tACS to Enhance Language Abilities

Transcranial Alternating Current Stimulation (tACS) to Enhance Language Abilities

The goal of this study is to see if transcranial alternating current stimulation (tACS) can be used to enhance language abilities in people with post-stroke aphasia. Participants will receive real and sham tACS in conjunction with various language tests. Researchers will compare the post-stroke aphasia group with aged matched controls to see if brain response to tACS differs between groups.

Study Overview

• Status: Recruiting
• Conditions: Stroke; Aphasia; Aphasia, Acquired
• Intervention / Treatment: Device: Active transcranial alternating current stimulation (tACS)

Detailed Description

This research will investigate whether transcranial alternating current stimulation (tACS), a form of noninvasive brain stimulation, can be used to enhance language abilities in people with aphasia (PWA) due to stroke and healthy older adults when compared to placebo (sham) tACS. The investigators hypothesize that alpha vs. sham tACS will improve language abilities. In addition, the investigators propose that alpha vs. sham tACS will increase local alpha power as well as alpha-induced functional connectivity, and the degree to which alpha tACS increases will be related to the degree of language performance improvement. Finally, the investigators hypothesize that PWA will exhibit abnormalities in alpha-related activity when compared to matched controls, and aphasia severity will be associated with the degree of PWA dysfunction in alpha power and alpha-driven functional connectivity.

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Daniela Sacchetti, MS; Phone Number: 215 573 4336; Email: danielas@pennmedicine.upenn.edu
• Study Contact Backup: Name: Denise Harvey, PhD; Phone Number: 215 573 4336; Email: harveyde@pennmedicine.upenn.edu

Study Locations

• United States
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104
      • Recruiting
      • University of Pennsylvania
      • Contact: Daniela Sacchetti, MS; Phone Number: 215 573 4336; Email: danielas@pennmedicine.upenn.edu
      • Contact: Denise Harvey, PhD; Phone Number: 215-573-4336; Email: harveyde@pennmedicine.upenn.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria for Persons with Aphasia:

1. Presence of aphasia
2. Suffered a single, left hemisphere stroke
3. Stroke ≥6 months old (chronic) at the time of enrollment

Inclusion Criteria for Healthy Controls:

1. Right-handedness
2. Must be able to understand the nature of the study, and give informed consent

Exclusion criteria for Persons with Aphasia:

1. Inability to understand the nature of the study
2. Marked naming impairment
3. Impaired non-verbal, conceptual processing
4. History of significant medical or neurological disorder (other than stroke)
5. History of significant or poorly controlled psychiatric disorders
6. Current abuse of alcohol or drugs, prescription or otherwise
7. Nursing a child, pregnancy, or intent to become pregnant during the study
8. Clinically significant hearing loss
9. Contraindications to tACS
10. Contraindications to MRI

Exclusion Criteria for Healthy Controls

1. Diagnosis of a neurodegenerative disease or clinically significant cognitive complaint
2. Any unrelated neurologic or physical condition that impairs communication ability
3. History of unrelated neurological conditions including but not limited to traumatic brain injury, stroke, or small vessel disease that has resulted in a neurologic deficit
4. Any additional neurological condition that would likely reduce the safety of study participation, including central nervous system (CNS) vasculitis, intracranial tumor, intracranial aneurysm, multiple sclerosis or arteriovenous malformations
5. A medically unstable cardiopulmonary or metabolic disorder
6. Terminal illness associated with survival <12 months
7. Major active psychiatric illness that may interfere with required study procedures or treatments as determined by the enrolling physician
8. Current abuse of alcohol or drugs, prescription or otherwise
9. Contraindications to tACS
10. Contraindications to MRI

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: real-tACS; The active stimulation will consist of an alternating current delivered in the alpha frequency band with a peak-to-peak intensity of 4 milliamps (mA) for 20 minutes. Participants will complete sentence completion and verb generation task during stimulation.	Device: Active transcranial alternating current stimulation (tACS); Transcranial Alternating Current Stimulation (tACS) is a device that applies a low-intensity electrical current to the brain through electrodes on the scalp.; Other Names: Sham transcranial alternating current stimulation [(ACS)
Placebo Comparator: sham-tACS; Sham stimulation involves the delivery of 60 seconds of the actual stimulation waveform ("ramp up") which is then gradually reduced to 0 milliamps (mA) ("ramp down"). Participants will complete sentence completion and verb generation task during stimulation.	Device: Active transcranial alternating current stimulation (tACS); Transcranial Alternating Current Stimulation (tACS) is a device that applies a low-intensity electrical current to the brain through electrodes on the scalp.; Other Names: Sham transcranial alternating current stimulation [(ACS)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Performance on the Blocked-Cyclic Naming (BCN) Task	The BCN tasks involves naming a set of pictures repeatedly. Sets of pictures come from either the same semantic category (high competition condition; e.g., categorically related: "dog", "cat", "panda") or different semantic categories (low competition condition; e.g., unrelated: dog, eye, crib).	5-10 minutes after a single session of active (alpha tACS) and sham (fake tACS).

Collaborators and Investigators

• Sponsor: University of Pennsylvania

Study record dates

Study Major Dates

• Study Start (Actual): July 12, 2024
• Primary Completion (Estimated): August 31, 2028
• Study Completion (Estimated): August 31, 2028

Study Registration Dates

• First Submitted: September 28, 2023
• First Submitted That Met QC Criteria: October 17, 2023
• First Posted (Actual): October 23, 2023

Study Record Updates

• Last Update Posted (Actual): August 8, 2025
• Last Update Submitted That Met QC Criteria: August 4, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: EEG; non-invasive brain stimulation; transcranial alternating current stimulation (tACS)
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Neurobehavioral Manifestations; Communication Disorders; Language Disorders; Speech Disorders; Aphasia
• Other Study ID Numbers: 854139

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No