Assessing the Clinical Utility of tACS

Florida State University

Status: Completed

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

Treatments: Device: Transcranial Alternating Current Stimulation

Study type: Interventional

Funder types: Other

Identifiers

NCT03305328

2017.20700

Details and patient eligibility

About

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.

Full 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.

Enrollment: 38 patients

Sex: All

Ages: 18 to 60 years old

Volunteers: Accepts 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)

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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38 participants in 2 patient groups

Active

Experimental group

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.

Treatment:

Device: Transcranial Alternating Current Stimulation

Sham Control

Sham Comparator group

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.

Treatment:

Device: Transcranial Alternating Current Stimulation