Investigating Non-invasive Brain Stimulation to Enhance Fluency in People Who Stutter

NCT03335722 | Completed

• 1 other identifier: R52173/RE001_
• Study Type: interventional
• Target: 43
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to test whether the application of transcranial direct current stimulation (tDCS) concurrent with fluency training results in improvements in speech fluency in adults with developmental stuttering, measured up to three months after the intervention.

Conditions

Stuttering, Developmental

Keywords

stammering; speech motor disorder; electrical current stimulation; metronome-timed speech

Outcome Measures

Primary Outcomes (1)

• Change in Stuttering Severity Instrument (SSI-4) Score

  The Stuttering Severity Instrument (SSI-4) is a standardised measure of stuttering severity comprised of 3 sub-scores (frequency, duration and physical concomitants) which are summed to give a total score. We will use change from baseline in total score (i.e. baseline subtracted) on the Stuttering Severity Instrument version 4 measured post intervention. The maximum total score of the SSI-4 is 56, which corresponds to the highest stuttering severity. Therefore, larger negative change scores represent better outcomes (larger reductions in stuttering severity).

  1 week, 6 weeks and 12 weeks after the end of the 5-day intervention

Secondary Outcomes (3)

• Change in percentage of disfluent syllables produced during conversation

  1 week, 6 weeks and 12 weeks after the end of the 5-day intervention

• Change in percentage of disfluent syllables produced during reading

  1 week, 6 weeks and 12 weeks after the end of the 5-day intervention

• Change in Overall Assessment of the Speaker's Experience of Stuttering (OASES) score

  6 weeks and 12 weeks after the end of the 5-day intervention

Other Outcomes (6)

• Change in Premonitory Awareness in Stuttering Scale

  1 week, 6 weeks and 12 weeks after the end of the 5-day intervention

• Change in Beck Anxiety Inventory

  1 week, 6 weeks and 12 weeks after the end of the 5-day intervention

• Change in Subjective rating of stuttering severity

  1 week, 6 weeks and 12 weeks after the end of the 5-day intervention

Study Arms (2)

Active TDCS and Fluency Intervention

ACTIVE COMPARATOR

Participants will receive 1-milliamp (mA) tDCS with the anode (5 x 7 cm) placed over the left frontal cortex and the cathode (5 x 7 cm) placed symmetrically over the right frontal cortex. tDCS will be delivered using a direct current (DC) stimulator in 'study-mode' for 20 minutes a day for five consecutive days. he stimulation will be applied for the first half of a 40-minute speech fluency training paradigm, using metronome-timed speech.

Behavioral: Metronome-timed speech; Device: Active tDCS

Sham TDCS and Fluency Intervention

SHAM COMPARATOR

Participants will receive sham stimulation with the anode and cathode electrodes placed over the left and right frontal cortex as in the active arm. Sham stimulation will be delivered using a DC-stimulator in 'study-mode' for 20 minutes a day for five consecutive days. For sham stimulation, the current is ramped up over 15 seconds, maintained for 15 seconds at 1 mA and ramped down over 15 seconds at the start of stimulation and is then followed by brief (3ms) pulses every 55 seconds for the remainder of the 20-minute stimulation session. he stimulation will be applied for the first half of a 40-minute speech fluency training paradigm, using metronome-timed speech.

Behavioral: Metronome-timed speech; Device: Sham tDCS

Interventions

Metronome-timed speech BEHAVIORAL

Reading, narrative, and conversational speech tasks will be completed on each of the five intervention days. Metronome- timed speech will be practiced during these tasks, at near-normal (comfortable) speech rate for each participant. Each intervention session will be 40 minutes in duration.

Active TDCS and Fluency Intervention; Sham TDCS and Fluency Intervention

Active tDCS DEVICE

1-mA tDCS with the anode (5 x 7 cm) placed over the left frontal cortex and the cathode (5 x 7 cm) placed symmetrically over the right frontal cortex. tDCS will be delivered using a direct current (DC) stimulator in 'study-mode' for 20 minutes. The current is ramped up to 1 mA over the first 15 seconds of stimulation and maintained at this level for remainder of the 20-minute stimulation session.

Active TDCS and Fluency Intervention

Sham tDCS DEVICE

Sham stimulation will be delivered using a DC-stimulator in 'study-mode' for 20 minutes. Participants will receive sham stimulation with the anode and cathode electrodes placed over the left and right frontal cortex as in the active arm. For sham stimulation, the current is ramped up over 15 seconds, maintained for 15 seconds at 1 mA and ramped down over 15 seconds at the start of stimulation and is then followed by brief (3ms) pulses every 55 seconds for the remainder of the 20-minute stimulation session.

Sham TDCS and Fluency Intervention

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Participant is willing and able to give informed consent for participation in the study.
• Diagnosed with developmental stuttering of mild-moderate or greater severity
• Native speaker of English
• Normal or corrected-to-normal vision
• Normal hearing

You may not qualify if:

• Speech, language or communication disorder other than developmental stuttering.
• Contraindication to brain stimulation (tDCS or TMS)
• Contraindication to MRI
• History of drug abuse
• History of a neurological or psychiatric illness
• Any previous neurosurgical procedures
• Taking prescription or over-the-counter medication that may affect brain function (for example, anti-depressants)
• Family history of epilepsy (first degree relative)
• Severe claustrophobia (as they may be unable to tolerate scanner)

Sponsors & Collaborators

• University of Oxford: lead

Study Sites (1)

Department of Experimental Psychology, University of Oxford

Oxford, OX2 6BW, United Kingdom

Location

Related Links

• INSTEP trial website
• Speech and Brain Research Group website

MeSH Terms

Conditions

Stuttering

Condition Hierarchy (Ancestors)

Speech Disorders; Language Disorders; Communication Disorders; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Kate E Watkins, PhD

  University of Oxford

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: A researcher from another research group who is not involved in any aspect of the trial will perform the randomisation of participants into the sham and tDCS study arms using a minimisation procedure within "randPack" package in R (Carey and Gentleman, 2016). Allocation concealment will be achieved by assigning a unique 5-digit code per participant (containing no identifying information regarding trial arm). This will be emailed to the researcher. The code is used to deliver stimulation via study mode on the stimulator (http://www.neurocaregroup.com/dc\ stimulator\ plus.html). The participants and the researchers who will deliver the intervention, assess the outcomes, and analyse the data will be masked to trial arm.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Double-blind, placebo-controlled (sham tDCS), randomised trial, with 20 participants with developmental stuttering recruited for each of the two arms of the trial.

Study Record Dates

• First Submitted: October 26, 2017
• First Posted: November 8, 2017
• Study Start: November 15, 2017
• Primary Completion: June 1, 2020
• Study Completion: June 1, 2020
• Last Updated: May 18, 2022

Record last verified: 2022-05

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)