In vivo optical characterization of pediatric epileptogenic lesions

摘要

Epileptogenic lesions and their margins are often difficult to define intraoperatively. We hypothesize that optical spectroscopy can detect unique pathophysiological features of epileptogenic lesions in children and hence differentiate them from normal brain. This hypothesis was tested by comparing the in vivo optical and fluorescence characteristics of epileptogenic brain lesions (non-neoplastic) with those of normal brain. Patients were recruited from those receiving epilepsy surgeries at Miami Children's Hospital. Using a portable spectroscopic system, optical characterization of brain was performed intraoperatively. Fluorescence spectra were measured at 337 nm excitation, and diffuse reflectance spectra were measured between 400 and 850 nm. To date, seven epilepsy patients have been enrolled in the study. A couple interesting trends have been observed in the recorded optical spectra. First, sites within the resection zone, as defined by the intracranial electroencephalogram data, often show higher diffuse reflectance signals than normal sites do. This is especially prominent around 500 nm and between 650 and 850 nm. Secondly, several investigated sites with abnormal electroencephalogram and/or pathology show a unique blue shift in their fluorescence spectra, which is not seen in other cases.