Stuttering, Adult, Stammering
Conditions
Keywords
tDCS, Stuttering, Speech therapy, Camperdown Program
Brief summary
The proposed study aims to investigate the effect of combined transcranial direct current stimulation (tDCS) and behavioural speech training in improving speech fluency in Cantonese-speaking adults who stutter (AWS), and to examine its maintenance over a 6-week period.
Detailed description
The proposed study aims to 1. assess the effect of multiple sessions of tDCS over the supplementary motor area (SMA) combined with behavioural speech training on stuttering recovery in terms of a reduction of stuttering severity and increased speech satisfaction in Cantonese-speaking AWS; 2. investigate the maintenance of combined tDCS-behavioural speech training effects on speech fluency and speech satisfaction in Cantonese-speaking AWS over a 6-week period. Twenty Cantonese-speaking AWS will be randomly assigned to an experimental group and a control group. Both groups will receive behavioral treatment for stuttering, including the speech prolongation technique, for five sessions. Concurrent with behavioural training, the experimental group will receive anodal tDCS (1 mA for 20 minutes), while the control group will receive sham tDCS (1 mA for one minute), over the SMA. Stuttering severity and speech satisfaction will be assessed independently before, immediately after, one week and six weeks after treatment. It is anticipated that AWS will experience reduction in their stuttering severity after stimulation, and the improvement will be maintained for a longer period as compared with receiving behavioural treatment alone.
Interventions
DEVICEActive-tDCS
Active-tDCS (1 mA) over the supplementary motor area (SMA) for 5 sessions (20 minutes per session, weekly), along with behavioural therapy of speaking tasks (i.e., story narration and conversation) using the minimum prolongation technique based on the Camperdown Program.
DEVICESham-tDCS
Sham-tDCS (1 mA) over the supplementary motor area (SMA) for 5 sessions (one minutes per session, weekly), along with behavioural therapy of speaking tasks (i.e., story narration and conversation) using the minimum prolongation technique based on the Camperdown Program. Participants will receive initial stimulation for one minute, eliciting a tingling sensation on the scalp then it will be discontinued.
Sponsors
The Hong Kong Polytechnic University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Intervention model description
Double-blinded
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
No
Inclusion criteria
* Demonstrated features of stuttering; * More than 2% of syllables stuttered over three baseline speech samples, as measured by qualified speech therapists.
Exclusion criteria
* Personal or family history of epilepsy or seizures * History of a neurological condition * Speech disorders * Hearing impairment * Metallic foreign body implant * On medications that lower neural thresholds (e.g. tricyclines, antidepressants, neuroleptic agents, etc.) * Pregnant * Had speech therapy for stuttering in the past four months
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Stuttering severity [Percent syllables stuttered (%SS)] | Change before, immediately after, one week and six weeks after treatment | %SS is based on the proportion of spoken syllables that a judge perceives to be stuttered. It will be measured by a qualified speech therapist with prior training in stuttering assessment in Cantonese who will be blinded to the treatment conditions. To establish inter-rater agreement, 20% of the speech samples across different assessment data points will be randomly selected and rated by a second speech therapist. |
| Stuttering severity [Severity rating (SR)] | Change before, immediately after, one week and six weeks after treatment | The subjects will be trained to rate their own stuttering severity based on a 9-point SR scale, with 0 = no stuttering, 1 =very mild stuttering, and 8 = the most severe stuttering. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Subject satisfaction | One week and six weeks after treatment | For the assessment of subject satisfaction regarding the treatment, the following two Likert-type survey questions will be asked: 1. How much do you think the treatment helped you to speak more fluently? (1 = not at all, 2 = a little, 3 = somewhat, 4 = a lot, 5 = totally); and 2. How often/much do you think the treatment helped you to feel less stressed in your communication? (1 = never or not at all, 2 = rarely or a little, 3 = sometimes or somewhat, 4 = often or a lot, 5 = always or totally). |
Countries
Hong Kong
Outcome results
None listed