Validation of a New Non Invasive Method for Intracranial Pressure Monitoring

In clinical practice, intracranial pressure (ICP) represents a key parameter for diagnosing and treating several conditions. Physicians having to manage cases of head trauma, stroke and hydrocephalus need to assess the time course of ICP, yet they are often unwilling to implement invasive monitoring beyond the acute stage, on account of high septic risks. Standard techniques include direct ventricular manometry or measurement in the parenchyma with electronic or fiberoptic devices. Therefore, the design of non-invasive clinical methods for gaining access to pressure changes is an important challenge. Fluctuations of ICP are transmitted to the fluid spaces of the inner ear through the cochlear aqueduct. The Biophysics Laboratory (School of Medicine of Clermont-Ferrand) described that the intra-labyrinthic pressure modify the functional activities of the outer hair cells in the cochlea. Thereby, increases in ICP are transferred to increases in intra-cochlear pressure, which is detected as modifications in cochlear activities. Cochlear activities' recording are non-invasive and technically simple. A probe is gently inserted into the outer portion of the external ear canal.

The objective of this study is to assess prospectively the accuracy and the precision of a new method for ICP monitoring (using cochlear activities) compared with invasive gold standard CSF pressure monitoring.