Shunt-valve noise as an unusual reason for shunt revision

A 29-year-old male patient suffering from communicating hydrocephalus was treated by placement of a ventriculoatrial shunt (Pudenz-Heyer bur-hole valve). A disturbingly loud, pulse-synchronous, bruit in the ear on getting up from lying down remained unrecognized for 3 years as possibly generated by air bubbles in the valve. Clinical and technical investigations by a phonocardiographic and a transcranial Doppler device demonstrated that the noise was a functional indicator of shunting activity, relying on intracranial pressure conductional on arterial blood pressure as determined by its close relationship to the cardiac cycle. When this phenomenon was looked for, it was detected in three other patients, one of whom saw it as a shunt-function indicator.