Pathogenesis of hemifacial spasms is still obscure. To elucidate the etiology, 61 patients with this clinical syndrome were closely examined. Surgical findings of all patients and vertebral arteriograms of 51 patients disclosed characteristic changes of the vertebro-basilar artery system and its branches. The vertebral artery was invariably larger in diameter ipsilaterally to the affected side of the face, made a sharp or hair-pin like angulation at the origin of the third segment of the vertebral artery and gave off branches almost rectangularly from the top of this angulated part toward the internal auditory meatus. On the other hand, the S-shaped basilar artery with the abovementioned asymmetrical changes in diameter of the vertebral arteries gave off the anterior inferior cerebellar artery toward the internal auditory canal of the affected side with an absent or hypoplastic posterior inferior cerebellar artery. Operative procedures demonstrated that the facial nerve was invariably compressed by an ectated or radundant artery which showed right turn and local “arteriosclerotic” changes at its cross-compressing site. The peculiar vasculature changes of the vertebro-basilar artery and the compressing artery may be congenitally present, and subsequently, an exaggerated intraluminal blood stream or pressure of the larger sized vertebral artery is likely to apply a stronger hemodynamic force to the wall of the angulated part of the vertebral artery, resulting in ectasia or redundancy of the peripheral branches originating from this point and also wall thickening of the right-angled part of the compressing artery which just happens to lie close enough to the exit zone of the facial nerve from the brain-stem. These vasculature findings appear to provide an important key to solve the problem of why a certain artery can cross-compress the facial nerve and why the vast majority of hemifacial spasms develop on one side of the face.

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Digital subtraction angiography with intravenous injection of contrast medium was used to assess 10 patients with ischemic disease. The time-density curve (TDC) was evaluated for its usefulness in analyzing brain blood circulation (dynamics). Such other parameters as peak time (PT), mean transit time (MTT), and mode of transit time (MOTT) were also assessed. Particular attention was paid to high convexity, watershed, and perforator areas of the middle cerebral artery, which are regions of interest in the bilateral hemispheres. The dynamics of blood circulation demonstrated by this method were compared with those demonstrated by single photon emission computed tomography (SPECT).
In patients with carotid artery stenosis, the TDC at the convexity area on the affected side showed both a gentle upward slope and a slow downward slope, and all parameters (PT, MTT, MOTT) were prolonged. After endarterectomy, the delay in all parameters decreased and the laterality of the TDC diminished. In patients with middle cerebral artery occlusion, the TDC at the convexity area on the affected side showed delay of attenuation, and all parameters were prolonged. After superficial temporal artery-middle cerebral artery anastomosis, the peak on the operated side was higher than that on the unaffected side and prolongation of MTT and MOTT on the affected side was decreased. In cases of moyamoya disease, none of the parameters could be calculated because the TDC showed no downward slope. In all of the evaluable cases, TDC data were superior to SPECT determinations in detecting laterality of the circulation. These results indicate that this method accurately demonstrates laterality of circulation time and volume as well as the degree of collateral circulation. The TDC and other parameters appear useful in determining whether or not surgery is indicated and in estimating the postoperative circulation in patients with ischemic disease.

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The relationship between blood flow and the localized development of atherosclerosis and thrombosis were studied at the bifurcation and curving portion of a human cerebral artery. Blood flow patterns were studied by direct observation and by photographing of tracer particles flowing through the isolated arterial segment, which had been obtained at the time of death and had been prepared in such a way that it was transparent. A standing recirculation zone consisting of a pair of secondary flow spirals, located on both sides of the common median plane of the bifurcation, was formed on the lateral side of the daughter vessels over wide ranges of inflow Reynolds numbers (Re₀) and flow rate ratios (Q₁: Q₀; Q₀ and Q₁ indicating the quantity of flow in M₁ and M₂ segment of the middle cerebral artery, respectively). The formation and size of the recirculation zone were largely dependent on Q₁: Q₀ and Re₀. In addition, formation of eddies was observed on the inner side of the curving portion as well as at the bifurcation of the middle cerebral artery.
The results suggest that, under physiological conditions, there is a standing recirculation zone in the bifurcation and bending portion of the middle cerebral artery, which affects local mass transfer and interactions between blood cells and the vessel wall. This may contribute to the development of atherosclerosis and thrombosis in this and anatomically similar regions.

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In the previous report a new model was proposed for the understanding of the intracranial mutual pressure interactions after a bolus volume loading. In this report the intracranial volume-pressure relationship (VPR) is examined in 15 dogs. They were separated into two groups: the steady-state infusion group (9 dogs) and the epidural balloon inflation group (6 dogs). The former contained 3 dogs in which 50 mg/kg of kaolin emulsion had been injected into the basal cistern a week before the experiment. They were regarded as a model of cerebrospinal fluid (CSF) malabsorption. In comparison with the actual volume-pressure (VP) curves, theoretical curves were displayed which were extracted mathematically by using the pressure-response (p-r) curve of each dog.
The plateau level of the theoretical VP curve was always lower than the actual steady-state infusion curve. It was thought that more spatial compensation of the vascular bed occur in the actual plateau of the steady-state infusion than in the theoretical plateau, which was based on a single bolus injection. The r value calculated by the actual steady-state infusion was therefore very high because it demonstrated an exaggerated absorption rate under the pressure buffering effect of the venous system. So the CSF absorption resistance obtained by analyzing the p-r curve of a bolus injection should be closer to the true value than that obtained by steady-state infusion.
The shape of VP curves derived from steady-state infusions and balloon compressions were not monoexponential. The latter developed a plateau level under the maximal pressure buffering by the vascular bed. Consequently analytical methods in which the hypothesis that the VPR was exponential was used were proved to be untrustworthy.

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The purpose of this report is to clarify the origin of the pressure-response (p-r) curve after a bolus normal saline injection into the subarachnoid space. Eighteen adult mongrel dogs weighing 9-13 kg were intubated and ventilated artificially. A bolus normal saline injection (0.8 ml-sec) was performed and the changes in intracranial pressure, superior sagittal sinus pressure, and systemic arterial pressure were monitored and recorded continuously for 30 minutes. The following results were elicited: 1) The shape of the p-r curve was determined by three resistances: resistance to the cerebrospinal fluid (CSF) absorption (r), blood inflow resistance into the sinus (Ri), and blood outflow resistance from the sinus to the extracranial venous system (Ro). A new intracranial volume-pressure model was proposed for detailed analysis of the volume-pressure relationship. 2) Changes in the CSF pressure after a bolus injection were characterized by two components. The steep decay of the p-r curve was thought to occur because of the CSF absorption, and the gentle decay should be the result of sinus outflow resistance which might be equivalent to the CSF absorption resistance, since the CSF absorption resistance should be rapidly changeable and pressure dependent. Patterns of the p-r curve were divided into three groups, namely “normal, ” “borderline, ” and “delayed” patterns. The last one could result either from high r state or from high Ro conditions. The borderline group contained dogs in which the intracranial cavity was tight.
The CSF absorption resistance could be obtained by careful analysis of the p-r curve, but it might be modified by the spatial compensation of the venous system. It is thought to be important for the reasonable analysis of the p-r curve that the shape consideration, the baseline-peak pressure gradient (pressure increment), and the recovery time to the baseline pressure should all be included in a single analytical theory.

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6員環ラクトンを有する強心ステロイド，proscillaridin(PS)を接触還元して得られる5種類の還元体(bufa-4，20-dienolide(PH21)，bufa-4，20(22)-dienolide(PH22)，20R-bufa-4-enolide(PH4-R)，20S-bufa4-enolide(PH4-S)，chola-4-enoate(PH4-E))の心臓に対する薬理作用をモルモットを用いて実験した．各還元体の心筋に対する陽性変力作用(PIE)は摘出右心室乳頭筋駆動標本(lHz)を用いて行った．各還元体は母化合物PSよりもPIEの発現が速く，特徴ある形の濃度-PIE曲線を示した．最大収縮値の50%の収縮を起こさせる濃度(pD₂値)はPS7.4に対しPH22 6.2，PH21 5.8，PH4-R5.3，PH4-E 5.0，PH4-S 4.9であった．ラクトン環を還元したこれらの化合物ではPIEの発現時間は速くなった．各還元体の濃度-PIE曲線において効力は減少したが，PIEの最大効果の増大が認められた．PH21とPH4-Rは単一物質であるにもかかわらず広い濃度範囲でPIEを示した・このことを丸ごとの動物の心電図を測定することにより確かめた．即ち，モルモットの心電図においてPH21 11.9mg/kgあるいは，PH22 5.lmg/kgといずれもpD₂値の4.4倍に相当する量を頸静脈内に投与した時，PH21(n=5)は3時間不整脈を起こさず，PH22(n=5)は，30分以内にすべて不整脈を生じ・た，これらの結果から，PH21は母化合物PSよりも速いPIEの発現と広い濃度依存性のPIE域を持つ安全な化合物と思われる．一方，PH22は濃度-PIE曲線において急峻な立ち上がりを示し，不整脈が早い時点より出現した．

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A new technique for anastomosis of the superficial temporal-middle cerebral arteries (STA-MCA) is described. It uses a single newly designed angled clip to close the recipient artery during anastomosis.
Fifty two recipient arteries in 10 cerebral hemispheres of cadavers were selected from the perisylvian area by microanatomical survey. Each was at least 10 mm in length and more than 0.8 mm in diameter. Each artery was examined for 1) the external diameter, 2) the number and the diameter of its branches, 3) the number of branches to be cut in anastomosis by using the ordinary two clips or the new single clip, and 4) the territory of the collateral circulation from the central artery as examined by India ink injection study. The average diameter was 1.15±0.1 mm. The arteries had on average five cortical penetrating arteries; 45.3% of the branches were up to 0.2 mm in diameter while those of over 0.4 mm were less than 5.5%. The temporo-occipital artery was largest in diameter, but it had a large number of big branches (13%). By the ordinary method, all branches would have had to be cauterized and cut off. But 77% of the 52 arteries did not need to have any branches cut off during anastomosis when the new method was employed. Collateral circulation from the central artery to the anterior cerebral artery via the cortical lepto-meningeal anastomosis was shown by India ink injection study. Disconnection of the branches by using bipolar coagulation during anastomosis may cause some damage not only to the arterial wall and the brain, but also to such a lepto-meningeal anastomosis. The new single temporary clip method has certain advantages in bypass surgery. The first advantage is preservation of the cortical penetrating arteries and the collateral network, the second is the shortening of the operation time, and the third is the capability of performing anastomosis on the functional area or severe ischemic brain.
Seven clinical cases were operated on using this technique. Only 3 of 24 branches in 7 cortical arteries needed to be cut. The recipient artery was the central artery in 3 cases, the precentral artery in 2 cases and the prefrontal artery in 2 cases. All the cases had uneventful operations and postoperative courses. So it can be said that this is a very simple and useful method in bypass surgery.

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Of 344 patients with intracranial aneurysms treated at the Shimane Medical University and Matsue Red Cross Hospital, eighteen (5.2%) had aneurysms of the distal anterior cerebral artery (DACA). Five were male and thirteen were female. Their ages ranged from 39 to 67 years. Seventeen patients had had at least one episode of subarachnoid hemorrhage (SAH) caused by rupture of the aneurysm of DACA. Motor disturbance found in 8 cases was a rather specific clinical feature on admission. There were 4 cases with hemiparesis predominant in the lower limb, 3 with monoparesis of a leg, and 1 with tetraparesis. Six of the aneurysms were located at the bifurcation of the pericallosal artery (PCA) and callosomarginal artery, 6 at the bifurcation of PCA and anterior internal frontal artery, 3 at the distal end of azygos anterior cerebral artery (ACA), and 3 on the peripheral PCA. Eleven aneurysms were on the left side, 4 on the right, and 3 on the midline. Six patients were shown to have multiple aneurysms. Azygos ACA was noted in 3 cases and bihemispheric ACA in 2. In 7 cases, PCA made a sharp bend at the genu of the corpus callosum where the aneurysm was located. Computerized tomography (CT) scans were done in 6 cases. Blood was found in the basal cisterns and bilateral Sylvian fissures in symmetrical distribution, and extended into the anterior interhemispheric fissure and pericallosal cistern in all six. Two cases had a large intracerebral hematoma in the corpus callosum. Direct surgical attack on the aneurysm was made in 17 cases. Long-term follow-up results revealed that 10 cases had no neurological deficits, 2 had minimal deficits, 2 were moderately disabled, and 3 died.
From an analysis of these 18 cases and 191 cases reported in the literature, the following results were obtained: 1) The incidence of DACA aneurysm was approximately 5%. There was no difference in sex distribution, and most cases were found in the fifth to sixth decade. 2) Seventy-one percent were located at the pericallosal bifurcation, 15% in the infracallosal portion of PCA, and 6% on the supracallosal portion. Multiple aneurysms were found in 29%. 3) Leg monoparesis and predominantly crural hemiparesis may be rather specific clinical features. 4) Anomalies and anatomical variations of DACA were found, such as azygos ACA, bihemispheric ACA, supreme anterior communicating artery, and acute angulation of PCA at the genu of corpus callosum.

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Cerebral hemodynamics were studied in 38 children with “Moyamoya” disease. About 10mCi of Tc-99m was injected into the anterior cubital vein as a bolus, and serial brain scintigrams in one second intervals were obtained with a gamma scintilation camera (Ohio-nuclear Σ410s) and processed on an on-line radioisotope processing system including microcomputers (DEC PDP 11/34, 11/60).
The characteristic images of serial brain scintigraphy were obtained in preoperative cases: early accumulation of radioisotope activities in the base of the skull, corresponding to the basal “Moyamoya” vessels, and the poor filling in the territories of the anterior (ACA) and middle cerebral arteries (MCA), indicating disturbance of the cerebral circulation. After bypass surgery, early accumulation of RI activities in the base of the skull diminished and evidence of improved cerebral circulation in the territories of the middle cerebral artery was obtained, but poor filling in the territories of the anterior cerebral artery persisted, measurements of local mode of transit time (MOTT) were made by our modified method which was originally reported by Oldendorf. Regions of interest were bilaterally settled both in the areas of basal “Moyamoya” vessels and in the territories of MCA in the anterior view image. The mean values of MOTT in the MCA territories were significantly longer than in the basal “Moyamoya” (10.8±2.7 sec, 7.7±2.1 sec, N=17, respectively). After surgery, shortening of MOTT in the MCA territory was observed (5.8± 1.3 sec, N=17).
Positive static brain scintigrams were observed in only two cases. One patient was the case of cerebral infarction 14 days after the onset, the other patient showed a transient positive area in the region of the frontal lobe without neurological deficit, which was thought to be hyperpermeability of unknown origin. Findings of static brain scintigraphy of “Moyamoya” disease only indicated the results of damage of the blood-brain barrier.
From this evidence, it was concluded that dynamic studies using Tc-99m and a scinti-camera were useful not only in the diagnosis of “Moyamoya” disease, but also in the study of the pathophysiology of brain circulation.

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