The evaluation of the tensor veli palatini muscle function with electromyography in chronic middle ear diseases

Abstract

Although there are several factors affecting the pathogenesis of chronic otitis, the pathological process has not been entirely defined yet. One of the theories suggested for the development of middle ear diseases is tubal dysfunction. The aim of the study is to analyze the function of the tensor veli palatini (TVP) muscle electromyographically in chronic middle ear pathologies and to evaluate the role of this muscle in eustachian tube dysfunction and pathogenesis of associated middle ear diseases by comparing with the results of healthy individuals. A prospective, controlled, clinical trial. We enrolled 24 patients with chronic middle ear pathologies into our study and 18 controls without any previous ear problem. Electromyographic (EMG) needle was inserted into the TVP muscles in all patients transnasally. Functions of the TVP muscle were analyzed by using the amplitudes of the motor unit potential (MUP) and MUP durations detected on EMG. MUP amplitudes and MUP durations were compared statistically in all groups. When the mean MUP amplitudes and durations obtained from TVP muscles of all ears from the patient group were compared to the mean MUP amplitudes and durations obtained from healthy individuals, no statistically significant difference was observed between sick ears and control ears. Values obtained from the sick ears needed to be compared with mean values obtained from the control group separately, since absence of statistically significant difference cannot mean that we should ignore individual muscle dysfunction. The results we obtained from our study support that in the formation of different middle ear pathologies, myogenic defects in the eustachian tube have limited effects, except for existence of a predisposing factor like palate pathology. In all patients with chronic middle ear disease it is not appropriate to expect functional muscle dysfunction, however evaluation of TVP muscle function correctly may be helpful for bringing up the underlying possible muscle and nerve pathologies not in all patients.