Speaker
Description
Elevated intracranial pressure (ICP) is a common postnatal complication in premature infants and poses life-threatening risks to the developing brain. While early detection is crucial to patient outcomes, limited diagnostic techniques currently exist for continuous monitoring. The objective of this work was to assess the sensitivity of cerebral hemodynamics and metabolism to abrupt increases in ICP. Data were collected from 7 newborn piglets using an in-house built hybrid near-infrared spectroscopy (NIRS) and diffuse correlation spectroscopy (DCS) system. The NIRS subsystem was developed by pairing a broadband halogen lamp for emission with a charge-coupled-device-based spectrometer for detection. The DCS subsystem consisted of a 785-nm, long-coherence length laser for emission and a single photon counting module for detection. A fitting routine based on the diffusion approximation for a semi-infinite homogenous medium was used to quantify NIRS/DCS parameters. Specifically, NIRS was used to quantify hemoglobin oxygenation to assess the microvascular oxygen supply-consumption balance, as well as the redox state of cytochrome-c-oxidase to assess aerobic metabolism. DCS was used to monitor cerebral blood flow. ICP was gradually increased with a saline infusion into the ventricles. Segmented linear regression of cerebral blood flow, oxygenation, and metabolism revealed distinct breakpoints in the ICP level beyond which the slopes of changes in the parameters became substantially steeper. More specifically, while cerebral blood flow and hemoglobin oxygenation rapidly decreased with the induction of intracranial hypertension, the redox state of cytochrome-c-oxidase remained stable, indicating preserved metabolism despite the early hemodynamic compromise. These findings suggest the existence of compensatory mechanisms that resist hemodynamic and metabolic changes until a critical threshold of ICP is exceeded. This hybrid NIRS/DCS system is a promising non-invasive neuromonitoring tool for detecting early signs of elevated ICP to guide clinical management. Future work will aim to validate these findings in a diverse clinical population.
| Keyword-1 | Near-infrared spectroscopy |
|---|---|
| Keyword-2 | Intracranial pressure |
| Keyword-3 | Neuromonitoring |