INSERM U 318, CHU, Clinique Neurologique, BP 217, 38043 Grenoble Cedex 9, France
Claire Lise Tournier
Clinique Neurologique, Grenoble, France
Alim L. Benabid
Univ. Joseph Fourier, 38043 Grenoble Cedex 9, France
The relationship among several parameters of the ramp-and-hold force contraction and target force level was quantified for the upper lip, lower lip, and tongue on the one hand, and right and left index on the other hand, in 12 normal subjects (6 males and 6 females). Using visual feedback, subjects produced ramp-and-hold compression lip, tongue, and index forces as rapidly and accurately as possible to end-point target levels ranging from 0.25 to 2 newtons, these fine force occurring within physiologic levels presumably involved in speech production. Given the special anatomic and physiologic characteristics of the orofacial system, the purpose of this study was to compare lip, tongue, and finger force control in order to determine whether the motor control is uniform in both systems, that of the speech production and that of the limb, and within subsystems of speech production. Consequently, can be pathophysiology of a movement disorder in its stereotypic form be considered across limb and speech systems? It seems likely that measures of orofacial force control provide useful insights into the fundamental motor control problem of any individual with dysarthria.