Brain tissue pressure gradients created by expanding frontal epidural mass lesion

Abstract

A porcine model was used to study the regional intracranial pressure (ICP) differences caused by a frontal mass lesion. Intraparenchymal ICP monitors were placed in the right and left frontal lobes, right and left temporal lobes, midbrain, and cerebellum. A frontal epidural mass lesion was created by placing a balloon catheter through a burr hole into the right frontal epidural space. A computer was used to acquire data from all monitors at 50-msec intervals. The balloon was expanded by 1 cc over a period of 1 second every 5 minutes and maximum pressure immediately before and during expansion was determined for each balloon volume at each site. Prior to expansion of the mass, the morphology of the cerebellum pressure tracing was different from that seen in all supratentorial regions. Also, pressures in the midbrain, at baseline, were slightly but significantly lower than pressures in the frontal and temporal regions. During expansion of the mass, a pressure differential that increased as the size of the mass increased developed between intracranial regions. Furthermore, the regional pressures were found to vary in a consistent fashion expressed by the formula RF=LF>RT=LT>MB>CB, in which RF and LF are the right and left frontal lobes, RT and LT are the right and left temporal lobes, MR in the midbrain, and CB is the cerebellum. The study shows that an expanding epidural mass reproducibly results in a gradient of brain parenchymal pressure. This gradient results in parenchymal pressures that are significantly different in each region of the brain depending on the proximity of that region to the epidural mass. The results of this study have implications for clinical ICP monitoring and therapy.

Effect of early bilateral decompressive craniectomy on outcome for severe traumatic brain injury

“…More sufficient decompression and suitable ICP decreases may be achieved if this extracalvarial movement is bilateral. Wolfa et al reported the following formula for the brain tissue gradient in right frontal mass lesions: right frontal = left frontal > right temporal = left temporal > midbrain > cerebellum (28,29). Their formula for right temporal mass lesions was: right temporal> left frontal = left temporal > right frontal > midbrain > cerebellum.…”

Is it useful to measure supratentorial ICP in the presence of a posterior fossa lesion? Absence of transtentorial pressure gradients in an animal model

“…12 This mode of ICP transmission is possible only with high ICP values. In the opposite case, however, when a supratentorial ICP elevation occurs, there seems to be no such pressure transmission by tr ans tentorially hern iated brain tissu e, as demonstrated by Wol¯a et al 8 These authors worked with domestic pigs and placed pressure transducers in the frontal and temporal lobes, in the mesencephalon and in the cerebellum. The ICP elevation was caused by a balloon catheter placed epidurally on the right frontal lobe.…”

“…Absolute ICP values were highest in the frontal lobes and lowest in the cerebellum. 8 Our study employed infratentorial ICP elevation and did not register any gradients across the tentorium. Some species-speci® c anatomical differences, however, m ay contribute to these som ew hat discordant results in the animal studies.…”

Intracranial pressure monitoring during decompressive craniectomy in patients with severe traumatic brain injury

“…Розроблено формулу для визначення градієнту тиску тканин мозку в місцях ураження з мас-ефек-том у правій лобовій ділянці: права лобова ділянка = ліва лобова ділянка > права скронева ділянка = ліва скронева ділянка > середній мозок > мозочок; а формула для ураження з мас-ефектом у правій скроневій ділянці: права скронева ділянка > ліва ло-бова ділянка = ліва скронева ділянка > права лобова ділянка > середній мозок > мозочок [21,22].…”