Clinical Trial: Optimized tDCS for the Treatment of Migraine

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Optimizing the Effect of Transcranial Direct Current Stimulation (tDCS) for the Treatment of Migraine

Brief Summary: The aim of this study is to establish an optimized protocol of tDCS that normalize the lack of habituation and efficiency of inhibitory cortical circuits in migraine patients and determine tDCS polarity and the best cortical areas to stimulate which could normalize the lack of habituation and efficiency of inhibitory cortical circuits. For this, migraineurs volunteers will undergo to some tDCS protocols or sham tDCS.

Detailed Summary:

A crossover trial to establish an optimized tDCS protocol will be accomplished. Anodal and cathodal tDCS will be applied over the primary motor cortex (C3 - active and contralateral supra-orbital region - reference) and visual cortex (Oz - active and Cz - reference). Dual tDCS (anodal and cathodal - optimized protocol) will be applied on C3 - active and Oz - active.

Electrical cortical activity will be assessed on 14 migraineurs through: (i) MEP; (ii) MT; (iii) SICI; (iv) ICF; (v) PT and (vi) visual evoked-potential (VEP-habituation). An interval of 48hs between sessions will be taken. The order of the sessions will be randomized and counterbalanced among volunteers by site www.randomization.com.

Current Primary Outcome: Changes on VAS [ Time Frame: through study completion, assessed up to 3 weeks (before and after each section) ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

• Changes on Visual Evoked Potentials measures [ Time Frame: through study completion, assessed up to 3 weeks (before and after each section) ]
  volunteers will be invited to sit in a comfortable chair, in a calm and dark room, at 90 cm of distance from computer screen. It will be asked to fix his right eye visual field on a red point at the center of the screen (the left one will be blindfolded). Visual stimuli will be a black and White grid pattern, alternating at a frequency of 3.1 Hz. Electrodes used to record data will be localized on Oz and Fz points according International 10-20 system. During the test, 600 cortical answers will be recorded. Data will be collected and recorded in a personal computer, and after, converted to the ".txt" format to futures analysis with MATLAB.
• Changes on motor evoked potentials [ Time Frame: through study completion, assessed up to 3 weeks (before and after each section) ]
  to measure MEP, the intensity of the magnetic stimulator will be adjusted to 120% of rest motor threshold and 10 stimuli will be registered. For evaluation volunteers will be instructed to sit in a chair and get into a comfortable position. Initially, single-pulse TMS will be administered over the motor cortex to determine the cortical representation area of the first dorsal interosseous muscle (FDI). For all evaluations the same figure-eight coil is used, in order to avoid measurement bias. Amplitude means of evoked potentials will determine the MEP.
• Changes on intracortical inhibition [ Time Frame: through study completion, assessed up to 3 weeks (before and after each section) ]
  to evaluate these variables, subthreshold conditioning stimuli (80% of RMT) and suprathreshold test stimuli (120% of RMT) will be delivered at an inter stimulus intervals (ISI) of 2 milliseconds, to determine the short interval cortical inhibition (SICI). The Intracortical facilitation (ICF) will be evaluated by the MEP average at an ISI of 10 milliseconds. Ten stimulus will be applied in each condition (unconditioned pulse, and pairs of stimuli with ISI of 2 and 10 milliseconds). The order of stimulus delivered will be pseudorandomized and SICI and ICF will be expressed as a percentage of a conditioned stimuli in regarding an unconditioned stimuli.
• Changes on intracortical facilitation [ Time Frame: through study completion, assessed up to 3 weeks (before and after each section) ]
  to evaluate these variables, subthreshold conditioning stimuli (80% of RMT) and suprathreshold test stimuli (120% of RMT) will be delivered at an inter stimulus intervals (ISI) of 2 milliseconds, to determine the short interval cortical inhibition (SICI). The Intracortical facilitation (ICF) will be evaluated by the MEP average at an ISI of 10 milliseconds. Ten stimulus will be applied in each condition (unconditioned pulse, and pairs of stimuli with ISI of 2 and 10 milliseconds). The order of stimulus delivered will be pseudorandomized and SICI and ICF will be expressed as a percentage of a conditioned stimuli in regarding an unconditioned stimuli.
• Changes from phosphene threshold [ Time Frame: through study completion, assessed up to 3 weeks (before and after each section) ]
  a 10-cm circular coil was used that has giving a peak magnetic field strength of 2 tesla. Subjects were asked to wear a blindfold, sit comfortably in a chair and to close their eyes to diminish ambient light.In sagittal line, three points were scored: 2, 3 and 4 cm above the inion. The single pulse TMS was applied to one of the points scored and the subject was asked to report the presence or absence of a phosphene immediately after stimulation. The stimulation was repeated ten times at each intensity with a maximum frequency of 0.2 Hz, stimulation was initially applied to 60% of the maximum intensity of the stimulator. The intensity of stimulation was changed into blocks of 5% to minimum intensity that the subject can perceive the phosphene certainly, five times ten, then this value was set as the PT.

Original Secondary Outcome: Same as current

Information By: Universidade Federal de Pernambuco

Dates:
Date Received: September 22, 2015
Date Started: May 2016
Date Completion: April 2018
Last Updated: May 10, 2016
Last Verified: May 2016