Assessing the Clinical Utility of tACS

NCT03305328 | Completed

• 1 other identifier: 2017.20700
• Study Type: interventional
• Target: 38
• Locations: 0 countries
• Sites: N/A

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.

Conditions

Anxiety Disorders and Symptoms; Sensory Disorders; Hypervigilance; Post Traumatic Stress Disorder

Keywords

Oscillations; Non-invasive Brain Stimulation; Transcranial Alternating Current Stimulation

Outcome Measures

Primary Outcomes (1)

• 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.

  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 Outcomes (2)

• Immediate and lasting reductions in anxious arousal

  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.

• Immediate and lasting changes in affective perception of sensory stimuli

  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.

Study Arms (2)

Active

EXPERIMENTAL

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.

Device: Transcranial Alternating Current Stimulation

Sham Control

SHAM COMPARATOR

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.

Device: Transcranial Alternating Current Stimulation

Interventions

Transcranial Alternating Current Stimulation DEVICE

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.

Active; Sham Control

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Right-handed

You may not qualify if:

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

Sponsors & Collaborators

• Florida State University: lead

MeSH Terms

Conditions

Anxiety Disorders; Sensation Disorders; Stress Disorders, Post-Traumatic

Interventions

Transcranial Direct Current Stimulation

Condition Hierarchy (Ancestors)

Mental Disorders; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Stress Disorders, Traumatic; Trauma and Stressor Related Disorders

Intervention Hierarchy (Ancestors)

Electric Stimulation Therapy; Therapeutics; Convulsive Therapy; Psychiatric Somatic Therapies; Behavioral Disciplines and Activities; Electroshock; Psychological Techniques

Study Officials

• Wen Li, PhD

  Florida State University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Participants were unaware of the presence of a Sham condition. Therefore, all participants believed they received the Active stimulation.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Model Details: 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.

Study Record Dates

• First Submitted: October 4, 2017
• First Posted: October 9, 2017
• Study Start: July 29, 2016
• Primary Completion: March 31, 2017
• Study Completion: March 31, 2017
• Last Updated: October 9, 2017

Record last verified: 2017-10