OBJECTIVES: To analyze characteristic features and details on motor-evoked potentials (MEPs) of the cricothyroid and vocalis muscles from single-pulse cortical transcranial magnetic stimulation (TMS) in normal subjects to characterize cortical motor representation of laryngeal muscles. STUDY DESIGN: Prospective, experimental investigation on healthy volunteers. METHOD: MEPs of the cricothyroid and vocalis muscles elicited by cortical TMS with a figure-8-shaped coil were investigated in two groups of six healthy subjects each, with special regard to MEP amplitude as a function of the coil position on the head surface along the interaural line. RESULTS: Bilateral reproducible responses of the cricothyroid and the vocalis muscles could be observed in all subjects. For the cricothyroid muscle, maximal responses were obtained at mean stimulus positions of 7.5 +/- 1.4 cm (contralateral) and of 7.3 +/- 1.3 cm (ipsilateral), respectively. For the vocalis muscle, we found maximal responses at mean stimulus positions of 10.3 +/- 1.9 cm (contralateral) and of 9.6 +/- 1.6 cm (ipsilateral), respectively. Despite a considerable overlap of these coil positions, from which reproducible MEPs could be elicited in both groups of the laryngeal muscles, statistically significant separation of the cricothyroid-and vocalis-associated cortical representation areas was possible. CONCLUSIONS: Our observations point to two different cortical motor representation areas, with the cricothyroid muscle-related area being located more medially.
OBJECTIVES: To analyze characteristic features and details on motor-evoked potentials (MEPs) of the cricothyroid and vocalis muscles from single-pulse cortical transcranial magnetic stimulation (TMS) in normal subjects to characterize cortical motor representation of laryngeal muscles. STUDY DESIGN: Prospective, experimental investigation on healthy volunteers. METHOD: MEPs of the cricothyroid and vocalis muscles elicited by cortical TMS with a figure-8-shaped coil were investigated in two groups of six healthy subjects each, with special regard to MEP amplitude as a function of the coil position on the head surface along the interaural line. RESULTS: Bilateral reproducible responses of the cricothyroid and the vocalis muscles could be observed in all subjects. For the cricothyroid muscle, maximal responses were obtained at mean stimulus positions of 7.5 +/- 1.4 cm (contralateral) and of 7.3 +/- 1.3 cm (ipsilateral), respectively. For the vocalis muscle, we found maximal responses at mean stimulus positions of 10.3 +/- 1.9 cm (contralateral) and of 9.6 +/- 1.6 cm (ipsilateral), respectively. Despite a considerable overlap of these coil positions, from which reproducible MEPs could be elicited in both groups of the laryngeal muscles, statistically significant separation of the cricothyroid-and vocalis-associated cortical representation areas was possible. CONCLUSIONS: Our observations point to two different cortical motor representation areas, with the cricothyroid muscle-related area being located more medially.
Authors: S Groppa; A Oliviero; A Eisen; A Quartarone; L G Cohen; V Mall; A Kaelin-Lang; T Mima; S Rossi; G W Thickbroom; P M Rossini; U Ziemann; J Valls-Solé; H R Siebner Journal: Clin Neurophysiol Date: 2012-02-19 Impact factor: 3.708
Authors: J M Prades; M D Dubois; J M Dumollard; L Tordella; J Rigail; A P Timoshenko; M Peoc'h Journal: Surg Radiol Anat Date: 2012-07-11 Impact factor: 1.246