Multielectrode array for simultaneous recording of glucose, oxygen and electrocorticography from cerebral cortex in...

Delineating epileptic tissue before and during surgery is still a major problem. Electroencephalography (EEG), electrocorticography (ECoG), and magnetoencephalography (MEG) evaluations may not always correlate with outcome. Metabolic mapping, i.e. positron emission tomography (PET) or single photon emission tomography (SPECT), is not practical or not sensitive--both spatial and temporal--enough for use in neurosurgery. Amperometric electrochemical electrodes for recording oxygen and glucose from nervous tissue are developed and tested in rat experimental focal penicillin epilepsy model. With a three-by-three array of glucose electrodes, epileptic focus is mapped. Simultaneous recordings of ECoG, oxygen and glucose levels performed. During seizure, extracellular glucose level showed a biphasic response pattern while oxygen level decreased slightly. It has been concluded that such a combined subdural grid recording might help before and during surgery. This method can be used in ischemia and such experimental metabolic studies.