Clinical Trial: Analgesic Effect of Cathodal tDCS Over Right DLPFC in Subjects With Muscular TMD: a Double Blind Crossover RCT

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: ANALGESIC EFFECT OF CATHODAL TRANSCRANIAL CURRENT STIMULATION OVER RIGHT DORSOLATERAL PREFRONTAL CORTEX IN SUBJECTS WITH MUSCULAR TEMPOROMANDIBULAR DISORDERS: A Double Blind Crossover Randomized Clini

Brief Summary:

  1. BACKGROUND: Temporomandibular Disorders (TMD) have become part of the daily routine of all the health care professionals. Some studies have shown improvement in subjects with chronic pain using neuromodulation. Chronic pain is involved with neuronal excitability and the excitatory modulation is also being studied to treat chronic pain. Transcranial direct current stimulation (tDCS) allows the neuronal membranes to be neuromodulated. tDCS can enhance or inhibit the potential actions on the cortex. Studies with animals has shown that anodal stimulation modulate the membrane in the way to depolarize which results in a long term potential in the stimulated area.
  2. PROBLEM: Most strategies for the treatment of TMDs are local and aim to treat directly the cranial-facial muscles, applying kinesitherapy on Temporomandibular joint (TMJ) and/or on the jaws and on the occlusion of teeth. Some drugs, such as tricyclic antidepressants, that act in the CNS are used in these patients with positive results in the beginning of the treatment. However, many patients after using these drugs in a daily basis, are refractory to them and do not present an improvement in the pain anymore or present several side-effects. Therefore, the investigators want to know if tDCS over dorsolateral prefrontal cortex (DLPFC) would have an analgesic effect when reaching emotional areas.
  3. HYPOTHESIS: The investigators believe that neuromodulation by tDCS over DLPFC would decrease the anxiety level and consequently the muscular hyperactivity that is an important etiological factor of TMD. For that, the masseter motor evoked potential (MEP) will be used to verify any change.
  4. AIM: To investigate if cathodal tDCS over right DLPFC has analgesic effects in subjects with muscular TMD.
  5. METHOD: The inv

    Detailed Summary:

    1. INTRODUCTION Pain is among the main complaints of most patients that seek care in a hospital or a primary care unit. Temporomandibular Disorders (TMD) patients have become part of the daily routine of all the health care professionals. Temporomandibular and cranial-facial disorders are so prevalent that, since 1987, the International Headache Society holds meetings to classify different types of pain associated with head. This resulted in the publication of the Manual of Classification of Headaches - The International Classification of Disorders Headache was revised in 2013.

      There are different strategies to treat TMD patients, and the best is chosen depending on the type of problem diagnosed or the most suitable strategy according to professional experience. Strategies range from advice on lifestyle, psychotherapy, containment of the jaw, kinesitherapy, ultrasound, TENS, muscle relaxants plates, allopathic and homeopathic therapies and surgical interventions to the temporomandibular joint (TMJ). Some of these techniques aim to treat the muscles, others treat the dental occlusion or joint structures and there are those whose primary focus is the psycho-emotional factors. As The TMDs are due to various factors of muscular, joint, emotional, inflammatory, autoimmune or even infectious reasons, the treatment should include different therapies during the rehabilitation process, considering the best strategies for each patient. Literature has shown that the causes of muscular origin are more prevalent in patients with this type of disorder). A systematic review using studies with functional brain imaging, showed that, although the majority of disorders are associated with muscle pain, this would be secondary to a process triggered by the Central Nervous System (CNS). Following this theory, some beha
      Sponsor: Federal University of Bahia

      Current Primary Outcome: Change from baseline in Visual Analogic Scale [ Time Frame: 4 weeks ]

      The visual analogic scale allows us to convert subjective sensations as pain on numerical data. A 10cm scale where 0cm is no pain and 10cm the worse imaginable pain, will be used and the subjects will be asked to mark a point on the scale representing their pain. This instrument will be used by the subjects everyday during one week in a pain diary. A weekly response average will be calculated before the first interventions and after each one. Subjects will also fill a VAS before and after each tDCS session. The averages will be used to compare the VAS values before and after each intervention.


      Original Primary Outcome: Same as current

      Current Secondary Outcome: Change from baseline in Electroencephalogram (EEG) [ Time Frame: 4 weeks ]

      Another type of assessment is the electroencephalography, which measures the brain electrical current intensity using the analysis of waves. The alpha wave is related with relaxation and it is higher when the subject keeps her/his eyes closed, and lower when the eyes are open. The same can be seen in relaxation and alert states respectively. The EEG is a powerful tool to assess changes related to anxiety. The increase of alpha indicates reduction of chronic jitters (Hammond (2005).

      In this study a 24 channels EEG will be used associated with TMS, both according the international system 10x20 of electrodes. We will check alpha amplitudes before and after tDCS stimulation to see if the alpha waves will increase/decrease. The reference electrodes will be placed in the left ear lobe and in the masseter assessed spot. The data will be analyzed by MATLAB (The Mathworks, Inc., Natick, Massachusetts, USA) after the signals had been filtered from 0.1 to 35Hz and digitalized in 1450Hz.



      Original Secondary Outcome: Same as current

      Information By: Federal University of Bahia

      Dates:
      Date Received: May 24, 2014
      Date Started: July 2014
      Date Completion:
      Last Updated: February 3, 2016
      Last Verified: February 2016