Sten Cronqvist

Normal values of regional cerebral blood flow in man, including flow and weight estimates of gray and white matter. A preliminary summary

Seven normal young men (employed by the Fire Brigades of Lund and Malmci) volunteered for the study. None of them had a history of any severe disease or trauma. All were in excellent physical condition. The rCHF studies (double determinations with intracarotid injections of 5 ml isotope solution, about 15 to 20 min. apart) were carried out without prernedication. The position of the injection catheter within the internal carotid artery was checked with saline injections resulting in forehead blanching. During the studies the arterial pC& and the blood pressure was checked. Sone of the subjects had any sequelae of the procedure. For the rCBF measurements a four-channel detector equipment (Manufactured by NUKAB, Gciteborg) was used (Fig. 1). It consisted of a lead collimator block with nine parallel cylindrical holes (diameter 3.5 cm) for the detectors. The holes were set apart so as to cover the side of a human skull. In the present study four standard holes were used, covering “temporal”, “precentral”, “central”, and “postcentral” regions of the hemisphere injected. The central axis of each detector hole was marked on the skull of the subject and a control x-ray was taken in order to relate the measured regions to certain landmarks of the skull bones. Point source measurements (carried out by Mr. G. Suedberg, Department of Medical Radiophysies) showed that the overlap between two adjacent fields of measurement with the present collimator was very small. The efficiency of counting in the

Lateral medullary infarction Prognosis in an unselected series

We describe the acute and long-term prognosis in 43 patients with lateral medullary infarction (LMI) collected from a population-based stroke registry from 1982 to July 1988. Mean age was 63.9 years and median time of follow-up was 33 months. In the acute phase, 5 patients (11.6%) died from respiratory and cardiovascular complications and 2 new strokes occurred, both in the posterior circulation. During follow-up, recurrent vertebrobasilar territory strokes occurred in only 2 patients (a rate of 1.9% per year). The mechanisms of stroke were vertebral artery (VA) branch occlusion, causing a medial medullary syndrome, and basilar artery thrombosis propagating from a contralateral, distal VA stenosis. In the acute phase of LMI, respiratory and cardiovascular events, presumably caused by autonomic dysfunction related to the lateral medullary lesion, are the major hazards. Recurrent posterior circulation strokes were uncommon during follow-up.

Regional cerebral blood flow and angiography in apoplexy.

Cerebral lesions may be demonstrated roentgenographically not only as changes in anatomical structures but also as localized or generalized changes in the dynamic circulatory pattern. Such changes in the cerebral blood flow have also been demonstrated by means of quantitative measurements of the cerebral blood flow (EKBERG, CRONQVIST & INGVAR 1965, CRONQVIST, EKBERG & INGVAR 1965) . A series of cases of focal cerebrovascular lesions were investigated both by cerebral angiography and measurement of the regional cerebral blood flow (rCBF). New pathologic aspects on the focal cerebrovascular lesions were suggested by the combination of the two procedures, and new roentgendiagnostic criteria in focal cerebral ischaemia were indicated. Preliminary reports on the present material have recently been published (CRONQVIST 1966, CRONQVIST & LAROCHE 1967).

Regional cerebral blood flow in cerebrovascular disease.

In many cases of cercbrovascular disorders the clinical symptoms may point to a distinct localization of a lesion, but the available neuroradiological and electrophysiologica1 methods fail to demonstrate any abnormality. It is therefore important that our prcsent diagnostic tools in these disorders should be supplemented with other methods by which regional cerebral functional conditions, such as the circulation, can be measured. This is a report of fifteen patients with ccrcbrovascular disease in which we have used mu1 tiple simultaneous measurements of regional cerebral blood flow (rCBF) (1 ,2 ) , together with convcntional clinical diagnostic methods. A detailrd report of the findings will bc forthcoming (3). Here only a brief discussion will be made of the general relation between rCl3F measurements and the clinical and neurorddiological findings.

Roentgenologic Evaluation of Cranial Size in Children: A New Index

The roentgenologic evaluation of the size of the cranium is generally based upon the presence of a disproportion between the neurocranium and the face. Although measurement data on length, width and height of the skull in different age groups are available (HAAS 1952), the figures differ widely so that the evaluation of these interrelationships are generally made by inspection based upon experience (DORST 1964). The increasing number of neuroradiologic problems, especially in children, have however accentuated the need for more objective criteria and this initiated the attempt to construct new cranial indices. The indices have now been used in a series of children under 7 years of age. It was considered of importance in producing the index that the necessary measurements should be obtained from routine skull films so that the index could be of practical value and used in everyday work without any special VIews. Roentgen examinations of the skull in our department are performed with a Lysholm skull table (FFD 80 em) and include films in the axial, lateral, postero-anterior, and anteroposterior projections. Only the lateral and antero=

Regional Cerebral Blood Flow in Intracranial Tumours

An intracranial tumour may be demonstrated angiographically either as an avascular or a more or less vascular lesion. The absence of vessels or the presence of an abnormal vessel will probably also be reflected in the regional cerebral blood flow (rCBF). Some of the main changes in regional cerebral blood flow in cases with cerebral tumours have been reported in previous communications in which both general and local changes in flow were described (CRONQVIST et coll, 1965, 1966). Similar changes have recently been reported also in focal cerebral vascular disorders (CRONQVIST & LAROCHE 1967). A local increase in flow was found to correspond to angiographic findings of partly the same type as encountered in tumours, and this raised the question as to an eventual similarity in the pathology of cerebral lesions of different kinds. The results from a combined study of measurements of the regional cerebral blood flow and cerebral angiography in 39 cases of intracranial tumours will now be presented. The aim of the investigation was to determine: 1. The influence of the intracranial tumours on the overall cerebral blood flow.

REGIONAL CEREBRAL BLOOD FLOW RELATED TO NEURORADIOLOGICAL FINDINGS

Neuroradiological procedures sometimes give normal findings in cases with symptoms of brain disorder. In neuroradiology there is therefore a constant search for additional diagnostic tools. In the present summary some principal observations on the combined use of neuroradiological procedures and determinations of rCBF according to Lassen et al. ( 1 ) made in about 100 patients, will be described briefly (2 ) . The series included cases with cerebrovascular lesions, with arteriovenous malformations, with epilepsy and with diffcrent forms and degrees of atrophy. There were also cases with tumours, with and without signs of increased intracranial pressure. The results in the cerebrovascular group havc been reported by Ekberg et al. ( 3 ) . From a neuroradiological point of view, it should he stressed that in such patients the rCBF was oftcn found to bc decreased also in regions with very slight or no angiograyhic changes. Furthermore, in many cases without signs of slowing of flow demonstrated by the passage of the contrast bolus, a dccrcase in rCBF was nevertheless shown by the isotope study. The isotope studies have made it possible to quantitate a previously unclear phenomenon met with in angiography in some patients, the slowing of the passage of contrast material within a section of the cerebral vascular tree. Such a regional contrast slowing has bern shown to coincide with a regional decrease in rCBF. A demonstration of cerebral atrophy, central or cortical, localized or generalized, does not in most cases reveal anything about the functional significance of this particular change. Combined studies with rCBF measurements h a w shown a decrease in flow over the region with atrophy in some cases. The method also permits an analysis of the

Significance of Tortuous Filling Defects at Lumbar Myelography

At lumbar myelography, tortuous filling defects frequently occur in the presence of a marked local narrowing of the spinal canal. This may lead to a displacement and compression of nerve roots, which may partially or completely fill the subarachnoid space. However, truly elongated nerve roots have also been observed, both at myelography and at operation. Such elongation appears to be a congenital malformation. The recognition of the true nature of tortuous filling defects is important with regard to differentiation against arteriovenous malformations and congested veins.

MULTIPLE SIMULTANEOUS MEASUREMENTS OF REGIONAL CEREBRAL BLOOD FLOW IN MAN UNDER NORMAL AND PATHOLOGICAL CONDITIONS

For the present studies the isotope clearance method, developed by Lassen, Ingvar and their collaborators was used. This method implies an injection into the internal carotid artery of Krypton 85, or Xenon 133, dissolved in saline, and a subsequent external measurement of the uptake and clearance of the isotope from the brain tissue. In the present investigation we have used multiple detectors for quantitative measurement of regional cerebral blood flow in 4 cerebral regions simultaneovsly. The measurements were usually combined with angiographic studies. The measurements in patients were correlated with the findings in a series of normal young men which were investigated without premedication. For routine clinical use a simplified calculation method developed by Hcledt-Rasmussen, Xueinsdottir and Lassen (1965) was used. The clinical material so far investigated consists mainly of cerebrovascular cases. In most patients belonging to this group a general lowering of the blood flow values were found. In cases with circumscribed thrombotic lesions the lowest value were found within the area corresponding to the neurological symptoms and the angiographic abnormalities. In some cases with a fatal course a correlation was obtained between the cerebral blood flow measurements and the autopsy findings. A refined collimation technique will probably permit a better localization of regional circulatory disturbances. Observations have also been made in patients with brain tumours undergoing radiological treatment and in cases with rapid alterations of the intraventricular pressure. It is concluded, that measurements of regional cerebral blood flow in man is of clinical value, since i t permits both some degree of localization, and a quantitative analysis of regional cerebral circulatory disturbances.

Repeat angiography in temporal contusions

In the diagnosis of a temporal contusion bilater filling of the Sylvian vessels permits adequate comparison between the two sides. Such a comparison is important since even at a large contusion with marked upward or medial displacement of the Sylvian vessels no corresponding shift of the midline structure may exist in the acute stage. With increasing interval between trauma and angiography a shift may develop reflecting the true size of the lesion.