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Aphasia Following Cerebral InfarctionNCT07353879

Application of Cerebellar tDCS in Aphasia

A study testing anodal right posterolateral cerebellar high-definition tDCS and computerized visual speech perception naming intervention in people with Aphasia Following Cerebral Infarction, run by The University of Hong Kong at 2 sites in Hong Kong.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The goal of this clinical trial is to learn if adding brain stimulation (cerebellar anodal tDCS) helps a computer-based therapy improve word-finding in Cantonese-speaking adults with aphasia after stroke. It will also check if the stimulation is safe and comfortable. Read more about this study

Who is it for?
Ages 40 to 80 years
Conditions the study is for
Aphasia Following Cerebral Infarction
What is being tested?
anodal right posterolateral cerebellar high-definition tDCS and computerized visual speech perception naming intervention
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
6 participants
Where
2 sitesHong Kong
Study dates
3 Jan 2024to 1 Jun 2025
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 40 to 80 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Native Cantonese speakers
  • Age: 40-80 years
  • Diagnosed with aphasia
  • Single left-hemispheric stroke ≥6 months prior
  • Premorbid right-handedness
  • Normal or corrected-to-normal vision
  • Functional hearing (with or without hearing aids)

Who cannot join

  • History of brain surgery
  • Seizures within past 12 months
  • Conditions contraindicated for tDCS (e.g., metallic implants, pacemakers)
  • Prior neurological treatment (other than stroke-related)
  • Severe cognitive impairment
  • Naming accuracy <10% or >80% on noun/verb naming screening pretestt.

Trial locations and contacts

2 sites in 1 country.

Hong Kong2 sites
  • The University of Hong Kong

    Hong Kong, Hong Kong SAR

  • Speech and Neuromodulation Lab

    Hong Kong

Other trials in Hong Kong

About this study

Official title: Exploring the Effects of a Computerized Naming Intervention Combined With Cerebellar tDCS in Cantonese-Speaking Individuals With Aphasia

The goal of this clinical trial is to learn if adding brain stimulation (cerebellar anodal tDCS) helps a computer-based therapy improve word-finding in Cantonese-speaking adults with aphasia after stroke. It will also check if the stimulation is safe and comfortable.

The main questions it aims to answer are:

Read more

Does real brain stimulation during therapy help people name pictures (both objects and actions) better and faster than fake (sham) stimulation?

Are there different effects on naming nouns (objects) versus verbs (actions)? Do any participants feel side effects like tingling or discomfort from the stimulation?

Researchers will compare real brain stimulation to sham (fake) stimulation while everyone gets the same 5-day computer therapy.

Participants will:

Do 60 minutes of computer word-naming practice every day for 5 days, twice (once with real stimulation, once with sham), with at least 2 weeks break in between

Wear a cap with electrodes on the back of the head for the first 20 minutes of each session to receive either real or sham brain stimulation

Name pictures on a computer before and after each 5-day block to measure improvement

Report any feelings or side effects after each session

Read the detailed description

Aphasia is a frequent consequence of stroke, affecting about one-third of survivors and leading to significant emotional distress, functional limitations, and reduced social participation, all of which diminish quality of life. Speech-language therapy remains the primary treatment for language impairments, but its effectiveness varies considerably, and recovery is often incomplete. Non-invasive brain stimulation techniques, particularly transcranial direct current stimulation (tDCS), have emerged as promising adjuncts to therapy due to their portability, low cost, ease of use, and ability to enhance neural plasticity and cortical excitability in a polarity-dependent manner (anodal for excitation, cathodal for inhibition).

Traditionally, tDCS has targeted left-hemisphere cortical language areas, but post-stroke brain damage can disrupt current flow due to lesions and fluid accumulation. This has shifted attention to the cerebellum, which is often spared in aphasia, plays roles in linguistic and cognitive processing (especially right posterolateral regions), and connects to language networks. Despite its potential, few studies have examined cerebellar tDCS combined with language therapy for post-stroke aphasia, with existing evidence mostly from small trials in Western languages and limited data on tonal languages like Cantonese.

Additional Technical Information on the Methods

  1. Study design: This study employs a randomized, double-blind, sham-controlled, crossover clinical trial design: participants randomly assigned to either the "tDCS-first" or "sham-first" group; both participants and researchers administering clinical testing and treatment blinded to the type of tDCS delivered until data analysis is concluded and, two independent study coordinators conduct the randomization and facilitate the setup for either active or sham tDCS sessions. Each treatment phase consists of five consecutive daily sessions, in which participants receive 60-minute-computerized naming treatment, with the first 20 minutes involving either active or sham tDCS. A 2-week washout period separates the two phases to minimize carryover effects.
  2. Outcome measures: Timed confrontation naming task comprising 120 picture stimuli from the Object and Action Naming Battery (OANB) using the DMDX software for data collection. Each trial starts with a central fixation point displayed for 500 ms, followed immediately by a single picture stimulus presented centrally on the screen. The stimulus remains visible until a response is detected or 5000 ms had elapsed. DMDX records an error if no response is produced within the 2000 ms time limit. The task consisted of 60 trained and 60 untrained words, matched for imageability.
  3. Computerized Naming Treatment - described in "Arms and Interventions" The 60-minute computerized naming treatment was adapted to Cantonese from Fridriksson et al. and delivered using DMDX. The treatment engages all domains of lexical-semantic processing by providing auditory and visual articulatory cues. The program features 100 Cantonese picture stimuli (50 objects and 50 actions) from the OANB, 60 of which included in the outcome naming task (trained items).
  4. Adverse effects questionnaire: Participants were asked about adverse effects such as pain and/or discomfort (e.g., itching, irritation, tingling, or burning) before and after each session. The Wong-Baker FACES Pain Rating Scale was used to assess any tDCS-related discomfort.
  5. tDCS protocol Cerebellar tDCS was delivered using a Soterix Medical MxN High Definition tDCS Stimulator. Intervention described in "Arms and Interventions"

Additional Technical Information on Data Analysis:

R version 4.4.1 used to the statistical analyses on the effects of intervention on naming accuracy and Reaction time (RT). Responses audio-recorded and reviewed for suitability prior to RT analysis; stimuli excluded from the RT analysis if contaminated by extraneous sounds before naming (e.g., coughs, starters, or fillers) or when the response provided is incorrect. RT outliers exceeding 3 standard deviations (SD) from the participants' means removed. Generalized linear mixed-effects models run to assess naming accuracy, while linear mixed-effects (LME) models utilized to evaluate naming RT for correct responses. T-tests employed to compare adverse effects between the sham and active conditions. Individual variability assessed by plotting performance for visual inspection of accuracy and mean RT raw scores and McNemar's test to evaluate changes in naming accuracy for each participant across time (pre- vs. immediate post-treatment), condition (active vs. sham), and grammatical category (nouns vs. verbs).

Being tested
anodal right posterolateral cerebellar high-definition tDCS, computerized visual speech perception naming intervention
Keywords
Aphasia, Non-Invasive Brain Stimulation, Transcranial Direct Current Stimulation, Cerebellum, Stroke Rehabilitation, Computerized intervention, Speech Perception training, Naming intervention, Noun naming, Verb naming
Medical subject headings
Aphasia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • anodal right posterolateral cerebellar high-definition tDCSDevice

    Intervention delivered in two phases (active tDCS or sham tDCS first, order of treatment randomized across participants). Cerebellar tDCS: delivered using a Soterix Medical MxN High Definition tDCS Stimulator.

    Real tDCS applied to the right posterolateral cerebellum, with one anodal electrode (2 mA) placed at PO10 and two return electrodes (-1 mA each) at P10 and O10, using EEG-sized electrodes (external diameter of 1.2 cm) secured in an EEG cap. Participants received five sessions of tDCS combined with 60-min behavioral treatment. Real tDCS: delivered in the first 20 minutes of the behavioral intervention, 2 mA anodal stimulation with 30-second ramp-up and ramp-down periods.

    Sham tDCS - delivered using a Soterix Medical MxN High Definition tDCS Stimulator with similar montage as the active condition. Electrodes were placed similarly, but the stimulator was turned off after a 30-second ramp-up and ramp-down period.

  • computerized visual speech perception naming interventionBehavioural

    Computerized Naming Treatment: five consecutive 60-minute sessions. The computerized naming treatment adapted to Cantonese from Fridriksson et al. and delivered using DMDX. Lexical-semantic processing is engaged by providing auditory and visual articulatory cues. DMDX featured 100 Cantonese picture stimuli (50 objects and 50 actions), which have norms for timed-picture- naming in Cantonese. Participants viewed a black-and-white image of an item for 2 seconds, followed by a video showing the lower part of a speaker's face (nose and mouth) articulating the corresponding word. Participants then had up to 7 seconds to judge whether the picture stimulus matched the audio-visual presentation by pressing a "correct" or "incorrect" button.

Study groups in NCT07353879
Study groupRoleWhat they receive
Active tDCSExperimentalCerebellar tDCS is delivered using a Soterix Medical MxN High Definition tDCS Stimulator. Real tDCS is applied to the right posterolateral cerebellum, with one anodal electrode (2 mA) placed at PO10 and two return electrodes (-1 mA each) at P10 and O10, using EEG-sized electrodes (external diameter of 1.2 cm) secured in an EEG cap. For real tDCS, participants receive five sessions, each consisting of 20 minutes of 2 mA anodal stimulation with 30-second ramp-up and ramp-down periods, with simultaneous behavioral treatment administered for 60 minutes (additional 40 minutes following active tDCS).
Receives: Device: anodal right posterolateral cerebellar high-definition tDCS; Behavioral: computerized visual speech perception naming intervention
Sham tDCSSham comparatorFor sham tDCS, electrodes were placed similarly, but the stimulator was turned off after a 30-second ramp-up and ramp-down period. Five session, similar procedures for the paired behavioral intervention.
Receives: Device: anodal right posterolateral cerebellar high-definition tDCS; Behavioral: computerized visual speech perception naming intervention

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Accuracy on a timed confrontation naming task

    The timed confrontation naming task comprises 120 picture stimuli from the Object and Action Naming Battery (OANB) and is set for data collection using DMDX . Participants are instructed to name displayed pictures as quickly and ac-curately as possible using a microphone. Each trial started with a central fixation point displayed for 500 ms, followed immediately by a single picture stimulus presented centrally on the screen. The stimulus remains visible until a response is detected or 5000 ms have elapsed. DMDX records an error if no response was produced within the 2000 ms time limit.

    The naming task consists of 60 trained and 60 untrained words, half of them nouns and the other half verbs.

    Measured: - The baseline assessment on 'Day 1' - Outcome measure on 'Day 5'. - Data will be reported "through study completion, an average of 1 year"

  2. Reaction Time on a timed confrontation naming task

    The timed confrontation naming task comprises 120 picture stimuli from the Object and Action Naming Battery (OANB) and is set for data collection using DMDX . Participants are instructed to name displayed pictures as quickly and ac-curately as possible using a microphone. Each trial started with a central fixation point displayed for 500 ms, followed immediately by a single picture stimulus presented centrally on the screen. The stimulus remains visible until a response is detected or 5000 ms have elapsed. DMDX records an error if no response was produced within the 2000 ms time limit.

    The naming task consists of 60 trained and 60 untrained words, half of them nouns and the other half verbs.

    Measured: - The baseline assessment on 'Day 1' - Outcome measure on 'Day 5'. - Data will be reported "through study completion, an average of 1 year"

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted21 Jan 2026
  2. Study start3 Jan 2024
  3. Primary completion15 Apr 2024
  4. Study completion1 Jun 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Crossover
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
6 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07353879
Sponsor's protocol ID
EAU23035
Status last verified
Dec 2023
First submitted
29 Dec 2025
Last updated
21 Jan 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing anodal right posterolateral cerebellar high-definition tDCS and computerized visual speech perception naming intervention in people with Aphasia Following Cerebral Infarction, run by The University of Hong Kong at 2 sites in Hong Kong.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 7 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 21 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in Hong Kong. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Accuracy on a timed confrontation naming task (time frame: - The baseline assessment on 'Day 1' - Outcome measure on 'Day 5'. - Data will be reported "through study completion, an average of 1 year"). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Jan 2026.

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