Non Invasive Measurements of Intracranial Pressure in Patients With Malignant Glioma

In patients at risk of increased intracranial pressure (ICP), ICP measurements require invasive transducers, usually with insertion of a catheter into the cranium, or through a spinal tap. These invasive modalities involve risks and pain and they can be done only in specialized care units, with a high associated cost.

A novel method for detecting changes in ICP has developed recently. The auditory hair cells emit sounds and electric signals in response to sound, which can be easily detected and measured non-invasively with the help of a microphone probe placed in the external ear canal or regular electrodes. Indeed, the cochlear aqueduct connects the cerebrospinal fluid (CSF) spaces to the inner ear in such a way that ICP and inner-ear fluid pressure equalize within seconds.

A symptom of intracranial pressure (ICP) was observed in glioma patient due to a combination of causes: the inflammatory reaction around the tumor, the mass effect of the tumor, secondary vascular changes, a change in the flow of CSF.

The evaluation of intracranial hypertension by increased ICP (invasive) is not used in the monitoring of intracranial tumors. It is then detected by using routine clinical signs, in combination with a standard imaging method (MRI), but still subjective.

The measurement of noninvasive ICP could allow earlier detection of relapse, and evaluate whether the increase in ICP precedes tumor clinical worsening and / or imaging.