tDCS for Speech Impairment After Stroke

Overseen by Adam Buchwald, MD

Age: 18+

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Academic

Recruiting

Sponsor: NYU Langone Health

Disqualifiers: Laryngeal voice disorder, Dysarthria, others

No Placebo Group

Approved in 3 Jurisdictions

Trial Summary

What is the purpose of this trial?

This trial is testing whether combining a gentle brain stimulation technique called tDCS with regular speech therapy can better help people who have trouble speaking due to brain injury. tDCS uses a mild electrical current to help the brain learn and adapt, which has been successful in other types of stroke recovery. tDCS has been shown to be effective in improving language recovery in post-stroke aphasia.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What data supports the effectiveness of this treatment for speech impairment after stroke?

Research shows that combining transcranial direct current stimulation (tDCS) with speech-language therapy can improve speech in people with post-stroke aphasia, a condition affecting language skills. Studies found that tDCS helps enhance speech therapy outcomes, leading to better verbal performance and long-term improvements in speech tasks. ^{1 2 3 4 5}

Is transcranial direct current stimulation (tDCS) safe for humans?

Transcranial direct current stimulation (tDCS) is generally considered safe for humans, with no reports of serious adverse effects or irreversible injury in over 33,200 sessions across various populations, including potentially vulnerable groups like children, the elderly, and stroke patients. ^{6 7 8 9 10}

How does the tDCS treatment for speech impairment after stroke differ from other treatments?

The tDCS treatment is unique because it uses a low-intensity electrical current to stimulate the brain non-invasively, potentially enhancing the effects of traditional speech therapies and promoting long-term recovery of language skills in stroke patients. ^{2 3 11 12 13}

Research Team

Adam Buchwald, MD

Principal Investigator

NYU Langone Health

Eligibility Criteria

This trial is for right-handed, English-speaking individuals who have had a stroke at least six months ago and now have apraxia of speech. They must not have any voice disorders, other speech impairments from before the stroke, or risk factors that make tDCS unsafe like skin damage where the device goes, implants affected by electricity or magnets, metal inside their body, or a family history of epilepsy.

Inclusion Criteria

Monolingual (English)

I have been diagnosed with apraxia of speech.

You are right-handed.

Exclusion Criteria

I have had seizures or unexplained fainting spells.

I have been diagnosed with a voice disorder affecting my larynx.

I have damaged skin where the stimulation device would be placed.

Trial Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive behavioral treatment combined with tDCS, including both active and sham stimulation in a crossover design

6 months

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

Treatment Details

Interventions

• Sham (Behavioural Intervention)
• Soterix 1x1 line tDCS low-intensity stimulator (Non-invasive Brain Stimulation)

Trial Overview The study tests if adding brain stimulation with a Soterix low-intensity stimulator to regular speech therapy helps recovery in people with speech issues after a stroke. Some participants will get real stimulation (tDCS), while others receive sham treatment as a comparison; this is decided randomly.

Participant Groups

Group I: Active Stimulation Experimental Treatment 2 Interventions

crossover design such that each participant receives behavioral treatment twice - once with active stimulation and once with sham stimulation - in order to evaluate differences in improvement based on treatment condition.

Group II: Sham Stimulation Placebo Group 2 Interventions

crossover design such that each participant receives behavioral treatment twice - once with active stimulation and once with sham stimulation - in order to evaluate differences in improvement based on treatment condition.

Soterix 1x1 line tDCS low-intensity stimulator is already approved in Canada for the following indications:

Approved in Canada as tDCS for:

• Stroke rehabilitation
• Motor disorders
• Aphasia

Who Is Running the Clinical Trial?

NYU Langone Health

Lead Sponsor

Trials

1,431

Recruited

838,000+

Dr. Alec C. Kimmelman

NYU Langone Health

Chief Executive Officer

MD and PhD from Mount Sinai School of Medicine

Dr. Nicole M. Adler

NYU Langone Health

Chief Medical Officer since 2023

MD

National Institute on Deafness and Other Communication Disorders (NIDCD)

Collaborator

Trials

377

Recruited

190,000+

Joshua M. Levy

National Institute on Deafness and Other Communication Disorders (NIDCD)

Chief Medical Officer

MD, MPH, MS

Debara L. Tucci

National Institute on Deafness and Other Communication Disorders (NIDCD)

Chief Executive Officer since 2019

MD, MS, MBA

Findings from Research

In a study involving 10 patients with poststroke aphasia, bihemispheric transcranial direct current stimulation (tDCS) combined with speech-language therapy did not significantly improve spontaneous speech, as measured by the number of different nouns used in responses.

Despite the lack of improvement in spontaneous speech or other cognitive functions, the study reported no adverse events, suggesting that bihemispheric tDCS is safe for use in this patient population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Impact of Combined Transcranial Direct Current Stimulation and Speech-language Therapy on Spontaneous Speech in Aphasia: A Randomized Controlled Double-blind Study. Guillouët, E., Cogné, M., Saverot, E., et al.[2021]

A case study involving a child with cerebral palsy showed that combining transcranial direct current stimulation (tDCS) with integrative speech therapy led to significant improvements in speech, including an increase in the percentage of correct consonants and the ability to produce two- and three-syllable words.

The therapy involved two phases of tDCS targeting different brain areas, resulting in a notable increase in phoneme production, suggesting that tDCS can enhance the effectiveness of speech rehabilitation in children with speech impairments.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Neuromodulation: A combined-therapy protocol for speech rehabilitation in a child with cerebral palsy. Lima, VLCC., Cosmo, C., Lima, KB., 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]

Non-invasive brain stimulation techniques, particularly low-frequency rTMS and cathodal tDCS, can significantly improve naming accuracy in patients with post-stroke aphasia, as shown in a meta-analysis of nine trials with 215 participants, yielding a moderate effect size of 0.51.

The application of these techniques to the non-language dominant hemisphere may promote neural reorganization and reduce competition between brain hemispheres, suggesting a promising adjunct to conventional speech and language therapy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Inhibitory non-invasive brain stimulation to homologous language regions as an adjunct to speech and language therapy in post-stroke aphasia: a meta-analysis. Otal, B., Olma, MC., Flöel, A., et al.[2022]

Transcranial direct current stimulation (tDCS) applied to Broca's area showed significant improvements in speech recovery for three patients with stroke-induced aphasia over a 2-week period, particularly during intensive language training sessions.

All subjects demonstrated better performance in articulatory tasks with anodic tDCS compared to sham stimulation, and these improvements were maintained at follow-up assessments, indicating potential long-term benefits of tDCS in speech recovery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Electrical stimulation over the left inferior frontal gyrus (IFG) determines long-term effects in the recovery of speech apraxia in three chronic aphasics. Marangolo, P., Marinelli, CV., Bonifazi, S., et al.[2011]

Transcranial Direct Current Stimulation (tDCS) has been shown to be safe, with no reports of Serious Adverse Effects or irreversible injuries across over 33,200 sessions involving more than 1,000 subjects, including vulnerable populations.

Safety assessments indicate that the current densities used in conventional tDCS (≤4 milliamperes) are significantly lower than those that could potentially cause brain injury, suggesting that tDCS protocols are well within safe limits.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety of Transcranial Direct Current Stimulation: Evidence Based Update 2016. Bikson, M., Grossman, P., Thomas, C., et al.[2022]

The study involving 26 healthy subjects found that five sessions of anodal transcranial direct current stimulation (tDCS) delivered over 24 hours were safe, with no serious adverse events reported, although mild side effects occurred in 27% of participants.

While 50% of subjects showed a significant increase in motor cortex excitability (as measured by motor evoked potential amplitudes), the response varied among individuals, indicating that not everyone benefits equally from this treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety and effects on motor cortex excitability of five anodal transcranial direct current stimulation sessions in 24hours. Zappasodi, F., Musumeci, G., Navarra, R., et al.[2019]

Transcranial Direct Current Stimulation (tDCS) is generally considered safe, but there are concerns that it could lead to significant negative effects in healthy individuals.

The scientific community needs to be alerted about the potential risks of tDCS, emphasizing the importance of protecting healthy volunteers from possible harm.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety of transcranial direct current stimulation in healthy participants. Boccard-Binet, S., Sen, A.[2021]

A study involving 18 stroke patients found that a single session of transcranial direct current stimulation (tDCS) at currents up to 4 mA is safe and well-tolerated, with no major safety concerns reported.

While 50% of patients experienced mild, transient skin redness, there were no significant changes in skin temperature or body resistance, indicating that higher currents do not compromise skin integrity.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety and tolerability of transcranial direct current stimulation to stroke patients - A phase I current escalation study. Chhatbar, PY., Chen, R., Deardorff, R., et al.[2018]

Transcranial direct-current stimulation (tDCS) significantly improved articulatory accuracy in patients with aphasia after stroke, indicating its potential effectiveness in enhancing speech production.

While tDCS showed qualitative improvements in naming and syllable repetition tasks, these results were not statistically significant, suggesting that further research is needed to fully understand its impact.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of Anodal tDCS on Articulatory Accuracy, Word Production, and Syllable Repetition in Subjects with Aphasia: A Crossover, Double-Blinded, Sham-Controlled Trial. Vila-Nova, C., Lucena, PH., Lucena, R., et al.[2021]

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]

In a study involving 14 adults who stutter, high-definition transcranial direct current stimulation (HD-tDCS) was tested to see if it could improve speech fluency during synchronized reading, but no significant differences were found between active and sham stimulation.

However, the results indicated that for individuals with more severe stuttering, active stimulation reduced the abnormal brain activity associated with their condition, suggesting that HD-tDCS may have potential for enhancing fluency in stuttering and warrants further investigation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stuttering Severity Modulates Effects of Non-invasive Brain Stimulation in Adults Who Stutter. Garnett, EO., Chow, HM., Choo, AL., et al.[2020]

References

1. England pubmed.ncbi.nlm.nih.gov

Impact of Combined Transcranial Direct Current Stimulation and Speech-language Therapy on Spontaneous Speech in Aphasia: A Randomized Controlled Double-blind Study. [2021]

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

Neuromodulation: A combined-therapy protocol for speech rehabilitation in a child with cerebral palsy. [2022]

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

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

4. Switzerland pubmed.ncbi.nlm.nih.gov

Inhibitory non-invasive brain stimulation to homologous language regions as an adjunct to speech and language therapy in post-stroke aphasia: a meta-analysis. [2022]

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

Electrical stimulation over the left inferior frontal gyrus (IFG) determines long-term effects in the recovery of speech apraxia in three chronic aphasics. [2011]

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

Safety of Transcranial Direct Current Stimulation: Evidence Based Update 2016. [2022]

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

Tolerability and blinding of 4x1 high-definition transcranial direct current stimulation (HD-tDCS) at two and three milliamps. [2020]

8. France pubmed.ncbi.nlm.nih.gov

Safety and effects on motor cortex excitability of five anodal transcranial direct current stimulation sessions in 24hours. [2019]

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

Safety of transcranial direct current stimulation in healthy participants. [2021]

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

Safety and tolerability of transcranial direct current stimulation to stroke patients - A phase I current escalation study. [2018]

11. New Zealand pubmed.ncbi.nlm.nih.gov

Effect of Anodal tDCS on Articulatory Accuracy, Word Production, and Syllable Repetition in Subjects with Aphasia: A Crossover, Double-Blinded, Sham-Controlled Trial. [2021]

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

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

13. Switzerland pubmed.ncbi.nlm.nih.gov

Stuttering Severity Modulates Effects of Non-invasive Brain Stimulation in Adults Who Stutter. [2020]