International Meeting for Autism Research (May 7 - 9, 2009): A Novel Approach to Actigraphy in Children with Autism Spectrum Disorders

A Novel Approach to Actigraphy in Children with Autism Spectrum Disorders

Friday, May 8, 2009
Northwest Hall (Chicago Hilton)
3:30 PM
K. L. Surdyka , Neurology/Sleep, Vanderbilt University, Nashville, TN
K. Adkins , Neurology/Sleep, Vanderbilt University, Nashville, TN
S. E. Goldman , Neurology/Sleep, Vanderbilt University, Nashville, TN
D. Wofford , Neurology/Sleep, Vanderbilt University, Nashville, TN
B. A. Malow , Neurology/Sleep, Vanderbilt University, Nashville, TN
Background: Sensory sensitivities are common in children with autism spectrum disorders (ASD) , Actigraphy, which uses activity and rest as measures of wake and sleep, has shown promise as a non-intrusive measure of sleep patterns in clinical trials to improve sleep in ASD. In contrast to polysomnography, actigraphy does not involve placing electrodes on the scalp, and data can be collected in the home setting for many days and nights. However, in our research of sleep and ASD, we encountered children who were not able to tolerate wrist actigraphy but were able to tolerate placement of the actigraph in the shoulder pocket of a shirt.
Objectives: We modified the placement of the actigraph to enclose it in the pocket of a cotton tee-shirt. The pocket measured 2”x2” and was attached to the outside of the shirt. We hypothesized that measurements of sleep latency (SL), total sleep time (TST), and movement and fragmentation index (MFI) would be comparable to wrist actigraphy.
Methods: To determine if sleep measurements were comparable between the two methods, we placed actigraphs in both locations (wrist and shoulder) on three children with ASD tolerant of wrist actigraphy All children wore the actigraphs (Mini Mitter, Respironics) on their shoulder and wrist for 1 week; children 1 and 2 wore loose-fitting shirts and child 3 wore a snug-fitting shirt. Wilcoxon signed ranks tests for non-parametric paired data were used to determine if the location of the watches yielded comparable results for SL, TST, and MFI.
Results: Wrist (W) and shoulder (S) measures of SL (p = 1.0); TST (p =0.25), and MFI (p = 0.25) did not differ statistically. For all children, SL (in minutes) was very similar for the two placements, but closest in child 3 who wore the snug-fitting shirt. Values were: Child 1: SL (W) = 31.6, SL (S) = 30.9; Child 2: SL (W) = 12.9, SL (S) = 10.7; Child 3: SL (W) = 24.1, SL (S) = 24.6). For TST (minutes) and MFI, the two placements differed more than SL, but were relatively close in Child 3. Values were: Child 1: TST (W) = 421.4, TST (S) = 465.9, MFI (W) =  39.3, MFI (S) =  22.3; Child 2: TST (W) = 421.4, TST (S) = 465.9, MFI (W) =  39.3, MFI (S) =  22.3;  Child 3: TST (W) = 415.1, TST (S) = 430.4, MFI (W) =  28.4, MFI (S) =  26.2.
Conclusions: Our preliminary results support the hypothesis that shoulder actigraphy may be a reasonable substitute for wrist actigraphy in children unable to tolerate the wrist placement, especially if the shirt used is snug-fitting. Studies comparing the two placements in larger numbers of children will be necessary to confirm our results.
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