Bihemispheric Transcranial Direct Current Stimulation* on Speech Fluency

Stuttering, Adult Clinical Trial

— TDCS  

Official title:

An Investigation of the Effect of 5 Consecutive Days of Bihemispheric TDCS on Speech Fluency in Individuals With Stuttering

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT06278233
• Other study ID #: 2023/85-70
• Status: Recruiting
• Phase: N/A
• Start date: February 2024
• Est. completion date: September 2024

Study information

• Verified date: February 2024
• Source: Biruni University
• Contact: Çagdas karsan, Asst. prof.
• Phone: 05552934133
• Email: cagkarsan[@]gmail.com
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

It will be determined whether bihemispheric stimulation (anodal to the left IFG and cathodal to the right IFG) is used with fluency-facilitating conditions for 5 consecutive days in individuals with stuttering and whether there is a difference in terms of the effects seen in speech fluency compared to the sham condition.

Description:

Developmental stuttering is a fluency disorder that can negatively affect many aspects of an individual's life. Recent transcranial direct current stimulation (tDCS) studies with individuals with stuttering show that tDCS shows promise in increasing fluency when used in combination with situations that temporarily increase fluency. In this study, it was aimed to investigate the effect of bi-hemispheric tDCS on fluency in individuals with stuttering for 5 consecutive days. The hypothesis of the study is that bi-hemispheric stimulation, which includes anodal stimulation to the left hemisphere and cathodal stimulation to the right hemisphere, will be effective on reading and speech fluency when performed for 5 consecutive days. Thirty-six adults with developmental stuttering are expected to complete this double-blind, sham-controlled study. Participants will be divided into two groups by blocked randomization and one group will receive sham stimulation for 5 consecutive days and the other group will receive bihemispheric stimulation. Participants in the tDCS group will receive 20 minutes of tDCS stimulation accompanied by metronome-timed speech during the practice sessions. Reading and speaking fluency will be assessed immediately before, immediately after, and one week after the stimulation sessions. Data will be collected using the stuttering severity assessment instrument (SSI-4) Results will be compared both within and between groups in terms of percentage of stuttered syllables, stuttering severity, and evaluation of the speaker's experience of stuttering.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 36
• Est. completion date: September 2024
• Est. primary completion date: June 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 60 Years

Eligibility

Inclusion Criteria:

• developmental stuttering
• age between 18 and 60 years
• right hand dominant

Exclusion Criteria:

• history of seizures, head trauma, hearing problems, cochlear implant, intracranial metal implantation, medications that affects the central nervous system, implanted neurostimulators, cardiac pacemakers, or medication infusion devices
• any speech and language disorder other than developmental stuttering
• neurological or psychiatric disorders, brain surgery, tumours, neurodevelopmental disorders, or attention deficit hyperactivity disorder

Related Conditions & MeSH terms

• Stuttering
• Stuttering, Adult

Intervention

Device:
• Transcranial direct current stimulation
TDCS involves applying a weak electrical current across the head through electrodes placed on the scalp and modulating the resting membrane potential of neurons in the underlying cortex.

Locations

Country	Name	City	State
Turkey	Biruni University	Istanbul	Zeytinburnu

Sponsors (1)

Lead Sponsor	Collaborator
Biruni University

Country where clinical trial is conducted

Turkey, 

References & Publications (3)

Chesters J, Mottonen R, Watkins KE. Transcranial direct current stimulation over left inferior frontal cortex improves speech fluency in adults who stutter. Brain. 2018 Apr 1;141(4):1161-1171. doi: 10.1093/brain/awy011. — View Citation

Garnett EO, Chow HM, Choo AL, Chang SE. Stuttering Severity Modulates Effects of Non-invasive Brain Stimulation in Adults Who Stutter. Front Hum Neurosci. 2019 Nov 21;13:411. doi: 10.3389/fnhum.2019.00411. eCollection 2019. — View Citation

Yada Y, Tomisato S, Hashimoto RI. Online cathodal transcranial direct current stimulation to the right homologue of Broca's area improves speech fluency in people who stutter. Psychiatry Clin Neurosci. 2019 Feb;73(2):63-69. doi: 10.1111/pcn.12796. Epub 2018 Dec 11. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Disfluent syllables	change in % disfluent syllables from baseline	immediately before and immediately after the stimulation on each day of the 5-day intervention, and at 1 week after the end of the intervention.
Secondary	Stuttering Severity Instrument- Fourth Edition (SSI-IV) score	It measures stuttering severity in the following four areas of speech behavior: (1) frequency, (2) duration, (3) physical concomitants, and (4) naturalness of the individual's speech. Frequency is expressed in percent syllables stuttered and converted to scale scores of 2-18. Duration is timed to the nearest one tenth of a second and converted to scale scores of 2-18. The four types of Physical Concomitants (Distracting Sounds, Facial Grimaces, Head Movements, and Movements of the Extremities) are converted to scale scores of 0-20. Naturalness is ranked on a scale from 1 (Highly Natural Sound Speech) to 9 (Highly Unnatural Sound Speech). Overall naturalness is ranked at the discretion of the clinician. Scaled scores of Frequency, Duration, and Physical Concomitants are added together to derive a Total Score, Percentile Rank, and Severity Equivalent.	immediately before and immediately after the stimulation on each day of the 5-day intervention, and at 1 week after the end of the intervention.
Secondary	The Overall Assessment of the Speaker's Experience of Stuttering (OASES) score	The instrument, which requires approximately 20 min to complete, is organized into four sections: (a) General Information, (b) Reactions to Stuttering, (c) Communication in Daily Situations, and (d) Quality of Life. OASES consists of 100 items, each scored on a Likert scale ranging from 1 to 5. For each item on the OASES, response scales are that higher scores indicate a greater degree of negative impact associated with stuttering and lower scores indicate less negative impact. All impact scores range from a minimum score of 20 (if the speaker answers 1 for every item within a section) up to a maximum of 100 (if the speaker answers 5 for every item within the section).	baseline, after the 5-day stimulation and at the 1-week post-intervention time point