Regional cerebral blood flow studies in subarachnoid hemorrhage

1972 ◽  
Vol 37 (1) ◽  
pp. 36-44 ◽  
Author(s):  
M. Peter Heilbrun ◽  
Jes Olesen ◽  
Niels A. Lassen
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Subarachnoid Hemorrhage ◽  
Regional Cerebral Blood Flow ◽  
Surgical Intervention ◽  
Focal Ischemia ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Clinical Grading ◽  
Fine Print

✓ Regional cerebral blood flow (rCBF) studies using the intra-arterial 133xenon method were performed on 10 patients with subarachnoid hemorrhage. Both preoperative and postoperative studies showed evidence of decreased flow in the entire hemisphere studied, and, in addition, evidence of focal ischemia, focal hyperemia, focal vasoparalysis, and often global impairment of autoregulation. The degree of flow abnormalities correlated well with the clinical grading of the neurological deficit. It is suggested that analysis of the state of autoregulation might be useful in determining the time for surgical intervention and that rCBF studies are important in defining the effects of drugs used to counteract the ischemic effects of spasm.

Regional cerebral blood flow monitoring in the diagnosis of delayed ischemia following aneurysmal subarachnoid hemorrhage

2003 ◽  
Vol 98 (6) ◽  
pp. 1227-1234 ◽  
Author(s):  
Peter Vajkoczy ◽  
Peter Horn ◽  
Claudius Thome ◽  
Elke Munch ◽  
Peter Schmiedek
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Subarachnoid Hemorrhage ◽  
Thermal Diffusion ◽  
Regional Cerebral Blood Flow ◽  
High Grade ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Symptomatic Vasospasm ◽  
Fine Print

Object. The goal of this study was to evaluate regional cerebral blood flow (rCBF) monitoring, performed using thermal-diffusion (TD) flowmetry, as a novel means for the bedside diagnosis of symptomatic vasospasm. Methods. Fourteen patients with high-grade subarachnoid hemorrhage (SAH) who underwent early clip placement for anterior circulation aneurysms were prospectively entered into the study. Thermal-diffusion microprobes were implanted into the white matter of vascular territories that were deemed at risk for developing symptomatic vasospasm. Data on arterial blood pressure, intracranial pressure, cerebral perfusion pressure, rCBF measurement obtained using a TD probe (TD-rCBF), cerebrovascular resistance (CVR), and blood flow velocities were collected at the patient's bedside. The diagnosis of symptomatic vasospasm was based on the manifestation of a delayed ischemic neurological deficit and/or a reduced territorial level of CBF as assessed using stable Xe-enhanced computerized tomography (CT) scanning in combination with vasospasm demonstrated by angiography. Bedside monitoring of TD-rCBF and CVR allowed the detection of symptomatic vasospasm. In the 10 patients with vasospasm the TD-rCBF decreased from 21 ± 4 to 9 ± 1 ml/100 g/min (mean ± standard error of the mean), whereas in the four other patients the TD-rCBF value remained unchanged (mean TD-rCBF = 25 ± 4 compared with 21 ± 4 ml/100 g/min). A comparison of the results of TD-rCBF and Xe-enhanced CT studies, as well as the calculation of sensitivities, specificities, predictive values, and likelihood ratios, identified a TD-rCBF value of 15 ml/100 g/min as a reliable cutoff for the diagnosis of symptomatic vasospasm. In addition, TD flowmetry was characterized by a more favorable diagnostic reliability than transcranial Doppler ultrasonography. Conclusions. Thermal-diffusion flowmetry represents a promising method for the bedside monitoring of patients with SAH to detect symptomatic vasospasm. This is of major clinical interest for patients with high-grade SAH, who often cannot be assessed neurologically.

Regional cerebral blood flow in the acute stage of experimentally induced subarachnoid hemorrhage

1983 ◽  
Vol 58 (2) ◽  
pp. 210-216 ◽  
Author(s):  
Felix Umansky ◽  
Thalia Kaspi ◽  
Mordechai N. Shalit
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Subarachnoid Hemorrhage ◽  
Regional Cerebral Blood Flow ◽  
Internal Capsule ◽  
Acute Stage ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Steep Decline ◽  
Triphasic Pattern

✓ Subarachnoid hemorrhage (SAH) was induced in 13 adult mongrel cats by a slow injection of fresh autogenous blood into the cisterna magna. Serial determinations of regional cerebral blood flow (rCBF) in the cortex and deep-seated areas (internal capsule, thalamus, and caudate nucleus) were made during the following 2 hours, while intracranial pressure (ICP) was maintained at normal values. A decrease in rCBF was observed in all the areas examined. This reduction followed a characteristic triphasic pattern with an initial steep decline immediately after the SAH. The clinical implications of these findings are discussed.

Regional cerebral blood flow, sensory evoked potentials, and intracranial pressure in dogs with MCA occlusion by embolization or trapping

1983 ◽  
Vol 58 (4) ◽  
pp. 500-507 ◽  
Author(s):  
Yoshikazu Okada ◽  
Takeshi Shima ◽  
Mitsuo Yamamoto ◽  
Tohru Uozumi
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Intracranial Pressure ◽  
Evoked Potentials ◽  
Regional Cerebral Blood Flow ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Sensory Evoked Potentials ◽  
Sensory Evoked ◽  
Fine Print

✓ Regional cerebral blood flow (rCBF), sensory evoked potentials (SEP), and intracranial pressure (ICP) were investigated in dogs with focal cerebral ischemia produced by a silicone cylinder embolus in the middle cerebral artery (MCA) trunk as compared to that produced by trapping the same vessel. These variables were measured at intervals of 1 hour for a period of 6 hours after MCA occlusion. In the embolized animals, rCBF decreased most extensively at the basal ganglia, from a control level of 53.9 ± 3.9 (mean ± SE) to 21.5 ± 2.7 ml/100 gm/min at the 6th hour. Sensory evoked potentials decreased progressively from the resting level of 100% to 53.0% ± 7.2% at the 3rd hour. Intracranial pressure, measured by epidural pressure on the occluded side, increased rapidly during the first 3 hours, from 10.6 ± 0.3 to about 30 cm H2O. In the animals with trapping, the decreases in rCBF and declines of SEP were significantly less than those in the embolized animals, and no evident brain swelling was observed. This study demonstrates that MCA trunk occlusion by silicone cylinder embolization produces a more marked decrease in deep CBF, with diminution of SEP and increase in ICP, than that produced by trapping.

Continuous monitoring of regional cerebral blood flow: experimental and clinical validation of a novel thermal diffusion microprobe

2000 ◽  
Vol 93 (2) ◽  
pp. 265-274 ◽  
Author(s):  
Peter Vajkoczy ◽  
Harry Roth ◽  
Peter Horn ◽  
Thomas Lucke ◽  
Claudius Thomé ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Thermal Diffusion ◽  
Regional Cerebral Blood Flow ◽  
Linear Regression Analysis ◽  
Secondary Brain Injury ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Arterial Blood ◽  
Fine Print

Object. Current clinical neuromonitoring techniques lack adequate surveillance of cerebral perfusion. In this article, a novel thermal diffusion (TD) microprobe is evaluated for the continuous and quantitative assessment of intraparenchymal regional cerebral blood flow (rCBF).Methods. To characterize the temporal resolution of this new technique, rCBF measured using the TD microprobe (TD-rCBF) was compared with rCBF levels measured by laser Doppler (LD) flowmetry during standardized variations of CBF in a sheep model. For validation of absolute values, the microprobe was implanted subcortically (20 mm below the level of dura) into 16 brain-injured patients, and TD-rCBF was compared with simultaneous rCBF measurements obtained using stable xenon-enhanced computerized tomography scanning (sXe-rCBF). The two techniques were compared using linear regression analysis as well as the Bland and Altman method.Stable TD-rCBF measurements could be obtained throughout all 3- to 5-hour sheep experiments. During hypercapnia, TD-rCBF increased from 49.3 ± 15.8 ml/100 g/min (mean ± standard deviation) to 119.6 ± 47.3 ml/100 g/min, whereas hypocapnia produced a decline in TD-rCBF from 51.2 ± 12.8 ml/100 g/min to 39.3 ± 5.6 ml/100 g/min. Variations in mean arterial blood pressure revealed an intact autoregulation with pressure limits of approximately 65 mm Hg and approximately 170 mm Hg. After cardiac arrest TD-rCBF declined rapidly to 0 ml/100 g/min. The dynamics of changes in TD-rCBF corresponded well to the dynamics of the LD readings. A comparison of TD-rCBF and sXe-rCBF revealed a good correlation (r = 0.89; p <0.0001) and a mean difference of 1.1 ± 5.2 ml/100 g/min between the two techniques.Conclusions. The novel TD microprobe provides a sensitive, continuous, and real-time assessment of intraparenchymal rCBF in absolute flow values that are in good agreement with sXe-rCBF measurements. This study provides the basis for the integration of TD-rCBF into multimodal monitoring of patients who are at risk for secondary brain injury.

K-shell fluorescence for the study of regional cerebral blood flow

1971 ◽  
Vol 35 (2) ◽  
pp. 181-184 ◽  
Author(s):  
Robert A. Moody ◽  
Paul B. Hoffer ◽  
Robert E. Polcyn ◽  
Henry J. Lowe ◽  
Alexander Gottschalk ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Transit Time ◽  
Regional Cerebral Blood Flow ◽  
Clearance Time ◽  
Regional Cerebral Blood ◽  
Radioactive Materials ◽  
Content Type ◽  
Regional Flow ◽  
Fine Print

✓ A new method for determining regional cerebral blood flow is reported which utilizes K-shell fluorescence and thus avoids administration of radioactive materials to a patient. Due to its inherent laminographic features, K-shell fluorescence escapes interference from scalp and skull, while giving a true demonstration of regional flow. It is applicable to either clearance time or transit time techniques. The tracer can be administered either by inhalation or intra-arterial injection. The present study demonstrates its feasibility for use in both animals and humans.

Altered response to histamine in brain tumor vessels: the selective increase of regional cerebral blood flow in transplanted rat brain tumor

1993 ◽  
Vol 79 (5) ◽  
pp. 722-728 ◽  
Author(s):  
Tomojirou Nomura ◽  
Kiyonobu Ikezaki ◽  
Yoshihiro Natori ◽  
Masashi Fukui
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Tumor ◽  
Regional Cerebral Blood Flow ◽  
Blue Dye ◽  
Normal Brain ◽  
Regional Cerebral Blood ◽  
Tumor Vessels ◽  
Content Type ◽  
Fine Print

✓ The authors studied the effect of intracarotid administration of histamine on the regional cerebral blood flow (rCBF) in transplanted rat C6 glioma by the hydrogen clearance method. Histamine infusion at doses of 1 and 10 µg/kg/min produced an increase of rCBF in the tumor (24.6% ± 16.4%, p < 0.002, and 37.6% ± 18.2%, p < 0.0001, respectively) and also in brain surrounding the tumor (26.8% ± 16.2%, p < 0.002, and 34.9% ± 9.2%, p < 0.0001, respectively) without any significant changes in the ipsilateral hemisphere. Intravenous administration of pyrilamine (H1 antagonist) and cimetidine (H2 antagonist) reduced blood flow responses to histamine; cimetidine was a more effective blocking agent than pyrilamine. Intracarotid infusion of histamine (1 and 10 µg/kg/min) with intravenous injection of Evans blue dye disclosed the selective extravasation of dye in the tumor and the brain surrounding the tumor. These results indicated that brain tumor vessels could respond to histamine differently than normal brain capillaries. The mechanism of selective response to histamine could be explained either by increased permeability or by altered characteristics of histamine receptors in the tumor vessels.

Continuous monitoring of regional cerebral blood flow during temporary arterial occlusion in aneurysm surgery

2001 ◽  
Vol 95 (3) ◽  
pp. 402-411 ◽  
Author(s):  
Claudius Thomé ◽  
Peter Vajkoczy ◽  
Peter Horn ◽  
Christian Bauhuf ◽  
Ulrich Hübner ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Artery ◽  
Regional Cerebral Blood Flow ◽  
Arterial Occlusion ◽  
Aneurysm Surgery ◽  
Regional Cerebral Blood ◽  
Anterior Circulation ◽  
Content Type ◽  
Fine Print

Object. Temporary arterial occlusion (TAO) during aneurysm surgery carries the risk of ischemic sequelae. Because monitoring of regional cerebral blood flow (rCBF) may limit neurological damage, the authors evaluated a novel thermal diffusion (TD) microprobe for use in the continuous and quantitative assessment of rCBF during TAO. Methods. Following subcortical implantation of the device at a depth of 20 mm in the middle cerebral artery or anterior cerebral artery territory, rCBF was continuously monitored by TD microprobe (TD-rCBF) throughout surgery in 20 patients harboring anterior circulation aneurysms; 46 occlusive episodes were recorded. Postoperative radiographic evidence of new infarction was used as the threshold for failure of occlusion tolerance. The mean subcortical TD-rCBF decreased from 27.8 ± 8.4 ml/100 g/min at baseline to 13.7 ± 11.1 ml/100 g/min (p < 0.0001) during TAO. The TD microprobe showed an immediate exponential decline of TD-rCBF on clip placement. On average, 50% of the total decrease was reached after 12 seconds, thus rapidly indicating the severity of hypoperfusion. Following clip removal, TD-rCBF returned to baseline levels after an average interval of 32 seconds, and subsequently demonstrated a transient hyperperfusion to 41.4 ± 18.3 ml/100 g/min (p < 0.001). The occurrence of postoperative infarction (15%) and the extent of postischemic hyperperfusion correlated with the depth of occlusion-induced ischemia. Conclusions. The new TD microprobe provides a sensitive, continuous, and real-time assessment of intraoperative rCBF during TAO. Occlusion-induced ischemia is reliably detected within the 1st minute after clip application. In the future, this may enable the surgeon to alter the surgical strategy early after TAO to prevent ischemic brain injury.

Sign in / Sign up

Export Citation Format

Share Document