LAUSR

Introduction/Background Preliminary findings showed that head-mounted actigraphy is more sensitive to movements during sleep than wrist-mounted actigraphy, and suggested that it is a feasible alternative for sleep assessment in patients with C4 tetraplegia. To confirm these findings, sleep assessment based on actigraphy was compared with polysomnography (PSG) in these patients. Material and method Head and wrist actigraphy, and PSG were conducted out overnight, at the Sleep Disorders Unit of Loewenstein Rehabilitation Hospital, in 5 patients with AIS grade A C4 tetraplegia, and in 11 healthy control subjects. Several sleep assessment variables were computed concomitantly by head and wrist actigraphy, and by PSG. Results Patients’ PSG values of total sleep time (TST), sleep efficiency (SE = TST/time in bed), wake after sleep onset (WASO), sleep latency (SL), and number of awakenings during sleep (NOA) were 341.40 ± 12.42, 81.20 ± 5.09, 48.66 ± 20.38, 15.38 ± 10.96, and 21.80 ± 8.22, respectively. Head-mounted actigraphy values of the same variables were 422.75 ± 29.90, 97.90 ± 0.93, 1.75 ± 2.06, 5.25 ± 5.12, and 3.0 ± 3.56, respectively. Actigraphic head and wrist NOA and WASO values were highly correlated (r = 0.97, P  Conclusion Although sleep assessments using head-mounted actigraphy was similar to that of wrist-mounted actigraphy, both failed to detect wakefulness that was detected by PSG in patients with AIS A-C C4 tetraplegia. Therefore, our findings do not support the use of actigraphy for sleep assessment in these patients.