J Korean Neuropsychiatr Assoc.  2009 Nov;48(6):447-453.

Relationship of Neurocognitive Function with the Sleep-Wake Rhythm in Mild Cognitive Impairment Patients

• An KJ
• Kim TH
• Kim SJ
• Jhoo JH
• Lee JH

Abstract

OBJECTIVES
We compared the parameters of the sleep-wake rhythm in mild cognitive impairment (MCI) patients to those of normal elderly subjects, to illustrate how the characteristics of circadian rhythm relate to a specific neurocognitive function.
METHODS
We selected 12 MCI patients and 12 age- and sex-matched normal control (NC) subjects and administered the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K) Neuropsychological battery and Stroop Color-Word Test (SCWT) to each subject. We measured each subject's sleep-wake rhythm by applying actigraphy for 96 hours. The sleep-wake rhythm was examined by cosinor analysis.
RESULTS
There was no significant difference in the amplitude or acrophase of the sleep-wake rhythms between the NC and MCI groups. In the combined group, amplitude was positively correlated with Constructional Praxis scores (r=0.434, p<0.05), and acrophases tended to be positively correlated with Word List Memory scores (r=0.370, p=0.07).
CONCLUSION
There was no difference between MCI patients' sleep-wake rhythm's amplitude and acrophase and those of NC subjects. Furthermore, decreased amplitude was associated with impaired visuospatial function in the combined group. It will be necessary to confirm this result in an expanded MCI group in a future study.

Keyword

MCI; Sleep-wake rhythm; Neurocognitive function

MeSH Terms

Actigraphy
Aged
Alzheimer Disease
Circadian Rhythm
Humans
Memory
Mild Cognitive Impairment
Polymethacrylic Acids
Polymethacrylic Acids