Authors :
Presenting Author: Rima El Atrache, MD – Baylor College of Medicine
Saifina Karedia, BS – Baylor College of Medicine
Nandani Adhyapak, BS – Baylor College of Medicine
Anna Catherine Norman, BS – Baylor College of Medicine
Arindam Ghosh Mazumder, PhD – Baylor College of Medicine
Vaishnav Krishnan, MD, PhD – Baylor College of Medicine
Rationale:
Sleep and circadian rhythm disruptions are common in children with epilepsy, yet efforts to objectively quantify these disruptions have been limited. Wrist or limb actigraphy monitoring offers a noninvasive method to assess rest and activity rhythms (RARs) and obtain estimates of sleep occurrence and timing in populations where traditional sleep diaries can be unreliable. Here, we compared multiday-long actigraphy recordings in subjects with infantile epileptic spasms syndrome (IESS) to recordings from a publicly deposited control dataset from the Sleep Health in Infancy and Early Childhood (SHINE) study.
Methods:
All protocols were approved by the Baylor College of Medicine IRB. Consent was obtained from parents of infants with IESS during a follow-up overnight epilepsy monitoring unit (EMU) stay to assess initial treatment response. Actiwatch-2 (Phillips Respironics) devices were deployed at the left or right ankle, and parents were instructed to obtain at least 10 days of continuous recording and answer a paper-pencil survey regarding sleep and feeding habits. We reviewed associated raw EEG data and the timing of spasm occurrence. For SHINE subjects, annotated actigraphy recordings (collected at ~30d, 6, 12 and 24 months of age) were downloaded with permission from the National Sleep Research Resource. From raw actigraphy recordings, we calculated RAR amplitude, mesor, acrophase, intradaily variability (IV), interdaily stability (IS), and the normalized F-statistic (a measure of RAR robustness). The mean total daily sleep time was also calculated by defining sleep bouts as contiguous periods of zero mobility lasting ≥ 4 minutes.Results:
Within the SHINE dataset, we included 893 recordings from 335 subjects (50% female, aged between 15 and 804 days). Over this developmental trajectory, we observed steady increases in RAR amplitude, mesor, IS, F, and reductions in IV that were similar in males and females. In contrast, average acrophase and total daily sleep measurements remained relatively stable. We included actigraphy data from 10 IESS subjects (median age 192 days, 17% female). and selected four age-matched SHINE subjects as controls. IESS subjects displayed significantly lower RAR amplitudes, mesor, IS, and F-scores, and accumulated greater total daily sleep. During overnight simultaneous actigraphy-EEG recordings, periods of spasms did not consistently align with acute spikes in actigraphy counts, but rather occurred around periods of lower activity levels. Conclusions:
Our results show that compared with control subjects, infants with IESS display weak and unstable rest-activity rhythms irrespective of seizure times, and that may be multifactorial in etiology. Our pilot study supports the use of actigraphy-derived RAR metrics as a scalable, objective method to measure sleep and circadian integrity in infants with IESS. Funding:
NIH (K08NS110924, R01NS131399) and the Mike Hogg Fund.