Autoregulation of spinal cord flow: Is the cord a microcosm of the brain?

The purpose of this study was to measure simultaneously spinal cord blood flow (SCBF) and cerebral blood flow (CBF) under conditions of varying mean arterial pressure (MAP) to determine if this parallelism exists. The autoregulatory capability of the spinal cord mirrored that of the brain, with no significant difference in blood flows between the two tissues in the autoregulatory range. Regional areas of the brain and spinal cord also had similar autoregulatory patterns. Values of CBF and SCBF were comparable to those reported by other investigators in barbiturate anesthetized rats. These data provide a coherent reference point in establishing autoregulatory curves under barbiturate anesthesia. The need remains to establish autoregulatory curves for different anesthetic agents in both normal and cord injured animals. It is possible that intraspinal cord compliance, like intracranial compliance, might be adversely affected by the effects of anesthesia on autoregulation of spinal cord blood flow.