Global cerebral ischemia induces spatial propagation of cerebral blood flow during cardiac arrest and after resuscitation (Conference Presentation)

Cardiac arrest (CA) affects over 500,000 people in the United States. Although resuscitation efforts have improved, poor neurological outcome is the leading cause of morbidity in CA survivors, and only 8.3% of out-of-hospital CA survivors have good neurological recovery. Therefore, a detailed understanding of the brain before, during, and after CA and resuscitation is critical. To provide a more complete picture of CBF dynamics associated with CA and resuscitation, we postulate that both temporal and spatial CBF dynamics must be understood. To investigate spatiotemporal dynamics, we used laser speckle imaging (LSI) to image rats that underwent either 5- or 7-min asphyxial CA, followed by cardiopulmonary resuscitation until return of spontaneous circulation (ROSC). During induction of global cerebral ischemia through CA, we observed two time periods during which a decrease in CBF propagates in space in a cranial window over the right hemisphere. The first time-period is during CA and the second after the hyperemic peak, but before CBF plateaus at a hypoperfused state post-ROSC. During CA, the decrease in CBF propagates from the lateral region of the brain to the medial region of the brain. Conversely, post-ROSC, the decrease in CBF propagates from the medial region of the brain to the lateral region of the brain. We postulate that study of spatiotemporal dynamics in a global cerebral ischemia model may lead to important insight into our understanding of cerebral function during and after resuscitation from CA, which may provide clinicians with knowledge that can lead to improvements in neurological outcome.