Application of optical methods in the monitoring of traumatic brain injury: A review

Abstract

We present an overview of the wide range of potential applications of optical methods for monitoring traumatic brain injury. The MEDLINE database was electronically searched with the following search terms: “traumatic brain injury,” “head injury,” or “head trauma,” and “optical methods,” “NIRS,” “near-infrared spectroscopy,” “cerebral oxygenation,” or “cerebral oximetry.” Original reports concerning human subjects published from January 1980 to June 2015 in English were analyzed. Fifty-four studies met our inclusion criteria. Optical methods have been tested for detection of intracranial lesions, monitoring brain oxygenation, assessment of brain perfusion, and evaluation of cerebral autoregulation or intracellular metabolic processes in the brain. Some studies have also examined the applicability of optical methods during the recovery phase of traumatic brain injury . The limitations of currently available optical methods and promising directions of future development are described in this review. Considering the outstanding technical challenges, the limited number of patients studied, and the mixed results and opinions gathered from other reviews on this subject, we believe that optical methods must remain primarily research tools for the present. More studies are needed to gain confidence in the use of these techniques for neuromonitoring of traumatic brain injury patients.

Ultrasound-tagged near-infrared spectroscopy does not disclose absent cerebral circulation in brain-dead adults

“…25e28 To solve this contradiction, some authors argued that, during brain death, oxygenated blood may be somehow compartmentalised in the brain, so that the NIRS assessment of normal oxygenation in a nonperfused brain could be correct. 2,3,29 This hypothesis, however, conflicts with several lines of evidence in animals and in a limited number of human reports. Brain death is the result of progressive global cerebral ischaemia, in which raised intracranial pressure reduces cerebral perfusion pressure (CPP) and consequently CBF.…”

Improving Localization of Deep Inclusions in Time-Resolved Diffuse Optical Tomography

“…The superscript indicates that absorption values obtained at iteration k were used. The reconstructed absorption will be the result of adding all δµ a to the initial absorption estimation, that is, µ a = δµ (1) a + δµ (2) a + . .…”

“…Time-resolved diffuse optical technology is an emerging photonic technique to continuously quantify the concentrations of several physiological chromophores such as hemoglobin, lipid or collagen. Successful measurements have been done at different human body locations such as brain [1,2], breast [3] or thyroid [4]. An interesting extension of this technology is to perform diffuse optical tomography [5,6] by computing three-dimensional maps of oxy-and deoxy-hemoglobin; in this approach, photon propagation is modeled in a computer and results are compared with experimental measurements.…”

Prospective Evaluation of Post-Traumatic Vasospasm and Post-Injury Functional Outcome Assessment: Is Cerebral Ischemia Going Unrecognized in Patients with Traumatic Brain Injury?

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