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

Not Applicable
Completed
Conditions
Dysarthria
Stroke
Interventions
Device: Sham tDCS
Device: Real tDCS
Registration Number
NCT05497362
Lead Sponsor
The University of Hong Kong
Brief Summary

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

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.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
9
Inclusion Criteria
  • Cantonese-speaking adults
  • At least 6 months after their initial stroke
  • Dysarthria post-stroke
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.)

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Sham tDCSSham tDCSGroup 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.
Real tDCSReal tDCSGroup 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.
Primary Outcome Measures
NameTimeMethod
Acoustic measurement: Intensity perturbation (shimmer %)Change before and after tDCS stimulation at immediately post-treatment

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

Acoustic measurement: Harmonic to noise ratio (HNR)Change before and after tDCS stimulation at immediately post-treatment

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

Acoustic measurement: Frequency perturbation (jitter %)Change before and after tDCS stimulation at immediately post-treatment

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

Acoustic measurement: Noise to harmonic ratio (NHR)Change before and after tDCS stimulation at immediately post-treatment

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

Perceptual speech assessmentsChange before and after tDCS stimulation at immediately post-treatment

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.

Acoustic measurement: Fundamental frequency (F0)Change before and after tDCS stimulation at immediately post-treatment

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

Secondary Outcome Measures
NameTimeMethod
Kinematic measurement: DurationChange before and after tDCS stimulation at immediately post-treatment

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.

Kinematic measurement: Maximum decelerationChange before and after tDCS stimulation at immediately post-treatment

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.

Kinematic measurement: Maximum velocityChange before and after tDCS stimulation at immediately post-treatment

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.

Kinematic measurement: DistanceChange before and after tDCS stimulation at immediately post-treatment

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.

Kinematic measurement: Maximum accelerationChange before and after tDCS stimulation at immediately post-treatment

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.

Trial Locations

Locations (1)

University of Hong Kong

🇭🇰

Hong Kong, Hong Kong

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