ClinicalTrials.gg
CompletedNCT05497362Updated Sep 2, 2022

Non-invasive Brain Stimulation as a Treatment for Dysarthria Post-stroke

An interventional study of Real tDCS and Sham tDCS in Dysarthria and Stroke, sponsored by The University of Hong Kong. Completed at 1 site in Hong Kong. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2022-09-02.

Sponsored by The University of Hong Kong · Not applicable, Interventional, and Treatment

From the registry’s dates

  • Registered 6 years 3 months after the study started (first participant enrolled Apr 2016, registered Jul 2022).
Phase
Not applicable
Study type
Interventional
Enrollment
9
Allocation
Randomized
Ages
18 Years to 75 Years
Sex
All
01

Study summary

The proposed study aimed to determine if tDCS can help post-stroke patients with dysarthria.

Read the detailed description

A total of 9 Cantonese-speaking chronic post-stroke patients who are suffering from dysarthria was recruited and randomly divided into treatment group and sham group. For the treatment group, an anodal high-definition tDCS of 2 milliampere (mA) lasting for 15 minutes was delivered to the primary motor cortex (SM1) in 10 daily sessions during a 2-week period. For the sham tDCS group, the same setting of tDCS electrodes was applied on the scalp, but the stimulation only lasted for 30 sec in order to cause similar sensation on the scalp as the other group. Simultaneous to the tDCS stimulation, both groups will receive speech and voice therapy for 30 minutes.

An array of outcome measures reflecting speech production ability including acoustic, kinematic, perceptual and self-perceptual qualities was obtained before and after stimulation. It was anticipated that post-stroke dysarthric patients will see improvement in speech production after stimulation. The results provided important insights into the effects of tDCS on articulatory movement in individuals with dysarthria post-stroke.

02

Conditions studied

  • Dysarthria
  • Stroke

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03

In context

Dysarthria

60 studies on the registry are indexed under Dysarthria; 19 are open to participants now.

This study's enrollment of 9 is below the median of 39 across 44 interventional studies indexed under Dysarthria.

Browse Dysarthria studies →

Lead sponsor

The University of Hong Kong is the lead sponsor of 1,292 studies on the registry; 348 are open to participants now.

Of its 9 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 75 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Cantonese-speaking adults
  • At least 6 months after their initial stroke
  • Dysarthria post-stroke

Exclusion criteria

Exclusion Criteria:

  • A personal or family history of epilepsy or seizures
  • A history of another neurological condition
  • Speech disorders
  • Voice disorders
  • Oro-maxillo-facial surgery involving the tongue and/or lip
  • Severe cognitive impairment
  • Severe aphasia
  • Heart disease
  • Metallic foreign body implant
  • On medications that lower neural thresholds (e.g. tricyclines, antidepressants, neuroleptic agents, etc.)
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Outcomes assessor)
Enrollment
9 participants (actual)

Study arms

  • Experimental
    Real tDCS

    Group 1 (n = 5) received anodal tDCS stimulation and intensive speech and voice therapy; tDCS and speech therapy was applied in 10 daily sessions during a 2-week period, administered on Monday to Friday. The anodal stimulation was delivered to the primary motor cortex (SM1) of the orofacial area.

    Device: Real tDCS

  • Sham comparator
    Sham tDCS

    Group 2 (n = 4) received sham tDCS stimulation and intensive speech and voice therapy. For the sham tDCS group, the same setting of tDCS electrodes was applied on the scalp, but the stimulation only lasted for 30 sec in order to cause a similar sensation on the scalp. tDCS and speech therapy was applied in 10 daily sessions during a 2-week period, administered on Monday to Friday.

    Device: Sham tDCS

Interventions

  • DeviceReal tDCS

    2mA of tDCS was delivered to the orofacial area of the primary motor cortex (SM1) for 15 minutes. Speech therapy was delivered simultaneously.

  • DeviceSham tDCS

    2mA of tDCS was delivered to the orofacial area of the primary motor cortex (SM1) for 30 sec. Speech therapy was delivered simultaneously.

06

What researchers measure

Primary outcomes

  1. Perceptual speech assessments

    All participants were required to produce a sustained vowel /a/, repeated some syllables (i.e., /pa/, /ta/, /ka/ and /pataka/), produce some single words, read a standard paragraph in Cantonese and had a two-minute conversation with the investigator. A professional grade microphone (SM58, Shure, USA) was used to record the speech production. Experienced speech-language pathologists blinded to the neurological condition and history of each participant analyzed the speech samples independently using a perceptual rating scale including 21 speech dimensions covering eight categories, including pitch, loudness, voice quality, resonance, rate, articulation, tone, and general impression. The speech samples were rated using a seven-point equal-appearing interval scale, with a "1" indicating within typical limit performance and a "7" severely deviated from the normal.

    Time frame: Change before and after tDCS stimulation at immediately post-treatment

  2. Acoustic measurement: Fundamental frequency (F0)

    Fundamental frequency (F0) was obtained from sustained vowel phonation.

    Time frame: Change before and after tDCS stimulation at immediately post-treatment

  3. Acoustic measurement: Frequency perturbation (jitter %)

    Frequency perturbation (jitter %) was obtained from sustained vowel phonation.

    Time frame: Change before and after tDCS stimulation at immediately post-treatment

  4. Acoustic measurement: Intensity perturbation (shimmer %)

    Intensity perturbation (shimmer %) was obtained from sustained vowel phonation.

    Time frame: Change before and after tDCS stimulation at immediately post-treatment

  5. Acoustic measurement: Noise to harmonic ratio (NHR)

    Noise to harmonic ratio (NHR) was obtained from sustained vowel phonation.

    Time frame: Change before and after tDCS stimulation at immediately post-treatment

  6. Acoustic measurement: Harmonic to noise ratio (HNR)

    Harmonic to noise ratio (HNR) was obtained from sustained vowel phonation.

    Time frame: Change before and after tDCS stimulation at immediately post-treatment

Secondary outcomes

  1. Kinematic measurement: Duration

    The lip and tongue function during speech production were traced real time and objectively measured using an electromagnetic articulography. All participants were required to produce single-syllable real words of consonant-vowel (CV) construction at high level tone embedded in a carrier phrase and repeat some syllables (i.e., /pa/, /ta/, /ka/ and /pataka/). A custom-written analysis programme was used to annotate and calculate the kinematic measures, including duration (ms), distance (mm), maximum velocity (mm/s), maximum acceleration (m/s2) and maximum deceleration (m/s2) in the approach (movement towards the upper lip/palate) and release (movement away from the upper lip/palate) phases along the z-axis, i.e., along the mid-sagittal plane.

    Time frame: Change before and after tDCS stimulation at immediately post-treatment

  2. Kinematic measurement: Distance

    The lip and tongue function during speech production were traced real time and objectively measured using an electromagnetic articulography. All participants were required to produce single-syllable real words of consonant-vowel (CV) construction at high level tone embedded in a carrier phrase and repeat some syllables (i.e., /pa/, /ta/, /ka/ and /pataka/). A custom-written analysis programme was used to annotate and calculate the kinematic measures, including duration (ms), distance (mm), maximum velocity (mm/s), maximum acceleration (m/s2) and maximum deceleration (m/s2) in the approach (movement towards the upper lip/palate) and release (movement away from the upper lip/palate) phases along the z-axis, i.e., along the mid-sagittal plane.

    Time frame: Change before and after tDCS stimulation at immediately post-treatment

  3. Kinematic measurement: Maximum velocity

    The lip and tongue function during speech production were traced real time and objectively measured using an electromagnetic articulography. All participants were required to produce single-syllable real words of consonant-vowel (CV) construction at high level tone embedded in a carrier phrase and repeat some syllables (i.e., /pa/, /ta/, /ka/ and /pataka/). A custom-written analysis programme was used to annotate and calculate the kinematic measures, including duration (ms), distance (mm), maximum velocity (mm/s), maximum acceleration (m/s2) and maximum deceleration (m/s2) in the approach (movement towards the upper lip/palate) and release (movement away from the upper lip/palate) phases along the z-axis, i.e., along the mid-sagittal plane.

    Time frame: Change before and after tDCS stimulation at immediately post-treatment

  4. Kinematic measurement: Maximum acceleration

    The lip and tongue function during speech production were traced real time and objectively measured using an electromagnetic articulography. All participants were required to produce single-syllable real words of consonant-vowel (CV) construction at high level tone embedded in a carrier phrase and repeat some syllables (i.e., /pa/, /ta/, /ka/ and /pataka/). A custom-written analysis programme was used to annotate and calculate the kinematic measures, including duration (ms), distance (mm), maximum velocity (mm/s), maximum acceleration (m/s2) and maximum deceleration (m/s2) in the approach (movement towards the upper lip/palate) and release (movement away from the upper lip/palate) phases along the z-axis, i.e., along the mid-sagittal plane.

    Time frame: Change before and after tDCS stimulation at immediately post-treatment

  5. Kinematic measurement: Maximum deceleration

    The lip and tongue function during speech production were traced real time and objectively measured using an electromagnetic articulography. All participants were required to produce single-syllable real words of consonant-vowel (CV) construction at high level tone embedded in a carrier phrase and repeat some syllables (i.e., /pa/, /ta/, /ka/ and /pataka/). A custom-written analysis programme was used to annotate and calculate the kinematic measures, including duration (ms), distance (mm), maximum velocity (mm/s), maximum acceleration (m/s2) and maximum deceleration (m/s2) in the approach (movement towards the upper lip/palate) and release (movement away from the upper lip/palate) phases along the z-axis, i.e., along the mid-sagittal plane.

    Time frame: Change before and after tDCS stimulation at immediately post-treatment

07

Study locations

1 site
  • University of Hong Kong
    Hong Kong, Hong Kong
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Ran from Apr 2016 to primary completion in Jun 2017, 14 months.

Of 34 interventional studies with no phase under Dysarthria, half reached primary completion within 35 months of starting (the median), counting those still running; a quarter within 23 and three quarters within 55. This study's 14 months is below that.

How these figures are worked out, and which studies are left out of them.

Registered
Jul 23, 2022
First posted
Aug 11, 2022
StartActual
Apr 1, 2016
Primary completionActual
Jun 30, 2017
CompletionActual
Jun 30, 2017
Last update
Sep 2, 2022
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Sep 2, 2022, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05497362
Responsible party
Dr. Lawrence M.W. Ng (Associate Professor, The University of Hong Kong) — Principal investigator
First posted
Aug 11, 2022
Start date
Apr 1, 2016
Primary completion
Jun 30, 2017
Completion
Jun 30, 2017
Last update
Sep 2, 2022

Study contacts

Manwa L Ng, PhD
principal investigator · The University of Hong Kong

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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