TY - JOUR T1 - Actigraphy in brain-injured patients – A valid measurement for assessing circadian rhythms? JF - bioRxiv DO - 10.1101/839472 SP - 839472 AU - Monika Angerer AU - Manuel Schabus AU - Marion Raml AU - Gerald Pichler AU - Alexander B. Kunz AU - Monika Scarpatetti AU - Eugen Trinka AU - Christine Blume Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/03/20/839472.abstract N2 - Background Actigraphy has received increasing attention in classifying rest-activity cycles. However, in patients with disorders of consciousness (DOC), actigraphy data may be considerably confounded by passive movements, such as nursing activities and therapies. Consequently, this study verified whether circadian rhythmicity is (still) visible in actigraphy data from patients with DOC after correcting for passive movements.Methods Wrist actigraphy was recorded over 7-8 consecutive days in patients with DOC (diagnosed with unresponsive wakefulness syndrome [UWS; n=19] and [exit] minimally conscious state [MCS/EMCS; n=11]). Presence and actions of clinical and research staff as well as visitors were indicated using a tablet in the patient’s room. Following removal and interpolation of passive movements, non-parametric rank-based tests were computed to identify differences between circadian parameters of uncorrected and corrected actigraphy data.Results Uncorrected actigraphy data overestimated the interdaily stability and intradaily variability of patients’ activity and underestimated the deviation from a circadian 24h rhythm. Only 5/30 (17%) patients deviated more than 1h from 24h in the uncorrected data, whereas this was the case for 17/30 (57%) patients in the corrected data. When contrasting diagnoses based on the corrected dataset, stronger circadian rhythms and higher activity levels were observed in MCS/EMCS as compared to UWS patients. Day-to-night differences in activity were evident for both patient groups.Conclusion Our findings indicate that uncorrected actigraphy data overestimates the circadian rhythmicity of patients’ activity, as nursing activities, therapies, and visits by relatives follow a circadian pattern itself. Therefore, we suggest correcting actigraphy data from patients with reduced mobility.AIanoxic-ischemic brain injuryCRS-RComa Recovery Scale – RevisedDOCdisorders of consciousnessEMCSexit minimally conscious stateGCSGlasgow Coma ScaleIQRinterquartile rangeISinterdaily stabilityIVintradaily variabilityMCSminimally conscious stateNTBInon-traumatic brain injuryTBItraumatic brain injuryUWSunresponsive wakefulness syndrome ER -