Electroencephalography During Carotid Occlusion

Abstract

During a recent period of approximately five years it was the custom in this department to take an electroencephalogram (EEG) before, during, and after the operation of carotid artery ligation in the neck, and this was done on 34 occasions. A period of trial occlusion of the artery by a rubber-covered clamp, for approximately 20 to 30 minutes immediately before ligation, was observed in each case; and neurological examinations were carried out in order to detect any signs of cerebral disturbance. Previously, in all but one case, carotid angiography, besides demonstrating the lesion to be treated, had shown the presence or absence of a free anastomosis across the anterior communicating artery when the opposite carotid had been compressed.There has been a notion that this simultaneous EEG might in some subtle way give early warning (not evident clinically) of the occasional hemiplegia that still, despite the safeguards mentioned, follows this operation. Rogers'1 original advocacy of this test was, however, based only on negative evidence from three cases, in none of which had there been any significant change in the EEG as a result of ligation of the common carotid artery.No large series of cases has, it seems, been carefully studied to assess the usefulness of this procedure, which is tedious for all con¬ cerned. During the preparation of this paper, however, Wise and associates 2 described 13 cases, in 4 of which an EEG was taken during the period of carotid occlusion, and their results were thought to indicate that the pro¬ cedure is of limited value. Kidron 3 has re¬ ported 50 cases in which an EEG was taken during digital pressure to the "carotid vessels below the angle of the jaw." Others, e. g., Sweet and Bennetti and Hamby,5 besides ourselves have been doubtful of the reliability of the digital method of occluding carotid arteries, even against Chassaignac's (carotid) tubercle. The criterion of occlusion in Kidron's investigation was absence of temporal pulsation, but this does not distinguish be¬ tween common and external carotid compres¬ sion. Furthermore, digital compression may, as noted in his paper, be distressing to the patient, and it is possible that carotid sinus mechanisms may be more readily evoked by this method than during the more precise sur¬ gical technique. These doubts must, there¬ fore, be transferred in some measure to the results he obtained, which were none the less interesting: No change appeared in the rec¬ ords in 70% of the cases ; in 20% minimal changes were seen, and in 10% only were there obvious changes, in the form of added slow-wave activity. The EEG before com¬ pression had little relation to the changes seen after compression.From the additional information obtained in our series, we would say not only that its limitations are too great to warrant the trouble that the test entails, but that the capricious results which occur may confuse or mislead anyone not familiar with the wide variations that may be found. In particular, we have attempted-and without any notable

Results of deconstructive endovascular surgery in treatment of large and giant intracranial aneurysms

“…К таковым относятся артефакты, обусловленные помехами, создаваемыми находящимися в современной операционной приборами. В некоторых публикациях указывается на возможность ложнонегативных результатов, снижающих достоверность теста [10]. В этой связи мы практически не использовали тест с ЭЭГ.…”

Results of deconstructive endovascular surgery in treatment of large and giant intracranial aneurysms

“…К таковым относятся артефакты, обусловленные помехами, создаваемыми находящимися в современной операционной приборами. В некоторых публикациях указывается на возможность ложнонегативных результатов, снижающих достоверность теста [10]. В этой связи мы практически не использовали тест с ЭЭГ.…”

Results of deconstructive endovascular surgery in treatment of large and giant intracranial aneurysms

“…К таковым относятся артефакты, обусловленные помехами, создаваемыми находящимися в современной операционной приборами. В некоторых публикациях указывается на возможность ложнонегативных результатов, снижающих достоверность теста [10]. В этой связи мы практически не использовали тест с ЭЭГ.…”

Results of deconstructive endovascular surgery in treatment of large and giant intracranial aneurysms

“…К таковым относятся артефакты, обусловленные помехами, создаваемыми находящимися в современной операционной приборами. В некоторых публикациях указывается на возможность ложнонегативных результатов, снижающих достоверность теста [10]. В этой связи мы практически не использовали тест с ЭЭГ.…”