Rhythmic Light Therapy for Alzheimer's Disease Patients

Not Applicable

Completed

Interventions: Device: Tailored Rhythmic Lighting Intervention
Device: Placebo Rhythmic Lighting Intervention

Brief Summary: 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.

Detailed Description: 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.

Recruitment & Eligibility

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

Arm && Interventions

Group	Intervention	Description
Active Tailored Rhythmic Lighting	Tailored Rhythmic Lighting Intervention	1 hour intervention period where active lighting is experienced by participants.
Inactive Placebo Rhythmic Lighting	Placebo Rhythmic Lighting Intervention	1 hour intervention period where an inactive, placebo lighting condition is experienced by participants.

Primary Outcome Measures

Name	Time	Method
Change in Electroencephalography (EEG) Power at 40 Hertz (Hz)	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 Outcome Measures

Name	Time	Method
Mean Change in Subjective Sleepiness Using the Karolinska Sleepiness Scale (KSS)	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."
Cognition Using a Working Memory Task	1 hour after intervention (intervention is 2 hours)	Participants view a serial visual display of letters and math problems. They are asked to hold the letters in memory while simultaneously determining if the simple math problems are correct (e.g., 7+5=13). Performance is assessed in percent correct and by measuring accuracy and Reaction Time (RT).

Locations (2): Icahn School of Medicine at Mount Sinai
🇺🇸
New York, New York, United States
Light and Health Research Center
🇺🇸
Menands, New York, United States