Brain in a Box

The brain, despite its sophistication, resides in a rudimentary container. The rigid cranium restricts enlargement of its contents, so that intracranial pressure rises rapidly as brain volume expands. When pressure becomes greatly elevated, cerebral blood flow is impeded, and the result is brain death. For this reason, the reduction of elevated intracranial pressure is a central theme in the management of traumatic brain injury, cerebral hemorrhage, and most other intracranial mass lesions. The widely adopted recommendation of the Brain Trauma Foundation is to keep intracranial pressure below 20 mm Hg in order to avoid poor outcome1; adherence requires that . . .