Intracranial Compliance Assessed by Intracranial Pressure Pulse Waveform.

Area of Science:

• Neurosurgery
• Neurology
• Critical Care Medicine

Background:

• Intracranial pressure (ICP) pulse waveform (ICPW) alterations indicate neurological severity in intracranial hypertension (ICP >20 mmHg) and reduced intracranial compliance (ICC).
• Investigating ICPW changes after skull defects or decompressive craniectomy (DC) is an understudied area.
• This study assesses ICPW morphological alterations in neurocritical care patients with skull defects and DC, correlating ICPW features with elevated mean ICP.

Purpose of the Study:

• To evaluate morphological alterations in ICPW among neurocritical care patients with skull defects and DC.
• To compare ICPW variations based on elevated mean ICP levels in different skull integrity groups.
• To explore ICPW analysis as a potential real-time ICC assessment tool.

Main Methods:

• Included patients requiring ICP monitoring for acute brain injury.
• Performed 10-minute beat-by-beat ICPW analysis with ICP elevation via internal jugular vein compression.
• Analyzed ICPW features (P2/P1 ratio, TTP, pulse amplitude) comparing baseline and compression periods across three groups: intact skull, craniotomy/fractures, and DC.

Main Results:

• Analyzed 57 patients: 21 intact skull, 21 craniotomy/fractures, 15 DC.
• No significant difference in baseline ICP or ICP-induced elevation between groups.
• Significant P2/P1 ratio elevation in intact skull and craniotomy/fracture groups, but a reduction in the DC group (p=0.01). TTP and pulse amplitude showed no significant results.

Conclusions:

• ICPW analysis suggests significantly impaired intracranial compliance in decompressive craniectomy (DC) patients.
• ICPW analysis indicates DC may be protective against further ICP elevations.
• ICPW analysis shows promise as an alternative for real-time intracranial compliance assessment.