Effects of Combined Treatment With tDCS and Cognitive Training in Patients With Fibromyalgia

Effects of Combined Treatment With tDCS and Cognitive Training on Attention and Working Memory in Patients With Fibromyalgia

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

Chronic pain represents an important health problem responsible for decreases in quality of life, and is associated with great negative impact in society and economy. In many cases, its treatment does not reach therapeutic success causing health professionals and patients dissatisfaction. Chronic pain is also associated with somatization, hopelessness and catastrophizing thinking. These information processing includes sensorial, emotional and cognitive-appraisal thinking, which manifests the working of neural networks at cortical and sub-cortical levels. Attention and memory are a central aspect in the processing of pain modulation. Like in addictions (e.g. smoking, alcohol), chronic pain may debut with displacement in the focus of attention and alterations in the sensorial processing in the incentive-motivation tests. Considering that other studies have indicated that experimental and clinical pain is capable of modulating cognitive activities such as attention,memory and expectation, in this study the investigators will test whether cognitive training, tDCS, or the combination of both interventions decrease cognitive deficits associated with Fibromyalgia

Will be included women aged between 18 and 65 years, chronic pain fibromyalgia according to the criteria of the American College of Rheumatology, pain unresponsive to analgesics such as paracetamol, acetylsalicylic acid, ibuprofen, Carisoprodol, Zanaflex (Tizanidine) and Codeine and give informed consent to participate after initial evaluation. Primary outcome is to Evaluate whether the tDCS associated with cognitive retraining technique is able to modulate attentional bias in fibromyalgia patients. Secondary outcomes are: compare the effect of active tDCS and sham in: Assessed with the Visual Analog Scale for 8 days, Functional capacity, Conditional pain modulation (CPM), Maximal Heat Pain tolerance,Catastrophic thinking,Serum levels of Brain Derived Neurotrophic Factor (BDNF), Beck Depression Inventory, forward and backward digit span( WAIS),Pittsburgh sleep quality and State-Trait Anxiety Inventory (STAI) test.

tDCs active left dorsolateral prefrontal cortex (2mA,20 min) and Cognitive training (20min) at the same time.

tDCs Sham dorsolateral prefrontal cortex ((2mA,20 min) and Cognitive training (20min) at the same time.

Sham tDCS will involve an identical electrode montage, with stimulation ceasing after a 30-second ramp-up period to provide equivalent scalp sensation.

tDCS was delivered using the anode electrode positioned over the left dorsolateral prefrontal cortex (DLPFE) and the cathode electrode at supra orbital right region. The electrodes were placed into a 25-35 cm2 square sponge immersed in saline solution for better current conductivity. Current density used was 2 mA and electrodes attached to the scalp were sustained by rubber band.

. The cognitive training consisted of an online application of a Dual N-Back task .The Training will last for 8 days.

Evaluate whether the tdcs associated with cognitive training technique or the combination of both interventions decrease memory deficits associated with Fibromyalgia.

I will use the rey auditory-verbal learning test(RAVLT) to evaluate the memory functions of patients with fibromyalgia, before and after treatment with TDCS and cognitive training.

Measurement of functional capacity pre and pos application tDCS with scale functional capacity in chronic pain.

The protocol for heat pain threshold is repeated while the contralateral hand is placed on iced water. The pain due to heat and cold reported on a Visual Analog Scale are recorded.

Assessed using quantitative sensory testing. Briefly, the thermode placed in subjects forearm is heated until subject reports maximum tolerated pain. A maximal temperature of 52 Celsius has been previously programmed for the device to stop and cool down in order to avoid unintended injuries

Measurement of catastrophic thinking pre and pos application tDCS with catastrophizing.The level of catastrophic thinking will be assessed by the Pain Catastrophizing Scale on Treatment scale.

I will use the Paced Auditory Serial Addiction Test to evaluate the memory functions of patients with fibromyalgia, before and after treatment with TDCS and cognitive training.

I will use the Controlled Oral Word Association Test to evaluate the verbal fluency of patients with fibromyalgia, before and after treatment with TDCS and cognitive training.

I will use the forward and backward digit span to evaluate the working memory of patients with fibromyalgia, before and after treatment with TDCS and cognitive training.

I will use the Auditory Consonant Trigrams to evaluate the working memory of patients with fibromyalgia, before and after treatment with TDCS and cognitive training.

Inclusion Criteria: Female patients literate right-handed 18 to 65 years of age who meet the criteria of the American College of Rheumatology (ACR) for fibromyalgia. Exclusion Criteria: Pregnant women Contraindications to tDCS Metal implant in the brain History of alcohol or drug abuse in the last six months History of neurological disorders Unexplained fainting Self-reports of head injury or momentary loss of awareness Neurosurgery. Will also be excluded patients who have decompensated systemic diseases and / or chronic inflammatory diseases (ex .: lupus, rheumatoid arthritis).