Tools for the Differential Diagnosis of Fibromyalgia Based on Cognitive Tasks

Study Overview
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Brief Summary
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The goal of this observational study is to test for behavioural and neurophysiological biomarkers in fibromyalgia patients. The main questions it aims to answer are: Is there a measurable decline in working memory? Could these measures help in fibromyalgia differential diagnosis? Participants will: perform Color Comparison tasks perform n-back tasks

Detailed Description
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Fibromyalgia is a disease characterized by the presence of generalized musculoskeletal pain, accompanied by non-specific symptoms such as depression, sleep disturbances, anxiety, cognitive disabilities, among others. While widespread musculoskeletal pain is the predominant symptom in patients with fibromyalgia, cognitive impairments have also been widely reported, including decreased ability to concentrate, decreased short-term memory, and inability to multitask, which differentiate fibromyalgia patients from those with other chronic pain syndromes. Specifically, quantitative evidence has been found of impairment in executive functions in this group of patients, particularly in the domains of inhibitory control and working memory. In the present study, participants (both healthy individuals and those diagnosed with fibromyalgia) will perform two cognitive tasks designed to assess the capacity and retrieval of information from working memory. The first task is the Color Comparison task, in which colored squares will appear on a computer screen for a short period of time. After a blank delay, a new set of squares will appear, and a decision has to be made about whether or not the squares are the same as the ones shown first. The task will be divided into 10 blocks of 30 trials each, with 10 trials comparing 2 colored squares, 10 trials comparing 4 colored squares, and 10 trials comparing 6 colored squares. A resting period will be given between each block. The behavioral results of this task will include reaction times and hit rates. At the same time, electroencephalographic data will be recorded to evaluate the Contralateral Delay Activity (CDA). The amplitude of this waveform is linked to the number of items allocated in working memory. The second task that will be carried out by the participants is the n-back task. A sequence of letters will be presented, and participants will be asked to indicate whether the current stimulus matches the one presented two stimuli earlier. Sixty-two stimuli will be presented per block, and 5 blocks will be carried out. The results will be analyzed in terms of behavioral analysis and Event-Related Potentials (ERPs) analysis.

Official Title
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Development of Complementary Tools for the Differential Diagnosis of Fibromyalgia Based on Cognitive Task Performance

Conditions
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Fibromyalgia

Intervention / Treatment
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* Other: Color Comparison Task
* Other: N-back Task


Participation Criteria
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Eligibility Criteria
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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. 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. 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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Fibromyalgia Patients<br>Patients with primary fibromyalgia diagnosis. May include other chronic pain comorbidities, but the pain associated with those diseases should be less severe than the pain caused by fibromyalgia. | Other: Color Comparison Task<br>* Participants are presented with a series of colored squares and are instructed to compare the colors of two sequentially presented stimuli.<br>Other: N-back Task<br>* Participants are presented with a sequence of letters and they must indicate whether the current stimulus matches the one presented 2 steps back in the sequence.<br>|
| Healthy Controls<br>Volunteers with no clinical history of chronic pain, musculoskeletal or articular disorders. | Other: Color Comparison Task<br>* Participants are presented with a series of colored squares and are instructed to compare the colors of two sequentially presented stimuli.<br>Other: N-back Task<br>* Participants are presented with a sequence of letters and they must indicate whether the current stimulus matches the one presented 2 steps back in the sequence.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of correct answers in the Color Comparison task | Percentage of correct answers over total number of trial in the Color Comparison Task | Immediately after the intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fibromyalgia Impact Questionnaire-Revised version (FIQR) | Instrument for the assessment and evaluation of fibromyalgia patient's status | 10 minutes before the intervention | 
| Symptoms Impact Questionnaire (SIQ) | Instrument to assess healthy control's status regarding relevant clinical symptoms experienced in the last week. | 10 minutes before the intervention | 
| Hospital Anxiety and Depression Scale (HADS) | Widely used instrument to evaluate anxiety and depression | 10 minutes before the intervention | 
| Brief Pain Inventory-Short Form (BPI-SF) | It is an instrument to assess the severity of pain and its impact on functioning. | 10 minutes before the intervention | 
| Power in EEG bands | Analysis of EEG spectrum bands | Immediately after the intervention | 
| Event-related potentials amplitude | Amplitude, in microvolts, of event-related brain potentials | Immediately after the intervention | 
| Event-related potentials latency | Latency, in milliseconds, of event-related brain potentials | Immediately after the intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Contralateral Delay Activity, Electroencephalography, Cognitive task, Biomarker