Effect of Bright Light and Melatonin on Cognitive and Noncognitive Function in Elderly Residents of Group Care Facilities

Abstract

tia, cognitive decline is frequently accompanied by disturbances of mood, behavior, sleep, and activities of daily living, 1-3 which increase caregiver burden and the risk of institutionalization. [4][5][6][7] The limited treatment possibilities create an opportunity for other symptom management approaches. [8][9][10][11] Changes in the circadian pacemaker of the brain, located in the hypothalamic suprachiasmatic nucleus, may contribute to cognitive, mood, behavioral, and sleep disturbances. [12][13][14][15][16][17][18] The circadian timing system is highly sensitive to environmental light and the hormone melatonin 19 and may not function optimally in the absence of their synchronizing effects. In elderly patients with dementia, synchronization may be attenuated if light exposure and melatonin production are reduced. 20,21 Indeed, bright light ameliorates behavioral 22 and sleep 20 disturbances.To our knowledge, no previous studies in humans have applied long-term combined stimulation of the circadian timing system with daily light and melatonin. We conducted a multicenter, double-blind, randomized placebocontrolled trial that evaluated the ef-fects of up to 3.5 years of daily supplementation of light and/or melatonin. Using a practical clinical trial approach, 23 long-term treatment effective-Author Affiliations are listed at the end of this article.

Age Related Visual Pathologies among Nursing Home Residents: An Evaluation of Light Conditions and Recording in Client Files

“…Furthermore, uniform illumination is advised because adaptation to the dark can be impaired in older adults (Bouma, Weale, & McCreadie, 2006). The benefits of sufficient light levels inside nursing homes are not only "image-forming" (i.e., to improve sight) but they also play a role in regulating important biochemical processes, such as immunologic mechanisms, circadian rhythm, and behavior (Turner, Van Someren, & Mainster, 2010;Riemersma-Van der Lek, Swaab, Twisk, Hol, Witte, Hoogendijk, & Van Someren, 2008).…”

What Keeps Us Awake?—the Role of Clocks and Hourglasses, Light, and Melatonin

“…Similarly, in the study of Scheer et al (2005), all subjects with a complete cervical spinal cord injury, which interrupts the neural pathway required, had chronically impaired sleep efficiency and quality (Scheer et al, 2005). Furthermore, in a study investigating the effect of bright light and melatonin on neurocognitive function and sleep in elderly residents, long-term bright light (5 years) significantly increased endogenous melatonin levels at night concomitant with an improvement in subjective and objective sleep quality (Riemersma-van der Lek et al, 2008).…”

La lumière comme stimulant de l’activité cognitive cérébrale

“…Il a été rapporté, par exemple, qu'une fois enrichi en bleu, l'environnement lumineux améliore la perception subjective de la performance au travail et de la qualité du sommeil, ainsi que l'humeur [30]. Comme autre exemple, augmenter l'intensité lumineuse dans les institutions pour patients âgés souffrants de démence ralentit la progression des symptômes, augmente l'activité le jour et la diminue la nuit, et améliore donc potentiellement la qualité du sommeil (un facteur important dans la difficulté de la prise en charge et l'activité nocturne des patients) [31]. Il ne faut cependant pas s'exposer tout le temps à trop de lumière : une lumière excessive en soirée peut rendre le sommeil plus difficile à initier et moins profond en début de nuit [32], et peut retarder notre horloge circadienne [1].…”