EEG coherence and power spectra during REM sleep related to melatonin intake in mild-to-moderate Alzheimer’s disease: a pilot study

Abstract

Introduction:

It has been reported that melatonin diminishes rapid eye movement (REM) sleep latency in patients with Alzheimer’s disease (AD). Pharmacological studies suggest that melatonin promotes prompt sleep installation through interaction with GABA receptors, and that it is associated with acute suppression of neural electrical activity. Nevertheless, melatonin’s effects on electroencephalographic (EEG) activity related to REM sleep onset in AD patients have not been analyzed. Thus, in this pilot study we analyzed the effects of melatonin on EEG activity during the first episode of REM sleep in eight patients treated with 5-mg of fast-release melatonin.

Methods:

During a single-blind, placebo-controlled study, polysomnographic recordings were obtained from frontal, central, temporal, and occipital scalp derivations. REM sleep latency, as well as the relative power (RP) and EEG coherences of six EEG bands, were compared between the placebo and melatonin conditions.

Results:

Results showed that melatonin intake in AD patients decreased REM sleep onset, and that this was associated with lower RP and coherence of the β and γ EEG bands.

Discussion:

The possibility that the inhibitory GABAergic pathways related to REM sleep generation are well-preserved in mild-to-moderate AD is discussed. We conclude that the short REM sleep onset related to melatonin intake in AD patients is associated with a significant decrease in both RP and EEG coherence, mainly in the fast frequencies.

Keywords:

• Melatonin
• Alzheimer’s disease
• REM sleep
• GABA
• EEG coherence

Acknowledgment

The placebo and melatonin used were donated by the BIOQUIMED laboratory.

Geolocation information

Title: Instituto Nacional de Psiquiatría ‘Ramón de la Fuente Muñiz’

Coordinates: 19° 17′ 33.21″ N, 99° 9′ 8.63″ W

Decimals: 19.292558°, −99.152397°

UTM: 2133206 483988 14Q https://tools.wmflabs.org/geohack/geohack.php?language=es&pagename=Instituto_Nacional_de_Psiquiatr%C3%ADa&params=19.29255833_N_-99.15239722_E_type:landmark

Disclosure statement

The authors report no conflict of interest.

Data availability statement

The data that support the findings of this study are available from the corresponding author [M.A.C.A.] upon reasonable request.

Additional information

Funding

There was no funder for this study.