CORTICAL SPREADING DEPRESSION RECORDED FROM THE HUMAN BRAIN USING A MULTIPARAMETRIC MONITORING-SYSTEM

The number of parameters (i.e., EEG or ICP-intracranial pressure) rout inely monitored under clinical situations is limited. The brain functi on analyzer described in this paper enables simultaneous, continuous o n-line monitoring of cerebral blood now (CBF) rind volume (CBV), intra mitochondrial NADH redox state, extracellular K+ concentrations, DC po tential, electrocorticography and ICP from the cerebral cortex. Brain function of 14 patients with severe head injury (GCS less than or equa l to 8), who were hospitalized in the neurosurgical or general intensi ve care unit was monitored using this analyzer. Leao cortical spreadin g depression (SD) has been reported in many experimental animals but n ot in the human cerebral cortex. In one of the patients monitored. spr eading depression was observed. This is the first time that spontaneou s repetitive cortical SD cycles have been recorded from the cerebral c ortex of a patient suffering from severe head injury. Typical SD cycle s appeared 4-5 h after the beginning of monitoring this patient. Durin g the first 3-4 cycles the responses of this patient were very similar to the responses to SD recorded in normoxic experimental animals. Ele ctrocorticography was depressed whereas extracellular K+ levels increa sed. Tbe metabolic response to spreading depression was characterized by oxidation of intramitochondrial NADH concomitant to a large increas e in CBF. During brain death, an ischemic depolarization, characterize d by decrease in CBF and an irreversible increase in extracellular K+, was recorded.