Ga. Kerkhof et A. Wauquier, SLEEP IN HEALTHY AGED PERSONS AND INHABITANTS OF A RESIDENTIAL HOME, Journal of interdisciplinary cycle research, 24(2), 1993, pp. 90-100
Citations number
36
Categorie Soggetti
Medicine, Research & Experimental","Multidisciplinary Sciences
It was the aim of this study to estimate the impact of exogenous influ
ences on the sleep of elderly. To this end, ambulatory sleep recording
s were made in 2 groups (7 Ss each) of elderly females: inhabitants of
a residential home (mean age 85.9 yrs) and carefully selected healthy
controls (mean age 91.7 yrs) living independently. A recording consis
ted of a 48-h registration of the EEG, the EOG and EMG. The second 24-
h period of each recording was analyzed: - according to conventional p
olysomnographic criteria; and - by way of a FFT routine which calculat
ed one averaged spectrum for every 4 minutes EEG. Between-group compar
isons of the polysomnographically verified sleep times revealed 1. a p
redominance of napping among the residents; 2. an earlier phase positi
on of the main sleep of the residents, which was partly due to a longe
r sleep latency for the controls; and 3. a relatively advanced REM dis
tribution for the controls. The outcome of the spectral analyses of th
e sleep EEG showed a clear dominance of the theta band for both groups
. Moreover, detailed analysis gave evidence of a systematic variation
of the spectra throughout the sleep period. Whereas the delta band is
relatively best represented during the first half of the sleep period,
the theta band is maximal during the second half. The spectra for the
naps appeared to be most similar to the mean spectrum for the 4th 90
min period of main sleep. Finally, the accumulation of EEG energy in t
he delta and theta bands over the first 7 hours of main sleep was high
ly similar for the two groups. It is concluded that the observed group
differences in the timing of main sleep, in the occurrence of napping
, and in the phase of the REM distribution originate from differences
in living conditions. Differences in the exposure to daylight may have
played a major role in this. The sleep process itself, as manifested
in the accumulation of EEG energy, appeared invariant under these diff
erences.