Fibromyalgia and sleep in animal models: a current overview and future directions.

Sleep disorders are highly prevalent in patients with fibromyalgia (FM). Many of the daytime symptoms, such as chronic pain and fatigue, may be related to the non-restorative sleep patterns associated with the disease. Pain influences the sleep process and sleep disturbances decrease the pain threshold in a reciprocal framework. Thus, understanding the link between sleep and FM has become an important research topic in basic science. Therefore, in the current review we connect these topics and provide some insights into the cyclic relationship between sleep and pain, which has been addressed mainly in animal models. Additionally, we highlight the urgent need for sleep studies in FM animal models, which might improve the knowledge base and accelerate advances in this field.