Surface electromyographic characterization of five orofacial ideomotor praxis in 20 healthy individuals

Praxis is a voluntary nonverbal sequence of movements that allows the completion of programmed and organized movements in defined sequences. A type of praxis are the orofacial ideomotor, that allows to perform movements such as open and close the mouth, smiling, make tongue gestures, among others. In the execution of any praxis, a cortical cerebral component and a neuromuscular peripheral structure are involved. There is a limited literature related with the orofacial praxis recording using surface electromyography (sEMG) signals. The purpose of this paper is to describe the electromyographic characteristics of ideomotor orofacial praxis in 20 healthy individuals. Eight electrodes were placed during, the execution of five praxical orofacial movements and we evaluated the root mean square (RMS) of the sEMG signals for the orbicularis oris and masseter muscles. In the five executed praxis we found significant differences in the median values of RMS data, except for the smile praxis where median RMS values were similar. The evaluation of praxis is mainly used in the clinical neuropsychology field, done through tests highly dependent of the clinical expertise as a key element in determining the alteration or normal praxic funtions. This EMG characterization forecasts a progress in terms of the objective study of the praxical disorders with future implementation in diagnosis of apraxias secondary to brain lesions.