Assessing the Clinical Utility of tACS

NCT ID: NCT03305328

Last Updated: 2017-10-09

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 38 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2016-07-29
• Study Completion Date: 2017-03-31

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.

Conditions

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

Keywords

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

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

Active

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.

Group Type: EXPERIMENTAL

Transcranial Alternating Current Stimulation

Intervention Type: 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.

Sham Control

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.

Group Type: SHAM_COMPARATOR

Transcranial Alternating Current Stimulation

Intervention Type: 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.

Interventions

Transcranial Alternating Current Stimulation

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.

Intervention Type: DEVICE

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)

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 60 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Florida State University

OTHER

Sponsor Role: lead

Responsible Party

Wen Li

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Wen Li, PhD

Role: PRINCIPAL_INVESTIGATOR

Florida State University

Other Identifiers

2017.20700

Identifier Type: -

Identifier Source: org_study_id