First clinical results with a telemetric shunt-integrated ICP-sensor.

The telemetric shunt-integrated sensors available up to now do not deliver negative CSF pressure values. Therefore, a new sensor was designed which is incorporated into the shunt line proximally to the valve. The monitor calculates the pressure values in relation to the atmospheric pressure obtained by a built-in barometer. The sensor covers a pressure range of -100 cmH2O to 200 cmH2O with a resolution of +/- 1 cmH2O. First follow-up experiences are reported with seven patients over 14-17 months. Depending on the patient's body position telemetrically measured CSF-pressures varied between -20 cmH2O in erect and 15 cmH2O in supine position. In a patient with intermittent shunt dysfunction and stiff ventricular walls telemetrically measured CSF values corresponded earlier and were more sensitive with the clinical symptomatology than with the CT scan. So far, recognizable advantages of the telesensor are an improved assessment of shunt dysfunction and marginal CSF pressure increases, with practicability and simplicity of measurements in outpatients and a reduction of expensive CT or MRI controls.