The authors present a noninvasive method of measurement of Intracranial pressure (ICP) . In this experiment, we aim to detect interference echoes originating from the dura including membranous structures of the subarachnoid space through the skulls of normal thickness. The result showed that interfering echoes could be received through a 2.4-5.0mm thickness of bone flap from the skull which was removed by craniotomy, when we used a probe with a diameter of 17-20mm. With our probes, we recorded ICP continuously by changing the head position, Valsalva's maneuver, and compressing the superficial temporal artery. This measurement was performed using two peak-detectors at from the same echo pattern. The changes in pulse waves of ICP were evaluated. From these results the authors confirm the usefulness in clinical applications of our noninvasive method for the ICP measurement.
Hemodynamics were studied in 15 normal subjects and 9 patients with angiographically proven Moyamoya disease by transcranial Doppler ultrasound (TC2-64B) . Vascular reconstruction such as STA-MCA anastomosis, EMS, EDAS and DP were performed in 6 out of 9 patients. Two and 8 MHz probes were used for Intracranial arteries and superficial temporal arteries (STA) respectively. The most characteristic finding on cerebral arteries (MCA, ACA) was the significant decrease of flow velocity, although the decreased flow rate varied greatly from artery to artery. Decrease or absence of vascular reactivity to hypocapnia was characteristically seen in patients. Moreover, wave form of flow velocity of STA was transformed from external carotid artery pattern to internal carotid artery pattern. This change in flow pattern was more remarkably seen in cases with abundant transdural anastomosis. Postoperatively, flow velocity of STA increased dramatically and the flow pattern become similar to internal pattern. Although flow velocity of middle and anterior cerebral arteries increased in many cases, reactivity to hypocapnia still remained in a remarkably decreased state. Observation of these pre- and post-operative characteristic changes of flow velocity and vascular reactivity in patients with Moyamoya disease seemed to be quite useful for evaluation of the hemodynamics and should provide information for a follow- up study.
Using two-dimensional and Doppler echoencephalography, we examined ventricularsize and pulsatility index (PI) of 26 infants with various congenital cardiac diseases. Four cases with large ventricles showed a malformed syndrome. Two cases had chromosomal abnormalities, one case was a post-operative patient. The width of ventricles out particular episodes were normal. We believed the enlargement of ventricles in the four cases was due to those elements except cardiac disease. The cases with high PI were a Co/Ao, a Co/Ao+PDA, four TGAs, a DORV+PDA, a truncus arteriosus, a tricuspid atresia+PDA, and HLHS. All cases had left to right shunt in the great artery levels. The case of low P1 was ECD which had severe cardiac failure. Pl of other cases were within normal limits. The change of systemic flow pattern influences cerebral flow pattern. We must consider the systemic flow pattern when we evaluate PI of the cerebral arteries.