tDCS + Speech Therapy for Aphasia

Recruiting at 1 trial location

Overseen By E. Susan Duncan, PhD, CCC-SLP

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Louisiana State University and A&M College

Disqualifiers: Seizure history, Pregnancy, Pacemaker, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 21

Duration: 8 weeks

30 Participants Needed

Trial Summary

What is the purpose of this trial?

The purpose of this study is to assess changes in language abilities of participants with chronic, post-stroke aphasia following an 8-week therapy period combined with brain stimulation. The investigators use a stimulation method called transcranial direct current stimulation (tDCS). The investigators cover two electrodes in damp sponges, place them on the scalp, and pass a weak electrical current between them. Some of this current passes through the brain and can change brain activity. One electrode is placed over language areas a bit above and in front of the left ear. The other is placed on the forehead above the right eye. Stimulation is provided twice a week for 8 weeks during aphasia therapy. The investigators believe that this stimulation may increase the effectiveness of therapy.

Do I have to stop taking my current medications for the trial?

The trial protocol does not specify whether you need to stop taking your current medications. However, if you have a history of seizures or have changed seizure medication in the past 12 months, you may be excluded from participating.

What data supports the effectiveness of the treatment tDCS + Speech Therapy for Aphasia?

Research suggests that combining transcranial direct current stimulation (tDCS) with speech therapy can improve language skills in people with aphasia after a stroke, especially when applied early in rehabilitation. This combination seems to enhance brain activity and language performance more effectively than speech therapy alone. ^{1 2 3 4 5}

Is tDCS combined with speech therapy safe for humans?

Transcranial direct current stimulation (tDCS) combined with speech therapy is generally considered safe for humans, as studies have shown no serious adverse events during treatment sessions. ^{6 7 8 9 10}

How does the tDCS + Speech Therapy treatment for aphasia differ from other treatments?

The tDCS + Speech Therapy treatment is unique because it combines traditional speech therapy with transcranial direct current stimulation (tDCS), a non-invasive method that uses a low-intensity electrical current to stimulate the brain and potentially enhance language recovery in stroke patients with aphasia. ^{6 8 10 11 12}

Research Team

E. Susan Duncan, PhD, CCC-SLP

Principal Investigator

City University of New York

Eligibility Criteria

This trial is for right-handed, English-speaking adults with a high school education who had a single-event left hemisphere stroke over 6 months ago and have chronic aphasia. They must not be receiving other speech therapies during the study or have any conditions that would interfere with MRI scans, such as metal implants or pregnancy.

Inclusion Criteria

I can do the tasks needed for therapy, even with my speech difficulties.

High school education or equivalent

I can do the speaking and MRI tasks needed for the study.

Exclusion Criteria

I haven't had seizures or changed seizure medication in the last year.

You have a hairstyle that prevents electrodes from touching your scalp.

Failed vision or hearing screening

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person), 1 visit (virtual)

Pre-Treatment Assessment

Participants complete behavioral assessments and brain scans before therapy

4 weeks

2 visits (in-person)

Treatment

Participants receive tDCS and aphasia therapy for 8 weeks

8 weeks

16 visits (in-person)

Post-Treatment Assessment

Behavioral assessments and brain scans are conducted immediately after therapy

1 week

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

8 weeks

1 visit (in-person)

Treatment Details

Interventions

• Anodal transcranial direct current stimulation
• Sham transcranial direct current stimulation
• Speech-Language Therapy (SLT)

Trial Overview The study tests if brain stimulation using transcranial direct current stimulation (tDCS) can improve language abilities in people with post-stroke aphasia when combined with verb network strengthening treatment (VNeST). Participants receive weak electrical currents to their scalp twice weekly for 8 weeks during speech therapy sessions.

Participant Groups

Group I: A-tDCS & speech-language therapy Experimental Treatment 2 Interventions

Anodal transcranial direct current stimulation (2 milliamps \[mA\]) plus aphasia therapy for 16 sessions (20-minutes per each 60-minute treatment session) over the course of 8 weeks. The electrical current will be administered over ventral inferior frontal gyrus. The stimulation will be delivered at an intensity of 2 milliamps (mA) for a maximum of 20 minutes.

Group II: Sham-tDCS & speech-language therapy Placebo Group 2 Interventions

Sham transcranial direct current stimulation (2 milliamps \[mA\]) plus aphasia therapy for 16 sessions (20-minutes per each 60-minute treatment session) over the course of 8 weeks. Electrodes will be placed as in A-tDCS. Current will be ramped up for the first 30 seconds following which the intensity will drop to 0 milliamps (mA).

Who Is Running the Clinical Trial?

Louisiana State University and A&M College

Lead Sponsor

Trials

12

Recruited

1,100+

City University of New York

Lead Sponsor

Trials

23

Recruited

6,000+

Findings from Research

In a study of 37 stroke patients, speech therapy combined with transcranial direct current stimulation (tDCS) significantly improved language function, with an average increase in aphasia quotient (AQ%) of 14.94% after treatment.

Patients with less severe, fluent types of aphasia who started treatment within 30 days of their stroke showed the best responses, and those with hemorrhagic strokes had a higher likelihood of improvement compared to those with infarctions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Factors Associated with Good Responses to Speech Therapy Combined with Transcranial Direct Current Stimulation in Post-stroke Aphasic Patients. Jung, IY., Lim, JY., Kang, EK., et al.[2021]

In a study involving 11 chronic stroke patients with aphasia, dual transcranial direct current stimulation (tDCS) showed a significant improvement in naming response times compared to baseline, suggesting enhanced efficacy over single tDCS.

Both single and dual tDCS improved the number of correct responses in naming tasks, but dual tDCS, which targeted both the left and right inferior frontal gyri, may offer greater benefits for language recovery in stroke patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of dual transcranial direct current stimulation for aphasia in chronic stroke patients. Lee, SY., Cheon, HJ., Yoon, KJ., et al.[2021]

Transcranial direct current stimulation (tDCS) combined with language training showed improved verb production in a 43-year-old male with fluent-anomic aphasia after a stroke, suggesting enhanced language recovery.

The study indicates that using tDCS over Broca's area during language therapy may effectively support brain plasticity and improve language skills in individuals with aphasia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Translational treatment of aphasia combining neuromodulation and behavioral intervention for lexical retrieval: implications from a single case study. Galletta, EE., Vogel-Eyny, A.[2020]

In a study involving 37 participants with moderate to severe aphasia, repeated anodal transcranial direct current stimulation (A-tDCS) did not show a significant positive impact on language recovery when combined with language therapy, compared to a sham stimulation group.

Both groups showed improvement in language abilities after therapy, but there were no statistically significant differences in outcomes between the A-tDCS and control groups, indicating that A-tDCS may not provide functional benefits in early post-stroke rehabilitation for aphasia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

No effects of anodal transcranial direct stimulation on language abilities in early rehabilitation of post-stroke aphasic patients. Polanowska, KE., Leśniak, M., Seniów, JB., et al.[2019]

In a study involving 24 patients with non-fluent aphasia, both anodal transcranial direct current stimulation (A-tDCS) and sham stimulation (S-tDCS) combined with speech and language therapy (SLT) led to significant improvements in naming ability, indicating that therapy itself is beneficial.

While the A-tDCS group showed higher effect sizes in naming time post-treatment and at the 3-month follow-up, the overall evidence for A-tDCS providing additional language gains was weak, suggesting that more research is needed to confirm its effectiveness in early post-stroke rehabilitation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Anodal transcranial direct current stimulation in early rehabilitation of patients with post-stroke non-fluent aphasia: a randomized, double-blind, sham-controlled pilot study. Polanowska, KE., Leśniak, MM., Seniów, JB., et al.[2016]

A systematic review of five trials with 54 participants found no evidence that transcranial direct current stimulation (tDCS) improves speech and language therapy outcomes for stroke patients with aphasia.

While no adverse events were reported, the studies primarily measured picture naming rather than real-life communication, and cathodal tDCS over the non-lesioned hemisphere showed potential as a promising approach.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation (tDCS) for improving aphasia in patients after stroke. Elsner, B., Kugler, J., Pohl, M., et al.[2022]

Transcranial direct current stimulation (tDCS) combined with speech and language treatment (SLT) is safe for stroke survivors with aphasia, showing no serious adverse events during a six-week treatment involving 30 sessions.

Participants receiving active tDCS exhibited greater improvements in functional language compared to those receiving sham treatment, suggesting that tDCS may enhance the effectiveness of SLT, although the superiority of one stimulation polarity over another remains unclear.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Extended fMRI-Guided Anodal and Cathodal Transcranial Direct Current Stimulation Targeting Perilesional Areas in Post-Stroke Aphasia: A Pilot Randomized Clinical Trial. Cherney, LR., Babbitt, EM., Wang, X., et al.[2021]

A systematic review of 21 trials involving 421 participants found no evidence that transcranial direct current stimulation (tDCS) improves functional communication in people with aphasia after stroke, indicating low effectiveness for this purpose.

However, there is moderate evidence that tDCS may enhance noun naming accuracy, suggesting it could have some benefits in specific language tasks, although it did not show similar effects for verb naming.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation (tDCS) for improving aphasia in adults with aphasia after stroke. Elsner, B., Kugler, J., Pohl, M., et al.[2023]

In a study involving 10 individuals undergoing standard aphasia therapy, 70% expressed interest in and were eligible for transcranial direct current stimulation (tDCS), which was administered during therapy sessions.

Data from four participants showed a large effect size (Cohen's d = 1.32) favoring active tDCS over sham stimulation, suggesting that tDCS may enhance communication outcomes in aphasia therapy, although one participant with severe deficits did not benefit.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Clinical Feasibility of Combining Transcranial Direct Current Stimulation with Standard Aphasia Therapy. Duncan, ES., Nakkawita, SG.[2022]

A systematic review of 12 trials involving 136 participants found no evidence that transcranial direct current stimulation (tDCS) improves functional communication or language impairment in stroke patients with aphasia.

The meta-analysis of six trials indicated that tDCS did not significantly enhance outcomes in picture naming tasks, suggesting that it may not be an effective adjunct to speech and language therapy for aphasia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation (tDCS) for improving aphasia in patients with aphasia after stroke. Elsner, B., Kugler, J., Pohl, M., et al.[2022]

Transcranial direct current stimulation (tDCS) applied to the left inferior frontal gyrus significantly improved language abilities in patients with nonfluent poststroke aphasia when combined with speech language therapy, as shown by a higher Aphasia Quotient in the A-tDCS group compared to the sham group (72.99 vs. 46.18).

The study involved 18 patients over four weeks, with results indicating that tDCS enhances the effectiveness of speech language therapy, particularly in areas other than comprehension, suggesting a beneficial mechanism of action for language recovery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of Anodic Transcranial Direct Current Stimulation Combined With Speech Language Therapy on Nonfluent Poststroke Aphasia. Zhao, Q., Wang, J., Li, Z., et al.[2022]

Transcranial direct current stimulation (tDCS) shows promise as an adjuvant treatment for improving speech production in chronic stroke patients with aphasia, based on preliminary evidence.

Further research is needed to fully understand how tDCS works, its optimal application in language rehabilitation, and how it interacts with existing therapies to enhance long-term recovery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Can tDCS enhance treatment of aphasia after stroke? Holland, R., Crinion, J.[2022]

References

1. Korea (South) pubmed.ncbi.nlm.nih.gov

The Factors Associated with Good Responses to Speech Therapy Combined with Transcranial Direct Current Stimulation in Post-stroke Aphasic Patients. [2021]

2. Korea (South) pubmed.ncbi.nlm.nih.gov

Effects of dual transcranial direct current stimulation for aphasia in chronic stroke patients. [2021]

3. Switzerland pubmed.ncbi.nlm.nih.gov

Translational treatment of aphasia combining neuromodulation and behavioral intervention for lexical retrieval: implications from a single case study. [2020]

4. Poland pubmed.ncbi.nlm.nih.gov

No effects of anodal transcranial direct stimulation on language abilities in early rehabilitation of post-stroke aphasic patients. [2019]

5. Netherlands pubmed.ncbi.nlm.nih.gov

Anodal transcranial direct current stimulation in early rehabilitation of patients with post-stroke non-fluent aphasia: a randomized, double-blind, sham-controlled pilot study. [2016]

6. England pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation (tDCS) for improving aphasia in patients after stroke. [2022]

7. Switzerland pubmed.ncbi.nlm.nih.gov

Extended fMRI-Guided Anodal and Cathodal Transcranial Direct Current Stimulation Targeting Perilesional Areas in Post-Stroke Aphasia: A Pilot Randomized Clinical Trial. [2021]

8. England pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation (tDCS) for improving aphasia in adults with aphasia after stroke. [2023]

9. India pubmed.ncbi.nlm.nih.gov

Clinical Feasibility of Combining Transcranial Direct Current Stimulation with Standard Aphasia Therapy. [2022]

10. England pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation (tDCS) for improving aphasia in patients with aphasia after stroke. [2022]

11. United States pubmed.ncbi.nlm.nih.gov

Effect of Anodic Transcranial Direct Current Stimulation Combined With Speech Language Therapy on Nonfluent Poststroke Aphasia. [2022]

12. England pubmed.ncbi.nlm.nih.gov

Can tDCS enhance treatment of aphasia after stroke? [2022]