A "Brain Stethoscope" for Measurement of Brain Compliance: A Non-Invasive Tool for Intracranial Pressure Assessment

Determination of intracranial pressure (ICP) is essential for the diagnosis and management of papilledema due to pseudotumor cerebri or other causes. Currently, monitoring of ICP requires invasive procedures including lumbar puncture or an intra-cranial monitor. A non-invasive method to measure raised ICP is needed. It is know that alteration of brain compliance (dP/dV) is present in patients with raised ICP. The ICP waveform can be derived from tympanic membrane (TM) pulsation. Abnormal compliance is associated with faster rise time of the waveform. A modified stethoscope which "hears" the infrasonic movement of the TM can be used to detect this change. Previous data has shown waveforms identical to an implanted ICP sensor.