Relationship between intracranial hypertension and ultrasonic patterns of the common carotid artery and the internal jugular vein.

The Doppler technique has only been used in neurological practice to evidence local vessel pathology such as occlusion or stenosis. Both common carotid artery and internal jugular vein flows can change not only because of pathological processes of the vessels but also because of impedance of their distribution territory. In this report we analyze the relationship between flow velocity, one of the parameters of blood flow, and intracranial impedance variations which occur in cerebral concussion, tumors and acute vascular cerebral pathology. During our observations we noticed that the diastolic wave of the velocity curve of the common carotid artery is a very important signal of the flow variations in the internal carotid artery and, in turn, of variations in cerebral flow. We studied the behaviour of the common carotid artery velocity curve in our patients both during clinical disease development and during the action of mannitol in the acute phases of the disease. We found that the ultrasonic patterns during antiedema action were similar to the ones obtained during the recovery period. We were able to note some differences and some similarities of the curve morphology in relation to generalized or focal causes of cerebral edema. This may be very important considering that at present no non-invasive and therefore repeatable technique is available for monitoring cerebral blood flow in intracranial hypertension.