Pulsion hernias of the tympanic membrane

A pulsion hernia of the tympanic membrane is an outwardly bulging, thin, atrophic area of the tympanic membrane. Those patients who develop pulsion hernias repeatedly autoinflate the middle ear and consequently maintain a positive middle ear pressure, which pushes the thin atrophic portion of the tympanic membrane laterally beyond the normal plane of the tympanic membrane. The thinness of the tympanic membrane over the pulsion hernia suggests that the herniation has developed through a pre-existing area of weakness where the fibrous middle layer has disappeared.