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Differences in Tissue Oxygenation, Perfusion and Optical Properties in Brain Areas Affected by Stroke: A
1NEWCAT Research Institute, Department of Electrical and Electronic Engineering, College of Engineering, Nihon University, Tokyo, Japan.
Advances in Experimental Medicine and Biology
|September 5, 2018
Summary
Time-resolved near-infrared spectroscopy (TNIRS) can measure cerebral blood oxygenation (CBO) in stroke patients. Abnormal cortices show lower oxygen consumption and longer optical pathlengths, requiring careful interpretation of NIRS data.
Area of Science:
- Neuroscience
- Biomedical Engineering
- Medical Physics
Background:
- Near-infrared spectroscopy (NIRS) is used for cerebral blood oxygenation (CBO) measurements.
- NIRS accuracy in abnormal brain cortices with altered optical properties is uncertain.
Purpose of the Study:
- To compare baseline hemoglobin (Hb) concentrations and optical pathlengths (OPs) between normal and abnormal cortices in chronic stroke patients using time-resolved NIRS (TNIRS).
Main Methods:
- Utilized TNIRS (TRS-20, Hamamatsu Photonics) to measure Hb concentrations and OPs at 760, 800, and 830 nm in five chronic stroke patients.
- Compared measurements between affected and unaffected cortical areas.
Main Results:
- Affected cortices showed significantly lower deoxyhemoglobin (deoxy-Hb) concentrations (p < 0.01) and higher tissue oxygen saturation (p < 0.01), indicating reduced oxygen consumption.
- Significantly longer OPs at 760 and 800 nm were observed on the affected side (p < 0.05).
- Increased cerebrospinal fluid layer due to ischemic brain degeneration may explain altered OPs.
Conclusions:
- NIRS is applicable to patients with abnormal cerebral cortices.
- Consideration of differing optical characteristics between normal and abnormal brain tissues is crucial for accurate NIRS interpretation in stroke patients.
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