<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT03305328</url>
  </required_header>
  <id_info>
    <org_study_id>2017.20700</org_study_id>
    <nct_id>NCT03305328</nct_id>
  </id_info>
  <brief_title>Assessing the Clinical Utility of tACS</brief_title>
  <official_title>Assessing the Clinical Utility of tACS in the Treatment of Anxious Arousal and Sensory Sensitivity</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Florida State University</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Florida State University</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      The present study seeks to evaluate the clinical utility of repeated transcranial alternating&#xD;
      current stimulation (tACS) by assessing long-term, lasting changes in oscillatory activity&#xD;
      and subsequent changes in related behavioral processes of anxious arousal and sensory&#xD;
      sensitivity. To date, only transient effects of tACS have been reported, lasting no longer&#xD;
      than 30 to 70 minutes. In order to be truly impactful within a clinical setting, however,&#xD;
      evidence for long-term effects of tACS is needed.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Recent years have witnessed increasing recognition of &quot;oscillopathies&quot;, neuropsychiatric&#xD;
      disorders characterized by aberrations in the neural oscillations that orchestrate various&#xD;
      mental activities. Transcranial alternating current stimulation (tACS) provides an effective&#xD;
      way to directly modulate these oscillations in a non-invasive and frequency-specific manner,&#xD;
      offering groundbreaking insights into the workings of the brain and, importantly, the&#xD;
      development of novel treatments for these oscillopathies. However, evidence is lacking for&#xD;
      the ability of tACS to induce long-term neural plasticity and lasting behavioral changes,&#xD;
      which is critical for establishing the clinical utility of this novel intervention.&#xD;
&#xD;
      Here, we are administering 30 minutes of alpha-frequency tACS over occipitoparietal sites for&#xD;
      four consecutive days to evaluate both transient and long-term changes in alpha oscillatory&#xD;
      power and long-range, directed oscillatory connectivity. As both anxious arousal and sensory&#xD;
      sensitivity are highly related to alpha oscillations, as well as numerous neuropsychiatric&#xD;
      disorders, changes in these behavioral outcomes were subsequently evaluated to assess&#xD;
      clinically-relevant outcomes of the repeated tACS protocol.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date type="Actual">July 29, 2016</start_date>
  <completion_date type="Actual">March 31, 2017</completion_date>
  <primary_completion_date type="Actual">March 31, 2017</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>Randomized</allocation>
    <intervention_model>Parallel Assignment</intervention_model>
    <intervention_model_description>Participants were randomly assigned to either an Active or Sham Control group. The Active group received the 30 minutes of alpha-tACS for four consecutive days, whereas the Sham Control group received Sham (no) stimulation.</intervention_model_description>
    <primary_purpose>Treatment</primary_purpose>
    <masking>Single (Participant)</masking>
    <masking_description>Participants were unaware of the presence of a Sham condition. Therefore, all participants believed they received the Active stimulation.</masking_description>
  </study_design_info>
  <primary_outcome>
    <measure>Immediate and lasting changes in alpha oscillatory power and directed, long-range cortico-cortical connectivity.</measure>
    <time_frame>Immediately before, immediately after, and 30 minutes after stimulation on the first day. Immediately before (24 hours after most recent stimulation), immediately after, and 30 minutes after stimulation on the final (fourth) day.</time_frame>
    <description>Occipitoparietal alpha power and long-range, directed oscillatory connectivity within the alpha frequency will be assessed from 2 minutes of eyes-open, resting-state electroencephalogram (EEG) activity. Oscillatory power will be estimated using the multitaper spectral estimation technique, averaging over the alpha frequency bin of 8-12 Hz. Directed connectivity will be assessed using spectral Granger causality within the 8-12 Hz range. Specifically, long-range, posterior-frontal connectivity with be assessed.</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Immediate and lasting reductions in anxious arousal</measure>
    <time_frame>Immediately before, immediately after, 30 minutes after stimulation on the first and final day. Immediately before (24 hours after most recent stimulation) and immediately after stimulation on the second and third days.</time_frame>
    <description>Self-report ratings of subjective units of anxious arousal are acquired using a visual analog scale, ranging from 0 (not at all anxiously aroused) to 100 (extremely anxiously aroused).</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Immediate and lasting changes in affective perception of sensory stimuli</measure>
    <time_frame>Immediately before, immediately after, and 30 minutes after stimulation on the first day. Immediately before (24 hours after most recent stimulation), immediately after, and 30 minutes after stimulation on the final (fourth) day.</time_frame>
    <description>Pleasantness ratings of neutral and negative olfactory and auditory stimuli are acquired on a visual analog scale, ranging from 0 (extremely unpleasant) to 100 (extremely pleasant). Auditory stimuli consist of a simple tone (neutral) and scream (negative) at three different intensities (quiet, medium, and loud), each presented once for 2 seconds through headphones. Olfactory stimuli consist of a neutral odor (acetophenone) and negative odor (burning rubber), diluted in mineral oil for three different intensities (weak, medium, strong). Approximately 3 mL of each odor are presented in 30 mL amber bottles, upon which participants are asked to take one steady sniff.</description>
  </secondary_outcome>
  <number_of_arms>2</number_of_arms>
  <enrollment type="Actual">38</enrollment>
  <condition>Anxiety Disorders and Symptoms</condition>
  <condition>Sensory Disorders</condition>
  <condition>Hypervigilance</condition>
  <condition>Post Traumatic Stress Disorder</condition>
  <arm_group>
    <arm_group_label>Active</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
    <description>Participants within the Active condition receive 30 minutes of alpha-frequency Transcranial Alternating Current Stimulation (tACS) stimulation for four consecutive days. Participants are stimulated at their baseline peak alpha frequency, or the frequency at which they exhibit maximal power within the 8 to 12 Hz range. Stimulation was administered over occipitoparietal sites, where tACS current models showed maximal effect over the dorsal extrastriate.</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Sham Control</arm_group_label>
    <arm_group_type>Sham Comparator</arm_group_type>
    <description>Participants within the Sham condition receive 30 minutes of sham Transcranial Alternating Current Stimulation for four consecutive days, during which no current was passed. To control for awareness of the Sham stimulation, all Sham control participants receive a brief, 10 second pulse of random noise stimulation at the beginning and end of the 30 minutes.</description>
  </arm_group>
  <intervention>
    <intervention_type>Device</intervention_type>
    <intervention_name>Transcranial Alternating Current Stimulation</intervention_name>
    <description>Transcranial Alternating Current Stimulation passes a weak, 2 mA sinusoidal current through the scalp to the cortex at a specified frequency. Previous evidence suggests this exogenous sinusoidal stimulation interacts with the endogenous, cortical sinusoidal oscillatory activity, resulting in modulations of cortical oscillations. The intervention is non-invasive and virtually painless with no lasting adverse side-effects.</description>
    <arm_group_label>Active</arm_group_label>
    <arm_group_label>Sham Control</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Right-handed&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  History of severe neurological disorder or traumatic brain injury&#xD;
&#xD;
          -  Psychotropic medication use&#xD;
&#xD;
          -  Metal plates/implants in head&#xD;
&#xD;
          -  Pregnancy&#xD;
&#xD;
          -  Implanted medical devices (e.x. pacemaker)&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>60 Years</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Wen Li, PhD</last_name>
    <role>Principal Investigator</role>
    <affiliation>Florida State University</affiliation>
  </overall_official>
  <verification_date>October 2017</verification_date>
  <study_first_submitted>October 4, 2017</study_first_submitted>
  <study_first_submitted_qc>October 4, 2017</study_first_submitted_qc>
  <study_first_posted type="Actual">October 9, 2017</study_first_posted>
  <last_update_submitted>October 4, 2017</last_update_submitted>
  <last_update_submitted_qc>October 4, 2017</last_update_submitted_qc>
  <last_update_posted type="Actual">October 9, 2017</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Florida State University</investigator_affiliation>
    <investigator_full_name>Wen Li</investigator_full_name>
    <investigator_title>Associate Professor</investigator_title>
  </responsible_party>
  <keyword>Oscillations</keyword>
  <keyword>Non-invasive Brain Stimulation</keyword>
  <keyword>Transcranial Alternating Current Stimulation</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Sensation Disorders</mesh_term>
    <mesh_term>Stress Disorders, Traumatic</mesh_term>
    <mesh_term>Anxiety Disorders</mesh_term>
    <mesh_term>Stress Disorders, Post-Traumatic</mesh_term>
  </condition_browse>
  <patient_data>
    <sharing_ipd>Undecided</sharing_ipd>
  </patient_data>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT03305328
org study id: 2017.20700
nct id: NCT03305328
lead sponsor: 
has dmc: No
is fda regulated drug: No
is fda regulated device: No
The present study seeks to evaluate the clinical utility of repeated transcranial alternating
      current stimulation (tACS) by assessing long-term, lasting changes in oscillatory activity
      and subsequent changes in related behavioral processes of anxious arousal and sensory
      sensitivity. To date, only transient effects of tACS have been reported, lasting no longer
      than 30 to 70 minutes. In order to be truly impactful within a clinical setting, however,
      evidence for long-term effects of tACS is needed.
Recent years have witnessed increasing recognition of "oscillopathies", neuropsychiatric
      disorders characterized by aberrations in the neural oscillations that orchestrate various
      mental activities. Transcranial alternating current stimulation (tACS) provides an effective
      way to directly modulate these oscillations in a non-invasive and frequency-specific manner,
      offering groundbreaking insights into the workings of the brain and, importantly, the
      development of novel treatments for these oscillopathies. However, evidence is lacking for
      the ability of tACS to induce long-term neural plasticity and lasting behavioral changes,
      which is critical for establishing the clinical utility of this novel intervention.

      Here, we are administering 30 minutes of alpha-frequency tACS over occipitoparietal sites for
      four consecutive days to evaluate both transient and long-term changes in alpha oscillatory
      power and long-range, directed oscillatory connectivity. As both anxious arousal and sensory
      sensitivity are highly related to alpha oscillations, as well as numerous neuropsychiatric
      disorders, changes in these behavioral outcomes were subsequently evaluated to assess
      clinically-relevant outcomes of the repeated tACS protocol.
allocation: Randomized
intervention model: Parallel Assignment
intervention model description: Participants were randomly assigned to either an Active or Sham Control group. The Active group received the 30 minutes of alpha-tACS for four consecutive days, whereas the Sham Control group received Sham (no) stimulation.
primary purpose: Treatment
masking: Single (Participant)
masking description: Participants were unaware of the presence of a Sham condition. Therefore, all participants believed they received the Active stimulation.
measure: Immediate and lasting changes in alpha oscillatory power and directed, long-range cortico-cortical connectivity.
time frame: Immediately before, immediately after, and 30 minutes after stimulation on the first day. Immediately before (24 hours after most recent stimulation), immediately after, and 30 minutes after stimulation on the final (fourth) day.
description: Occipitoparietal alpha power and long-range, directed oscillatory connectivity within the alpha frequency will be assessed from 2 minutes of eyes-open, resting-state electroencephalogram (EEG) activity. Oscillatory power will be estimated using the multitaper spectral estimation technique, averaging over the alpha frequency bin of 8-12 Hz. Directed connectivity will be assessed using spectral Granger causality within the 8-12 Hz range. Specifically, long-range, posterior-frontal connectivity with be assessed.
measure: Immediate and lasting reductions in anxious arousal
time frame: Immediately before, immediately after, 30 minutes after stimulation on the first and final day. Immediately before (24 hours after most recent stimulation) and immediately after stimulation on the second and third days.
description: Self-report ratings of subjective units of anxious arousal are acquired using a visual analog scale, ranging from 0 (not at all anxiously aroused) to 100 (extremely anxiously aroused).
measure: Immediate and lasting changes in affective perception of sensory stimuli
time frame: Immediately before, immediately after, and 30 minutes after stimulation on the first day. Immediately before (24 hours after most recent stimulation), immediately after, and 30 minutes after stimulation on the final (fourth) day.
description: Pleasantness ratings of neutral and negative olfactory and auditory stimuli are acquired on a visual analog scale, ranging from 0 (extremely unpleasant) to 100 (extremely pleasant). Auditory stimuli consist of a simple tone (neutral) and scream (negative) at three different intensities (quiet, medium, and loud), each presented once for 2 seconds through headphones. Olfactory stimuli consist of a neutral odor (acetophenone) and negative odor (burning rubber), diluted in mineral oil for three different intensities (weak, medium, strong). Approximately 3 mL of each odor are presented in 30 mL amber bottles, upon which participants are asked to take one steady sniff.
arm group label: Active
arm group type: Experimental
description: Participants within the Active condition receive 30 minutes of alpha-frequency Transcranial Alternating Current Stimulation (tACS) stimulation for four consecutive days. Participants are stimulated at their baseline peak alpha frequency, or the frequency at which they exhibit maximal power within the 8 to 12 Hz range. Stimulation was administered over occipitoparietal sites, where tACS current models showed maximal effect over the dorsal extrastriate.
arm group label: Sham Control
arm group type: Sham Comparator
description: Participants within the Sham condition receive 30 minutes of sham Transcranial Alternating Current Stimulation for four consecutive days, during which no current was passed. To control for awareness of the Sham stimulation, all Sham control participants receive a brief, 10 second pulse of random noise stimulation at the beginning and end of the 30 minutes.
intervention type: Device
intervention name: Transcranial Alternating Current Stimulation
description: Transcranial Alternating Current Stimulation passes a weak, 2 mA sinusoidal current through the scalp to the cortex at a specified frequency. Previous evidence suggests this exogenous sinusoidal stimulation interacts with the endogenous, cortical sinusoidal oscillatory activity, resulting in modulations of cortical oscillations. The intervention is non-invasive and virtually painless with no lasting adverse side-effects.
arm group label: Active
arm group label: Sham Control
criteria: 
gender: All
minimum age: 18 Years
maximum age: 60 Years
healthy volunteers: Accepts Healthy Volunteers
last name: Wen Li, PhD
role: Principal Investigator
affiliation: Florida State University
responsible party type: Principal Investigator
investigator affiliation: Florida State University
investigator full name: Wen Li
investigator title: Associate Professor
mesh term: Sensation Disorders
mesh term: Stress Disorders, Traumatic
mesh term: Anxiety Disorders
mesh term: Stress Disorders, Post-Traumatic
sharing ipd: Undecided