Clinical Edge

Summaries of Must-Read Clinical Literature, Guidelines, and FDA Actions

AD, Rest-Activity Rhythm Fragmentation Linked

JAMA Neurology; ePub 2018 Jan 29; Musiek, et al

Preclinical Alzheimer disease (AD) is associated with rest-activity rhythm fragmentation, independent of age or sex, according to a recent study. The presence of circadian rhythm abnormalities in the preclinical phase of AD suggests that circadian dysfunction could contribute to early disease pathogenesis or serve as a biomarker of preclinical disease. This cross-sectional study was conducted using cognitively normal participants who underwent 7 to 14 days of actigraphy in their home environment between 2010 and 2012, in addition to clinical assessment, amyloid imaging with Pittsburgh Compound B (PiB), and cerebrospinal fluid biomarker collection. Data from 189 participants were included; mean (SD) age was 66.6 (8.3) years, and 121 participants (64%) were women. Researchers found:

  • Older age and male sex, in the absence of amyloid pathology, were associated with a significant increase in intradaily variability, a nonparametric measure of rest-activity rhythm fragmentation, as well as decreased amplitude by several measures.
  • After correction for age and sex, the presence of preclinical amyloid plaque pathology, assessed by positive PiB imaging or increasing cerebrospinal fluid phosphorylated-tau to amyloid β 42 ratio, was associated with increased intradaily variability, indicating rest-activity rhythm fragmentation.


Musiek ES, Bhimasani M, Zangrilli MA, Morris JC, Holtzman DM, Ju Y-E S. Circadian rest-activity pattern changes in aging and preclinical Alzheimer disease. [Published online ahead of print January 29, 2018]. JAMA Neurology. doi:10.1001/jamaneurol.2017.4719.

This Week's Must Reads

Diet Characteristics Examined in People with MS, Mult Scler Relat Disord; ePub Feb 27; Fitzgerald, et al

Cognitive Fatigue Examined in Patients with MS, Mult Scler; 2018 Feb; Golan, Doniger, et al

Community Isolation, Functional Connectivity in MS, Brian Struct Funct; ePub 2018 Feb 16; Patel, et al

New Technique Accurately Estimates MS Lesion Size, Am J Neuroradiol; ePub 2018 Feb 22; Dworkin, Linn, et al

MS, Crohn’s Share Similar Birth-Cohort Patterns , Mult Scler; 2018 Feb; Sonnenberg, Ajdacic-Gross

Must Reads in Alzheimer's & Cognition

Neighborhoods, Sleep Quality, and Cognitive Decline, Alzheimers Dement; ePub 2018 Feb 3; Hunter, et al

AD, Rest-Activity Rhythm Fragmentation Linked , JAMA Neurology; ePub 2018 Jan 29; Musiek, et al

Setting Plays Role in Evaluating Cognitive Decline, Alzheimers Dement; ePub 2018 Jan 17; Snitz, et al

AD Biomarkers Lead to Earlier Driving Cessation, Alzheimers Dement; ePub 2018 Jan 9; Stout, et al

Better CVH Linked with Reduced Cognition Decline, Alzheimers Dementia; ePub 2017 Dec 18; González, et al