The Presence of Ganglion Cells in the Human Middle Ear: A Histological Survey

Abstract

A histological survey of 871 previously sectioned temporal bones from the Ear Pathology Research Laboratory (EPRL) of the University of Toronto was undertaken to determine the presence of ganglion cell and ganglion cell rests within the human middle ear. The presence of ganglion cells within the middle ear was a common finding noted in 52.3% of temporal bones surveyed. So-called 'ectopic' ganglion cells were identified most often in the greater superficial petrosal nerve (38.7%), the lesser superficial petrosal nerve (12.4%) and on the promontory (11.4%). They were also identified in the main trunk of the intratemporal facial nerve, but in smaller numbers (3%), and for the first time in the tensor tympani muscle. Their consistent presence implies that they should not be considered an abnormal anatomic variant, and further questions accepted conventional anatomic descriptions of middle ear innervation.