The effect of sleep and nocturnal movement on stiffness, pain, and psychomotor performance in ankylosing spondylitis

Abstract

Objective: This study was carried out in order to assess whether AS patients are adversely affected by a "good" night's sleep accompanied by little nocturnal movement.

Methods: Objective and subjective nocturnal movement, flexibility, stiffness, pain and psychomotor performance were measured in 22 subjects, 11 with ankylosing spondylitis and 11 controls.

Results: A better sleep integrity with little nocturnal movement was related to a decrease in lumbar flexibility. Difficulty in awakening and feeling tired and clumsy in the morning correlated with stiffness. Pain was correlated with a subjective difficulty in getting to sleep and a worse quality of sleep, but was also correlated with less objective sleep disruption. In the control group a better sleep integrity was correlated with an overnight decrease in psychomotor performance. In the spondylitic group a significant increase in performance occurred. Stiffness and pain did not correlate with performance.

Conclusion: Sleep in ankylosing spondylitis differs from sleep in normals.