Does the ENoG Value of the Orbicularis Oris Muscle Reflect All Facial Nerve Degeneration

Objectives:1) Compare electroneuronography (ENoG) values in patients with facial palsy using two different methods, the midline method that records compound muscle action potentials (CMAPs) from the orbicularis oris muscle (the standard muscle for facial ENoG) and five electroneurogram recordings that records five CMAPs from five different facial muscles. 2) Reveal whether the ENoG value obtained with the midline method reflects entire facial nerve degeneration.Methods:Forty patients with facial palsy were enrolled. CMAPs were recorded using the midline method, in which the anode was placed on the mental protuberance and the cathode was placed on the philtrum. Additionally, five electroneurogram recordings were obtained by placing the anode on the skin of the parietal region and five cathodes on the skin over five facial muscles (frontalis, orbicularis oculi, nasalis, orbicularis oris, and depressor anguli oris muscles). ENoG values recorded using the two methods were compared.Results:The ENoG values of t...