Clinical trial NCT06278233: Bihemispheric Transcranial Direct Current Stimulation* on Speech Fluency
Official title: An Investigation of the Effect of 5 Consecutive Days of Bihemispheric TDCS on Speech Fluency in Individuals With Stuttering
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Stuttering, Adult
Keywords: stuttering
tDCS
non-invasive brain stimulation
speech therapy
Lead sponsor: Biruni University
Sponsor class: OTHER
First posted: 2024-02-26
Enrollment: 36
Sex: ALL
Minimum age (years): 18
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: In this study, a double-blind, randomized controlled research design from experimental research methods will be applied.
Primary purpose: TREATMENT

Brief 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.

Detailed 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.

Eligibility criteria: 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

Primary outcomes:
measure: Disfluent syllables
timeFrame: 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 outcomes:
measure: Stuttering Severity Instrument- Fourth Edition (SSI-IV) score
timeFrame: 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.
measure: The Overall Assessment of the Speaker's Experience of Stuttering (OASES) score
timeFrame: baseline, after the 5-day stimulation and at the 1-week post-intervention time point
Other outcomes:
Locations:
city: Istanbul
country: Turkey
facility: Biruni University
state: Zeytinburnu
Study officials:
affiliation: Atlas University
name: Feyzanur Ocak, Slp
role: PRINCIPAL_INVESTIGATOR
affiliation: Medipol University
name: Talat Bulut, Asst. prof.
role: STUDY_CHAIR
affiliation: Biruni University
name: Çağdaş Karsan, Asst. prof.
role: STUDY_DIRECTOR
References:
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.
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.
citation: 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.