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Assessing the Clinical Utility of tACS

Primary Purpose

Anxiety Disorders and Symptoms, Sensory Disorders, Hypervigilance

Status
Completed
Phase
Not Applicable
Locations
Study Type
Interventional
Intervention
Transcranial Alternating Current Stimulation
Sponsored by
Florida State University
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional treatment trial for Anxiety Disorders and Symptoms focused on measuring Oscillations, Non-invasive Brain Stimulation, Transcranial Alternating Current Stimulation

Eligibility Criteria

18 Years - 60 Years (Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria:

  • Right-handed

Exclusion Criteria:

  • History of severe neurological disorder or traumatic brain injury
  • Psychotropic medication use
  • Metal plates/implants in head
  • Pregnancy
  • Implanted medical devices (e.x. pacemaker)

Sites / Locations

    Arms of the Study

    Arm 1

    Arm 2

    Arm Type

    Experimental

    Sham Comparator

    Arm Label

    Active

    Sham Control

    Arm 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.

    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.

    Outcomes

    Primary Outcome Measures

    Immediate and lasting changes in alpha oscillatory power and directed, long-range cortico-cortical connectivity.
    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.

    Secondary Outcome Measures

    Immediate and lasting reductions in anxious arousal
    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).
    Immediate and lasting changes in affective perception of sensory stimuli
    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.

    Full Information

    First Posted
    October 4, 2017
    Last Updated
    October 4, 2017
    Sponsor
    Florida State University
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    1. Study Identification

    Unique Protocol Identification Number
    NCT03305328
    Brief Title
    Assessing the Clinical Utility of tACS
    Official Title
    Assessing the Clinical Utility of tACS in the Treatment of Anxious Arousal and Sensory Sensitivity
    Study Type
    Interventional

    2. Study Status

    Record Verification Date
    October 2017
    Overall Recruitment Status
    Completed
    Study Start Date
    July 29, 2016 (Actual)
    Primary Completion Date
    March 31, 2017 (Actual)
    Study Completion Date
    March 31, 2017 (Actual)

    3. Sponsor/Collaborators

    Responsible Party, by Official Title
    Principal Investigator
    Name of the Sponsor
    Florida State University

    4. Oversight

    Studies a U.S. FDA-regulated Drug Product
    No
    Studies a U.S. FDA-regulated Device Product
    No
    Data Monitoring Committee
    No

    5. Study Description

    Brief Summary
    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.
    Detailed Description
    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.

    6. Conditions and Keywords

    Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
    Anxiety Disorders and Symptoms, Sensory Disorders, Hypervigilance, Post Traumatic Stress Disorder
    Keywords
    Oscillations, Non-invasive Brain Stimulation, Transcranial Alternating Current Stimulation

    7. Study Design

    Primary Purpose
    Treatment
    Study Phase
    Not Applicable
    Interventional Study Model
    Parallel Assignment
    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.
    Masking
    Participant
    Masking Description
    Participants were unaware of the presence of a Sham condition. Therefore, all participants believed they received the Active stimulation.
    Allocation
    Randomized
    Enrollment
    38 (Actual)

    8. Arms, Groups, and Interventions

    Arm Title
    Active
    Arm Type
    Experimental
    Arm 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 Title
    Sham Control
    Arm Type
    Sham Comparator
    Arm 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(s)
    Transcranial Alternating Current Stimulation
    Intervention 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.
    Primary Outcome Measure Information:
    Title
    Immediate and lasting changes in alpha oscillatory power and directed, long-range cortico-cortical connectivity.
    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.
    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.
    Secondary Outcome Measure Information:
    Title
    Immediate and lasting reductions in anxious arousal
    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).
    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.
    Title
    Immediate and lasting changes in affective perception of sensory stimuli
    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.
    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.

    10. Eligibility

    Sex
    All
    Minimum Age & Unit of Time
    18 Years
    Maximum Age & Unit of Time
    60 Years
    Accepts Healthy Volunteers
    Accepts Healthy Volunteers
    Eligibility Criteria
    Inclusion Criteria: Right-handed Exclusion Criteria: History of severe neurological disorder or traumatic brain injury Psychotropic medication use Metal plates/implants in head Pregnancy Implanted medical devices (e.x. pacemaker)
    Overall Study Officials:
    First Name & Middle Initial & Last Name & Degree
    Wen Li, PhD
    Organizational Affiliation
    Florida State University
    Official's Role
    Principal Investigator

    12. IPD Sharing Statement

    Plan to Share IPD
    Undecided

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