Regional cerebral blood flow and regional metabolism in cold induced oedema.

24 hours following a cold induced oedema in cats rCBF was measured in the lesion area, the bluish stained cortex immediately adjacent to the lesion, a cortical area remote from the lesion, and in the contralateral uninjured hemisphere. Thereafter the brain was frozen and the respective tissue areas were removed and analyzed for water and electrolyte content as well as metabolite concentrations. It seems, that in the neighbourhood of a local lesion at least 3 different brain regions can be differentiated with regard to their characteristic pattern of data. In non-oedematous regions either hyperaemia or hypoaemia could be observed. In areas with local brain oedema rCBF was reduced inversely p…

Clinical significance of the quantitative and qualitative determination of the cerebral blood flow through the use of isotopes

Es wird über die bisher entwickelten Methoden zur bestimmung der Hirndurchblutung mit radioaktiven Isotopen berichtet, wobei die quantitativen Untersuchungsmethoden hinsichtlich ihrer klinischen Bedeutung den qualitativen gegenübergestellt werden. Während die quantitativen Methoden eine genaue Bestimmung des cerebralen Blutvolumens und damit der Gesamtdurchblutung des Hirns bzw. bestimmter Hirnareale ermöglichen, bieten die qualitativen Untersuchungsmethoden hinsichtlich der klinisch-diagnostischen Aussagekraft besondere Vorteile. Aus der Bestimmung der Zirkulationszeit des Hirns und dem Verlauf der über beiden Hemisphären registrierten Aktivitätskurven lassen sich differenzial-diagnostisch…

Regional blood flow in deep structures of the brain measured in acute cat experiments by means of a new beta-sensitive semiconductor needle detector.

Regional cerebral blood flow was measured by means of isotope clearance with a new type of solid state beta-sensitive needle detector (diameter 0.9 mm) introduced into the brain tissue in acute cat experiments. The flow values obtained within the cortex were compared with values recorded above the same cortical region with the same needle detector, or with a small GM-tube. The insertion of the needle detector into the brain tissue gave rise to injury (checked histologically) which deformed the clearance curves in a manner suggesting that the normal circulation had been destroyed within the tissue from which the measurements were made.

The Two-Minutes-Flow-Index (TMFI)

While performing clinical rCBF functional tests it is difficult to maintain the patient in a stationary condition over the entire clearance period. For this reason it has become a common practice to restrict the recording of the clearance curves to the first 2 min [1, 2, 3]. This gives rise to one question: 1. Is it possible to evaluate the information contained in these 2 min of the clearance curve so as to obtain a quantifiable measure for rCBF?

Experimental „Luxury Perfusion” in the Cerebral Cortex of the Cat

Publisher Summary Preliminary studies have been performed, on the changes of cortical rCBF (Krypton- 85 Beta clearance technique) in response to a localized pressure applied to the cerebral cortex (suprasylvian gyrus) of 8 cats under Nembutal anesthesia (30 to 40 mg/kg bodyweight). No change in rCBF is found at regions as distant as the contralateral hemisphere. The increase of rCBF at the compressed site, during the compression, seems to be more marked in animals with higher blood (i.e. perfusion) pressure, and may be absent in cats with blood pressure of about 80 mm Hg. The augmentation of rCBF around the compressed area during the compression is always very marked, and after some time fl…

Possible Adverse Effects of Hyperventilation on rCBF during the Acute Phase of Total Proximal Occlusion of a Main Cerebral Artery

Recent studies seem to favor a beneficial effect of hyperventilation (HV) in cases of cerebrovascular occlusion [1, 4] and brain trauma [2, 5]. On the other hand, it seems that, at least under certain circumstances, HV may exert an adverse effect upon cerebral blood flow and metabolism [3]. Since this question is not settled yet, it seems worthwhile to report briefly the present case of reversible total occlusion of the middle cerebral artery closely followed by successive rCBF studies (133Xe-gamma-clearance method), in which, during the acute phase, HV caused a latent ischemia to become manifest.

Temporal retrogasserian resection of trigeminal root versus controlled elective percutaneous electrocoagulation of the ganglion of gasser in the treatment of trigeminal neuralgia. Report on a series of 531 cases.

In his experience with 531 surgical procedures for the relief of trigeminal neuralgia between 1955 to 1970, the author developed a strong preference for the percutaneous electro-coagulation of the gasserian ganglion. Although the method was repeatedly modified in the early years, a standardized technique of controlled, selective and fractional coagulation in the semiawake state of neurolept-anaesthesia was used since 1963 in 183 of his 311 patients, treated in this manner. The advantages of the method, particularly in comparison to open intracranial root sections, are: Minimal operative risk, control of operative effect during the operation, small sensibility deficit, low rate of complicati…

Acute electrocorticographic changes following localized cortical freezing in the cat. Preliminary report.

Regional Cerebral Blood Flow in Cases of Brain Tumor

The present series consists of 21 patients with brain tumors: 12 malignant gliomas, 4 oligo- dendro gliomas, 3 meningeomas and 2 metastases, studied by the133Xe-gamma-clearance rCBF method. In 16 patients at least 3 determinations of rCBF were performed: a) in the resting state, R; b) during hyperventilation, HV, and c) during hypertension, HT. Of the remaining 5 patients, 1 was studied only during R, while the other 4 were submitted either to HV or to HT additionally to the R study. The average age of this series of patients was 47 years, the youngest being 19 and the oldest 64. rCBF studies had to be performed under general anesthesia (N2O + O2, Engstrom respirator) in 5 instances in whic…

Arterial pCO2 and Blood Flow in Different Parts of the Central Nervous System of the Anesthetized Cat

It cannot be regarded as proven that the mechanisms involved in the regulation of local circulation are identical in all parts of the central nervous system. Evidence has been presented that carbon dioxide exerts differential effects in different parts of the CNS [2, 3, 7, 10].

Correlation between rCBF, Angiography, EEG and Scanning in Brain Tumors

The findings with techniques of different sensitivity, and which investigate different aspects of brain structure and/or function are difficult to correlate. However, such a comparison should help in elucidating the physiopathological mechanisms of brain lesions and the postoperative clinical evolution and prognosis in cases of brain tumors.

Regional cerebral blood flow (rCBF) changes following local brain compression in the cat.

Effect of arterial oxygen tension on cerebral blood flow at different levels of arterial PCO2.

Die Wirkung des arteriellen O2-Partialdruckes auf die Durchblutung des Grosshirns, Kleinhirns und Hirnstammes bei normalen und erhohten CO2-Partialdrucken im arteriellen Blut wird an der anaesthesierten Katze untersucht. Die Wirkung des PaO2 ist von der Hohe des PaCO2 abhangig.

The Effect of Intracranial Pressure on Perifocal Hyperemia

It is known that a reversiblecortical trauma caused by local brain compression in the cat is accompanied by a pronounced decrease of rCBF at the compressed area and by a transient perifocal hyperemia [1].

Cerebral blood flow and cerebral death

At present the diagnosis of cerebral death is based on the absence of manifestations of cerebral function (deep coma, wide pupils, absence of reflexes and spontaneous respiration, isoelectric EEG, etc.) during a variable period of time. However, the absence of vital signs of an organ, even for prolonged periods, is no proof of its death. The death of an organ can only be considered as proved by the demonstration that this organ has remained completely deprived of its blood flow during a period of time that surpasses its ability to survive circulatory arrest. In the case of the brain, the permanent absence of clearance of a radioactive tracer deposed within the brain is considered to demonst…

Cessation of Cerebral Blood Flow in Total Irreversible Loss of Brain Function

After the demonstration, by our group [3, 4], that in cases of so-called “cerebral death” there is an absence of clearance from the brain of 133Xe selectively injected into the internal carotid artery, further attention was dedicated to establish possible sources of error in this technique.