Magnesium, Stress and Fibromyalgia

Measure of stress with stress subscale in magnesium and placebo group. This subscale consists of 14 questions of self-evaluation

The revised FIQ questionnaire is a 10-item self-questionnaire that assesses the impact of fibromyalgia

The FIRST questionnaire is a 6-item self-questionnaire that detects fibromyalgia.

Heart rate variability (HRV / HRV) is a measure of changes in heart rate that will provide an estimate of stress. It is usually calculated by analyzing time series of beat-by-beat intervals of the ECG or blood pressure plots.

This scale allows the patient to note the pain on a graduation whose minimum score is 0 and the maximum score is 10.

This self-assessment scale allows the patient to characterize the pain in relation to its psychosocial intensity and impact. The patient is asked to answer 9 graduated questions by circling a number from 0 (no pain) to 10 (the most horrible pain you can imagine).

The Trail Making Test (TMT) is recognized as one of the most frequently used neuropsychological tests in clinical practice alternating numbers and letters (1-A-2-B-3- C, etc.).

The Cantab® is a comprehension test, executive functions, memory, attention and decision-making.

The Trail Making Test (TMT) is recognized as one of the most frequently used neuropsychological tests in clinical practice alternating numbers and letters (1-A-2-B-3- C, etc.).

The Cantab® is a comprehension test, executive functions, memory, attention and decision-making.

The International Affective Picture System (IAPS) is a library of 1200 standardized images that can induce an emotional reaction, constituting as many emotional stimuli (positive or negative) or not (neutral).

The Global Impression of Change Patient is a scale of global perception of change ("deterioration" or "improvement") completed by the patient. This scale is graduated from 1 = much better to 7 = significantly worse

The Pittsburg Sleep Quality Index is a self-administered questionnaire with 19 items. It has been developed to measure the quality of sleep in the month preceding the interview with the patient. This questionnaire has 7 components: subjective sleep quality, sleep latency, sleep duration, usual sleep efficiency, sleep disorders, use of a sleep medication, and poor daytime fitness

The fatigue severity scale is a 9-item self-questionnaire to assess the patient's fatigue intensity. The patient is asked to circle a number from 1 to 7 for each question, a low value representing a low intensity

The EPICES questionnaire is composed of 11 binary questions (yes / no) allowing to calculate an individual score indicating the precariousness and inequalities of health ranging from 0 to 100.

Pain Catastrophizing Scale (PCS) is a questionnaire in which the patient is asked to describe the kind of thought and emotions they feel during pain. This questionnaire consists of 13 items describing different thoughts or emotions that may be associated with the pain. The patient will have to indicate how much he has these thoughts or emotions when he feels pain by giving a score between 0 and 4, 0: not at all, 4: all the time. The final score is the sum of the scores for each question.

assessed by a quality of life questionnaire (Short Form 12 items Short Form survey (SF12)

Sudoscan® (Impeto Medical, Paris, France) is a new device that provides a rapid, non-invasive and reproducible quantitative assessment of sweat function.

A skin biopsy will be realized for histological analysis to determine the presence of small fiber neuropathy.

The intracellular magnesium concentrations will be determined by the blood samples taken at the inclusion visit, at the end of the treatment on visit 3 (D0 + 28) and on visit 4 (D0 + 84).

The erythrocyte magnesium concentrations will be determined by the blood samples taken at the inclusion visit, at the end of the treatment on visit 3 (D0 + 28) and on visit 4 (D0 + 84).

The urinary concentration of magnesium will be determined by the urine collected for 24 hours, the day before visits 3 and 4.

The urinary concentration of magnesium will be determined by the urine collected for 24 hours, the day before visits 3 and 4.

The creatinine concentrations will be determined by the blood samples taken at the inclusion visit.

Analysis of the microbiota: the patient must carry out the collection at her home maximum 24 hours before the visit 2 by following the technical instructions described in the explanatory note that will be provided. She will then ensure that the stool preservation and transport procedure described in this document is followed.

Identification of genes involved

Stress intensity will be assessed by the numerical stress rating scale: the scale ranges from 0 "no stress" to 10 "maximal stress" following different visual stimulation induced by different colors during the anticipatory phase of pain.

Pain intensity will be assessed by the numerical pain rating scale (NPRS): the scale ranges from 0 "no pain" to 10 "maximal tolerable pain" following different thermal stimulations (using Pathway Medoc®).

EMG motor and sensitive of the median nerve on both arm to control the speed of electrical conduction. For this purpose, we will measure the amplitude, latency and speed for the motor test, and the amplitude and speed for the sensitivity test.