Utilidad de los potenciales evocados y niveles de serotonina plaquetar en la comprensión de los mecanismos fisiopatológicos de la fibromialgia.

Abstract

Fibromyalgia (FM) is a chronic rheumatism of an unknown aetiology. Alterations have been described in the neuromodulation of pain and in psychopathological disorders. Objectives: ? Classify the neuromodulation alteration by means of Auditive Evoked Potentials (AEP). ? Determine the biochemical pattern of platelet serotonin. ? Evaluate the importance of both depressive and sleep disorders. ? Evaluate the utility of instruments that assess the dimensions of the personality (TPQ). Material and Methods Case-Control Study. The following were conducted: 1) Clinical assessment of the Fibromyalgia process 2) Haematic serotonin values 3) AEP study 4) Psychological assessment a) Beck Depression Inventory (BDI) b) Three-dimensional Personality Questionnaire (TPQ) c) MMPI sleep subscale 5) Statistical analysis Results. The mean AEP ranges in FM are higher in all the intensities, with a greater intensity in stimulation where the maximum difference is observed (p=0.003). Harm avoidance (HA) is the only dimension of the TPQ with significantly different values between both groups (p<0.0001). The applied logistic regression analysis reveals that the HA and PEA105 variables provide a predictive value of 0.27 and of 0.16 respectively in the equation, with a significance of p<0.001 in both cases, where the OR for the association of both variables is 6.234. No differences were found in the blood seratonin values. Differences are seen between cases and controls for Depression (p<0001), and a positive correlation is observed between depression and the evolution of the disease. Sleep disorders in FM were apparent from the start of the process. Discussion. Differences exist between both groups with regards to the regulation capacity of the cortical auditive stimuli. In FM, there would be an inadequate cortical regulation capacity to stimuli in relation with a low level of preactivation of the inhibitor system, which would in turn correspond to a poor central serotonergic activity. This finding, along with the HA dimension in FM, is highly consistent with a high predictive value for the diagnosis of these patients. The combined usage of both determinations could prove useful in assessing this disease.