Assessment of ischemic stroke rat using near infrared spectroscopy

Abstract

Although varied approaches have been developed for quantifying the severity of cerebral dysfunction under ischemic stroke, the neurological scoring and behavior assessment cannot provide noninvasively time-course assessment. The aims of this study are to design non-invasive electrophysiological and optical method to assess the brain recovery of ischemic stroke. The recording system for somatosensory evoked potentials (SSEPs) using surface electrode and neurovascular response using near infrared spectroscopy (NIRS) was developed. A cranial probe was designed to arrange sensing electrodes and optical fibers for concurrent electrical and optical signal acquisition. The pin electrodes consist of spring electrode probe which can provide the well-contact between brain skull and electrode. The Continuous-Wave (CW) NIRS was employed to monitor in-vivo hemodynamic response using avalanche photodiodes (APD). Our results of SSEPs show decayed P1-N1 amplitude and frequency shifted in time frquency analysis after cerebral ischemia. In the future study, our NIRS system will be expanded to employ three wavelengths, which allows the assessment of cytochrome C oxidase. The integration of neurovascular assessment and low level laser therapy (LLLT) system should provide useful tool for time-course monitoring of various novel treatments to the animal of ischemic stroke. © 2011 Springer-Verlag.