Cerebellar tDCS + Language Therapy for Aphasia

(CeSAR Trial)

Recruiting at 1 trial location

Overseen By Becky Lammers, MS

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Johns Hopkins University

Must not be taking: Seizure threshold reducers, NMDA antagonists

Disqualifiers: Right cerebellum lesion, Seizures, others

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

Compensation: Varies

Number of Visits: 16

Duration: 3-5 weeks

60 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores a new method to help people regain language skills after a stroke. It combines brain stimulation, known as cerebellar tDCS (a gentle electrical treatment), with language therapy to determine if this enhances recovery from aphasia (difficulty with speech and understanding language). Participants will receive either the actual treatment or a placebo, both paired with naming exercises. The trial seeks individuals who have experienced a stroke causing aphasia and naming issues, are fluent in English, and have lived with these conditions for at least six months. As an unphased trial, this study offers participants the chance to contribute to groundbreaking research that could improve recovery options for stroke survivors.

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

You may need to stop taking certain medications, especially those that lower the seizure threshold or NMDA antagonists, as they are listed in the exclusion criteria.

What prior data suggests that cerebellar tDCS is safe for post-stroke aphasia therapy?

Research has shown that cerebellar cathodal transcranial direct current stimulation (tDCS) is generally safe for people. In earlier studies, participants who received this treatment often noticed only slight improvements in language or quality of life. Importantly, these studies did not find any serious side effects or negative reactions. This suggests that the treatment is safe, although its effectiveness in improving language can vary.

Since this trial is studying cerebellar tDCS, a method previously tested, the safety profile is likely similar to past studies. Participants can feel reassured that this treatment has been tested and is considered safe for humans. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about cathodal cerebellar tDCS for aphasia because it offers a new approach to improving language function. Unlike traditional speech therapy alone, this treatment combines non-invasive brain stimulation with Semantic Feature Analysis (SFA) to potentially enhance speech recovery. The treatment specifically targets the right cerebellum with electrical currents to help retrain the brain's language pathways, which could lead to more effective results in a shorter timeframe. This innovative combination could provide new hope for those with aphasia by accelerating and amplifying the benefits of standard speech therapy.

What evidence suggests that cerebellar tDCS is effective for aphasia?

This trial will compare the effects of cathodal cerebellar transcranial direct current stimulation (tDCS) combined with Semantic Feature Analysis (SFA) naming treatment to a sham version of the same treatment. Studies have shown that cathodal cerebellar tDCS, when paired with speech therapy, can help people with post-stroke aphasia improve their language skills. This treatment appears to ease everyday conversations. Some research suggests that while overall language abilities might not change significantly, certain aspects of quality of life could improve. In simple terms, people may find it easier to express themselves in daily life. Early evidence supports the idea that this approach can be a helpful addition to language therapy for aphasia recovery. ^{1 2 4 6 7}

Who Is on the Research Team?

Rajani Sebastian, PhD

Principal Investigator

Johns Hopkins University

Are You a Good Fit for This Trial?

This trial is for English-speaking adults over 18 who had a stroke in the left hemisphere of their brain at least 6 months ago, resulting in aphasia and difficulty naming things. They must have been right-handed before the stroke. People with cerebellum damage, other neurological or psychiatric disorders, recent seizures, severe sensory loss, certain medication use, high baseline naming test scores, metal in their head or body implants are excluded.

Inclusion Criteria

Fluent speaker of English by self-report

I had a stroke in the left side of my brain.

It has been at least 6 months since my stroke.

Exclusion Criteria

I have had brain surgery or have metal in my head.

Individuals with severe claustrophobia, cardiac pacemakers or ferromagnetic implants, and pregnant women will be excluded from the MRI portion of the study.

I am taking medication that could increase my risk of seizures.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive 15 sessions of cerebellar tDCS combined with Semantic Feature Analysis (SFA) over 3-5 weeks

3-5 weeks

15 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

6 months

Follow-up assessments at 1 week, 1 month, 3 months, and 6 months post-treatment

What Are the Treatments Tested in This Trial?

Interventions

• Cathodal Cerebellar tDCS

Trial Overview The study tests if cerebellar tDCS—a non-invasive brain stimulation—combined with language therapy (Semantic Feature Analysis) helps people recover from post-stroke aphasia better than sham (fake) treatment. It also aims to identify which patients might benefit most from this approach.

How Is the Trial Designed?

Group I: Cathodal Cerebellar tDCS and SFA Active Control 2 Interventions

Cathodal cerebellar tDCS, 2 milliamp (mA) plus Semantic Feature Analysis (SFA) naming treatment for 15 sessions (25-minutes per each 60-minute treatment session) over the course of 3-5 weeks. The electrical current will be administered to the right cerebellum. The stimulation will be delivered at an intensity of 2 mA for a maximum of 25 minutes. SFA will be delivered by a Speech and Language Pathologist to improve naming

Group II: Sham Cerebellar tDCS and SFA Placebo Group 2 Interventions

Sham cerebellar tDCS plus SFA for 15 sessions (25-minutes per each 60-minute treatment session) over the course of 3-5 weeks. Current will be administered in a ramp-like fashion, but after the ramping, the intensity will drop to 0 mA. SFA will be delivered by a Speech and Language Pathologist to improve naming.

Who Is Running the Clinical Trial?

Johns Hopkins University

Lead Sponsor

Trials

2,366

Recruited

15,160,000+

National Institute on Deafness and Other Communication Disorders (NIDCD)

Collaborator

Trials

377

Recruited

190,000+

Published Research Related to This Trial

Transcranial direct current stimulation of the right cerebellum, combined with computerized aphasia therapy, significantly improved untrained naming skills in individuals with chronic aphasia, with effects lasting up to two months post-treatment.

Participants receiving cathodal stimulation showed greater improvements in both trained and untrained naming tasks compared to sham stimulation, suggesting that targeting the right cerebellum may be an effective strategy for aphasia rehabilitation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Cerebellar neuromodulation improves naming in post-stroke aphasia. Sebastian, R., Kim, JH., Brenowitz, R., et al.[2023]

Cerebellar transcranial direct current stimulation (tDCS) significantly improved verb generation in 12 aphasic individuals, suggesting its potential as a tool for language recovery when cognitive strategies are involved.

The study found no significant improvement in verb naming tasks, indicating that the effectiveness of cerebellar tDCS may depend on the specific language task and its cognitive demands.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial Cerebellar Direct Current Stimulation Enhances Verb Generation but Not Verb Naming in Poststroke Aphasia. Marangolo, P., Fiori, V., Caltagirone, C., et al.[2018]

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]

In a study involving eight chronic non-fluent post-stroke aphasic patients, cathodal transcranial direct current stimulation (tDCS) significantly improved picture naming accuracy by an average of 33.6%.

Anodal and sham tDCS did not produce any noticeable changes in performance, suggesting that cathodal tDCS may be a promising technique for enhancing language recovery in stroke patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Improved naming after transcranial direct current stimulation in aphasia. Monti, A., Cogiamanian, F., Marceglia, S., et al.[2022]

In a study involving a bilingual patient with chronic post-stroke aphasia, 9 sessions of anodal cerebellar transcranial direct current stimulation (ctDCS) combined with language therapy led to improvements in picture naming in both the patient's second language (L2) and first language (L1).

While both anodal ctDCS and sham treatment improved trained picture naming in L2, only the anodal ctDCS resulted in enhanced naming of untrained items and improved picture description in both languages, suggesting its potential as an effective tool for language rehabilitation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Case report: the effects of cerebellar tDCS in bilingual post-stroke aphasia. Coemans, S., Struys, E., Tsapkini, K., et al.[2023]

Cathodal transcranial direct current stimulation (tDCS) applied to the right inferior frontal gyrus significantly improved picture naming speed in 24 healthy subjects, suggesting a potential enhancement in language function.

The improvement in naming speed was linked to increased anatomical connectivity between the right Broca's area and the supplementary motor area, indicating that the effects of tDCS may depend on the brain's structural and functional connections.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Connectivity between right inferior frontal gyrus and supplementary motor area predicts after-effects of right frontal cathodal tDCS on picture naming speed. Rosso, C., Valabregue, R., Arbizu, C., et al.[2016]

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]

In a study of 20 non-fluent aphasics, transcranial direct current stimulation (A-tDCS) over the left inferior frontal gyrus improved language performance, but the effectiveness depended on the integrity of specific left hemisphere structures.

Damage to areas such as the basal ganglia, insula, and white matter pathways significantly reduced the benefits of A-tDCS, indicating that the anatomical condition of these regions is crucial for recovery from language impairment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Combining Voxel-based Lesion-symptom Mapping (VLSM) With A-tDCS Language Treatment: Predicting Outcome of Recovery in Nonfluent Chronic Aphasia. Campana, S., Caltagirone, C., Marangolo, P.[2019]

Transcranial direct current stimulation (tDCS) shows promise as an adjunct treatment for improving speech-language deficits in patients with chronic post-stroke aphasia and primary progressive aphasia, by enhancing cortical excitability in language areas.

Current research emphasizes the need for more studies to connect improvements in neuropsychological test performance with real-world functional communication outcomes, as most existing studies focus on impairment rather than practical communication skills.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation in post stroke aphasia and primary progressive aphasia: Current knowledge and future clinical applications. Sebastian, R., Tsapkini, K., Tippett, DC.[2019]

Transcranial direct current stimulation (tDCS) applied to the right cerebellum significantly enhanced spelling recovery in a patient with post-stroke aphasia, showing greater improvement compared to sham treatment after 15 sessions.

The study demonstrated that tDCS not only improved spelling for both trained and untrained words but also increased connectivity in the cerebro-cerebellar network, suggesting a mechanism for its effectiveness in language recovery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Cerebellar tDCS: A Novel Approach to Augment Language Treatment Post-stroke. Sebastian, R., Saxena, S., Tsapkini, K., et al.[2023]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12550330/

Efficacy of cerebellar cathodal transcranial direct current ... Cerebellar cathodal tDCS combined with speech therapy improved language scores in post-stroke aphasia. fNIRS showed decreased right and ...

2. clinicaltrials.gov clinicaltrials.gov/study/NCT05093673

Cerebellar Stimulation for Aphasia Rehabilitation This study will investigate whether multiple sessions of cerebellar transcranial direct current stimulation (tDCS) boosts language therapy in helping people ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11566018/

Cerebellar tDCS Enhances Functional Communication ... Our study provides preliminary evidence that cerebellar tDCS coupled with computerized aphasia treatment has the potential to improve the overall qualitative ...

4. nature.com nature.com/articles/s41598-025-90927-y

Cerebellar transcranial direct current stimulation improves ... Cerebellar tDCS did not significantly improve language outcomes in PSA individuals but enhanced specific aspects of quality of life. These ...

5. pure.johnshopkins.edu pure.johnshopkins.edu/en/publications/cerebellar-tdcs-enhances-functional-communication-skills-in-chron/

Cerebellar tDCS enhances functional communication skills ... Outcomes and Results: The results showed significant tDCS-induced gains for the overall QDC mean score, but not for the overall CI mean score. Cerebellar ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC4229333/

Transcranial cerebellar direct current stimulation and ... In this article we review the major experimental works on cerebellar tDCS and on spinal tDCS, and their preliminary clinical applications. Cerebellar tDCS ...

7. sciencedirect.com sciencedirect.com/science/article/pii/S1878747923010814

Cerebellar Transcranial Direct Current Stimulation in ... Directly after the last stimulation session, 50% of participants who had undergone real tDCS reported a slight overall improvement, as measured by the Patient ...