Fibromyalgia
Conditions
Keywords
Event-Related Potentials, Electroencephalography, Habituation
Brief summary
The goal of this observational study is to assess event-related potentials and habituation in patients with fibromyalgia. The main research questions are: * Is there a measurable difference in sensory responses between fibromyalgia patients and healthy control? * Could these measures provide evidence supporting claims of hypersensitivity? Participants will: \- receive randomized sensory stimuli (auditory, visual, somatosensory, audiovisual, auditory-somatosensory, visual-somatosensory, and auditory-visual-somatosensory) in blocks of 20 trials.
Detailed description
Fibromyalgia is a disorder characterized primarily by widespread musculoskeletal pain. It is often accompanied by symptoms such as fatigue, insomnia, cognitive difficulties, etc. In addition to chronic pain, patients frequently report hypersensitivity to sensory stimuli, both nociceptive and non-nociceptive. Studies using psychophysical and electrophysiological tests have found altered sensory processing in fibromyalgia patients. Research focused on event-related potentials (ERPs) have found differences in amplitude in the responses to auditory, nociceptive, and non-nociceptive somatosensory stimuli in fibromyalgia patients . One key aspect evaluated through ERPs is habituation, defined as a decrease in response due to repeated stimulation. In healthy individuals, ERPs amplitude decreases with repeated sensory input due to progressive neuronal response reduction. In fibromyalgia patients, reduced habituation has been observed for laser-induced ERPs and somatosensory ERPs, though no differences were found for auditory ERPs. ERPs not only provide information about sensory modalities but also contain non-specific components related to stimulus expectation, motor preparation, and attentional orientation. Previous studies have attempted to isolate this non-specific component, as part of habituation may stem from a decrease in its amplitude rather than from a direct sensory response reduction. Using an analytical model, researchers successfully separated this component in experiments with individually or simultaneously presented stimuli, yielding promising results. In the present study, participants (both fibromyalgia patients and healthy controls) will attend one experimental session in which stimulation in different sensory modalities will take place along with electroencephalographic (EEG) recordings. For each stimulus type, 2 blocks of 20 trials will be performed.The order of the stimulus will be selected randomly, but they can be divided into three categories: * Unimodal stimulus * Auditory (A): a 1000 Hz tone delivered at a comfortable volume through a speaker * Visual (V): a checkerboard pattern, inverted every 25 ms, presented on a computer screen. * Somatosensory (S): a train of 3 electrical stimuli that elicits a pricking sensation. * Bimodal stimulus * Auditory-Visual (AV) * Auditivo-Somatosensory (AS) * Visual-Somatosensory (VS) * Trimodal Stimulus * Auditory-Visual-Somatosensory (AVS) The aim of the study is to evaluate neurophysiological parameters related to habituation in multimodal sensory stimulation environments to characterize ERPs in fibromyalgia patients.
Interventions
OTHERAuditory Stimulation
A tone at a 1000 Hz frequency, delivered through speakers at a comfortable volume
OTHERVisual Stimulation
A checkerboard pattern displayed on a monitor, with colors alternating every 25 ms
OTHERSomatosensory Stimulation
A train of three electrical stimuli, each lasting 1 ms, separated by 8 ms, at an intensity that clearly elicits a pricking sensation
OTHERAuditory-Visual Stimulation
Stimulation using auditory and visual stimuli concomitantly
OTHERVisual-Somatosensory Stimulation
Stimulation using visual and somatosensory stimuli concomitantly
OTHERAuditory-Somatonsensory Stimulation
Stimulation using auditory and somatosensory stimuli concomitantly
OTHERAuditory-Visual-Somatosensory Stimulation
Stimulation using auditory, visual and somatosensory stimuli concomitantly
Sponsors
National Council of Scientific and Technical Research, Argentina
Study design
Observational model
CASE_CONTROL
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
Fibromyalgia patients: * Primary diagnosis of fibromyalgia according to the criteria used by the healthcare professional in charge of the patient. * Other comorbidities are accepted as long as the pain caused by them is less severe than the pain caused by fibromyalgia. * Willingness and ability to fully understand the content and scope of the experiment and to comply with the experiment instructions. * Normal or corrected-to-normal vision. * Normal hearing Healthy controls: * No history of neurological diseases, chronic pain or musculoskeletal disorders. * Willingness and ability to fully understand the content and scope of the experiment and to comply with the experiment instructions. * Normal or corrected-to-normal vision. * Normal hearing
Exclusion criteria
Fibromyalgia patients: * Pregnancy * History of addictive behavior, defined as alcohol, cannabis, opioids or other drugs abuse. * Presence of fever, tuberculosis, malignant tumors, infectious processes, acute inflammatory processes. * Lack of cooperation Healthy controls: * Pregnancy * History of chronic pain or musculoskeletal or articular disorders * History of addictive behavior, defined as alcohol, cannabis, opioids or other drugs abuse. * Presence of fever, tuberculosis, malignant tumors, infectious processes, acute inflammatory processes. * Lack of cooperation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Percentual Habituation | Immediately after the intervention | Relative reduction in the amplitude of evoked potentials between consecutive stimuli |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Symptoms Impact Questionnaire (SIQ) | 10 minutes before the intervention | Instrument to assess healthy control's status regarding relevant clinical symptoms experienced in the last week. Scores range from 0 to 100, with a higher number indicating more impacts of their symptoms in daily life activities |
| Hospital Anxiety and Depression Scale (HADS) | 10 minutes before the intervention | Widely used instrument to evaluate anxiety and depression. It is divided into 7 questions assessing anxiety and 7 assessing depression. The scores range from 0 to 21, with higher scores indicating worse clinical symptoms. |
| Numeric Rating Scale Pain (NRSp) | 10 minutes before the intervention | Pain at the moment of the experimental session. Scores range from 0 to 10, with higher number indicating worse pain. |
| Stimulus saliency | Immediately after the intervention | A number reflecting the ability of a stimulus to stand out relative to the sensory background or relative to the preceding stimuli |
| Fibromyalgia Impact Questionnaire-Revised version (FIQR) | 10 minutes before the intervention | Instrument for the assessment and evaluation of fibromyalgia patient's status. Scores range from 0 to 100, with a higher number indicating more impacts of fibromyalgia symptoms in daily life |
| Event-related potentials latency | Immediately after the intervention | Latency, in milliseconds, of event-related brain potentials |
| Non-specific components amplitude | Immediately after the intervention | Amplitude, in microvolts, of the non/specific component derived from the ERPs |
| Non-specific components latency | Immediately after the intervention | Latency, in milliseconds, of the non-specific component derived from the ERPs |
| Event-related potentials amplitude | Immediately after the intervention | Amplitude, in microvolts, of event-related brain potentials |
Countries
Argentina
Outcome results
None listed