Article

OBJECTIVE: To use focal cortical inhibition and create a "virtual" lesion in the
oropharyngeal motor cortex in healthy subjects to determine whether this provokes
swallowing dysfunction. DESIGN: Intervention study: before and after cortical
stimulation. SETTING: Tertiary care center. PARTICIPANTS: Healthy adult
volunteers (N=9; age range, 21-44y) participated in the study. INTERVENTIONS:
Active or sham 1-Hz repetitive transcranial magnetic stimulation (rTMS) over the
cortical sites in each hemisphere evoking the largest mylohyoid motor-evoked
potentials (mMEPs) to single pulse transcranial magnetic stimulation. MAIN OUTCOME MEASURES: Videofluoroscopic assessment was performed before and 5, 30,
and 60 minutes after rTMS. RESULTS: The motor threshold was 83%+/-10% for the
hemisphere with the larger mMEP (dominant) and 92%+/-9% for the hemisphere with
the smaller mMEP (nondominant). When rTMS was performed over the dominant
hemisphere, there was a decrease in oral transit time (P=.05), an increase in
swallow reaction time (P=.0001), but no change of pharyngeal transit time or
laryngeal closure duration. When rTMS was performed on the nondominant
hemisphere, there was also a decrease in oral transit time (P=.05), but no change
in any of the other swallowing measures. Neither active intervention produced any
signs of aspiration or penetration. Sham stimulation had no effect. CONCLUSIONS:
Inhibiting the human oropharyngeal motor cortex using rTMS transiently modifies
swallowing behavior in a way reminiscent to that seen in stroke patients.
CI - Copyright (c) 2012 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS