Sleep and pain

Abstract

The high prevalence of sleep disturbance in chronic pain conditions is due in part to bi-directional influences in which pain disturbs sleep and poor sleep reduces pain thresholds and aggravates pain. Other variables, especially depression and anxiety, may mediate this relationship, although supporting data has been equivocal. Trauma exposure and resulting PTSD symptoms have not been adequately evaluated in the pain-sleep relationship. The hyperarousal symptoms of PTSD are conceived to impact sleep directly in the manner that hyperarousal maintains insomnia. Even when pain severity, depression, and anxiety are decreased, sleep disturbance may persist due to the perpetuating factors of insomnia not being fully addressed in most patients. The importance of ruling out primary sleep disorders other than insomnia (sleep apnea and PLMD) must be underscored as they can contribute to sleep disruption that leads to increased pain sensitivity. Several lines of inquiry in regard to underlying sleep-pain mechanisms promise to unravel this complex relationship. Treatment of sleep complaints in chronic pain patients with antidepressant is best approached with caution. Nonpharmacological approaches to insomnia warrant further study and a tempered call for increased utilization based on a growing literature of successful treatment of insomnia secondary to medical conditions.