TY - JOUR
T1 - Bright light therapy
T2 - Improved sensitivity to its effects on rest- activity rhythms in Alzheimer patients by application of nonparametric methods
AU - Someren, Eus J.W. Van
AU - Swaab, Dick F.
AU - Colenda, Christopher C.
AU - Cohen, Wayne
AU - McCall, William Vaughn
AU - Rosenquist, Peter
N1 - Funding Information:
This research was supported by the following grant awards: Senter, The Hague, The Netherlands (Project MTR 89026); ZON, The Hague, The Netherlands (Prevention Project 2830030); and Research Infrastructure Support Program Award, R24-MH5 1552, General Clinical Research Center, MOI-RR07 122, Wake Forest University School of Medicine, Winston-Salem, North Carolina.
PY - 1999
Y1 - 1999
N2 - Sleep-wake rhythm disturbances in patients with Alzheimer's disease (AD) make a strong demand on caregivers and are among the most important reasons for institutionalization. Several previous studies reported that the disturbances improve with increased environmental light, which, through the retinohypothalamic tract, activates the suprachiasmatic nucleus (SCN), the biological clock of the brain. The data of recently published positive and negative reports on the effect of bright light on actigraphically assessed rest-activity rhythms in demented elderly were reanalyzed using several statistical procedures. It was demonstrated that the light-induced improvement in coupling of the rest-activity rhythm to the environmental zeitgeber of bright light is better detected using nonparametric procedures. Cosinor, complex demodulation, and Lomb-Scargle periodogram-derived variables are much less sensitive to this effect because of the highly nonsinusoidal waveform of the rest-activity rhythm. Guidelines for analyses of actigraphic data are given to improve the sensitivity to treatment effects in future studies.
AB - Sleep-wake rhythm disturbances in patients with Alzheimer's disease (AD) make a strong demand on caregivers and are among the most important reasons for institutionalization. Several previous studies reported that the disturbances improve with increased environmental light, which, through the retinohypothalamic tract, activates the suprachiasmatic nucleus (SCN), the biological clock of the brain. The data of recently published positive and negative reports on the effect of bright light on actigraphically assessed rest-activity rhythms in demented elderly were reanalyzed using several statistical procedures. It was demonstrated that the light-induced improvement in coupling of the rest-activity rhythm to the environmental zeitgeber of bright light is better detected using nonparametric procedures. Cosinor, complex demodulation, and Lomb-Scargle periodogram-derived variables are much less sensitive to this effect because of the highly nonsinusoidal waveform of the rest-activity rhythm. Guidelines for analyses of actigraphic data are given to improve the sensitivity to treatment effects in future studies.
KW - Actigraphy
KW - Alzheimer's disease
KW - Bright light
KW - Circadian rhythm
KW - Complex demodulation
KW - Cosinor
KW - Dementia
KW - Lomb-Scargle periodogram
KW - Periodogram
KW - Sleep
KW - Statistical Methodology
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U2 - 10.3109/07420529908998724
DO - 10.3109/07420529908998724
M3 - Article
C2 - 10442243
AN - SCOPUS:0032814897
SN - 0742-0528
VL - 16
SP - 505
EP - 518
JO - Chronobiology International
JF - Chronobiology International
IS - 4
ER -