Abstract Fibromyalgia (FMS) is a chronic syndrome of widespread pain and fatigue;

1. Dissociated States in Fibromyalgia T.F.Oliveira1,2,4, L.Ferreira2,3, Teresa Paiva2,4 and J. Miguel Sanches1 1Institute for Systems and Robotics / Instituto Superior Técnico, Lisboa, Portugal 2Centro de Electroencefalografia e Neurofisiologia Clínica, Lisboa, Portugal 3Laboratório EEG Sono (CHLN -HSM) 4Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal Background FMS is a disorder of unknown aetiology which occurs in 3-4% of the general population, 80-90% are females (ACR). FMS patients suffer from severe fatigue, sleep disturbances, morning stiffness, cognitive problems, affective disturbances, multiorgan dysfunctions and other symptoms (anxiety, depression, sensory hypersensitivity). Alternatively, FMS is a psycho-neuro-endocrine-immune disorder, so it has an organic basis. However the biological markers are still not found. Clinical assessment of FMS brings to light the inconsistency between the severity of complaints and the lack of explanatory biological markers, which in our opinion can be explained by a central nervous system (CNS) dysfunction, via DS, and must be investigated. Considering this, we hypothesize as a basic general mechanism, the concept of DS, which can take several forms. • Abstract • Fibromyalgia (FMS) is a chronic syndrome of widespread pain and fatigue; • Here, it is hypothesized, that this disorder is explained by the Dissociated States (DS) concept. • Objectives: • to identify sleep DS, both in NREM and REM • to provide data for sleep electroencephalogram (EEG) mapping abnormalities both in specific sleep stages and across sleep stages (this analysis will be performed by computing sleep EEG mapping in the conventional frequency of bands - , , 1, 2,  and ). • Methods • 12 FMS patients + 12 healthy controls • Ages 30 to 58 years • Nocturnal polysomnography (PSG) at sleep laboratory (19 EEG channels + conventional PSG data) Dissociated States (DS) A DS is a state that gathers characteristics from two functional states that shouldn’t coexist. A clear example of that is alpha-delta sleep pattern. The presence of alpha rhythm pattern is typical from awake disappearing at sleep onset, while delta EEG patterns are characteristic of sleep. In FMS these two features coexist reflecting a “sleeping-awake” state. What is common? REM Sleep NREM Sleep • Rapid eye movement • with muscular atonia • Saw-tooth like waves(e.g. theta rhythm) – normally associated to rapid eye movements • REM Mioclonies • sudden and very brief muscle contractions Spindles transitory activity bursts, observed in central electrodes (12-15 Hz) Alpha activity Alpha activity (8 - 13 Hz) Caracteristic from awakeful states K-complexes transitory events observed in central electrodes which last between 0,5 and 2 seconds What are we looking for? • NREM events occurring during REM • 2.1. Spindles 2.2. K- complexes Alpha activity in REM and NREM • REM events occurring during NREM • 1.2. Rapid eye movements 1.3. Mioclonies 1.2. Saw tooth like waves • Funded by: FCT PRAXISXXI/BD/36746/2007 & FCT PTDC/SAU-BEB/104948/2008 RecPad2010 - 16th edition of the Portuguese Conference on Pattern Recognition, UTAD University, Vila Real city, October 29th