders Cognitive Dysfunction Mental Disorders Neurocognitive Disorders

Age range

55 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Light and Health Research Center, Menands, New York, United States

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About this study

The investigator will demonstrate the effect of 40 hertz (Hz) rhythmic light (RL) to promote gamma wave entrainment (rhythmic light [RL]) on: brain response (electroencephalography [EEG]); cognitive performance (working memory task); and subjective sleepiness (questionnaires). The study will recruit 20 adult mild cognitive impairment (MCI) patients and 20 healthy, age-matched controls (HC) to participate in this study.

Sessions will initiate with a 10-minute adaptation period to a low-level ambient light providing illuminance of 15 lux at participants' eye level on a vertical plane, followed by a pre-exposure data collection period, including Karolinska Sleepiness Scale (KSS), EEG, and a working memory task. Participants will experience either 40 Hz RL or placebo RL conditions for a duration of 1 hour, followed by the second data collection period. On the second data collection day, participants will experience the other condition, so that all participants experience both lighting conditions. The experimental sessions will start at 14:00 on each experimental day which will be separated by 1 week.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Participants must be diagnosed with amnestic mild cognitive impairment or mild Alzheimer's disease, as defined by a Montreal Cognitive Assessment (MoCA) score between 17 and 25
  • For the age-matched healthy controls, participants must not be diagnosed with mild cognitive impairment or Alzheimer's disease related dementias (MoCA score above 25).
  • Participants must score a 5 or less in the Pittsburgh Sleep Quality Index (PSQI)

Exclusion criteria

  • All participants must not be taking sleeping medication or oral melatonin
  • Presence of another brain disease that fully explains the dementia (extensive brain vascular disease, Parkinson's disease, dementia with Lewy bodies, traumatic brain injury, or multiple sclerosis)
  • residence in a skilled nursing facility or long-term care
  • Major organ failure (e.g., kidney failure)
  • Uncontrolled generalized disorders such as hypertension or diabetes
  • Obstructing cataracts, macular degeneration, and blindness
  • Severe sleep apnea or restless leg syndrome
  • History of epilepsy

Treatment and study plan

Tailored Rhythmic Lighting Intervention

Device

40 hertz (Hz) rhythmic lighting (RL) for a duration of 1 hour. The flicker frequency of the 40 Hz RL will be 40 Hz and the stimulation will be a square wave with a 50 % duty cycle (i.e., 12.5 milliseconds light- on and 12.5 milliseconds light-off). The RL will provide a 30 lux of red light on a vertical plane at the eye level.

Placebo Rhythmic Lighting Intervention

Device

Placebo rhythmic light (RL) for a duration of 1 hour. In the placebo RL condition, the duty cycle will be delivered at randomly varying frequencies of 20 Hz and 50 Hz, specifically avoiding the frequency of 40 Hz. The placebo RL conditions will provide a 30 lux of red light on a vertical plane at the eye level.

Primary outcomes

  1. Change in Electroencephalography (EEG) Power at 40 Hertz (Hz)

    Time frame: baseline and during the light intervention

    Electroencephalography (EEG) recordings - the change in 40 Hz gamma power, computed by calculating the difference between the average gamma power at baseline (T1) and during the light intervention (T2). This difference was obtained by subtracting baseline 40 Hz power from the intervention 40 Hz power to assess acute neural effects

Secondary outcomes

  1. Mean Change in Subjective Sleepiness Using the Karolinska Sleepiness Scale (KSS)

    Time frame: Baseline and 1 hour after intervention (intervention is 2 hours)

    The Karolinska Sleepiness Scale (KSS) outcome prompts participants to rate how sleepy or alert they are feeling on a scale ranging from 1 to 9, where 1 = "very alert," 3 = "rather alert," 5 = "neither alert nor sleepy," 7 = "sleepy, but no difficulty remaining awake," and 9 = "very sleepy, fighting sleep, an effort to remain awake."

Sponsors and collaborators

Lead sponsor

Icahn School of Medicine at Mount Sinai

Other

Collaborators

  • National Institute on Aging (NIA)

Registry information

Official study title

Phase 1 - The Use of Rhythmic Light Therapy to Entrain Gamma Oscillations and the Circadian System in Patients With Alzheimer's Disease

Important dates

Study start
2022
Primary completion
2023
Study completion
2023
First posted
Aug 20, 2021
Registry last updated
Jun 23, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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