Precerebral arterial blood flow pattern in intracranial hypertension with cerebral blood flow arrest.

A pulsed echo Doppler flowmeter was used to confirm cerebral flow arrest in patients with intracranial hypertension resulting in a cerebral perfusion pressure of zero or close to zero. The cerebral angiograms showed non-filling. The term brain tamponade is used for this condition. The patient had a mean arterial blood pressure at the time or recording ranging from 70 to 160 mmHg. Under these conditions the transcutaneous recording of internal carotid artery flow velocity immediately distal to the carotid bifurcation showed a reverberating flow pattern with marked pulsations. The forward flow in systole was counterbalanced by the retrograde flow during diastole resulting in a net flow of zero. This flow pattern is basically caused by a combination of intracranial vascular obstruction, the arterial blood pressure at the site of measurement, and finally the compliance of the distal arterial segment as well as the intracranial compliance. This non-invasive method is of potential value in the determination of intracranial flow arrest.