In vivo detection of cortical optical changes associated with seizure activity with optical coherence tomography

Abstract

The most common technology for seizure detection is with electroencephalography (EEG), which has low spatial resolution and minimal depth discrimination. Optical techniques using near-infrared (NIR) light have been used to improve upon EEG technology and previous research has suggested that optical changes, specifically changes in near-infrared optical scattering, may precede EEG seizure onset in in vivo models. Optical coherence tomography (OCT) is a high resolution, minimally invasive imaging technique, which can produce depth resolved cross-sectional images. In this study, OCT was used to detect changes in optical properties of cortical tissue in vivo in mice before and during the induction of generalized seizure activity. We demonstrated that a significant decrease (P < 0.001) in backscattered intensity during seizure progression can be detected before the onset of observable manifestations of generalized (stage-5) seizures. These results indicate the feasibility of minimally-invasive optical detection of seizures with OCT.

INS-fOCT: a label-free, all-optical method for simultaneously manipulating and mapping brain function

“…15,23,57 The fast temporal part of the fOCT signal might also involve neuronal membrane displacements (or deformations) during stimulation, which has been detected with phase-sensitive interferometric or low-coherence imaging techniques. [24][25][26][58][59][60][61] Typically, nanometer-scale displacements were detected on a millisecond time scale and were thought to be caused by the swelling and shrinkage of the nerve fiber 24,25,60 and neural cell bodies. 58,61 Akkin et al 25 reported that the nerve displacements accompanied fast light scattering changes.…”

First in vivo visualization of the human subarachnoid space and brain cortex via optical coherence tomography

“…In animal studies, OCT recently proved to be a valuable and diverse neurophysiological imaging tool in domains like haemodynamic imaging, 24–27 functional imaging 28,29 and molecular imaging. 30 In experimental setups OCT could not only differentiate grey and white matter 12 but furthermore, healthy and tumor-invaded brain tissue.…”

Optical Coherence Tomography: Basic Concepts and Applications in Neuroscience Research

“…Moreover, the ability to noninvasively map the variations of CBF over a long period of time using OCT angiography would contribute to the understanding of the complex mechanisms related to TBI recovery [ 3 ]. Some research groups are utilizing OCT to detect cortical optical changes during seizure activity [ 92 , 93 ]. As it is a relatively newer field of research, future studies should compare the temporal performance of seizure detection with OCT with that of gold standard EEG.…”