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
POTTER JM, TAYLOR FM. Electroencephalography During Carotid OcclusionConfusing Results in Thirty-Four Cases. AMA Arch NeurPsych. 1955;74(4):414-423. doi:10.1001/archneurpsyc.1955.02330160064009