Cerebral Artery Dissection Research Articles

繰り返すTIAを呈した前大脳動脈解離の1例

Spontaneous arterial dissection in the anterior circulation is extremely uncommon. The natural course of this phenomenon is far from being understood, and the treatment is controversial. In this study, we report a case of anterior cerebral artery dissection presenting recurrent transient ischemic attack.A 37-year-old male suffered from right hemiparesis and aphasia. On admission, CT scans revealed no lesion. However, in the left carotid angiography, an irregularity of the wall was observed at the left A2 proximal portion. The symptoms disappeared after about 4 hours. Under conservative treatment, the symptoms appeared intermittently. Since the progress of the dissection of the left callosomarginal artery was observed in the cerebral angiography, we performed an emergency operation. We performed side-to-side anastomoses on the left obstructed pericallosal artery and the left callosomarginal artery whose dissection had progressed to the other side. Furthermore, we ligated the left A2 proximal portion, which had expanded with a dark red color. The postoperative course was uneventful. Ischemic attack was not observed.We believe that an arterial progressive dissection with ischemic symptoms requires surgical treatment.

Temporary occlusion of the middle cerebral artery in intracranial aneurysm surgery: time limitation and advantage of brain protection

The risk of focal infarction secondary to the induced reversible arrest of local arterial flow during microsurgical dissection of middle cerebral artery (MCA) aneurysms was evaluated further to define the optimal approach to temporary arterial occlusion. To compare the effectiveness of potential brain-protection anesthetics, a group of patients treated with the intravenous agents propofol, etomidate, and pentobarbital, administered individually or in combination, was compared to a group treated with the inhalational agent isoflurane. Forty-nine consecutive MCA aneurysm surgeries involving the temporary clipping of the parent vessel were retrospectively reviewed. Thirty-eight patients received intravenous brain-protection (IVBP) anesthesia. Groups of patients with and without infarctions, and receiving and not receiving IVBP anesthesia, were compared based on the duration and nature of temporary arterial occlusion. Postoperative radiographic evidence of new infarction was used as the threshold for failure of occlusion tolerance. The overall infarction rate was 22.4% (11 of 49 patients), including 15.8% (six of 38 patients) in the IVBP group versus 45.5% (five of 11 patients) in the group that did not receive brain protection (NBP). In the NBP group, the mean duration of temporary occlusion was 3.9 +/- 2.2 minutes for patients without infarction versus 12.2 +/- 4.3 minutes for patients with focal infarction (p < 0.01). In contrast, the mean duration was 13.6 +/- 10.6 minutes for patients without infarction and 18.5 +/- 9.9 minutes for patients with infarction in the IVBP group. All patients (four of four) in the NBP group who underwent occlusion lasting 10 minutes or longer suffered an infarction versus five of 23 patients in the IVBP group (p < 0.0001). Patients with multiple aneurysms were found to be at increased risk of developing focal infarction, whereas those treated with intermittent temporary clip application were at decreased risk. It is concluded that patients in whom focal iatrogenic ischemia is induced during MCA aneurysm clip ligation have a significant advantage compared with those receiving isoflurane when they are given pentobarbital as the primary neuroprotective agent or when they receive propofol or etomidate titrated to achieve electroencephalographic burst suppression, particularly if more than 10 minutes of occlusion time is required. It is also concluded that 10 minutes is a general guideline for safe, temporary occlusion of the MCA. The use of intermittent temporary arterial occlusion and its use in patients with multiple aneurysms need further evaluation before specific recommendations can be made.

Temporary occlusion of the middle cerebral artery in intracranial aneurysm surgery: time limitation and advantage of brain protection

The risk of focal infarction secondary to the induced reversible arrest of local arterial flow during microsurgical dissection of middle cerebral artery (MCA) aneurysms was evaluated further to define the optimal approach to temporary arterial occlusion. To compare the effectiveness of brain-protection anesthetics, a group of patients treated with the intravenous agents, propofol, etomidate, and pentobarbital, administered individually or in combination, was compared to a group treated with the inhalational agent isoflurane. Forty-nine consecutive MCA aneurysm surgeries involving the temporary clipping of the parent vessel were retrospectively reviewed. Thirty-eight patients received intravenous brain-protection (IVBP) anesthesia. Groups of patients with and without infarctions, and receiving and not receiving IVBP, were compared based on the duration and nature of temporary arterial occlusion. Postoperative radiographic evidence of new infarction was used as the threshold for failure of occlusion tolerance. The overall infarction rate was 22.4% (11 of 49 patients), including 15.8% (six of 38 patients) in the IVBP group versus 45.5% (five of 11 patients) in the isoflurane (ISO) group. In the ISO group, the mean duration of temporary occlusion was 3.9 ± 2.2 minutes for patients without infarction versus 12.2 ± 4.3 minutes for patients with focal infarction (p &lt; 0.01). In contrast, the mean duration was 13.6 ± 10.6 minutes for patients without infarction and 18.5 ± 9.9 minutes for patients with infarction in the IVBP group. All patients in the ISO group who underwent occlusion lasting 10 minutes or longer suffered an infarction versus five of 23 patients in the IVBP group. Patients with multiple aneurysms were found to be at increased risk of developing focal infarction, whereas those treated with intermittent temporary clip application were at a decreased risk. It is concluded that patients in whom focal iatrogenic ischemia is induced during MCA aneurysm clip ligation have a significant advantage compared with those receiving ISO when they are given pentobarbital as the primary neuroprotective agent or when they receive propofol or etomidate titrated to achieve electroencephalographic burst suppression, particularly if more than 10 minutes of occlusion time is required. It is also concluded that 10 minutes is a general guideline for safe, temporary occlusion of the MCA. The use of intermittent temporary arterial occlusion and patients with multiple aneurysms need further evaluation before specific recommendations can be made.

Middle Cerebral Artery Dissection

A 12-year-old girl had minor head trauma, with resultant mild headache, one day prior to onset of an apparently generalized tonic clonic seizure, right hemiparesis and dysphasia. A cranial CT scan showed evidence of a left middle cerebral artery infarct. Despite ventilation, fluid restriction, mannitol, thiopental infusion and intracranial pressure monitoring she deteriorated and died. Autopsy demonstrated dissection of the left middle cerebral artery with an intact internal carotid artery and no evidence of vasculitis. Middle cerebral artery dissection in children is very rare. Most reported cases are diagnosed at autopsy. The pathogenesis of cerebral artery dissection may include preceding minor head trauma or exertion and this should be sought for in the history.

Cerebral Infarction and Intracranial Arterial Dissection in Closed Head Injury

This report describes the autopsy findings in three cases of closed head injury dying of cerebral infarction, with brain swelling and herniation. In each instance the cause of the infarct was found to be subintimal dissection involving intracranial anterior circulation arteries. The autopsy findings underscore the value of histological examination of vessels that macroscopically appear thrombosed. We discuss factors that impact on the reported incidence and make brief mention of problems surrounding the true pathogenesis of this lesion.

Interhemispheric approach for microsurgical removal of olfactory groove meningiomas.

Eighteen consecutive patients with olfactory groove meningiomas, with diameters ranging from 1.5 to 7 cm, underwent microsurgical tumour resection using a unilateral frontal interhemispheric approach. Unilateral frontal craniotomy, superior to the frontal sinus, exposing the superior sagittal sinus was performed. The ipsilateral frontal lobe was gently retracted laterally, and the tumour resected through the gap between the falx and the medial aspect of the frontal lobe, anteriorly to the genu of the corpus callosum. Gross total tumour resection was achieved in all the patients. There was no evidence of damage to the frontal lobes, the anterior cerebral arteries or the optic system. Compared with the more commonly applied subfrontal route, the interhemispheric approach has the advantages of sparing the frontal sinuses and providing excellent overview of the dissection of the anterior cerebral arteries and the optic system, as well as for the resection of tumour invading the frontal cranial base.

Fatal stroke in a patient with carotid and middle cerebral artery dissection associated with cystic medial necrosis

Fatal stroke in a patient with carotid and middle cerebral artery dissection associated with cystic medial necrosis

Spontaneous extracranial carotid artery dissection in children

Dissection of cerebral arteries as a cause of stroke is rarely recognized in children. Two patients with stroke due to extracranial carotid artery dissection are reported. A 7-year-old girl with a 2-week history of right arm chorea had a left basal ganglia infarct and is receiving haloperidol for persistent chorea. The second patient, a 15-year-old boy, developed aphasia and right hemiparesis a day before admission during a football game without obvious trauma. He had a large left middle cerebral artery infarct and died of cerebral edema and herniation. We believe that strokes due to arterial dissection are more common than currently recognized, partly because of a lack of history of trauma, and suggest that cerebral artery dissection be considered as an etiology of childhood strokes. Greater awareness of arterial dissection as a cause of stroke and availability of noninvasive techniques like magnetic resonance angiography should result in a more accurate diagnosis and improved prognosis in these patients.

Cerebral artery dissection as cause of stroke

Cerebral artery dissection as cause of stroke

Benign arterial dissections of the posterior circulation

Four young adults with spontaneous dissection of the vertebrobasilar system are reported. Clinically, two patients presented with subarachnoid hemorrhage and two with brain-stem ischemia. In two cases of ruptured arterial dissection of the posterior cerebral artery, angiography demonstrated fusiform and "sausage-like" dilatation of the involved vessel. In two cases of occlusive dissection of the basilar artery, angiography revealed the typical "string sign." All four patients were treated conservatively: three survive in good clinical condition and one remains disabled. Follow-up angiograms showed spontaneous healing of the lesion with return to an almost normal arterial configuration in two cases; residual narrowing corresponding to the dissection was the most notable finding in the other two. It is recommended that, in a subset of neurologically stable patients, angiographic monitoring is undertaken to assess the tendency for spontaneous repair before surgical intervention is planned.

Effects of vasospasm on levels of prostacyclin and thromboxane A2 in cerebral arteries of the monkey

To determine whether cerebral arteries in spasm have an altered capacity to synthesize the vasoactive substances prostacyclin and thromboxane A2, we measured levels of these arachidonic acid metabolites using a primate model of vasospasm. Twenty-four cynomolgus monkeys were assigned at random to one of three groups designated sham, clot, or clot-removal. All animals underwent base line cerebral angiography and bilateral dissection of the major cerebral arteries from the arachnoid. The clot and clot-removal groups had autologous hematomas placed around the vessels to simulate subarachnoid hemorrhages. The sham group had a similar volume of saline instilled into the subarachnoid space. Twenty-four hours later, the clot-removal group underwent a second craniotomy to remove the hematomas. Seven days after the initial operation, angiography was repeated on all animals. The animals were then killed, and the cerebral arteries were removed. Basal levels of prostacyclin and thromboxane in the cerebral vessels were measured after incubation in vitro by radioimmunoassay. No detectable leukotriene C4 release by these arteries was measurable using radioimmunoassay. Angiography revealed severe cerebral vasospasm in the clot group, but not in the clot-removal or sham groups. There were no statistical differences among the groups in thromboxane release, but prostacyclin levels were significantly lower in the clot group than in the clot-removal group (P less than 0.05). It thus seems that, if an imbalance in constrictor and dilator eicosanoids occurs in association with vasospasm, this is more likely to arise from a relative lack of the vasodilator component prostacyclin than from a surplus of the vasoconstrictor thromboxane.(ABSTRACT TRUNCATED AT 250 WORDS)

脳動脈硬化の実験病理学的研究

We succeeded in producing cerebral atherosclerotic lesions in hypertensive rabbits fed with cholesterol. To examine the location and progression of atherosclerotic lesions, frontal dissection of cerebral arteries (vertebral arteries, basilar artery and posterior cerebral arteries) was performed and thus an overall view of these vascular luminal surface was acquired. Initial atherosclerotic lesions developed at the Y-bifurcation of arteries (from basilar artery to right and left posterior cerebral arteries) and confluent portion of arteries (from right and left vertebral arteries to basilar artery). Lesions observed by the scanning electron microscopy showed passing figures of macrophages and protrusion or distortion of endothelial cell configurations. These features are almost consistent with those described in aortic lesions. The location of lesion at the arterial Y-bifurcation made reminiscent of that in human cerebral atherosclerosis. In addition, it has been said that a peculiar form of eddies developes at Y-bifurcation of artery; observations on the normal rabbit cerebral artery disclosed that these vascular Y-bifurcation and confluent portions correspond to the turning and confluent points of endothelial arrangement of the corresponding arteries respectively. From these observations it was concluded that these specialities in blood stream and endothelial arrangement may relate to atherogenesis of the cerebral arteries.

Dissections of Cervical and Cerebral Arteries

Dissections have been reported with increasing frequency in recent years. The authors discuss dissection of extracranial carotid, intracranial cerebral, and vertebrobasilar arteries and consider differences in clinical features and in pathophysiologic and therapeutic considerations.

Dissecting aneurysm of cerebral arteries in childhood and adolescence

A nine year old girl died with a massive infarct of the right cerebral hemisphere causing transtentorial and foramen magnum herniation. The infarction was secondary to an idiopathic dissecting aneurysm. The case is unusual in that the supraclinoid segment of the right internal carotid artery, the anterior cerebral artery, and the middle cerebral artery and its three branches were embedded and sectioned longitudinally. The dissection commenced in the supraclinoid segment of the right internal carotid artery, extended into the middle and anterior cerebral arteries, and was accompanied by thrombosis of the false lumen. A literature review of 20 pediatric cases indicates the malignant natural course of the disease (76% mortality in the first two months), and emphasizes the characteristic angiographic "string sign". The diagnosis of cerebral arterial dissection during life depends on angiography and a high index of suspicion.