Study of regional cerebral blood flow in experimental head injury: changes following cerebral contusion and during spreading depression.

Changes in regional cerebral blood flow (rCBF) following fluid-percussion brain injury (cerebral contusion) were studied in rats using the autoradiographic method. The direct current potential was monitored to identify spreading depression (SD). The rCBF was measured during SD and 2, 4, and 24 hours after injury. rCBF was almost nil in the contused area and decreased considerably in the cortices of the injured side for 4 hours after insult, then recovered by 24 hours. Focal relative rCBF increase occurred in the parietal cortex during SD, and was probably hyperperfusion due to SD. However, the rCBF did not increase over the sham-operated control. The injury probably caused hypoperfusion within 4 hours of insult and abolished the vascular response to SD.