Effect of Hypnosis Combined to Transcranial Direct Stimulation in Pain

Effect of Hypnosis Combined to Transcranial Direct Stimulation in Cortical Activity and Pain Perception in Healthy Females

Pain is a public health condition, which causes great functional disability. Its consequences pervade the personal and social life of the patient, leading to significant changes in their interpersonal relationships, including work, family and social spheres, reducing the ability to perform daily activities. Conventional treatment modalities have been show a very poor therapeutic response, in that most individuals end up becoming polymedicated patients and refractory to treatment. Among non-pharmacological techniques with promising analgesic effects it includes both the hypnotic analgesia and the transcranial stimulation of direct current (tDCS).

Introduction: Pain is a public health condition, which causes great functional disability. Its consequences pervade the personal and social life of the patient, leading to significant changes in their interpersonal relationships, including work, family and social spheres, reducing the ability to perform daily activities. Conventional treatment modalities have been show a very poor therapeutic response, in that most individuals end up becoming polymedicated patients and refractory to treatment. Among non-pharmacological techniques with promising analgesic effects it includes both the hypnotic analgesia and the transcranial stimulation of direct current (tDCS). Objective: To evaluate the synergistic effect of hypnotic analgesia associated with tDCS under metabolites parameters and pain levels in healthy individuals before a nociceptive stimulation pattern. Methods: it will be performed a blinded crossover sham controlled randomized clinical trial. It will be included 32 woman healthy subjects, Susceptible to the hypnosis technique according to the Scale of Hypnotic Susceptibility (WSGC) Scale of Hypnotic Scale score. aged 18 to 65. They will be allocated in one of the following groups: active tDCS + hypnotic analgesia, sham tDCS + hypnotic analgesia, hypnotic analgesia and tDCS . After a 7 days interval, the groups will be crossed in order to receive the opposite intervention of the first week. The primary endpoints will be the electrophysiological brain parameters, such as changes in the Theta, Alpha and Gamma waves, as measured by EEG. The secondary endpoints will be the level of pain, measured against nociceptive induced by the cold test and stimuli standardized pressure through algometry pressure and power down system modulatory pain, pain using the subject test - CPM - task. The intra and inter-group comparisons will be made by means of two-way ANOVA followed by Bonferroni. A p significance level of <0.05 was established. Expected results: This study hypothesizes that a synergistic effect of analgesic techniques in pain levels in healthy subjects compared to isolated character.

Subjects are blinded to wether group they will be allocated Assessor will be blinded and the investigator not involved in subjects assessment will perform the hypnosis.

Intervention: transcranial direct current stimulation - tDCS active tDCS stimulation montage: bilateral DLPFC anodal/left and cathodal/right current:2 milliamps time: 20 minutes

Sham comparator: transcranial direct current stimulation - tDCS sham tDCS stimulation montage: bilateral DLPFC anodal/left and cathodal/right current: 0 milliamps time: 20 minutes

Intervention: hypnotic analgesia active tDCS stimulation montage: bilateral DLPFC anodal/left and cathodal/right current:2 milliamps time: 20 minutes

Subjects will receive transcranial direct stimulation over bilateral DLPFC left/anode right/cathodal, 2mA, 20 minutes

Subjects will receive hypnotic analgesia associated to transcranial direct stimulation over bilateral DLPFC left/anode right/cathodal, 2mA, 20 minutes

Subjects will receive sham transcranial direct stimulation over bilateral DLPFC left/anode right/cathodal, 0mA, 20 minutes

Variations in the alpha waves power from post to pre-intervention using electroencephalography during a cold pressor test

Variations in the theta waves power from post to pre-intervention using electroencephalography during a cold pressor test

Variations in the beta waves power from post to pre-intervention using electroencephalography during a cold pressor test

Variations in the gamma waves power from post to pre-intervention using electroencephalography during a cold pressor test

Variations in the delta waves power from post to pre-intervention using electroencephalography during a cold pressor test

The measure will be assessed by Quantitative Sensorial Test - QST, in which a thermode delivers a heat stimulus of increasing magnitude. Heat thermal threshold (HTT) is the averaged temperature for 3 stimuli where participant indicates the first heat sensation.

The measure will be assessed by Quantitative Sensorial Test - QST, in which a thermode delivers a heat stimulus of increasing magnitude. Heat pain threshold (HPT) is the averaged temperature for 3 stimuli where participant indicates the first heat pain sensation.

The measure will be assessed by Quantitative Sensorial Test - QST, in which a thermode delivers a heat stimulus of increasing magnitude. Heat pain tolerance (HPTo) is the temperature for the stimulus where participant indicates the maximum pain tolerance.

The measure will be assessed by the conditioned pain modulation (CPM) task in which an ice cold water (0 a 1 degrees Celsius) is the conditioning stimulus presented to the left hand and a moderate heat pain stimulus from the QST to the contralateral hand. The measure consists of the response using a numeric pain scale (0 - 10) for the heat pain stimulus during the CPM task.

Participant puts his right hand in an ice cold water (0 a 1 degrees Celsius). Measure consists of the time (in seconds) the participant keeps his hand in the water the maximum he could tolerance.

Participant puts his right hand in an ice cold water (10 degrees Celsius). Measure consists of the time (in seconds) the participant keeps his hand in the water the maximum he could tolerate.

Participant puts his right hand in an ice cold water (10 degrees Celsius). Measure consists of the response to a numeric pain scale (0 to 10) to the pain sensation when the participant withdraw his hand from the water.

Inclusion Criteria: Healthy Female 11 years of schooling 12 cut-off at Waterloo-Stanford Group C (WSGC) Exclusion Criteria: hearing loss subjects formal contraindication to tDCS (pregnancy, deep brain device, epilepsy, seizure)

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