Reduced brain habituation to somatosensory stimulation in patients with fibromyalgia.
OBJECTIVE
To examine brain activity elicited by repetitive nonpainful stimulation in patients with fibromyalgia (FM) and to determine possible psychophysiologic abnormalities in their ability to inhibit irrelevant sensory information.


METHODS
Fifteen female patients with a diagnosis of FM (ages 30-64 years) and 15 healthy women (ages 39-61 years) participated in 2 sessions, during which electrical activity elicited in the brain by presentation of either tactile or auditory paired stimuli was recorded using an electroencephalogram. Each trial consisted of 2 identical stimuli (S1 and S2) delivered with a randomized interstimulus interval of 550 msec (+/-50 msec), which was separated by a fixed intertrain interval of 12 seconds. Event-related potentials (ERPs) elicited by 40 trials were averaged separately for each sensory modality.


RESULTS
ERP amplitudes elicited by the somatosensory and auditory S2 stimuli were significantly reduced compared with those elicited by S1 stimuli in the healthy controls. Nevertheless, significant amplitude reductions from S1 stimuli to S2 stimuli were observed in FM patients for the auditory, but not the somatosensory, modality.


CONCLUSIONS
Our findings suggest that in FM patients, there is abnormal information processing, which may be characterized by a lack of inhibitory control to repetitive nonpainful somatosensory information during stimulus coding and cognitive evaluation.
Montoya
Pedro
P
Research Institute on Health Sciences (IUNICS), University of the Balearic Islands, Palma, Spain. pedro.montoya@uib.es
Sitges
Carolina
C
García-Herrera
Manuel
M
Rodríguez-Cotes
Alfonso
A
Izquierdo
Raúl
R
Truyols
Magdalena
M
Collado
Dolores
D
D000161:Acoustic Stimulation; D000328:Adult; D001921:Brain / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D005356:Fibromyalgia / Q000503:physiopathology*; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D010812:Physical Stimulation; D014110:Touch / Q000502:physiology*