Related Experiment Video
Updated: May 26, 2026
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Assessing Primary Motor Cortex Excitability and Excitability Modulation by Pairing Transcranial Magnetic Stimulation with Electromyography
Published on: October 7, 2025
Motor excitability evaluation in developmental stuttering: a transcranial magnetic stimulation study
Pierpaolo Busan1, Alessandro D'Ausilio, Massimo Borelli
1DSBTA, Section of Human Physiology, University of Ferrara, Ferrara, Italy. pbusan@units.it
Summary
Developmental stuttering (DS) may stem from a broader motor deficit, not just speech. Lower corticospinal excitability in the left hemisphere of adults who stutter suggests a general motor control issue.
Area of Science:
- Neuroscience
- Speech-language pathology
Background:
- Developmental stuttering (DS) is often considered a motor speech disorder.
- Emerging evidence suggests DS might be a symptom of a more general motor disorder.
Purpose of the Study:
- To investigate corticospinal excitability in adults with DS compared to typical speakers.
- To explore the potential link between DS and broader motor deficits.
Main Methods:
- Utilized transcranial magnetic stimulation (TMS) over the motor cortex.
- Recorded motor evoked potentials (MEPs) from the first dorsal interosseous (FDI) muscle.
- Measured resting/active motor thresholds, silent period, and stimulus-response curves.
Main Results:
- Adults with DS exhibited reduced peak-to-peak MEP amplitudes in the left hemisphere compared to controls.
- This indicates lower corticospinal excitability in the left hemisphere for individuals with DS.
Conclusions:
- Findings support the hypothesis that DS may involve general motor deficits affecting non-speech structures.
- Results suggest DS is associated with left hemisphere hypoactivation or reduced dominance.
- The study proposes potential diagnostic applications for DS subtypes and pharmacological interventions targeting cortical excitability.
