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The hemodynamic effect of carotid endarterectomy was studied in 69 patients with transient ischemic attacks or, completed or progressing strokes. Significant increases were found in internal carotid artery flow and in the amount of brain tissue perfused by the artery. In patients operated under hypocapnia autoregulation was preserved as regional cerebral blood flow remained unchanged in spite of increased internal carotid pressure. In normocapnic and hypercapnic patients regional cerebral blood flow increased after endarterectomy. The significance of these findings is discussed. [ABSTRACT FROM AUTHOR]

A method has been described of producing brain lesions in dogs with some regularity. Hypotension was induced by bleeding, together with administration of Arfonad, and cerebral ischemia by a period of head-up tilt during the induced hypotension. Ten of 30 animals survived 5 days or more, and the clinical and neuropathologic sequelae are described. Nine brains showed ischemic lesions of varying degree and distribution, only two being cortical Seven showed centrum ovale lesions only partly explicable on the basis of boundary zones. These lesions showed considerable variation in depth, for which the causes are thus far unclear. They may include the dual nature of the central circulation, closure of small arteries when their internal pressure drops below a critical point, and relative preservation of completely bloodless areas where organic acid formation is minimal. The cause of white matter lesions is considered to be endothelial damage due to local hypoxemia, which provides a mechanism through which arterial hypotension and the classic mechanism of venous stasis may either cause leukomalacia. The shortcomings of the experimental technique are discussed, together with criteria for a better method. A review of reported neuropathologic sequelae of open-heart surgery shows a great variety of lesions, of which hypotension is but one possible cause. [ABSTRACT FROM AUTHOR]

Experimental production of cerebral ischemia in both cats and rabbits has been attempted using as an initial procedure occlusion of the basilar artery. Both preparations suggest that the period of temporary ischemia compatible with life does not exceed 6 to 8 minutes. [ABSTRACT FROM AUTHOR]

Focuses on the effects of vasodilatation on patients with ischemic infarction in the brain. Improvement on the quality of life; Reduction risks of complications; Assessment on the response of the immune system from the treatment.

1. In twelve patients with communications between the carotid artery and the cavernous sinus, thirty-four operations were required to control the bruit. Early control of the fistula by multiple operations if necessary, is mandatory to avoid disabling symptoms. In one patient the presence of the fistula for ten years led to marked displacement of the eyeball through retrobulbar engorgement accompanied by complete suppression of vision in the affected eye. 2. Digital compression of the common carotid on the side of the lesion should precede operative intervention for several weeks and repeated many times daily to insure adequate collateral circulation when the carotid is ligated. 3. All ligations of arteries in the neck for carotid-cavernous sinus fistula should be performed under local anesthesia, and should be in the form of temporary occlusions which are maintained for about one hour before permanent occlusion is effected to determine if any symptoms of cerebral ischemia will appear. If they do, the occlusion is removed and operation is delayed for two weeks more while repeated digital occlusion of the artery is continued. 4. In two cases of ligation in continuity of the common carotid and in two cases of ligation of the internal carotid in continuity the lumen was re-established at the site of ligation, requiring secondary ligations to control the bruit. This corroborates previous studies that when complete ligation of a large vessel is intended, ligation and division is preferable. However, ligation of the carotid vessels is dangerously liable to be followed by the disastrous sequel of hemiplegia or other cerebral disturbances and an exception must be made in the ligation of these arteries. The occurrence of two cases of delayed hemiplegia after 24 and 48 hours suggests that the first operation for a carotid-cavernous sinus fistula should consist of occlusion of the common carotid with a broad fascial band, which may be removed if necessary, to be followed by ligation and division of the external and internal carotids should the bruit persist or recur. 5. In the presence of a carotid-cavernous fistula, occlusion of the common carotid may be followed by reversal of flow from the external carotid into the internal carotid. Three cases demonstrated this reversal of flow which resulted in reactivation or persistence of the fistula. Ligation of the internal carotid at a second operation controlled the bruit. This suggests that protection against delayed hemiplegia may be effected by a graded occlusion of the carotids: the first operation to consist of occlusion of the common carotid by a fascial band, the second operation, if the bruit persists or recurs, to be performed several weeks later and to consist of ligation and division of the external carotid. A fascial band is preferable to silk as it can be removed more easily without harm to the vessel and is not so liable to cut through the vessel wall. To insure complete carotid control, ligation of the internal carotid is also indicated at the second operation in case partial restoration of the common carotid has occurred. 6. Concomitant ligation of the internal jugular vein at the time of common carotid occlusion is considered necessary in the presence of a carotid-cavernous sinus fistula in order to obstruct the easy return flow of blood through the fistula back to the heart which might more readily permit reactivation of the fistula through collateral circulation, but it should be performed cephalad to the entrance of the external facial vein to avoid congestion of the orbit and its contents. In ten cases in which concomitant ligation of the internal jugular was performed, twenty operations were necessary to control the bruit. In two of the cases in which concomitant jugular ligation was performed only one operation was found necessary to control the bruit. These experiences justify and probably make internal jugular ligation advisable in all instances. 7. Intracranial occlusion of the internal carotid may be necessary to control the fistula when other occlusions in the neck have failed. Intracranial clipping of the internal carotid was performed in five patients with a satisfactory result in four, and a fatality in one. 8. In one case when unilateral ligation and division of the carotids had not controlled the bruit, cure followed division of small arteries palpable in the supraorbital and infraorbital areas. 9. Normal vision in the affected eye followed control of the bruit in only three of twelve patients. The following ocular complications limited to the affected eye occurred in the thirteen patients: Extraocular muscle palsies in six, exophthalmos in eleven, cataracts in three, glaucoma in four, enucleation in one and impaired vision in nine. 10. Operations upon the vessels of the neck are easily performed through incisions parallel to, or coincident with, normal creases of the skin, thus preventing unsightly scars. [ABSTRACT FROM AUTHOR]

A simple technique is described, which permits the interruption of circulation of blood to the intracranial nervous system of the dog without production of general circulatory collapse. The injection of a special polymerising mixture into both common carotide arteries results in a complete arrest of the cerebral circulation within a few seconds. The immediate and complete arrest of the cerebral circulation is proved electroencephalographically and by macerated preparations of the injected brains. [ABSTRACT FROM AUTHOR]

In 25 experiments isolated canine brains perfused with blood from donor dogs were subjected to complete ischemias of 1, 5, 10, 20 and 30 min. The perfusion of the brain was performed from the internal maxillary arteries. The perfusion pressure was recorded in the circle of Willis. Cerebral blood flow and venous O-saturation were monitored continuously. Arterial pO, pCO and pH as well as brain temperature were kept constant. The ECoG before complete ischemia was not pathologically altered and the cerebral vasculature showed autoregulatory behaviour. The mean O-availability was 8.1±1.4 ml/100g·min and the mean O-consumption was 3.4±0.4 ml/100 g·min. [ABSTRACT FROM AUTHOR]

In 13 experiments the brains of dogs were perfused through an extracorporeal circuit connecting the donor's femoral artery to the internal maxillary artery of the isolated head, whose extracerebral vessels were ligated. Complete ischemias of 1, 5, 10, 20 and 30 min were performed. Cerebral blood flow was measured as total outflow from the confluence of sinuses. Perfusion pressure in the circle of Willis was recorded via a cannula in the basilar artery. Cerebral oxygen-consumption, ECoG and temperature of the brain as well as arterial pO, pCO and pH were controlled. Only those experiments are included in this study, in which these parameters were normal. The pressure-flow relationship of the cerebral vasculature tested prior to each complete ischemia showed autoregulatory behavior. [ABSTRACT FROM AUTHOR]

Copyright of Pflügers Archiv: European Journal of Physiology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Presents abstracts of articles published in the April 1970 issue of the "Annals of Internal Medicine". "Serial blood gas studies during cardiopulmonary resuscitation"; Transient cerebral ischemia due to arrhythmia"; An improved method of digitoxin therapy"; "Alternate-day steroid therapy in lupus nephritis".

The diagnostic value of a continuous 10-hr tape-recorded electrocardiogram was evaluated in 39 ambulatory patients with symptoms of cerebral ischemia. Twenty-eight had symptoms of diffuse cerebrovascular insufficiency (dizziness, giddiness or syncope); 11 had classic transient cerebral ischemic attacks. No patient had a prior significant arrhythmia or conduction abnormality diagnosed clinically or by standard electrocardiogram. Patients with bradycardia below 40/min, tachycardia over 150/min, or high-grade atrioventricular (AV) block were considered to have arrhythmias capable of producing their symptoms. Ten of the 39 patients had one of the above arrhythmias: in seven of these the arrhythmias correlated with symptoms. Eight of the 10 "positives" occurred in patients with diffuse cerebrovascular insufficiency; 7 of these had supraventricular tachycardia, and 1 had sinus bradycardia. Specific antiarrhythmic therapy gave an excellent result in five patients and fair improvement in three. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift Für Neurologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)