The effect of cerebrospinal fluid pressure on perilymphatic flow in the opened cochlea.

Scala tympani of guinea pigs was perfused with elevated potassium solutions whose concentraus recovery, the concentration curve showed a 'break' approximately 3 min after perfusion ceased. When the CSF pressure was released by opening the cisterna magna, cochlear flow was markedly reduced, and the recovery curve became smoothly exponential, following a much slower return to control levels. This finding lends support to the idea proposed by Moscovitch, Gannon & Laszlo (1973) that longitudinal flow of CSF contributes to perilymph efflux in the patent cochlea.