Transcranial Direct Current Stimulation Effect on Pain Threshold and Working Memory: Impact of Age and Protocol Type
Condition: Transcranial Direct Current Stimulation; Working Memory; Pain
Study type: Interventional

Summary: 
      Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation method which
      has great potential as an aid in the therapeutic management of neuropsychiatric disorders and
      chronic pain syndromes. However, despite promising results, the response to stimulation
      presents great variability among subjects. Age is a factor that is known to influence the
      tDCS effect forging the inconsistency of clinical effect.The purpose of this study is to
      evaluate the effect of tDCS on pain perception and working memory in healthy women from 3
      different age groups: adolescents, young adults and elderly. This is a randomized,
      single-blinded, cross-over study of 2 different active interventions and sham.
    

Detailed description: 
      Transcranial direct current stimulation (tDCS) is a neuromodulation method that has great
      potential as an aid in the therapeutic management of neuropsychiatric disorders and chronic
      pain syndromes. tDCS modulates the neuronal membrane potential , facilitating neuronal
      depolarization or hyperpolarization, hence modifying the cortical excitability of the
      stimulated area. However, despite promising results the response to stimulation presents
      great variability among subjects. Chronological age is an important factor in the variation
      of brain plasticity. The dorsolateral prefrontal cortex (DLPFC) is associated with cognitive
      and emotional aspects of pain, in addition to being related to executive components of
      working memory. Anodal tDCS on DLPFC modulates pain level in patients with chronic pain and
      modifies working memory performance in healthy subjects and patients with memory impairment.
      The prefrontal cortex presents a great structural difference throughout lifespan: it is under
      maturational process in the adolescence, reaching peak of maturation in the adult life, and
      initiating process of cerebral senescence in elderly subjects. Therefore, the use of tDCS on
      DLPFC in these three age groups presents potential for a large variation in response. Faced
      with the potential of tDCS for adjuvant use in the treatment of several diseases, it is
      imperative to understand the variability of this intervention between different age groups.
      This knowledge may allow the optimization of neuromodulation protocols, allowing more careful
      and refined use in the clinic. The study primary outcomes is the difference between and
      within age groups on the variation of pre and post tDCS on pain threshold evaluated by Heath
      pain threshold on a Quantitative sensory testing paradigm and working memory performance
      evaluated by n-back test in healthy subjects of three age groups: adolescents, young adults,
      elderly. This is a randomized, single blinded, cross-over, sham-controlled clinical trial.
      The study will be conducted at the Clinical Research Center of the Hospital de Clínicas of
      Porto Alegre (HCPA). It will include 30 women, 10 women by age group: adolescents between 15
      and 16 years,young adults between 30 and 40 years old and elderly women between 60 and 70
      years. Participants will be randomized for a cross-over of three sessions: anodal stimulation
      in DLPFC, anodal stimulation in primary motor cortex (M1) as active control and sham
      stimulation.
    

Intervention name(s): Anodal tDCS on DLPFC; Anodal tDCS on M1; Sham tDCS
Intervention type(s): Device; Device; Device
Intervention description(s): Participants will receive anodal tDCS on the left DLPFC for 30 min duration, cathode will be placed over the right supra orbital area. The electrodes are 25cm², The stimulation current is 2 milliamperes (2mA).; Participants will receive anodal tDCS on the left M1 for 30 min duration, cathode will be placed over the right supra orbital area. The electrodes are 25cm², The stimulation current is 2 milliamperes (2mA).; Participants will receive sham tDCS. The anode will be placed on the left DLPFC and the cathode on the over the right supra orbital area. The electrodes are 25cm², There will be a ram up and down of 30 seconds each, after the ramp up the current will be turned off.
Other intervention name(s): DLPFC; M1; Sham
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: Age Groups; Pain Threshold