151
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Kuhl DE, Alavi A, Hoffman EJ, Phelps ME, Zimmerman RA, Obrist WD, Bruce DA, Greenberg JH, Uzzell B. Local cerebral blood volume in head-injured patients. Determination by emission computed tomography of 99mTc-labeled red cells. J Neurosurg 1980; 52:309-20. [PMID: 7359185 DOI: 10.3171/jns.1980.52.3.0309] [Citation(s) in RCA: 80] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Local cerebral blood volume (CBV) was mapped in 10 normal subjects and in 30 patients after head injury. In normal subjects, the mean CBV was 4.34 ml/100 gm. The coefficient of variation was 12% for the group mean, and 3% for values obtained in duplicate studies of individuals. Patients with head injuries were divided into three groups according to the stage of their illness: acute illness, early recovery, and later recovery. Averages of mean CBV were within one standard deviation of normal. In contrast, consistent changes were found in serial studies of the mean CBV in the same patient. Compared to recovery values, levels of mean CBV measured soon after injury were reduced, largely at the expense of the gray-matter compartment. In five adults with predominantly unilateral lesions, there was an average early reduction in mean CBV and cerebral blood flow of 15% and 36%, respectively. In three children with diffuse brain swelling, there was an average early mean CBV reduction of 12%; a single child had early increased mean CBV at a time when intracranial pressure was high. Greater changes were seen in local CBV on individual sections. There were mixed zones of hypervolemia and hypovolemia in regions of infarction and intracerebral hematoma. Subdural hematomas had consistent medial margins of increased local CBV, representing dilated blood vessels of the underlying cortex. The presence and displacement of this hypervolemic zone were sensitive indicators of persistent subdural collection and mass effect, even when the collection was lucent to x-ray computed tomography.
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152
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Avezaat CJ, van Eijndhoven JH, Wyper DJ. Cerebrospinal fluid pulse pressure and intracranial volume-pressure relationships. J Neurol Neurosurg Psychiatry 1979; 42:687-700. [PMID: 490174 PMCID: PMC490301 DOI: 10.1136/jnnp.42.8.687] [Citation(s) in RCA: 193] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In six anaesthetised and ventilated dogs the CSF pulse pressure was compared with the volume-pressure response (VPR) during continuous inflation of an extradural balloon. Both pulse pressure and VPR increased linearly with the ventricular fluid pressure (VFP) up to a mean VFP of 60 mmHg. At this pressure a breakpoint occurred above which the CSF pulse pressure showed a steeper linear increase, while the VPR remained constant. It is suggested that the breakpoint is related to failure of autoregulation, and that in non-autoregulating patients the CSF pulse pressure is a better parameter of the clinical state than the VPR.
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153
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Matsuda M, Yoneda S, Handa H, Gotoh H. Cerebral hemodynamic changes during plateau waves in brain-tumor patients. J Neurosurg 1979; 50:483-8. [PMID: 423003 DOI: 10.3171/jns.1979.50.4.0483] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The plateau wave, one of the wave forms observed in patients with increased intracranial pressure, has previously been extensively investigated, but its pathophysiological aspect is as yet unclear. The authors undertook a study of cerebral hemodynamic changes while the plateau waves were observed in five brain-tumor patients. Although the number of cases studied was small, a remarkable decrease in cerebrovascular resistance was seen in all patients during the plateau waves. It is suggested that the plateau waves are caused by a marked cerebral vasodilatation. The present results support the thesis that cerebral blood volume is increased during the plateau waves. The plateau waves are closely related to the intrinsic vasomotor control of cerebral circulation, and can occur as long as cerebral vasodilating ability is maintained, irrespective of the existence of cerebral autoregulation.
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154
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Hallenbeck JM, Furlow TW, Ruel TA, Greenbaum LJ. Extracorporeal glass-wool filtration of whole blood enhances post-ischemic recovery of the cortical sensory evoked response. Stroke 1979; 10:158-64. [PMID: 35863 DOI: 10.1161/01.str.10.2.158] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In twenty dogs, anticoagulated with heparin 300 units/kg, the right cortical sensory evoked response (CSER) to contralateral median nerve stimulation was suppressed during 60 min ischemia induced by periodic infusion of 50 to 100 microliter increments of air via the right internal carotid artery. The post-ischemic recovery of the CSER was followed an additional 60 min in 19 of these animals divided into 2 groups. Ten dogs were subjected to glass-wool filtration of their blood by extracorporeal shunting from femoral artery to femoral vein for one hr prior to infusing air. Nine dogs did not receive glass-wool filtration. Post-ischemic recovery of CSER amplitude, a quantifiable electrophysiologic index of neuronal function, was significantly greater in the filtered group than in the non-filtered group. 14C-antipyrine autoradiographic blood flow studies were performed in 3 dogs. One was studied at the end of a 60 min ischemic CSER suppression period and showed severe flow disruption by air embolism. Two dogs, one from each group, were studied at the conclusion of the 60 min recovery period. In the filtered animal, cortical blood flow exceeded the threshold for CSER maintenance while cortical flow rates in the unfiltered animal fell below this threshold. The enhanced postischemic neuronal recovery in the filtered group as indicated by the CSER in attributed to the preservation of injury zone nutrient blood flow that is supported by collateral circulation.
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155
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Lin SR, O'Connor MJ, King A, Harnish P, Fischer HW. Effect of dextran on cerebral function and blood after cardiac arrest. An experimental study on the dog. Stroke 1979; 10:13-20. [PMID: 432896 DOI: 10.1161/01.str.10.1.13] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
EEG activity and regional cerebral blood flow were monitored during 5 hour survival following cardiac arrest in 32 pentobarbital anesthetized mongrel dogs. The animals were mechanically ventilated and blood gases were maintained at physiologic levels. Regional cerebral blood flow and cardiac output were measured using 15 mu microspheres. EEG was recorded from 6 epidural electrodes using bipolar techniques. The animals were divided into 3 groups. The animals in Group I had an arrest of 8-11 minutes and those in Group II and III had an arrest of 12-16 minutes. Group II animals received no treatment. Group III animals were given 1 g/kg of dextran 40 at a concentration of 10% in normal saline following the arrest and maintained with 10 mg/kg/min during the 5 hours of recovery. In Groups I and III there was shorter duration of a flat EEG and 5 hours after the arrest the EEG activity was closer to normal than in Group II. After 5 hours the EEG scores of Group III were significantly greater than Group II (p less than 0.03). The cortical grey matter and hippocampus had the greatest reduction of blood flow following cardiac arrest. The mean cortical grey matter blood flow in Group II was less than in Groups I and III at 3 hours. After 5 hours the grey matter blood flow was greater in Group III than in Group II (p less than 0.09). The findings of this study are consistent with the hypothesis that after cardiac arrest perfusion abnormalities persist or develop after return of blood pressure and that these can be corrected or prevented with improved functional survival by treatment with dextran 40 after the arrest.
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156
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Boisvert DP, Overton TR, Weir B, Grace MG. Cerebral arterial responses to induced hypertension following subarachnoid hemorrhage in the monkey. J Neurosurg 1978; 49:75-83. [PMID: 96231 DOI: 10.3171/jns.1978.49.1.0075] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Regional cerebral blood flow (rCBF), angiographic cerebral arterial caliber, and cerebrospinal fluid (CSF) pressure were measured in rhesus monkeys to determine the effect of experimentally induced subarachnoid hemorrhage (SAH) on cerebral arterial responses to graded increases in blood pressure. These measurements were also performed in a control group of monkeys subjected to a mock SAH by injection of artificial CSF into the cerebral space. Before subarachnoid injection of blood or artificial CSF, graded increases in mean arterial blood pressure (MABP) to a level 40% to 50% above baseline values had no effect on rCBF. The major cerebral arteries constricted and CSF pressure remained unchanged. Similar responses were observed after injections of artificial CSF. When MABP was increased in animals that had been subjected to subarachnoid injection of blood, rCBF increased and was associated with dilatation of the major cerebral arteries and moderate increases in CSF pressure. These results demonstrate that cerebral arterial responses to increases in blood pressure may be abnormal in the presence of subarachnoid blood. The manner in which abnormal cerebral arterial reactivity, changes in blood pressure, and vasospasm combine to determine the level of cerebral perfusion following SAH is postulated.
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157
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Symon L. Disordered cerebro-vascular physiology in aneurysmal subarachnoid haemorrhage. Acta Neurochir (Wien) 1978; 41:7-22. [PMID: 665340 DOI: 10.1007/bf01809133] [Citation(s) in RCA: 84] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The technical problems of surgery for anterior circle aneurysm have in large measure been solved. The problem of reduced perfusion to the brain which characterises the patient with aneurysmal subarachnoid haemorrhage in a poor clinical condition demands more subtle physiological handling. It appears likely that maintenance of an intact cell membrane and blood brain barrier may be aided by the exhibition of pre and post-operative steriods, and that concentration on regional perfusion should be the main aim in post-operative management of such cases. This demands maintenance of adequate blood volume, avoidance of platelet stickiness, and utilisation of the pathological paralysis of autoregulation to improve flow to ischaemic zones by hypertensive agents if necessary. The possibility that early operation with evacuation of blood from the basal cisterns may in the end prevent the vascular damage and disordered vaso-reactivity which encourages the development of transient ischaemic deficits, is a concept which has to be actively pursued. The problem is a continuing one which has bedevilled aneurysm surgery for 25 years, but the omens suggest that a solution is appreciably nearer at hand.
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158
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Marmarou A, Shulman K, Rosende RM. A nonlinear analysis of the cerebrospinal fluid system and intracranial pressure dynamics. J Neurosurg 1978; 48:332-44. [PMID: 632857 DOI: 10.3171/jns.1978.48.3.0332] [Citation(s) in RCA: 433] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A mathematical model of the cerebrospinal fluid (CSF) system was developed to help clarify the kinetics of the intracranial pressure (ICP). A general equation predicting the time course of pressure was derived in terms of four parameters: the intracranial compliance, dural sinus pressure, resistance to absorption, and CSF formation. These parameters were measured in the adult cat, and the equation was tested by comparing experimental and calculated values of the time course of pressure in response to volume changes. The theoretical and experimental results were in close agreement, and the role of each parameter in governing the dynamic equilibrium of the ICP was determined. From this analysis, dynamic tests were developed for rapid measurement of CSF formation, absorption resistance, and the bulk intracranial compliance. These techniques are applicable to clinical settings, providing data that are useful in characterizing the physiological mechanisms responsible for raised ICP and assessing changes induced by therapy.
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159
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Abstract
A case of intraoperative early rupture of an infraclinoid aneurysm is reported with data showing the specific dynamics of cerebral arterial flow during aneurysm haemorrhage. Internal carotid artery flow and arteriial blood pressure were recorded throughout the surgical procedure. The rupture took place during preparations for dural opening at a mean blood pressure of 160 mmHg and at a low intracranial pressure of 5 to 6 mmHg. The dura became instantly tight, and was non-pulsatile within 10 seconds. The parietal epidural pressure rose rapidly to 110 mmHg. There was a brief initial increase in flow as the haemorrhage started, followed by a marked reduction within seconds. End-diastolic blood flow arrest was observed at this stage, demonstrating the self-limiting effect of a subarachnoid haemorrhage. This impaired cerebral perfusion pressure, or transmural pressure, is discussed with regard to the risk of cerebral damage as well as the beneficial effect in the staunching of haemorrhage. Carotid artery flow showed a moderately impaired autoregulation and an increased vascular resistance suggesting a no-reflow phenomenon subsequent to these events.
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160
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Sklar FH, Elashvili I. The pressure-volume function of brain elasticity. Physiological considerations and clinical applications. J Neurosurg 1977; 47:670-9. [PMID: 908932 DOI: 10.3171/jns.1977.47.5.0670] [Citation(s) in RCA: 73] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The intracranial pressure-volume function as determined by brain elasticity is reported in normal dogs. Rapid subarachnoid infusions clearly define an exponential relationship between pressure and volume. An aliquot technique to measure elastance (dP/dV) at multiple intracranial pressures demonstrates a linear relationship between elastance and pressure. This follows mathematically from the exponential nature of the basic pressure-volume function. The clinical significance of brain elastance measurements is discussed. It is emphasized that the effects of pressure on CSF dynamics are superimposed on the pressure-volume function of brain elasticity and probably account for the process of spatial compensation for an expanding mass lesion. It is not apparent that elastance measurements can serve as indicators of impending decompensation, since the pressure-volume function of brain elasticity provides no direct information about CSF dynamics. Accordingly, the clinical usefullness of elastance measurements is seriously questioned.
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161
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Reilly PL, Farrar JK, Miller JD. Vascular reactivity in the primate brain after acute cryogenic injury. J Neurol Neurosurg Psychiatry 1977; 40:1092-1101. [PMID: 413885 PMCID: PMC492907 DOI: 10.1136/jnnp.40.11.1092] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The effects of an acute cryogenic injury on cerebral flow (CBF) and cerebral vascular reactivity were studied in 12 anaesthetised, ventilated baboons. Autoregulation, defined in this study as intact with a greater than 20% change in cerebrovascular resistance in response to a change in cerebral perfusion pressure, was tested before the lesion by arterial hypotension. Intact autoregulation was found in half the animals, but all animals showed an increase in CBF with hypercarbia. The cryogenic lesion was followed by a marked rise in intracranial pressure, and a fall in CBF which was only partly related to the status of autoregulation beforehand. After injury, arterial hypertension caused an increase in cerebrovascular resistance of more than 20% in half the animals. This response was not related to the presence of autoregulation before the lesion, and was accompanied by a greater impairment of the cerebrovascular response to carbon dioxide, more severe brain oedema, and lower cerebral oxygen consumption, than in the remaining baboons which had a pressure passive response to arterial hypertension. This study confirms that the failure of CBF to increase with arterial hypertension may indicate severe brain damage rather than intact physiological autoregulation.
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162
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Nordström CH, Rehncrona S. Postischemic cerebral blood flow and oxygen utilization rate in rats anesthetized with nitrous oxide or phenobarbital. ACTA PHYSIOLOGICA SCANDINAVICA 1977; 101:230-40. [PMID: 920215 DOI: 10.1111/j.1748-1716.1977.tb06002.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The present experiments were undertaken to measure postischemic regional cerebral blood flow (rCBF) and oxygen utilization rate (CMRo2) in rats anesthetized with either 70% N2O or phenobarbital (150 mg x kg-1). In previous studies we have found that extensive restitution of cerbral energy metabolites occurs after 30 min of complete cerebral ischemia irrespective of the type of anesthesia used. Following 30 min of pronounced, incomplete ischemia, however, a comparable restitution of cerebral energy state was obtained in deeply anesthetized (phenobarbital 150 mg x kg-1) but not in superfically anesthetized (70% N2O) rats. The objectives of the present investigation were (1) to study whether postischemic cerebral blood flow was higher in barbiturate-anesthetized animals during the initial recirculation period, and (2) to investigate if the protective effects of phenobarbital previously observed could be attributed to a decrease in CMRo2. In both groups of animals a considerable variability in postischemic rCBF was observed between different animals. However, no signs of gross inhomogeneity in blood flow were found and no consistent differences in flow values between the two groups of animals were observed. Since the measured postischemic CMRo2 were identical in both groups of animals and since cerebral venous oxygen contents were above normal the results leave little support to the assumption that, in the present model of transient, incomplete cerebral ischemia, failure of recovery of cerebral metabolism (N2O group) is primarily due to impaired recirculation, nor do they indicate that the protective effects of barbiturates is due to their ability to reduce rate of cerebral energy utilization.
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163
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Sullivan HG, Miller JD, Becker DP, Flora RE, Allen GA. The physiological basis of intracranial pressure change with progressive epidural brain compression. An experimental evaluation in cats. J Neurosurg 1977; 47:532-50. [PMID: 903806 DOI: 10.3171/jns.1977.47.4.0532] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Sequential cerebrospinal fluid (CSF) pressure-volume studies were carried out in seven cats during the expansion at a constant rate of an epidural balloon. The same studies were performed in three control cats. Beginning after 20 minutes of inflation and continuing to the point of pupillary dilatation there was a progressive increase in the pressure-volume index (volume required to change intracranial pressure (ICP) by tenfold). During the course of balloon inflation, there was also a progressive increase in CSF elastance (instantaneous ICP change per unit change in CSE volume). At the point of pupillary dilatation there was a marked, abrupt increase in the pressure-volume index and an equally dramatic decrease in CSF elastance. The CSF outflow resistance increased to a variable extent during balloon inflation. The plot of the CSF pressure versus balloon volume (the mass lesion pressure-volume curve) was of the classical configuration with an initial relatively flat segment and a final steep segment. A hypothesis is presented that interprets the shape of the mass lesion pressure-volume curve in terms of changes occurring in the elastic properties of the tissues surrounding the CSF space and the volume of the CSF space. It is proposed that this hypothesis will explain most of the commonly observed variations in CSF pressure. Confusion regarding the ICP-volume relationships has arisen because of lack of specificity regarding which anatomical spaces are being perturbed.
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164
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James HE, Langfitt TW, Kumar VS, Ghostine SY. Treatment of intracranial hypertension. Analysis of 105 consecutive, continuous recordings of intracranial pressure. Acta Neurochir (Wien) 1977; 36:189-200. [PMID: 848367 DOI: 10.1007/bf01405391] [Citation(s) in RCA: 84] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
One hundred and five consecutive recordings of intracranial pressure (ICP) in 95 patients over a three-year period, using a Scott cannula inserted through a burr hole or a twist drill hole into the anterior horn of the lateral ventricle, represent the patient material for this report. The clinical diagnoses were head injury 32, intracranial tumour 31, aneurysm and arteriovenous malformation 18, brain swelling secondary to systemic disease 8, and brain swelling of unknown etiology 6. ICP exceeded 20 mm/Hg in 86 of the recordings (maximum 110 mm/Hg). Hypertonic mannitol was administered 73 times in 48 patients. ICP was reduced 10% or more (mean 52%) in all but three administrations. The effect of hyperventilation was tested in 50 trials in 34 patients. ICP was reduced 10% or more (mean 47%) in 34 trials. The mean time to maximum reduction of ICP was eight minutes, and ICP returned to control almost immediately after cessation of hyperventilation. Hypothermia was studied in 40 trials in 40 patients. ICP was reduced 10% or more (mean 51%) in half the patients. The infection rate was 6.3% in this four-hospital setting, but four of the six infections were in one hospital. If this hospital is excluded, the infection rate is 3.1%.
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165
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166
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Nakagawa Y, Motomiya M, Tsuru M, Bando M, Tabata M. Role of the posterior hypothalamus in the development of acute brain swelling. J Neurosurg 1977; 46:723-30. [PMID: 16091 DOI: 10.3171/jns.1977.46.6.0723] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Destructive stereotaxic lesions were made in the posterior hypothalamus, unilaterally or bilaterally, in 26 dogs. In 21 dogs the intracranial pressure (ICP) was maintained in normal range, and in five dogs the ICP was artificially elevated to 300 to 400 mm h2o, preceding the procedures to the hypothlamus. Arterial oxygen and carbon dioxide pressure ((PaO2 and PaCO2) were maintained in the normal range. Before and after each procedure, systemic arterial pressure (SAP) was elevated by intravenous injection of norepinephrine (5 X 10(-3) mg/kg) to determined whether the ICP increases coincidentally with elevation of the systemic arterial pressure. The intracranial pressure/mean arterial pressure ratio of elevation by injection of norepinephrine was not significant regardless of the level of the ICP, or of uni-or bilateral lesions of the hypothalamus. The authors conclude that dysfunction of posterior hypothalamus does not play a specific role in the development of vasomotor paralysis leading to acute brain swelling, under conditons of normal or moderately raised ICP with normal PaCO2 and Pato2 levels.
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167
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Wald A, Hochwald GM. An animal model for the production of intracranial pressure plateau waves. Ann Neurol 1977; 1:486-8. [PMID: 617262 DOI: 10.1002/ana.410010515] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This communication describes a reproducible model for the generation of intracranial pressure plateau waves by obstructing the spinal cord central canal of cats with experimentally induced hydrocephalus.
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168
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Hayashi M, Marukawa S, Fujii H, Kitano T, Kobayashi H, Yamamoto S. Intracranial hypertension in patients with ruptured intracranial aneurysm. J Neurosurg 1977; 46:584-90. [PMID: 845646 DOI: 10.3171/jns.1977.46.5.0584] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Simultaneous continuous recording of intracranial pressure (ICP) and systemic blood pressure was carried out in 26 patients admitted within 1 week after subarachnoid hemorrhage (SAH) due to a ruptured intracranial aneurysm. The patients were graded as described by Hunt and Hess. Recordings were made for 1 to 5 days. The more impaired the consciousness, the higher the rate of ICP. In Grade III, IV, and V patients, the mean ICP level was in the range of 15 to 40 mm Hg, 30 to 75 mm Hg, and exceeded 75 mm Hg, respectively. A definite correlation between vasospasm shown by cerebral arteriogram and the clinical grade was not observed. In our series of ICP recordings, we never observed a typical plateau wave. The variations of ICP seen in Grade III and IV patients were the B- and C-waves (15 to 45 mm Hg in amplitude) described by Lundberg, and those in Grade V patients were the high amplitude monotonous waves synchronous with the arterial pulses (15 to 40 mm Hg in amplitude). These phenomena may indicate that Grade III and IV patients with SAH are in a condition of cerebral vasomotor instability, and Grade V patients have cerebral vasomotor paralysis.
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169
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Hamer J, Alberti E, Hoyer S, Wiedemann K. Influence of systemic and cerebral vascular factors on the cerebrospinal fluid pulse waves. J Neurosurg 1977; 46:36-45. [PMID: 830813 DOI: 10.3171/jns.1977.46.1.0036] [Citation(s) in RCA: 78] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In anesthetized, artificially ventilated dogs, the intracranial cerebrospinal fluid (CSF) pulse waves were studied simultaneously with the central aortic pressure, central venous pressure (CVP), and the sagital sinus pressure under physiological conditions and in normovolemic arterial hypotension and hypertension, in acute cardiac insufficiency of the right atrium, in raised intracranial pressure (ICP), and in arterial hypoxemia. The physiological CSF pulsations are shown to be mainly arterial in origin. In the diastolic phase, the descending part of the pulse curve can be modified by venous superpositions coinciding with the right atrial "A" wave. With increase of ICP the configuration of the CSF pulsations changes: the venous superpositions disappear and the waves become more and more arterial in shape. Furthermore, the pulse amplitude increases considerably. The same change can be observed when cerebral vessels are dilated by arterial hypoxemia. During cardiac insufficiency and consecutive increase of CVP, the CSF pulse curve is venous in shape and the right atrial "A" wabe predominates. In arterial hypotension, CSF pressure decreased. Conversely, in angiotensin-induced systemic arterial hypertension, CSF pressure and its pulse amplitude increased. It is concluded that both systemic arterial blood pressure and cerebrovascular reactivity are major determinants for the shape and the pressure amplitude of the intracranial CSF pulse waves. In the presence of cerebral vasodilatation, systemic arterial blood pressure may be an important factor in raising ICP and altering the brain tissue compliance, because cerebral vascular damping of the arterial pulse is diminished and the arterial pressure head may be directly transmitted to the cerebral capillary bed.
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170
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Symon L, Crockard HA, Juhasz J, Branston NM. The effect of intracranial hypertension on cerebrovascular resistance--an experimental study. Acta Neurochir (Wien) 1976; 35:221-32. [PMID: 826129 DOI: 10.1007/bf01406118] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Pulse transmission through cortex between a vein and artery in the middle cerebral distribution has been used as an index of vascular resistance in the middle cerebral field in baboons. Following catheterisation of these small vessels, the skull has been reconstituted and the effect of intracranial hypertension produced by cisternal infusion has been studied. An earlier linear relaxation of resistance in relation to rising intracranial pressure has been succeeded by a second phase in which pulse transmission increases quite profoundly despite minimal further increase in intracranial pressure. This appears to represent the exhaustion of the compliance of the vascular compartment, and corresponds closely to levels of intracranial pressure at which failure of autoregulation to increased intracranial pressure has been observed in previous experiments. Spontaneous bursts of transient increased pressure made their appearance in a number of animals at this level of pressure. The possible significance of increased pulse transmission following exhaustion of compliance in relation to breakdown of the blood brain barrier and potential spreading oedema is discussed.
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171
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Hamer J, Hoyer S, Alberti E, Weinhardt F. Cerebral blood flow and oxidative brain metabolism during and after moderate and profound arterial hypoxaemia. Acta Neurochir (Wien) 1976; 33:141-50. [PMID: 941710 DOI: 10.1007/bf01886665] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In anaesthetized artificially ventilated dogs, the effect of graded arterial hypoxaemia on cerebral blood flow (CBF) and on the oxidative carbohydrate metabolism of the brain was tested. It is shown that the hypoxic vasodilatory influence on cerebral vessels is present even at moderate systemic hypoxaemia, provide that PaCO2 is kept within normal limits. At PaO2 of about 50 Torr, CBF increased from 56.6 to 89.7 ml/100g/min. With increasing cerebral hyperamia (CBF increased to 110.9 ml/100g/min, at PaO2 of 30 Torr), CMRO2 (4.2 ml/100g/min) was not significantly raised above its normal level (4.7 ml/100g/min) even with profound arterial hypoxaemia. This shows that CMRO2 levels are poor indices of hypoxic hypoxia. A disproportionately high increase in cerebral glucose uptake (CMR glucose levels rose from 4.4 to 10.4 mg/100g/min) and enhanced cerebral glycolysis (CMR lactate changed from 0.2 to 1.6 mg/100g/min) at moderately reduced PaO2 (50 Torr) indicated early metabolic changes which became more marked with further falls in arterial oxygen tension. However, 60 minutes after restoration of a normal PaO2 level, CBF and brain metabolism were found to have completely recovered. It is concluded that a short period of profound systemic hypoxaemia does not produce long lasting metabolic and circulatory disorders of the brain provided the cerebral perfusion pressure does not vary, and is kept at normal levels.
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172
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Szewczykowski J, Dytko P, Kunicki A, Korsak-Sliwka J, Sliwka S, Dziduszko J, Grochowski W, Augustyniak B. A method of estimating intracranial decompensation in man. J Neurosurg 1976; 45:155-8. [PMID: 939974 DOI: 10.3171/jns.1976.45.2.0155] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A new method of estimating intracranial decompensation in man is described. An on-line computer system is connected to an intracranial pressure (ICP) monitoring system to compute regression plots of mean ICP vs standard deviation; standard deviation is used as a measure of ICP instability. Two zones with distinctly different slopes are a characteristic feature of these plots. It is thought that the changes of slope signify intracranial decompensation.
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173
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Cuypers J, Matakas F, Potolicchio SJ. Effect of central venous pressure on brain tissue pressure and brain volume. J Neurosurg 1976; 45:89-94. [PMID: 932805 DOI: 10.3171/jns.1976.45.1.0089] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In cats, brain tissue pressure (BTP) was measured by the wick-catheter method. The BTP was positive, but lower than cerebrospinal fluid pressure. Elevation on central venous pressure led only to a transient proportional increase of BTP. When the calvaria and dura of one hemisphere were removed, the rise of BTP was even less. Water content of the brain was normal in either case, even after prolonged venous hypertension. Venous hypertension led in all cases to a marked increase of the brain volume which was caused by vessel dilatation. In brain edema, produced by rinsing the brain surface with ouabain and concentrated saline, BTP was increased permanently by venous hypertension. The water content of the brain was much greater than normal. From these results it was concluded that congestive edema does not occur in the brain unless the tissue is damaged. However, venous hypertension does cause brain swelling.
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174
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Magnaes B. Body position and cerebrospinal fluid pressure. Part 1: clinical studies on the effect of rapid postural changes. J Neurosurg 1976; 44:687-97. [PMID: 1271089 DOI: 10.3171/jns.1976.44.6.0687] [Citation(s) in RCA: 132] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cerebrospinal fluid (CSF) pressure was recorded in 149 patients and arterial blood pressure (BP) in 11 patients while moving between lateral and sitting positions. Rapid tilting initiated waves in BP and CSF filling pressure. The postural CSF pressure wave manifested itself either as a transient or as a stationary wave similar to a plateau wave. When patients sat up, transient waves had amplitudes up to 550 and stationary waves up to 1000 mm H2O. When they lay down, transient waves had amplitudes up to 800 mm H2O. Stationary waves were found only among patients with elevated intracranial pressure and a diseased brain. The waves were mainly caused by changes in cerebral blood volume probably reflecting the postural BP wave and brain autoregulation. Most patients with stationary and large transient waves also manifested clinical symptoms. These symptoms were aggravated when a craniospinal block developed in the sitting position, and were reduced or avoided when the tilting was performed slowly over 2 to 3 minutes.
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175
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Rosenthal M, Martel D, LaManna JC, Jöbsis FF. In situ studies of oxidative energy metabolism during transient cortical ischemia in cats. Exp Neurol 1976; 50:477-94. [PMID: 174928 DOI: 10.1016/0014-4886(76)90020-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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176
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Verdura J, Resnikoff S, Orozco A. A new method for chronic intraventricular measurement of intracranial pressure. Resuscitation 1976; 5:43-8. [PMID: 996377 DOI: 10.1016/0300-9572(76)90019-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A new simple method, which allows rapid access to the ventricular system to monitor intracranial pressure, is described. One of the lateral ventricles is punctured percutaneously, with a hand drill operated by a flash-light battery, and a lumbar puncture needle (20 gauge) attached to a water manometer or to a strain gauge connected to a venous pressure monitor.
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177
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178
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Matakas F, Eibs G, Cuypers J. Effect of systemic arterial blood pressure on cerebral blood flow in intracranial hypertension. J Neurol Neurosurg Psychiatry 1975; 38:1206-10. [PMID: 815513 PMCID: PMC492189 DOI: 10.1136/jnnp.38.12.1206] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In five baboons and 11 cats cerebral ischaemia was produced either by inflating an epidural balloon and or by ligating major arteries supplying the brain. Fifteen of the animals developed intracranial hypertension after cerebral ischaemia. If ICP were high, but still significantly lower than MABP, elevation of MABP by noradrenaline infusions was accompanied by a proportional increase of ICP. However, the increase of ICP was lower than that of MABP so that CPP was raised. CBF measured by the 133Xenon clearance technique was significantly increased by arterial hypertension in eight cases. The proportional increase of CPP and CBF by elevation of arterial blood pressure was substantially greater, the lower ICP was immediately after ischaemia. There was no effect of MABP in cases in which ICP equalled MABP.
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179
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Grubb RL, Raichle ME, Phelps ME, Ratcheson RA. Effects of increased intracranial pressure on cerebral blood volume, blood flow, and oxygen utilization in monkeys. J Neurosurg 1975; 43:385-98. [PMID: 808593 DOI: 10.3171/jns.1975.43.4.0385] [Citation(s) in RCA: 146] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The relationship of cerebral blood volume (CBV) to cerebral perfusion pressure (CPP), cerebral blood flow (CBF), and the cerebral metabolic rate for oxygen (CMRO2) was examined in rhesus monkeys. In vivo tracer methods employing radioactive oxygen-15 were used to measure CBV, CBF, and CMRO2. Cerebral perfusion pressure was decreased by raising the intracranial pressure (ICP) by infusion of artificial cerebrospinal fluid (CSF) into the cisterna magna. The production of progressive intracranial hypertension to an ICP of 70 torr (CPP of 40 torr) caused a rise in CBV accompanied by a steady CBF. With a further increase in ICP to 94 torr, CBV remained elevated without change while CBF declined significantly. Cerebral metabolic rate for oxygen did not change significantly during intracranial hypertension. For comparison, CPP was lowered by reducing mean arterial blood pressure in a second group of monkeys. Only CBF was measured in this group. In this second group of animals, the lower limit of CBF autoregulation was reached at a higher CPP (CPP approximately to 80 torr) than when an increase in ICP was employed (CPP approximately to 30 torr).
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180
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181
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Nemoto EM, Snyder JV, Carroll RG, Morita H. Global ischemia in dogs: cerebrovascular CO2 reactivity and autoregulation. Stroke 1975; 6:425-31. [PMID: 1154479 DOI: 10.1161/01.str.6.4.425] [Citation(s) in RCA: 85] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
One hypothesis on the pathogenesis of post-ischemic-anoxic encephalopathy is impaired cerebral perfusion or the no-reflow phenomenon. Therapies aimed at preventing the development of this phenomenon are increased cerebral perfusion pressure (CPP) and hyperventilation or hypercapnia. Using a dog model in which we have described the progressive development of post-ischemic (PI) cerebral hypoperfusion after 15 minutes of global ischemia induced by aortic and vena cavae clamping, our aims in this study were to determine during the PI cerebral hypoperfusion period: (1) cerebrovascular reactivity to CO2, and (2) cerebral blood (CBF) autoregulation. Post-ischemic cerebral hypoperfusion to about 50% of normal was not accompanied by raised intracranial pressure (ICP) but cerebrovascular CO2 reactivity was markedly attenuated while maintaining some kind of autoregulatory phenomenon. Cerebral uptake of oxygen was not significantly affected by changing PACO2 from 20 to 60 torr at constant CPP or by changing CPP from 64 to 104 torr at constant PaCO2. These results suggest that increasing both CPP and hypocapnia/hypercapnia would not significantly attenuate PI neurological deficit after global cerebral ischemia. However, in two dogs inadvertently hemodiluted in the PI period, increasing CPP from 50 to 200 torr increased CBF by 200%, suggesting that hemodilution plus increased CPP may be effective therapy for amelioration of post-ischemic-anoxic encephalopathy. The significance of our findings on cerebrovascular CO2 reactivity and autoregulation with respect to the mechanism of the no-reflow phenomenon is discussed.
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182
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Di Rocco C, McLone DG, Shimoji T, Raimondi AJ. Continuous intraventricular cerebrospinal fluid pressure recording in hydrocephalic children during wakefulness and sleep. J Neurosurg 1975; 42:683-9. [PMID: 167135 DOI: 10.3171/jns.1975.42.6.0683] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Continuous 24-hour recordings of intracranial pressure and electroencephalographic activity were made on five hydrocephalic children in whom, in the resting wakefulness state, the intracranial pressure (ICP) was considered normal. An increase in both the mean ICP and its oscillations related to cardiac systole was recorded during slow-wave sleep. Further episodic increases, up to a factor of 7 compared to wakefulness values, occurred during sleep. In three patients it was possible to correlate such episodic increases to the rapid eye movement phases of sleep. The authors discuss these phenomena and their possible implication in the progression of hydrocephalus.
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183
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Kuhl DE, Reivich M, Alavi A, Nyary I, Staum MM. Local cerebral blood volume determined by three-dimensional reconstruction of radionuclide scan data. Circ Res 1975; 36:610-9. [PMID: 1122571 DOI: 10.1161/01.res.36.5.610] [Citation(s) in RCA: 74] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We developed a method to determine in man absolute values of local cerebral blood volume (LCBV) localized throughout the brain in three dimensions and presented in a cross-sectional picture format. Previously, absolute values of LCBV have been determined in vivo by stimulated X-ray fluorescence, but these determinations have been limited to one point in the brain at a time. All other previous estimates of LCBV by external emission counting have been contaminated by the significant contribution of blood in the overlying scalp and cranium. In our method, a transverse section scan is made after the injection of -99m-Tc-labeled red blood cells into a peripheral vein. Data processing then gives a point-to-point estimate of absolute radionuclide concentration analogous to an autoradiograph. After the concentration of blood activity is determined, counting data are converted to a two-dimensional map of LCBV representing a cross section at a known level of the brain. In a series of five baboons, the following equation was obtained for the regression plane that relates LCBV in the center of the brain to arterial carbon dioxide tension (P-ALPHA-CO2) and mean arterial blood pressure (MABP): LCBV equals 2.88 + 0.049P-ALPHA-CO2 MINUS 0.013MABP. In patients, LCBE values ranged from 2 to 4 ml/100 g depending on location; higher values corresponded to regions of cerebral cortex. Differences in blood volumes of focal brain lesions were also quantified.
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184
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Miller JD, Leech P. Effects of mannitol and steroid therapy on intracranial volume-pressure relationships in patients. J Neurosurg 1975; 42:274-81. [PMID: 1117324 DOI: 10.3171/jns.1975.42.3.0274] [Citation(s) in RCA: 161] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The intracranial volume-pressure response was measured in 61 patients undergoing continous monitoring of intraventicular pressure. This test, which determlnes the increase in intracranial pressure induced by an addition of 1 ml in ventricular CSF volume in 1 sencond, yields information concerning spatial compensation in patients with intracranial space-occupying processes. On the basis of variability tests, a change in volume-pressure response of 2 mm Hg/ml was accepted as significant. Pronounced enlargement of the ventricles interferes with the test. In patients with intracranial hypertension, intravenous mannitol (0.5gm/kg) and intramuscular betamethasone (26 mg) both reduce the volume-pressure response significantly more than they reduce intracranial pressure. This suggests that these agents favorably alter the configuration of the volume-pressure curve.
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185
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Matakas F, Von Waechter R, Knüpling R, Potolicchio SJ. Increase in cerebral perfusion pressure by arterial hypertension in brain swelling. A mathematical model of the volume-pressure relationship. J Neurosurg 1975; 42:282-9. [PMID: 1117325 DOI: 10.3171/jns.1975.42.3.0282] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Brain swelling was produced in monkeys and cats by the inflation af an epidural balloon against the parietal lobe. Resulting changes in intracranial pressure (ICP) were correlated to variation in systemic arterial pressure (SAP). Intracranial perfusion pressure (ICPP) defined as the difference between SAP and ICP, was found to vary with the degree of arterial hyper-and hypotension. The relationship between SAP and ICP can be explained by an existing equilibrium between extramural pressure and vessel wall circumferential tension. A positive perfusion pressure can exist in brain swelling as long as vessel wall tension is preserved and the degree of expanding brain tissue volume is held below certain limits.
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186
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Zimmermann V, Hossmann KA. Resuscitation of the monkey brain after one hour's complete ischemia. II. Brain water and electrolytes. Brain Res 1975; 85:1-11. [PMID: 162836 DOI: 10.1016/0006-8993(75)90997-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Adult normothermic rhesus monkeys were submitted to one hour's complete cerebral ischemia, followed by periods of blood recirculation varying from 45 min to 24 h. The functional impact of ischemia and the subsequent recovery was monitored by electrophysiological recording and a distinction was made between animals with signs of functional recovery and animals without recovery. Prior to ischemia the water content of the gray matter was 81.1 plus or minus 0.3% (mean plus or minus S.D.) and of the white matter 68.9 plus or minus 0.8%. The sodium-potassium ratio in the gray matter was 0.43 plus or minus 0.02 and in the white matter 0.62 plus or minus 0.06. During one hour's ischemia brain water did not change significantly, but the differences in the sodium-potassium ratio in white and gray matter were reduced. Blood recirculation of the brain after ischemia caused a considerable increase in brain water content and a shift in the sodium-potassium ratio up to 1.0. Calculated brain swelling was maximal after 45 min when it reached 11.1% of the total brain volume in an animal with recovery and 12.2% in another one without recovery. In animals with signs of functional recovery brain swelling rapidly diminished, followed by a more gradual normalization of brain electrolytes within 24 h. In animals without functional recovery electrolyte shifts were irreversible or even progressed further. It is concluded that brain swelling and electrolyte derangements following one hour's cerebral ischemia are fully reversible when signs of functional recovery appear and brain metabolism returns.
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187
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Nagao S, Okumura S, Nishimoto A. Effects of hyperbaric oxygenation on cerebral vasomotor tone in acute intracranial hypertension: an experimental study. Resuscitation 1975; 4:51-9. [PMID: 1188193 DOI: 10.1016/0300-9572(75)90065-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The effects of hyperbaric oxygenation with 2 atm. pressure and 100 percent oxygen on cerebrovascular tone were assessed by the reactivity of the cerebral vessels to CO2 and vasomotor capacitance index (the cranial pressure divided by the mean arterial pressure) in 50 anaesthetized artifically ventilated dogs, in which intracranial pressure was raised by slow inflation of an extradural balloon. Hyperbaric oxygenation reduced the intracranial pressure only at the stage when the cerebral vessels were still responsive to CO2, as indicated by a rise in intracranial pressure of 30-70 mmHg; under these circumstances, both the reactivity of CO2 and the vasoconstrictor tone of cerebral vessels were improved by hyperbaric oxygenation. At this stage, rapid decrease of the intracranial pressure produced by deflation of the extradual balloon showed no rebound, and hyperbaric oxygenation rapidly restored the vasomotor tone. When CO2 failed to influence the intracranial pressure of about 100 mmHg hyperbaric oxygenation did not aid the recovery of the reactivity of the cerebral vessels to CO2 or the vasoconstrictor tone. In extreme intracranial hypertension (above 100 mmHg) when there was reactivity to CO2 and the electroencephalogram was flat, rapid balloon deflation was followed by a further gradual increase of intracranial pressure and hyperbaric oxygenation did not restore the cerebrovascular tone. The effect of hyperbaric oxygenation in experimental intracranial hypertension appeared to be dependent upon the vasoconstrictor tone of the cerebral vessels, which would be indicated by a vasodilator response to CO2.
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188
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189
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Leech P, Miller JD. Intracranial volume--pressure relationships during experimental brain compression in primates. 2. Effect of induced changes in systemic arterial pressure and cerebral blood flow. J Neurol Neurosurg Psychiatry 1974; 37:1099-1104. [PMID: 4443804 PMCID: PMC494851 DOI: 10.1136/jnnp.37.10.1099] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In eight anaesthetized, ventilated adult baboons, the intracranial volume-pressure response was examined at differing levels of raised intracranial pressure during induced changes in systemic arterial pressure and cerebral blood flow. The volume-pressure response is defined as the change in ventricular fluid pressure caused by a volume addition of 0·05 ml to the lateral ventricle. At normal intracranial pressure, the volume-pressure response was unchanged by alterations in systemic arterial pressure and cerebral blood flow. At raised intracranial pressure, however, systemic arterial hypertension rendered the intracranial contents more sensitive to the effects of an addition to the ventricular volume as shown by an increased volume-pressure response. When intracranial pressure was increased, there was a significant linear correlation between the volume-pressure response and both arterial pressure and cerebral blood flow. The clinical implication of this phenomenon is that arterial hypertension in patients with increased intracranial pressure is likely to have a deleterious effect by increasing brain tightness.
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190
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Leech P, Miller JD. Intracranial volume--pressure relationships during experimental brain compression in primates. 1. Pressure responses to changes in ventricular volume. J Neurol Neurosurg Psychiatry 1974; 37:1093-8. [PMID: 4443803 PMCID: PMC494850 DOI: 10.1136/jnnp.37.10.1093] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Intermittent additions of 0·05 ml saline were made into the lateral ventricle of anaesthetized, ventilated baboons at regular intervals during continuous inflation of a supratentorial extradural balloon. Close correlation was observed both between the increase in ventricular fluid pressure (VFP) immediately after the injection and the volume in the balloon (P < 0·001); and between the increase in ventricular pressure and the pressure immediately before the injection (P < 0·001). This change in ventricular fluid pressure, which is termed the volume-pressure response (VPR), helps to delineate the stage reached on the intracranial volume-pressure curve, and is therefore a measure of the capacity of the intracranial contents to compensate for the volume changes produced by an expanding intracranial lesion. The VPR is currently being used in patients and the clinical implications of confirming its validity experimentally are therefore discussed.
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191
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Hamer J, Alberti E, Hoyer S. Effects of arterial hypoxaemia, hypercapnia, and changes in cerebral perfusion pressure on mean cerebrospinal fluid and sagittal sinus pressure. Acta Neurochir (Wien) 1974; 30:167-79. [PMID: 4432782 DOI: 10.1007/bf01405576] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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192
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Shalit MN, Cotev S. Interrelationship between blood pressure and regional cerebral blood flow in experimental intracranial hypertension. J Neurosurg 1974; 40:594-602. [PMID: 4817804 DOI: 10.3171/jns.1974.40.5.0594] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
✓ The interrelationship between systemic blood pressure (BP), regional cerebral blood flow (rCBF), and intracranial pressure (ICP) was investigated in two experimental models of intracranial hypertension in cats. In one group, ICP was raised by the inflation of an extradural balloon; in the other, brain swelling was produced. The effects of raised blood pressure on rCBF and ICP in the two groups differed considerably. In the “brain-swelling” group, elevated BP had no beneficial effects on rCBF. When ICP approached diastolic BP, an increase in BP was followed by a marked increase in ICP and a decrease in rCBF. Therefore, the elevated BP often observed in extreme intracranial hypertension (Cushing response) cannot be regarded as a beneficial, compensatory defense mechanism, but rather as a deleterious phenomenon.
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193
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Aebi M, Huber P. The diameter of the cerebral arteries before and after surgical drainage of brain abscesses. Neuroradiology 1974. [DOI: 10.1007/bf00341597] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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194
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Miller JD, Stanek AE, Langfitt TW. Cerebral blood flow regulation during experimental brain compression. J Neurosurg 1973; 39:186-96. [PMID: 4719697 DOI: 10.3171/jns.1973.39.2.0186] [Citation(s) in RCA: 90] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
✓ The effect of brain compression on cerebral blood flow was measured in 13 anesthetized, ventilated dogs by inflation of extradural balloons. The effects of the raised intracranial pressure, so produced, were correlated with the presence or absence of autoregulation of cerebral blood flow to induced changes of arterial pressure, which was tested immediately prior to each episode of inflation of the balloon. Cerebral blood flow was measured by a venous outflow method and monitored continuously, together with arterial and supratentorial intracranial pressure; arterial pCO2 and body temperature were held constant. Three stages were identified. When autoregulation to a change of arterial pressure was intact, initial inflation of the balloon did not reduce cerebral blood flow until the difference between arterial and intracranial pressure (which was taken to represent cerebral perfusion pressure) was less than 40 mm Hg. When autoregulation was impaired, which occurred after the first inflation of the balloon or was due to preceding arterial hypotension, raised intracranial pressure caused an immediate reduction of cerebral blood flow. At this stage of impaired autoregulation there was a tendency for hyperemia to develop on deflation of the balloon. Finally, after repeated inflation and deflation of the balloon, when brain swelling supervened, cerebral blood flow decreased steadily and failed to increase despite induced increases of arterial pressure and cerebral perfusion pressure.
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195
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Magun JG. The effect of pharmacologically increased blood pressure on brain circulation. Angiographic investigation of arterial diameter and blood flow in patients with normal and pathological angiograms. ZEITSCHRIFT FUR NEUROLOGIE 1973; 204:107-34. [PMID: 4121466 DOI: 10.1007/bf00315937] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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196
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Hamer J, Hoyer S, Stoeckel H, Alberti E, Weinhardt F. Cerebral blood flow and cerebral metabolism in acute increase of intracranial pressure. Acta Neurochir (Wien) 1973; 28:95-110. [PMID: 4724540 DOI: 10.1007/bf01405406] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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197
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Hossmann KA, Lechtape-Grüter H, Hossmann V. The role of cerebral blood flow for the recovery of the brain after prolonged ischemia. ZEITSCHRIFT FUR NEUROLOGIE 1973; 204:281-99. [PMID: 4155720 DOI: 10.1007/bf00316009] [Citation(s) in RCA: 159] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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198
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The Effects of Hypercarbia on Cerebral Blood Flow and Carbohydrate Metabolism in Deep Normovolemic Arterial Hypotension. ACTA ACUST UNITED AC 1973. [DOI: 10.1007/978-3-642-65734-4_22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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199
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Katsurada K, Minami T, Ogawa M, Sugimoto T. Cerebrospinal fluid acidosis and its possible relation to acute brain swelling. THE JAPANESE JOURNAL OF SURGERY 1972; 2:131-40. [PMID: 4680068 DOI: 10.1007/bf02470400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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200
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Paul RL, Polanco O, Turney SZ, McAslan TC, Cowley RA. Intracranial pressure responses to alterations in arterial carbon dioxide pressure in patients with head injuries. J Neurosurg 1972; 36:714-20. [PMID: 5030400 DOI: 10.3171/jns.1972.36.6.0714] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
✓ Cerebral vasomotor responses to alterations in arterial carbon dioxide (PaCO2), as manifested by intraventricular pressure changes, were studied in a group of patients with head injuries. These patients could be classified into three types based on various degrees of responsiveness thought to reflect the integrity of their cerebral vasomotor reactivity.
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