IT IS generally assumed that the cochlear aqueduct is a canal through which spinal fluid flows from the subarachnoid spaces to the scala tympani of the cochlea. This theory of the physiology of the cochlear aqueduct is based entirely on histopathologic observations. Grunberg, Voss, Ulrich, Grove, Crowe, and Perlman and Lindsay1, among others, collected a number of temporal bones of patients who succumbed soon after an intracranial operation or a fracture of the skull. When blood was found in the subarachnoid spaces of these specimens, blood was also noted in the perilymphatic spaces of the cochlea. In addition, red blood cells were demonstrated in the cochlear aqueduct, especially near its cochlear opening. From these observations Crowe deduced that "there is a normal flow of cerebrospinal fluid in the cochlear aqueduct from the meninges to the scala tympani."
Experiments done on animals and cadavers up to the present time have led