Stapedius Muscle Reflexes and OTO-Neurological Examinations in Brain-Stem Tumors

Abstract
Stapedius-muscle-reflex examinations were performed on two patients shown to have brain stem tumours. The reflexes were tested with an impedance-measuring device capable of measuring the stapedius reflexes not only by contralateral stimulation but with homolateral stimulations as well. In these patients, the contralateral stimulation produced no response, while homolateral stimulation resulted in normal reactions. These indications can only be explained by an interruption of the reflex arch of the stapedius muscle at a point within the brain stem, between the cochlear nuclei on the one side and the facial nucleus on the other side. An apparatus of the type mentioned above is valuable in the diagnosis and localization of brain stem affections and in the further in vestigation of the stapedius muscle reflex arch.