Cerebro-vascular Occlusive Diseases and Intracranial Pulsation

Many studies have been reported to know hemodynamics of brain and the degree of intracranial pressure by analyzing the midline echo pulsation curve and various discussions have been done about diagnostic value of the midline echo pulsation curve. Echo pulsation curves of midline (the third ventricle), sylvian complex and siphon have been analyzed in cerebrovascular occlusive diseases such as the occlusion of middle cerebral arteries, intracranial or extracranial occlusion of the internal carotid arteries by measuring the rise time (time interval of ascending or descending phase of echo pulsation curve corresponding to systolic phase of ECG), the latency time (time interval from Q-wave in ECG to arising point of echo pulsation curve) and amplitude. 1) In cases of the intracranial occlusion of internal carotid arteries there was found the lowering of amplitude and the prolongation of latency time of the echo pulsation in siphon and sylvian complex on the affected side. 2) In cases of the extracranial occlusion of internal carotid arteries it was recognized on the affected side that the amplitude of echo pulsation was slightly lowered in siphon and sylvian complex and that the latency time was prolonged in siphon. 3) In cases of the occlusion of middle cerebral arteries the latency time was prolonged and the amplitude was lowered in the echo pulsation of sylvian complex on the affected side. 4) As for the midline in all these occlusive diseases there was no marked difference in the rise time between the affected side and normal side, whereas there was prolongation in latency time on the affected side. 5) In these occlusive diseases there was no characteristic in the rise time of echo pulsation curve of siphon and sylvian complex. 6) The difference of echo pulsation curve between the affected side and the normal side shows less marked changes of echo pulsation curves in cases showing improvement. 7) From these facts it is probable that the pathological condition and changes in the time course of diseases may be able to estimate their severity by analyzing the intracranial echo pulsation curves such as midline, siphon and sylvian complex.