Study of the posterior circulation in moyamoya disease. Clinical and neuroradiological evaluation

Eighty-two cases of cerebrovascular moyamoya disease were studied by cerebral angiography and computerized tomography. Occlusive lesions were demonstrated not only in the anterior circulation but also in the posterior circulation, and they were associated with the development of an abnormal vascular network (moyamoya vessels). Although occlusive lesions do occur in the vertebrobasilar system, the vertebrobasilar system also acts as a source of collateral channels to the anterior circulation in this disease.

[Digital subtraction angiography of the cerebral vessels by intraarterial injection]

Three hundred and fifty-seven digital subtraction angiography (DSA) were performed in 184 neurosurgical patients by intraarterial injection. Examinations consisted of 192 carotid angiography, 110 vertebral angiography, 23 aortography, 11 spinal angiography and 21 other angiography. In all examinations, visualization of the vessels was excellent and the complications were never experienced. High contrast sensitivity of DSA resulted in better visualization of tumor stains, phlebogram, and arteries in cerebral arteriovenous malformations with large shunt blood flow than conventional angiography. Selective catheterization into each cerebral arteries was not necessarily demanded for good opacification of the vessels because of high sensitivity. High contrast sensitivity also permitted low concentration of contrast material, small dose of contrast material, and slow injection rate. Low concentration of contrast material reduced pain and heat during injection especially in the external carotid and vertebral angiography. Using slow injection, recoiling of catheter into the aorta was reduced, so that injection from the innominate and subclavian arteries for visualization of origin of the cerebral arteries were always successful. Full study of cerebral arteries by Seldinger's method, if necessary, was easily achieved using DSA even in patient with high age or with severe atherosclerosis. Bolus injection of small dose of contrast material as well as serial imaging was helpful in evaluating hemodynamics in the lesion. Real time display of DSA reduced the time required for angiography and was very convenient for artificial embolization. Besides these advantages, DSA became comparable to conventional angiography in special resolution by use of intraarterial injection and could be a preoperative genuine examination as well as a screening method.

Surgical treatment for spontaneous carotid dissection with impending stroke. Case report

A case of spontaneous carotid artery dissection is presented. In the case described, superficial temporal artery-middle cerebral artery anastomosis was performed because of impending stroke. Surgical revascularization is indicated in a case that shows such a rapid evolution of stroke that spontaneous resolution of the dissection cannot be awaited.

[Minimal-flow xenon and semiclosed circuit anesthesia for computed tomographic measurement of local cerebral blood flow (LCBF)]

For the purpose of decreasing the volume of expensive xenon, anesthesia with minimal-flow xenon and semiclosed circuit were induced for computed tomographic LCBF measurement. Eighteen patients with ischemic cerebral disease were studied. Anesthesia was induced with minimum dose of thiopental, diazepam and fentanyl. Muscle relaxation was obtained by means of pancuronium bromide. Patients were intubated and ventilated mechanically with flows of 6 l/min. O2 for 20 to 30 minutes to eliminate nitrogen from the system. O2 concentrations in semiclosed circuit were monitored throughout the procedures using galvanic battery. Endtidal CO2 tension was also measured for maintaining normocarbia. Blood gas analyses were carried out before xenon inhalation, during xenon inhalation and immediately before stopping inhalation of xenon-oxygen mixture. Xenon inhalation programs were subdivided into three groups, each of them consisted of 6 patients. The formula for calculating fresh gas flow for low flow semiclosed circuit was introduced according to Shimoji's which was based on the original formula of Foldes. O2 concentration in circuit was predicted to be 25%. Mean xenon uptake for initial 20 minutes was predicted to be 125 ml/min. or 360 ml/min. (Formula: see text) (CRO2: O2% in semiclosed circuit. FO2: fresh O2 flow ml/min. FXe: fresh xenon flow ml/min. VO2: oxygen consumption ml/min. VXe: mean xenon uptake ml/min.) The first group started xenon inhalation during pure xenon inflow into semiclosed circuit for two minutes and followed by about 68% xenon in O2 inhalation for 23 minutes. FXe and VXe were fixed at 700 ml/min and 360 ml/min respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Moyamoya disease associated with bilateral occlusion of the vertebral artery

An unusual case of moyamoya disease associated with bilateral occlusion of the vertebral artery is reported. This case shows several embryologic collateral channels, which are typical of moyamoya disease, around the brainstem, that is, a transdural anastomosis between the superior cerebellar artery and the posterior meningeal artery, a leptomeningeal anastomosis between the superior cerebellar artery and the posterior inferior cerebellar artery, and moyamoyalike collateral vessels via primitive lateral anastomotic channels of Padget . Bilateral encephalomyosynangiosis (temporal muscle graft) were performed. Postoperatively, no ischemic attacks have developed for 6 years.

[Study on the vertebro-basilar system in "moyamoya" disease]

Posterior circulation in 82 children of "moyamoya" disease are studied. Two aspects of "moyamoya" disease, (ie; occlusive lesion of cerebral vessels and the development of abnormal vascular network as collateral channel,) are also detected in the vertebrobasilar system. Among 82 cases, 49 cases showed the occlusion of posterior cerebral artery at their quadrigeminal segment. Twenty-three showed the more proximal occlusive lesions. Vertebral artery occlusion were found in 3 cases. As the occlusive lesion progresses, abnormal vascular network at the posterior portion of skull base developed. This network consists mainly of thalamogeniculate artery, posterior choroidal artery, and also of other thalamoperforators. Visual field defect as an ischemic symptom of occipital lobe was detected in 9 cases (11%). Superficial temporal artery-middle cerebral artery anastomosis and encephalo-myo-synangiosis (temporal muscle graft), which were not considered to be so effective to the ischemia of the posterior circulation, were shown to exert indirect redistribution effect upon the vertebrobasilar system. However, this effect is such an indirect one that these surgical treatments cannot prevent the occurrence of ischemic stroke in the vertebrobasilar system. For this purpose, omentum transplantation to the occipital lobe may be needed as a method of direct revascularization.

Intracerebral arteriovenous malformation fed by the anterior ethmoidal artery: case report

The authors report a case of intracerebral arteriovenous malformation fed by the anterior ethmoidal artery. The nidus was located in the brain parenchyma, although its feeder was a dural artery. The etiology of this rare condition is discussed.

[Study for lateralization of hemispheric cerebral blood flow by argon method with catheterization into the bilateral internal jugular bulbs]

Only 24 patients with chronic ischemic cerebrovascular lesions, which had been lateralized to either hemisphere of the cerebrum, were analyzed by argon desaturation method measuring bilateral hemispheric blood flows. Their ages varied from 10 to 72 years with a mean of 49 years. Fifteen patients (62.5%) had localized ischemic lesions in the left cerebral hemispheres and remaining 9 patients (37.5%) had in the right hemispheres. The clinical symptom of each patient was lateralized due to localized ischemic focus. Bilateral transfemoral catheterization of the internal jugular bulbs was successfully performed. Each hemispheric blood flow was calculated by argon desaturation method using mass spectrometry based on Fick's principle. Half of the patients, 12 cases revealed lateralization over 20% significant differences of its values. 8 patients (66.7%) were reduced significantly in the left hemispheres and 4 patients were contralaterally. Finally 9 patients revealed that CBF values at the affected side was significantly reduced with no anatomical differences among sinus systems. It is probably that CBF value at the affected side reflects its ischemic lesion more than that at the non-affected side. Several authors reported no predominant lateralization between bilateral sinus draining systems. Based on possibility of "laminar flow" in the confluence, CBF value at the affected side is more important. So further investigations are needed for the future.

Spinal cord arteriovenous malformations associated with spinal aneurysms

Two patients with spinal cord arteriovenous malformations (AVMs) had coexisting spinal aneurysms on their main feeding arteries. The angiographic disappearance of these coexisting aneurysms after artificial embolization of the spinal cord AVMs suggests that hemodynamic stress is the important factor in the development of spinal aneurysms. The incidence of hemorrhage increases when spinal cord AVM is associated with spinal aneurysm.

[Multilocular encapsulated intracerebral hematoma]

Encapsulated intracerebral hematoma is so rarely seen that only two cases have been reported, by Hirsh et al. Recently, we experienced a case of multilocular encapsulated intracerebral hematoma containing 9 to 10 capsules of different sizes. The capsules of the hematoma were easily dissected from the surrounding brain tissues and found to be grayish white in color, tough in hardness and 1 to 3 mm in thickness. The capsular contents ranged from very old to relatively new, which contents were hard on soft solid hematomas, liquid hematomas or xanthochromic fluid. These findings indicated the development of intracerebral hematomas with different chronic courses at different times. It is very interesting that the frequency of the convulsive seizure was almost consistent with the number of capsules. For etiology of multilocular intracerebral hematoma, either occult vascular malformation or bleeding from the sinusoidal channel layer of the capsules like that of chronic subdural hematoma is considered.

[Embolization and detached balloon occlusion by the femoral route in craniofacial lesions]

Embolization and detached balloon occlusion by the femoral route were performed in 45 cases: 19 cases of meningiomas, 5 of scalp arteriovenous malformations (AVMs), 4 of dural AVMs, 6 of cerebral AVMs, 8 of facial angiomas and 3 of carotid cavernous sinus fistulas (CCFs); and favorable results were attained. In meningiomas, there is only a short interval between the embolization and the removal of tumor (we usually perform the embolization a couple of days before the removal), and we use Gelfoam as embolus material. We aim at central tumor embolization with small emboli. The embolization reduced bleeding in removing the tumors, simplifying the surgical procedure, and 12 of 19 cases required no blood transfusion. Almost all cases of scalp AVMs, dural AVMs and facial angiomas could most probably be cured only by the embolization without surgery. Gelfoam was the first choice, because it would probably dissolve, and also because it would be relatively safe even if pulmonary embolism might occur as a result of probable passage of its emboli onto the venous side. In recanalized cases, the embolization was performed again with Ivalon, a permanent embolus material. The most important of this procedure is to inject the emboli of the suitable size for each case together with a suitable contrast material at as low a rate as possible under the image intensifier. Embolization by the injection pressure should never be tried, but the emboli be allowed to be carried only on the blood flow to the distal side. And the embolization should be discontinued at the stage when the contrast material has stagnated. CCFs are very good indications for the detached balloon occlusion, while this technic proved to serve for no more than occluding the feeding vessels in cerebral AVMs; in other words, it is indicated in a rather limited range of AVMs. We have encountered no severe complications in any of the cases treated by the embolization and detached balloon occlusion.

Dynamic CT in patients with superficial temporal-middle cerebral artery anastomosis

Using dynamic computed tomographic (CT) scanning and an iodinated contrast material, changes in cerebral hemodynamics in cerebrovascular occlusive disease were studied before and after anastomosis of the superficial temporal artery and the middle cerebral artery. Because the iodinated contrast material is a nondiffusable indicator, it does not pass through the bloodbrain barrier. Thus, this method is capable of measuring the relative tissue blood flow (intravascular blood flow) but incapable of measuring the absolute cerebral blood flow. However, it does allow the three-dimensional measurement of cerebral hemodynamics by a simple procedure, and when the primarily clear brain structure seen with CT is considered, it is a very useful diagnostic method.

[Monitoring system of cerebral blood flow and cerebral metabolism. Part II. Relationship between internal jugular O2 tention and cerebral blood flow (author's transl)]

Changes of PjO2 values of internal jugular vein were monitored in patients with various types of cerebrovascular disease. The significance of PjO2 monitoring was evaluated. 1) Control value of PjO2 in thirteen normal control cases was 36.7 +/- 1.9 mmHg (mean +/- SD). 2) Limit of brain hypoxia showing no neurological sign and symptom in patients with occlusive cerebrovascular disease was studied by the stepwise reduction of arterial blood pressure, using drip infusion of trymetaphan camsylate, under the careful monitoring of signs and symptoms and monitoring of PjO2 and EEG. Appearance of signs and symptoms of brain hypoxia were checked by yawning and EEG slowing. At the time of the appearance of brain hypoxia PjO2 was 28.6 +/- 3.2 mmHg. 3) CO2 reactivity of CBF was studied in patients with occlusive cerebrovascular disease. Relation between PaCO2 and PjO2 was as follows; PjO2 = 0.68 . PaCO2 + 7.55 4) Within 24 hours after the onset of stroke, ipsilateral PjO2 of the cases with disturbance of consciousness was lower than that of the cases without disturbance of consciousness, which might indicate the significant decrease of CBF in the former cases. During 3rd to 7th day after the onset the cases with disturbance of consciousness showed the significant elevation of PjO2, which might indicate the reduction of cerebral metabolism. 5) The elevation of ipsilateral PjO2 were well correlated to the degree of hemispheric brain swelling. 6) During general convulsion, high level of PjO2 values were observed. 7) PjO2 values were inversely correlated to the hemoglobin values after blood transfusion, which was mainly due to the decrease of CBF by high content of hemoglobin.