Lower corticospinal responses in the left hemisphere of DS were found, as indicated by a reduction of peak-to-peak MEP amplitudes compared to normal speakers.
CONCLUSIONS:
This provides further evidence that DS may be a general motor deficit that also involves motor non-speech-related structures. Moreover, our results confirm that DS may be related to left hemisphere hypoactivation and/or lower left hemisphere dominance. The present data and protocol may be useful for diagnosis of subtypes of DS that may benefit from pharmacological treatment by targeting the general level of cortical excitability.