# A Multimodal Non-invasive Approach for Intracranial Pressure Assessment: A Single-Center Study

## TL;DR

This study validates a non-invasive method using multiple tests to detect high intracranial pressure in patients with brain injuries.

## Contribution

The study introduces a multimodal non-invasive approach with high specificity and predictive value for detecting elevated intracranial pressure.

## Key findings

- Combining three or more non-invasive measures showed excellent specificity and positive predictive value for ICP ≥ 15 mm Hg.
- The multimodal method achieved an area under the ROC curve of 0.84 for detecting elevated ICP.
- The approach includes ocular ultrasound, transcranial Doppler, and pupillary reactivity assessments.

## Abstract

Background: Intracranial pressure (ICP) monitoring is an integral part of acute brain injury management. While invasive ICP monitoring is the gold standard, there are several medical conditions that preclude its placement. The aim of the present study is to validate a multimodal approach for increasing ICP detection.

Material and methods: In this retrospective study, patients with acute brain injury who had an external ventricular drain (EVD) placement were included. We measured bilateral optic nerve sheath diameter (ONSD) and assessed for optic nerve disk elevation (ONDE) by using ocular ultrasound, bilateral middle cerebral artery pulsatility index (PI) by using transcranial Doppler, and assessed pupillary reactivity with or without a pupillometer as part of a multimodal assessment. We assessed the correlation and agreement of these values with the ICP measured by the EVD.

Results: A total of 56 measurements from 40 patients were included. The presence of three or more variables among mean ONSD > 5 mm, unilateral or bilateral presence of ONDE, at least one MCA PI > 1.2, and bilateral unreactive pupils demonstrated excellent specificity (1, 95%CI 0.92 - 1) and positive predictive value (PPV) (1, 95%CI 0.39-1) for association with ICP ≥ 15 mm Hg, with area under receiver operating characteristic curve of 0.84 (95%CI 0.74-0.94).

Conclusion: Non-invasive multimodal assessment can be easily done at the bedside and seems to correlate well with higher ICP.