Correlation between the degree of contrast enhancement and the volume of peritumoral edema in meningiomas and malignant gliomas

Peritumoral edema and contrast enhancement of brain tumors are both thought to be due to breakdown of the blood-brain barrier (BBB); however, the exact mechanism by which these two phenomena occur and whether there is a quantitative or etiological relationship is not known. Our purpose was to determine whether the relationship between the breakdown of the BBB, defined radiologically as the degree of contrast enhancement, and the volume of surrounding edema is different for high-grade gliomas and meningiomas. We analyzed 13 meningiomas and 23 gliomas. A direct linear relationship between the degree of contrast enhancement (dC) and volume of peritumoral edema (V) with a high correlation coefficient (R = 0.66, P = 0.0006) was established for gliomas. A mathematical relationship between dC and V could not be established for meningioma. The findings for gliomas offer indirect radiological evidence that the defect in the BBB which causes edema is quantitatively and etiologically related to the defect in the BBB responsible for contrast enhancement. For meningiomas, the lack of a relationship between dC and V implies either that the mechanisms responsible for formation of edema and contrast enhancement are fundamentally different or that a physical barrier in certain meningiomas limits propagation of edema into the adjacent white matter. Received: 4 March 1999 Accepted: 18 March 1999     

Noninvasive assessment of the elastance and reserve capacity of the craniovertebral contents via flow velocity measurements in the straight sinus by TCD during body tilting test.

Invasive recording of intracranial pressure (ICP) changes during cerebrospinal fluid (CSF) infusion-drainage tests have been used to estimate elastance and reserve capacity of craniovertebral contents. The increase in ICP and its pulse-related oscillations lead to "cuff constriction" of cerebral veins. The purpose of this study is noninvasive assessment of elastance and reserve capacity of craniovertebral contents (RCCC) by measurement of flow velocity (FV) in the straight sinus by transcranial Doppler (TCD) during body tilt tests, which cause changes in ICP. The study was performed in 14 healthy volunteers (age 12-49 y, 6 men) and 32 patients with Intracranial Hypertension (IH) (Benign Intracranial Hypertension, n = 14; Brain Tumors, n = 18). The straight sinus was insonated through the occipital window during body tilt tests (BTT). Tilt table position was changed gradually from head up (+75 degrees) to head down (-45 degrees). It was established that systolic flow velocity and amplitude of FV pulsations (Amp) in horizontal position in patients is usually higher than in healthy volunteers. We found that reserve capacity of craniovertebral contents in patients with IH was usually exhausted. Elastance in patients was usually significantly higher than in healthy volunteers. Evaluation of cerebral venous circulation during body tilt tests clearly differs between the patients with IH and the healthy volunteers. The degree of this difference depends on the localization and character of the pathologic process.     

CO2 and indomethacin vasoreactivity in patients with head injury

Summary The purpose of this study was to compare the effect of hyper-ventilation and indomethacin on cerebral circulation, metabolism and pressures in patients with acute severe head injury in order to see if indomethacin may act supplementary to hyperventilation. Fourteen severely head injured patients entered the study. Intracranial pressure (ICP), mean arterial blood pressure (MABP) and cerebral perfusion pressure (CPP) were monitored continuously. Within the first four days after the trauma the CO₂ and indomethacin vasoreactivities were studied by measurements of cerebral blood flow (CBF) (Cerebrograph 10a, intravenous¹³³Xe technique) and arterio-venous difference of oxygen (AVdO₂). Ischaemia was evaluated from changes in CBF, saturation of oxygen in the jugular bulb (SvjO₂), lactate and lactate/oxygen index (LOI). Data are presented as medians and ranges, results are significant unless otherwise indicated. Before intervention ICP was well controlled (14.8 (9–24) mmHg) and basic CBF level was 39.1 (21.6–75.0) ml/100 g/min). The arterio-venous oxygen differences were generally decreased (AVdO₂ = 4.3 (1.8–8.1) ml/100 ml) indicating moderate luxury perfusion. Levels of CMRO₂ were decreased (1.54 (0.7–3.2) ml/100 g/min) as well.Duringhyperventilation (APaCO₂ = 0.88 (0.62–1.55) kPa) CBF decreased with 11.8 (–33.4–29.7) %/kPa and ICP decreased with 3.8 (0–10) mmHg. AVdO₂ increased 34.0 (4.0–139.2) %/kPa, MABP was unchanged, CMRO₂ and CPP increased (CPP = 3.9 (–10–20) mmHg). AVD (lactate) and LOI were unchanged. No correlations between CBF responses to hypocapnia and outcomes were observed.An i.v. bolus dose ofindomethacin (30 mg) decreased CBF 14.7 (–16.7–57.4) % and ICP decreased 4.3 (–1–17) mmHg. AVdO₂ increased 27.8 (–40.0–66.7)%, MABP (MABP = 4.9 (–2–21) mmHg) and CPP (CPP = 8.7 (3–29) mmHg) increased while CMRO₂ was unchanged. No changes in AVd (lactate) and LOI indicating cerebral ischaemia were found.Compared to hyperventilation (changes per 1 kPa, at PaCO₂ level = 4.05 kPa) the changes in MABP, CPP and CBF were significantly greater after indomethacin, while the changes in AVdO₂, ICP, SvjO₂, and LOI were of the same order of magnitude.Nocorrelation between relative reactivities to indomethacin and CO₂, evaluated from changes in CBF and AVdO₂, or between the decrease in ICP after the two procedures were found. Thus, some patients reacted to indomethacin but not to hyperventilation, and vice versa.These results suggest that indomethacin and hyperventilation might act independently, or in a complementary fashion in the treatment of patients with severe head injury.     

Benign intracranial hypertension vs. intracranial arteriovenous malformation: A possible CT dilemma

Summary A nine-year-old boy, presenting only with signs of increased ICP, underwent computerized tomography. This examination demonstrated no abnormalities in the precontrast scan. Following C. E., it showed scattered areas of blood-like density in both hemispheres, as well as a presumedly abnormal vessel in the left occipital region and dilated vein of Galen, sinus rectus, and tentorial veins. The presumptive diagnosis of left occipital AVM was not confirmed by angiography, which also ruled out obstructions of the intracranial sinuses.The possible mechanism responsible for this atypical CT picture is briefly discussed in the light of pertinent literature. It is suggested that careful consideration should be given to the indications for angiography in similar cases, in the presence of a hypervascular aspect of the postcontrast CT scan, particularly if a considerable amount of contrast medium has been used.     

Analysis of intracranial pressure

Methods for the acquisition and analysis of intracranial pressure (ICP) signals are reviewed from clinical and technical perspectives. The clinical importance of ICP monitoring is presented, and methods for ICP transduction are briefly discussed. These methods include intraventricular catheters, subarachnoid screws, epidural techniques, and the new fiberoptic ICP measurement systems. Approaches to the visual analysis of the ICP waveform are presented, with special emphasis on the relationship between the ICP waveform and the arterial blood pressure signal. Methods of computer-based ICP analysis are also reviewed, including histogram and systems analysis methods. Methods to predict ICP pressure rises and to estimate intracranial compliance are also discussed. Finally, ICP monitoring is reviewed from the point of view of patient outcome. It is concluded that advanced ICP waveform analysis methods warrant further clinical evaluation to demonstrate their clinical usefulness.     

Mass lesions of the frontal lobes in acute head injuries. A comparison with temporal lesions

Summary Contusions and lacerations of the frontal lobes are very frequent; 43.4% in the whole series of traumatic brain mass lesions. Clinical, ICP, CT scan data and neuropathological findings in patients with such lesions are analysed and correlated. Moreover, the clinical features and the outcome of frontal masses undergoing surgery are also compared with similar lesions located in the temporal lobes.Frontal lesions cannot be differentiated on purely clinical grounds and the factors governing the outcome in both locations are the same. On the whole, surgical indications nowadays seem to be rather rare; only lesions behaving truly as expanding lesions with obvious intracranial hypertension benefiting from surgery.Brain contusion-laceration syndromes in general can no longer be considered separate entities. Neither should they be included in the miscellaneous group of traumatic intracranial mass lesions, since the pathophysiological significance of purely extracerebral effusions is entirely different.Traumatic contusions and lacerations and/or intracerebral haematomas, whether frontal or located elsewhere, should, instead, be considered in the context of head injuries of a different degree of gravity, as having collateral features which, on occasion, may call for surgical management.     

Combined endovascular therapy of ruptured aneurysms and cerebral vasospasm

We describe two patients with subarachnoid haemorrhage due to a ruptured intracranial aneurysm and severe symptomatic vasospasm. The aneurysm was occluded with detachable coils followed by intra-arterial infusion of papaverine to treat vasospasm as an one-stage procedure. There was significant resolution of the vasospasm. The long-term clinical outcome in one patient was excellent, the other still has minor deficits. Combined endovascular aneurysm therapy followed by intra-arterial spasmolysis with papaverine is a technically feasable therapeutic alternative in patients with symptomatic vasospasm. Received: 5 November 1999/Accepted: 12 July 2000     

急性脑肿胀去大骨瓣减压术后迟发性血肿

目的探讨外伤后急性脑肿胀去大骨瓣减压术后迟发性血肿的发病机制及临床表现，以提高该类病人的手术疗效。方法回顾性分析28例急性脑肿胀去大骨瓣减压术后迟发性颅内血肿病人的临床表现。结果外伤后急性脑肿胀去大骨瓣术后迟发性血肿的发生率为19．56％，术区继发硬膜外血肿10．87％。死亡率为32．12％。结论急性脑肿胀去大骨瓣术后迟发性血肿的发生率较高，多见于脑肿胀缓解病例，对术中出现的急性脑膨出和术后病情恶化应考虑到迟发性血肿的可能，早期的诊断是提高疗效的关键。     

PRIMARY INTRACRANIAL GERM CELL TUMORS: Clinicopathologic Review of 32 Cases

Primary intracranial germ cell neoplasms are rare tumors and constitute a heterogeneous group. We have reviewed 32 cases, over a 21-year period, from the University of Florida. The cases include 22 germinomas, 6 mixed germ cell tumors, and 4 teratomas. The clinical presentations in these cases were more closely related to the location of the tumor, that is, pineal or suprasellar, rather than the histologic subtype. Neuroimaging evaluation was useful in distinguishing between germinomas, teratomas, and other mixed germ cell tumors (MGCTs), primarily by evaluation of cystic versus solid lesions (teratoma versus germinoma), contents of cysts (teratoma versus MGCT), and infiltrative nature of the tumors (MGCT), although cytologic-histopathologic confirmation remains necessary. Germinomas responded favorably to radiation therapy with survival periods of over 16 years; MGCTs were treated with combination chemotherapy and radiation, with a markedly poorer prognosis. This study underlines the critical significance of histopathologic evaluation of the tumor in determining therapeutic interventions as well as prognosis.     

急性颅内血肿清除后继发对侧迟发性血肿

目的：急性外伤性颅内血肿清除的术中及术后，如及时发现对侧迟发性血肿并治疗可提高疗效。方法：在术中发生急性脑肿胀时应在对侧钻颅探查或术后病人恶化时行ＣＴ检查。结果：治疗３０例对侧迟发血肿病人其中１０例死亡，手术死亡率为３３．３％。结论：在清除急性外伤性颅内血肿时发生急性脑肿胀或术后病情恶化应想到对侧可能是迟发性血肿形成，宜尽早钻颅探查或复查ＣＴ，早诊早治可改善预后。