Thrombosis of the carotid artery is now being recognized as a frequent cause of cerebral ischemia and infarction.1 Surgical removal of the occlusive lesion in the vessel may have considerable therapeutic value,2 and for this reason early diagnosis of this condition is becoming increasingly important. Although arteriography is without doubt the most direct method of making the diagnosis, this procedure may have serious complications and other methods of recognizing carotid occlusion have been introduced. These include ophthalmodynamometry,3 manual compression of common carotid arteries,4 palpation of pharyngeal pulsations,5 and auscultation for arterial bruits.6 None of these techniques is completely reliable, and there is a need for other methods of making the diagnosis.
The present report describes a new diagnostic procedure which is safe, simple, and can be carried out at the bedside. It consists of the intravenous injection of a solution of fluorescein and measurements