Diffuse optical tomography for mapping cerebral hemodynamics and functional connectivity in delirium

Area of Science:

• Neuroscience
• Biomedical Engineering
• Critical Care Medicine

Background:

• Delirium is linked to mortality and dementia, but its pathophysiology is unclear.
• Imaging delirious patients is challenging, hindering biomarker development.
• Diffuse optical tomography (DOT) is a portable, 3D imaging technique suitable for bedside use.

Purpose of the Study:

• To investigate cerebral oxygenation and prefrontal cortex functional connectivity in delirium using DOT.
• To compare these measures during and after a delirium episode and with non-delirious controls.

Main Methods:

• A portable DOT system was developed for bedside functional neuroimaging.
• Twenty-five delirious and 25 matched non-delirious patients were studied.
• Novel DOT task-focused seed-based correlation analysis was implemented.

Main Results:

• Delirious patients showed significantly decreased total hemoglobin (cerebral oxygenation).
• Functional connectivity in the prefrontal cortex was altered in delirium patients, even after resolution.
• Connectivity remained weaker in recovered delirium patients compared to controls.

Conclusions:

• DOT is a promising imaging biomarker for assessing cerebral oxygenation and functional dysconnectivity in delirium.
• Further research should explore cerebral oxygenation's role in delirium and its link to dementia.