Brain Skull Deformation as a Non-invasive Intracranial Pressure (ICP) Measure

Brain Skull Deformation as a Non-invasive Intracranial Pressure (ICP) Measure: Comparison Between Invasive and Noninvasive Methods.

Background: Although placement of an intra-cerebral catheter remains the gold standard method for measuring intracranial pressure (ICP), there are several limitations to the method. Objectives: The main objective of this study was to compare the correlation and the agreement of the wave morphology between the ICP (standard ICP monitoring) and a new nICP monitor in patients admitted with stroke. Our secondary objective was to estimate the accuracy of four non-invasive methods to assess intracranial hypertension. Methods: We prospectively collected data of adults admitted to an intensive care unit (ICU) with subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH) or ischemic stroke (IS) in whom invasive ICP monitoring placed. Measures had been simultaneously collected from the following non-invasive indices: optic nerve sheath diameter (ONSD), pulsatility index (PI) using transcranial Doppler (TCD), a 5-point visual scale designed for Computed Tomography (CT) and two parameters (time-to-peak [TTP] and P2/P1 ratio) of a non-invasive ICP wave morphology monitor (Brain4care[B4c]). Intracranial hypertension was defined as an invasively measured ICP > 20 mmHg for at least five minutes.

Inclusion Criteria:

- Adult inpatients from a dedicated neurological intensive care unit with ischemic (IS) or hemorrhagic stroke who needed invasive ICP monitoring were prospectively evaluated from March 2019 to March 2020 (before the COVID-19 pandemic).

Exclusion Criteria:

• We excluded patients with chronic neurological diseases (demyelinating diseases, chronic hydrocephalus, pseudotumor brain), suspected brain death, and patients monitored with non-ventricular sensors (e.g., subdural or epidural).