Body illusions and misperception in fibromyalgia: how chronic pain impacts on body representation and imagery of actions

Background. That chronic pain changes individuals’ perception of the body is a well-known notion. However, to date, data on which kinds of misperceptions are experienced by patients suffering from Fibromyalgia (FPs) and how these may impact action representations are meagre. Objective. The study assesses the body misperceptions in FPs and their potential correlations with clinical symptoms and motor imagery. Methods. A comprehensive questionnaire battery investigated Corporeal Illusions (Body Feelings and Illusions questionnaire), Motor Imagery (Vividness of Motor Imagery 2) and mood disorders (Hospital Anxiety and Depression Score) in 30 FPs and 30 age- and gender-matched control participants. A comparison between the two groups was executed and correlations with clinical symptoms were carried out. Furthermore, Explorative Factor Analysis assessed the potential integration among pain, body misperception and motor imagery. Results. FPs report feelings of disownership of body parts and somatoparaphrenic-like sensations (e.g., detachment or changes in form and size of body parts). They also show reduced abilities in motor imagery and the presence of illusory movements of body parts. Although the feeling of misoplegia towards the sore body parts are reported, these bodily misperceptions are not associated with mood disorders (which are not different between the two groups). The disorders in motor imagery (but not bodily illusions) correlate with the pain. Conclusion. Specific disorders in body representations and motor imagery are present in FPs. This should be specifically investigated and taken into consideration when interventions are planned to help patients in maintaining autonomy and ameliorate their body perception.