title: Ipsilateral cortical activation in fibromyalgia patients during brushing correlates with symptom severity.
abstract: OBJECTIVE
  To evaluate cortical activation patterns during mechanical-tactile stimulation in fibromyalgia syndrome (FMS) patients and to correlate cortical activation changes with clinical symptoms.
  
  
  METHODS
  Nineteen female FMS patients and 18 matched, healthy control subjects underwent EEG examination during brushing stimulation of the right forearm. Participants rated any pain experienced and underwent a manual tender point scale (MTPS) examination. Amplitude changes of cortical rhythms during brushing were analysed in alpha (8-13 Hz) and beta (16-24 Hz) frequency bands.
  
  
  RESULTS
  Thirteen patients reported pain during brushing. Independent t-test comparison of event related desynchronisation (ERD) during brushing revealed a cluster of electrodes over ipsilateral (right) central-parietal region which demonstrated ERD in patients only. Clinical MTPS scores correlated with beta-band ERD in this cluster of electrodes. Beamformer analysis revealed a widespread array of source activations in patients, including bilateral insula and primary and secondary somatosensory cortices. Control subject source activations were limited to contralateral (left) hemisphere.
  
  
  CONCLUSIONS
  Results indicate ipsilateral cortical activations in FMS patients, but not in healthy controls, during brushing. Ipsilateral ERD during brushing is associated with MTPS score suggesting abnormal processing of somatosensory input which may contribute to clinical pain.
  
  
  CONCLUSIONS
  Altered functioning in FMS may reflect physiological changes in response to afferent somatosensory information manifesting in chronic pain.
authors: Department of Experimental Psychology, Institute of Psychology, Health, and Society, University of Liverpool, Liverpool, United Kingdom. nickfal@liverpool.ac.uk
authors: Nicholas
authors: N
authors: Fallon
authors: Yee Ho
authors: YH
authors: Chiu
authors: Xiaoyun
authors: X
authors: Li
authors: Turo J
authors: TJ
authors: Nurmikko
authors: Andrej
authors: A
authors: Stancak
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001611:Beta Rhythm; D002540:Cerebral Cortex / Q000503:physiopathology*; D003344:Cortical Synchronization; D003627:Data Interpretation, Statistical; D004569:Electroencephalography; D005260:Female; D005356:Fibromyalgia / Q000503:physiopathology*; D005542:Forearm / Q000294:innervation; D007839:Functional Laterality; D006801:Humans; D008875:Middle Aged; D009460:Neurologic Examination; D010147:Pain Measurement; D010812:Physical Stimulation; D055815:Young Adult