The feasibility of sleep assessment by actigraph in patients with tetraplegia

Abstract

Background: Sleep disturbances are frequent in patients with high spinal cord lesions, and are difficult to diagnose by means of polysomnography (PSG). Design: Retrospective cohort study. Objective: Examine the feasibility of sleep assessment by actigraph in patients with tetraplegia. Setting: A rehabilitation center in Israel. Subjects: Twenty-one patients with tetraplegia and 20 healthy persons. Interventions: Sleep assessment by actigraphs attached to the head and the wrist. Main outcome measures: The actigraphic movement index (MI), total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), sleep latency (SL), and number of awakenings (NOA). Results: In the control group actigraphy showed that during sleep the hand moves more than the head but that the movements were highly correlated. In patients with tetraplegia below C 5-C7 the hand also moved more than the head, but in patients with tetraplegia below C4, the head moved more (P<0.05). No significant differences were found between patients with C5-C 7 tetraplegia and healthy controls in the sleep indices obtained by hand movements, or between patients with C4 tetraplegia and healthy controls in the indices obtained by head movements. Control subjects and patients showed similar subjective assessment of sleep quality. Conclusions: These preliminary findings support the validity of wrist actigraphy for sleep assessment in patients with C5-C7 tetraplegia, and suggest that head-mounted actigraphy is a feasible alternative for sleep assessment in patients with tetraplegia below C4. To establish these findings, further investigations are required, with a larger number of patients and comparison with PSG. © 2007 International Spinal Cord Society All rights reserved.