Brain Response to Single Dose of Pregabalin in Fibromyalgia
Status:
Completed
Trial end date:
2017-01-01
Target enrollment:
Participant gender:
Summary
Fibromyalgia syndrome represents a "spectrum disorder" characterized by widespread chronic
pain, fatigue, sleep disturbances, mood and cognitive alterations. The most accepted models
explaining the causes of the disease have focused on the reduced pain inhibitory systems
activity, that allow low intensity stimuli to be processed easier, and that finally amplify
pain stimuli. One of the interventions approved for Fibromyalgia is Pregabalin, which
demonstrated to be effective reducing pain. Different studies in animals have shown that it
works reducing the liberation of neuronal messengers, which slow the conduction of pain
signals. Although studies in humans have confirmed Pregabalin clinical benefits, there are
still few studies aiming to explain how it actually works in patients with fibromyalgia,
though.
A better understanding of the mechanisms by which Pregabalin reduces pain in patients with
fibromyalgia would allow designing new interventions to enhance its clinical effects. Thus,
the investigators propose to study in real-time the electrical, vascular and hormonal
response of the brain of patients with fibromyalgia who receive a single dose of Pregabalin.
The vascular response will be assessed using functional near infrared spectroscopy (fNIRS)
neuroimaging techniques. The electrical response will be assessed using Transcranial Magnetic
Stimulation (TMS). The hormonal response will be assessed in blood, measuring neurotrophins
(Brain Derived Neurotrophic Factor) and inflammatory mediators (Tumor Necrosis Factor). These
responses will be studied in consideration of the patients' characteristics that will be
assessed using validated scales.
Taken into account the above considerations, a crossover, double-blinded randomized clinical
trial is proposed. In the investigators' study, patients and healthy volunteers will be asked
to visit the investigators' laboratory in three opportunities: one for a baseline assessment,
and the other two to test the effects of either Pregabalin 150 mg PO or Placebo. All
participants will eventually receive both, Pregabalin and Placebo. In each visit a brain
hemodynamic, electrical, hormonal and clinical evaluation will be performed.
Phase:
Phase 2/Phase 3
Details
Lead Sponsor:
Hospital de Clinicas de Porto Alegre
Collaborators:
Conselho Nacional de Desenvolvimento Científico e Tecnológico Coordenação de Aperfeiçoamento de Pessoal de Nível Superior. Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul, Brazil