Stuttering, Adult
Conditions
Keywords
stuttering, tDCS, non-invasive brain stimulation, speech therapy
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.
Interventions
DEVICETranscranial 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.
Sponsors
Biruni University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Masking description
One researcher not involved in any aspect of the study will randomize participants to the sham and tDCS study arms using blocked randomization. To ensure blinding, one researcher will record the administration of the tDCS and assessments, while independent speech-language pathologists will monitor the assessment recordings and score the test items.
Intervention model description
In this study, a double-blind, randomized controlled research design from experimental research methods will be applied.
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Stuttered Syllables in Passage Reading (Change in the Percentage of Stuttered Syllables After 5 Days of Intervention 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. | Percentage of syllables stuttered (%SS) was calculated as the number of stuttered syllables divided by the total number of syllables produced, multiplied by 100. Repetitions, prolongations, syllable repetitions, tense pauses and pre-speech sound blocking were defined as moments of disfluency. Whole-word and whole-phrase repetitions were included in the total syllable count but were not counted as stuttered syllables.Video recordings have been used in assessment procedures and pre-speech sound blocking identified by postural fixations. For both reading and speaking measures, the first 300 syllables were used for analysis (syllable count ranged from 139-490 syllables). |
| Stuttered Syllables in Passage Reading (Change From Baseline in Percentage of Disfluent Syllables 1 Week After Intervention) | 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. | Percentage of syllables stuttered (%SS) was calculated as the number of stuttered syllables divided by the total number of syllables produced, multiplied by 100. Repetitions, prolongations, syllable repetitions, tense pauses and pre-speech sound blocking were defined as moments of disfluency. Whole-word and whole-phrase repetitions were included in the total syllable count but were not counted as stuttered syllables.Video recordings have been used in assessment procedures and pre-speech sound blocking identified by postural fixations. For both reading and speaking measures, the first 300 syllables were used for analysis (syllable count ranged from 139-490 syllables). |
| Stuttered Syllables in Conversation (Change in the Percentage of Stuttered Syllables After 5 Days of Intervention 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. | Percentage of syllables stuttered (%SS) was calculated as the number of stuttered syllables divided by the total number of syllables produced, multiplied by 100. Repetitions, prolongations, syllable repetitions, tense pauses and pre-speech sound blocking were defined as moments of disfluency. Whole-word and whole-phrase repetitions were included in the total syllable count but were not counted as stuttered syllables.Video recordings have been used in assessment procedures and pre-speech sound blocking identified by postural fixations. For both reading and speaking measures, the first 300 syllables were used for analysis (syllable count ranged from 139-490 syllables). |
| Stuttered Syllables in Conversation (Change From Baseline in Percentage of Disfluent Syllables 1 Week After Intervention) | 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. | Percentage of syllables stuttered (%SS) was calculated as the number of stuttered syllables divided by the total number of syllables produced, multiplied by 100. Repetitions, prolongations, syllable repetitions, tense pauses and pre-speech sound blocking were defined as moments of disfluency. Whole-word and whole-phrase repetitions were included in the total syllable count but were not counted as stuttered syllables.Video recordings have been used in assessment procedures and pre-speech sound blocking identified by postural fixations. For both reading and speaking measures, the first 300 syllables were used for analysis (syllable count ranged from 139-490 syllables). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Stuttering Severity Instrument (SSI-IV) Scores After 5 Days of Intervention 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. | The Stuttering Severity Instrument - Fourth Edition (SSI-4) is a standardized tool measuring stuttering severity based on three components: frequency of stuttering, duration of the three longest stuttering events, and physical concomitants. Each is converted to scaled scores-frequency and duration range from 2 to 18, and physical concomitants from 0 to 20-and summed to produce a Total Score ranging from 4 to 56, where higher scores indicate more severe stuttering. Speech naturalness is assessed separately on a 9-point scale (1 = highly natural, 9 = highly unnatural) and is not included in the Total Score. Scores are reported in scores on a scale. |
| Change From Baseline in Stuttering Severity Instrument (SSI-IV) Scores 1 Week After Intervention | 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. | 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. |
| Change in The Overall Assessment of the Speaker's Experience of Stuttering (OASES) Scores After 5 Days of Intervention From Baseline | baseline, after the 5-day stimulation and at the 1-week post-intervention time point | The Overall Assessment of the Speaker's Experience of Stuttering - Adult Version (OASES-A) is a self-assessment instrument that requires approximately 20 minutes to complete and is organized into four sections: General Information, Reactions to Stuttering, Communication in Daily Situations, and Quality of Life. It consists of 100 items scored on a 5-point Likert scale ranging from 1 to 5. For each item, higher scores indicate a greater negative impact of stuttering, while lower scores indicate less impact. Impact scores for each section range from a minimum of 20 (if the respondent answers 1 for every item) to a maximum of 100 (if the respondent answers 5 for every item). The total score ranges from 100 (minimum) to 500 (maximum), with higher scores indicating a greater negative impact of stuttering. Scores are reported as scores on a scale. |
| Change From Baseline in The Overall Assessment of the Speaker's Experience of Stuttering (OASES) Scores 1 Week After Intervention | baseline, after the 5-day stimulation and at the 1-week post-intervention time point | The Overall Assessment of the Speaker's Experience of Stuttering - Adult Version (OASES-A) is a self-assessment instrument that requires approximately 20 minutes to complete and is organized into four sections: General Information, Reactions to Stuttering, Communication in Daily Situations, and Quality of Life. It consists of 100 items scored on a 5-point Likert scale ranging from 1 to 5. For each item, higher scores indicate a greater negative impact of stuttering, while lower scores indicate less impact. Impact scores for each section range from a minimum of 20 (if the respondent answers 1 for every item) to a maximum of 100 (if the respondent answers 5 for every item). The total score ranges from 100 (minimum) to 500 (maximum), with higher scores indicating a greater negative impact of stuttering. Scores are reported as scores on a scale. |
Countries
Turkey (Türkiye)
Contacts
PRINCIPAL_INVESTIGATORFeyzanur Ocak, Slp
Atlas University
STUDY_CHAIRTalat Bulut, Asst. prof.
Medipol University
STUDY_DIRECTORÇağdaş Karsan, Asst. prof.
Biruni University
Participant flow
Recruitment details
Participants were recruited between January 2024 and July 2024 at a university clinic. Recruitment was conducted through clinician referral and study advertisements placed at the clinic.
Pre-assignment details
A total of 48 individuals who stutter were assessed for eligibility between January 2024 and July 2024. During the initial assessment session, four individuals showed no observable stuttering symptoms and were therefore excluded. One additional individual was excluded due to left-handedness (n = 1). Seven individuals withdrew from the study prior to enrollment. Thus, 36 participants met the eligibility criteria, provided informed consent, and were assigned to the study arms.
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Categorical <=18 years | 1 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 35 Participants |
| Age, Continuous | 26.89 years STANDARD_DEVIATION 6.85 |
| Conversation (%SS) | 11.49 %syllables STANDARD_DEVIATION 10.16 |
| Duration | 1.65 Seconds (s) STANDARD_DEVIATION 1.44 |
| OASES-A Communication in daily situation | 68.97 scores on a scale STANDARD_DEVIATION 14.42 |
| OASES-A General information | 56.55 scores on a scale STANDARD_DEVIATION 9.82 |
| OASES-A Quality of life | 73.47 scores on a scale STANDARD_DEVIATION 19.25 |
| OASES-A Reactions to stuttering | 93 scores on a scale STANDARD_DEVIATION 13.36 |
| OASES-A Total Score | 296.42 scores on scale STANDARD_DEVIATION 39.02 |
| Passage Reading (%SS) | 7.34 %syllables STANDARD_DEVIATION 10.11 |
| Physical concomitants | 4.38 Score (0-5 per item) STANDARD_DEVIATION 3.66 |
| Race and Ethnicity Not Collected | 0 Participants |
| Region of Enrollment Turkey | 36 participants |
| Sex: Female, Male Female | 5 Participants |
| Sex: Female, Male Male | 16 Participants |
| Speech naturalness | 3.35 scores on scale STANDARD_DEVIATION 2.14 |
| SSI-IV total | 20 scores on a scale STANDARD_DEVIATION 9.69 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 19 | 0 / 17 |
| other Total, other adverse events | 0 / 19 | 0 / 17 |
| serious Total, serious adverse events | 0 / 19 | 0 / 17 |
Outcome results
None listed