The Feasibility of Sleep Assessment by Actigraph in Patients with Tetraplegia

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)-C(7) the hand also moved more than the head, but in patients with tetraplegia below C(4), the head moved more (P<0.05). No significant differences were found between patients with C(5)-C(7) tetraplegia and healthy controls in the sleep indices obtained by hand movements, or between patients with C(4) 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 C(5)-C(7) tetraplegia, and suggest that head-mounted actigraphy is a feasible alternative for sleep assessment in patients with tetraplegia below C(4). To establish these findings, further investigations are required, with a larger number of patients and comparison with PSG. Link to Abstract: http://www.ncbi.nlm.nih.gov/pubmed/17339889