Showing papers on "Middle cerebral artery published in 1979"
TL;DR: In ten patients, 11 infarcts involving mainly the internal capsule have been examined pathologically, and the clinical correlate was a pure motor hemiplegia or hemiparesis involving the face, arm, and leg without sensory deficit, homonymous hemianopia, receptive aphasia, or apractognosia.
Abstract: In ten patients, 11 infarcts involving mainly the internal capsule have been examined pathologically Serial sections of the involved basal ganglia were studied in ten infarcts and only a gross dissection was made in the other The implicated penetrating arteries were traced throughout their length and obstructive vascular lesions were found in nine instances In two of the nine there was an atheromatous plaque with a superimposed thrombus, in four an atheromatous plaque had caused severe stenosis, in one a destructive arterial process lipohyalinosis had occurred, in one case the nature of the obstruction remained "uncertained," and in one the penetrating arteries were obstructed at their orifices by an atheroma in the superior division of the middle cerebral artery In two cases the vessels were patent, suggesting embolism The atheromas consisted almost exclusively of a conglomerate of fat-filled macrophages The clinical correlate was a pure motor hemiplegia or hemiparesis involving the face, arm, and leg without sensory deficit, homonymous hemianopia, receptive aphasia, or apractognosia Confusion was prominent in one patient
423 citations
TL;DR: Bypass grafts and circulatory arrest with extracorporeal circulation may have a role in giant aneurysms of the posterior circulation.
Abstract: The authors report experience with the surgical management of 80 giant intracranial aneurysms (greater than 2.5 cm in diameter) during a 10-year period in which they performed 594 operations for aneurysms. The overall incidence of giant aneurysms was 13% but varied according to location: 20% of aneurysms of the internal carotid artery (ICA); 13% of middle cerebral artery (MCA) aneurysms; 1% of anterior cerebral artery (ACA) aneurysms; 15% of aneurysms of the basilar artery caput (BAC); and 18% of vertebrobasilar trunk (VB) aneurysms. Twenty-five patients had a subarachnoid hemorrhage (SAH), 49 had mass effect from the aneurysm, and six had ischemic events. There was no apparent difference in results related to the presence or absence of an SAH. Poor results were attributable to the operation except in the two cases of ACA aneurysm in which preexisting dementia persisted. Mortality was 4% and morbidity was 14%, varying from a combined low morbidity-mortality of 8% for ICA lesions to a high to 50% for BAC aneurysms. During the period of the study, different techniques were developed in an attempt to lower the risks of surgery. Ultimately ICA aneurysms were monitored with cerebral blood flow measurements and electroencephalography before and after temporary ICA ligation, then approached following resection of the anterior clinoid or treated with bypass in combination with ICA ligation. Aneurysms of the MCA were either opened during temporary MCA occlusion or resected in combination with a bypass procedure. Bypass grafts and circulatory arrest with extracorporeal circulation may have a role in giant aneurysms of the posterior circulation.
272 citations
TL;DR: Giant aneurysms can be treated with respectable results if the surgeon selects the technique best suited to the particular aneurym, and intramural thrombosis is best for those of the posterior circulation.
Abstract: ✓ The author has operated on 40 patients with giant intracranial aneurysms, using various surgical approaches. Giant aneurysms predominated in females (3:1) and were most common in the age group 30 to 60 years. Patients presented with subarachnoid hemorrhage (17), visual disturbance (18), chronic headache (14), transient or progressive hemispheric deficit (6), seizure (2), dementia (2), and cerebrospinal fluid rhinorrhea (1). Giant aneurysms were located at the carotid artery (25), the basovertebral artery (8), the anterior communicating artery (5), and the middle cerebral artery (2). Eight of 40 patients had one or more other aneurysms and/or associated arteriovenous malformations. Aneurysms were treated with intramural thrombosis (21), neck occlusion (7), trapping (10), proximal parent artery ligation (1), and aneurysmorrhaphy (1). After as much as 8 years of follow-up, 32 patients (80%) showed complete or marked improvement in signs and symptoms; two patients (5%) had a poor recovery. There were six su...
174 citations
TL;DR: The authors report microsurgical treatment in 32 cases of basilar artery aneurysms, operated on with good results in 28 cases, fair results in one, and poor results in two; there were two deaths.
Abstract: The authors report microsurgical treatment in 32 cases of basilar artery aneurysms, operated on with good results in 28 cases, fair results in one, and poor results in one; there were two deaths. Twenty-nine patients (91%) were able to return to social activities. Characteristics of the surgical techniques include 1) taking a transsylvian route; 2) retracting the M1 portion of the middle cerebral artery (occasionally the C1 portion of the internal carotid) medially with tapered brain retractors; and 3) approaching the aneurysm through and between perforators arising from the posterior cerebral artery in cases of high-placed basilar bifurcation. With regard to instrument improvements, tapered brain retractors, a multipurpose head frame, and bayonet clips (Sugita design) proved very helpful.
145 citations
TL;DR: In monkeys and cats with or without MCA occlusion the detrimental effects of hypothermia were not favorably influenced either by hemodilution or by deliberate alterations in PacOj, and the effect of 48 h of Hypothermia and rewarming on cerebral blood flow and cerebral metabolites was evaluated.
Abstract: In a previous study occlusion of a middle cerebral artery (MCA) followed by 48 h of hypothermia (29 degrees) was lethal in 5 of 5 monkeys as compared to only 3 of 9 normothermic animals. The present study extended these observations in monkeys and cats with or without MCA occlusion. In monkeys MCA occlusion plus 48 h of hypothermia was consistently lethal. Without MCA occlusion of 2 of 3 monkeys survived, but were comatose the first 12 h post-hypothermia. In normothermic cats, MCA occlusion was lethal in only one of 5 animals whereas hypothermia was lethal in 20 of 21 cats with or without MCA occlusion. The detrimental effects of hypothermia were not favorably influenced either by hemodilution or by deliberate alterations in PaCO2. The effect of 48 h of hypothermia and rewarming on cerebral blood flow (CBF) and cerebral metabolites was evaluated in 6 normal monkeys. CBF was reduced 60 to 70 percent at 29 degrees C and returned to only a maximum of 50 percent of control with re-warming. Prior to re-warming distribution of CBF was inhomogeneous. Cerebral metabolites were borderline normal prior to re-warming but energy stores decreased while lactate increased with re-warming.
123 citations
TL;DR: The low risk and high potential benefit of prophylactic bypass justifies its use before major vessel occlusion in selected cases, and this to be an effective and safe mode of therapy in cases in which direct approach is not feasible.
Abstract: Eleven patients with lesions of the internal carotid and middle cerebral arteries that could not be treated by direct approach are presented. Major vessel occlusion was chosen as definitive therapy. Prophylactic extracranial-intracranial bypass was employed in an attempt to reduce the incidence of ischemic complications. Emphasis is placed on complications, from which several important lessons were learned. Our best results occurred in patients with carotid artery lesions treated with bypass and immediate internal carotid ligation. We believe this to be an effective and safe mode of therapy in cases in which direct approach is not feasible. The low risk and high potential benefit of prophylactic bypass justifies its use before major vessel occlusion in selected cases.
120 citations
TL;DR: The clinical course of 16 consecutive patients with stenosis of the middle cerebral artery angiographically diagonosed between 1970 and 1977 was reviewed and supports the need for a randomized study of bypass efficacy in these patients.
Abstract: The clinical course of 16 consecutive patients with stenosis of the middle cerebral artery angiographically diagonosed between 1970 and 1977 was reviewed. All were managed nonsurgically with medical treatment including anticoagulation. Prior to therapy, transient ischemic attacks had occurred in 15 and cerebral infarction in 11. Initially, none exhibited more than a minor neurological deficit. Follow-up from one month to six years showed a benign course in 14 patients: 13 experienced no subsequent transient attacks or new stroke; 1 had repeated transient attacks for two years but not in the following four years. Two of the 16 developed a severe stroke early in the course, before medical therapy was started. No distinctive clinical or radiographic features were identified that permitted prediction of the outcome. This small series supports the need for a randomized study of bypass efficacy in these patients.
105 citations
TL;DR: Cerebral infarction was documented by arteriography and serial computed cranial tomography in four young adulte (ages 16 to 32 years) with migraine and may be more prevalent in “complicated” migraine than is generally appreciated.
Abstract: Cerebral infarction was documented by arteriography and serial computed cranial tomography (CT) in four young adults (ages 16 to 32 years) with migraine. In one case, posterior cerebral artery occlusion produced a deep parietotemporal infarct. The other three cases all had frontotemporal infarcts (one hemorrhagic) in the territory of the middle cerebral artery, without major arterial occlusion. Two infarcts produced lasting neurologic deficits; one was associated with mild, transitory symptoms, and one was asymtomatic. Laboratory investigations in two cases revealed no hematologic or cardiovascular predisposition to cerebrovascular disease. Cerebral infarction, as revealed by CT, may be more prevalent in "complicated" migraine than is generally appreciated. Such lesions may or may not develop in chronologic and anatomic relationship to the headache, and may involve either large or small arteries. The prognosis for functional recovery, based on this limited sample, seems favorable.
76 citations
TL;DR: The use of a pulsed echo Doppler technique during procedures for occlusion of intracranial aneurysms is described, and special emphasis has been placed on the parent artery flow, particularly the effect of lumen reduction on flow velocity.
Abstract: The use of a pulsed echo Doppler technique during procedures for occlusion of intracranial aneurysms is described. Saccular aneurysms can be located with reference to probe position and depth setting. Tracings of intra-aneurysmal flow are presented, and the characteristic flow pattern is disucssed. Special emphasis has been placed on the parent artery flow, particularly the effect of lumen reduction on flow velocity. Results of flow velocity studies on the cognate (direct) and collateral flow in the middle cerebral artery and the proximal anterior cerebral artery are presented and discussed.
71 citations
TL;DR: Fluorescein angiography provided an immediate assessment of anastomotic patency and clearly displayed the distribution of blood entering the epicerebral circulation through the STA and an immediate, substantial increase in rCBF was demonstrated in 73% of patients after anASTomosis.
Abstract: ✓ Fluorescein angiography and xenon-133 (133Xe) clearance studies were performed during surgery on 15 patients who were undergoing superficial temporal artery (STA) to middle cerebral artery (MCA) anastomosis. Fourteen patients had occlusive disease of the internal carotid artery (ICA), and one patient had severe stenosis of the MCA. Before anastomosis, fluorescein angiography showed slow filling of the MCA branches through collateral channels. Focal areas of impaired microcirculatory filling and washout were seen in the territory of severely sclerotic cortical arteries. The findings of preanastomotic 133Xe clearance studies were variable and a uniform pattern of regional cerebral blood flow (rCBF) changes was not defined. In 55% of the patients, rCBF was reduced to 25 ml/100 gm/min or less at one or more detector sites. Fluorescein angiography provided an immediate assessment of anastomotic patency and clearly displayed the distribution of blood entering the epicerebral circulation through the STA. In 67...
65 citations
TL;DR: The present results indicate the potential usefulness of Y-9179 in the management of strokes and a statistically significant decrease in the infarction rate was found both in Y- 9179 and pentobarbital-treated groups compared to the control group.
Abstract: For the purpose of investigating the protective action against cerebral ischemia by a new imidazole derivative (Y-9179) and pentobarbital, regional cerebral ischemia was produced in 53 cats by permanent occlusion of the middle cerebral artery (MCA) via the transorbital approach. In 20 cats, the clips were applied at the origin of the right MCA whereas in the remaining 33 they were applied laterally. The administration of Y-9179 (6.25 and 12.5 mg/kg/day), pentobarbital (25 mg/kg/day) and saline was started 30 min after MCA occlusion and continued for 3 days. The cats were observed for 7 days and then sacrificed. Since there was a remarkable difference in mortality between the medial (65%) and the lateral occlusion groups (15%), the evaluation of drug effects was based only on the results obtained with the lateral occlusion group. The brains were sliced at 4 fixed coronal planes, in which the ratios of the infarcted area in the 2 hemispheres were obtained by planimetry. A statistically significant decrease in the infarction rate was found both in Y-9179 and pentobarbital-treated groups compared to the control group. Since the CNS depressant action of Y-9179 is far less potent than that of pentobarbital, the present results indicate the potential usefulness of Y-9179 in the management of strokes.
TL;DR: The effect of mannitol for prolongation of the tolerance time for cerebral artery occlusion is discussed based on data in 384 patients with cerebral aneurysm and it was revealed that 82% of all patients were living normal social lives.
Abstract: The effect of mannitol for prolongation of the tolerance time for cerebral artery occlusion is discussed based on data in 384 patients with cerebral aneurysm. Intracranial direct surgery was performed by employing temporary occlusion of the afferent artery and preoperative administration of mannitol under normothermia and normotension. (1) In the patients who experienced sequelae or died, the causes of deterioration were studied. Most of them were due to vasospasm, surgical complication, or infection. In 4 patients, the cause of deterioration was obscure. The possibility that these patients were affected by temporary occlusion of cerebral arteries could not be ruled out. (2) The longest occlusion time in the patients without sequelae for each main artery was 80 minutes at the unilateral A1 of the anterior cerebral artery, 65 minutes at the bilateral A1, 57 minutes at the intracranial internal carotid artery and 65 minutes at the middle cerebral artery. (3) The surgical result of the 384 patients at discharge included 13 deaths, a mortality rate of 3%. Follow-up study of 371 surviving patients after at least 6 months from surgery revealed that 82% of all patients were living normal social lives.
TL;DR: Measurements of regional cerebral hemodynamics and metabolism in patients undergoing a superficial temporal artery-middle cerebral artery anastomosis to bypass cerebrovascular lesions not amenable to extracranial operative procedures suggest that measurements of this type could provide objective criteria for surgery as well as assess the effect of surgery.
Abstract: ✓ Regional cerebral blood flow (rCBF) and regional cerebral oxygen utilization (rCMRO2) were measured before and after surgery in nine patients undergoing a superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis to bypass cerebrovascular lesions not amenable to extracranial operative procedures. The objective of these studies was to determine whether measurements of this type could provide objective criteria for surgery as well as assess the effect of surgery. The preliminary data, although limited, suggest that measurements of regional cerebral hemodynamics and metabolism in these patients before and after surgery provide valuable data upon which to develop criteria and assess results. For example, 1) a significant depression of rCBF and rCMRO2 in patients in whom a major cerebral infarction has not occurred, or 2) relative preservation of rCMRO2 despite depressed rCBF seem to be favorable indications for establishing a functioning STA-MCA anastomosis. In such patients, STA-MCA anastomo...
01 Jan 1979
TL;DR: A new neurosurgical procedure, anastomosis of the superficial temporal artery to the middle cerebral artery, is being performed with increasing frequency, and progressing venous stasis retinopathy and ischemic orbital pain are believed to be indications for bypass surgery of the carotid artery.
Abstract: A new neurosurgical procedure, anastomosis of the superficial temporal artery to the middle cerebral artery, is being performed with increasing frequency. Over a 7-year period (1971 through 1977), 121 patients have undergone this operation in our institution. Ophthalmodynamometry may be of great help in identifying occlusion of an internal carotid artery. Progressing venous stasis retinopathy and ischemic orbital pain are believed to be indications for bypass surgery of the carotid artery.
TL;DR: The animals with left hemispheric lesion showed no postoperative change in either mean spontaneous 24 hour activity or mean catecholamine concentrations in several areas of the brain, demonstrating a remarkable asymmetry in the behavioral and biochemical response to cerebral cortical infarction.
TL;DR: The study shows that the STA and its anastomotic branch increase in size over time, measured in months, in the majority of patients, which suggests that a static analysis at one time may belie the true effect of the surgery.
Abstract: ✓ Pre- and postoperative angiograms on 40 patients undergoing superficial temporal-middle cerebral artery (STA-MCA) bypass surgery have been examined in detail. Multiple postoperative angiograms have been obtained to evaluate the change in both the bypass circuit and the intracranial circulation over time. A reproducible system for evaluating the degree of intracranial vascular filling via the bypass is introduced. The study shows that the STA and its anastomotic branch increase in size over time, measured in months, in the majority of patients. This is paralleled by a progressive increase in the degree of intracranial vascular filling. These changes are proportional to the severity of the vascular disease before surgery. The pattern of preoperative collateral circulation may change over time following the addition of the bypass circuit. The progressive change over time suggests that a static analysis at one time may belie the true effect of the surgery. The change of collateral circulation, with augmenta...
Journal Article•
TL;DR: Two cases of cardiac myxoma with secondary involvement of the brain and death are reported, and the second case represents the only instance of cardiacMyxoma behaving as a true malignant neoplasm with actual invasion of the neural tissues recorded in the literature.
TL;DR: The clinical outcome of the first 40 patients treated with a superficial temporal artery-middle cerebral artery anastomosis with no operative mortality and Neurological deficits were either unchanged or improved, showed patency in 97% of the anASTomoses.
Abstract: • The clinical outcome of our first 40 patients (six with transient ischemic attacks, 22 with mild ischemic infarctions, and 12 with moderate ischemic infarctions) treated with a superficial temporal artery-middle cerebral artery anastomosis was analyzed. All cerebral ischemias or infarctions occurred in the internal carotid artery distribution. An independent neurologist observer recorded the patient's preoperative and postoperative medical and neurological histories and objective neurological findings. There was no operative mortality. During the period of observation (up to 36 months), four patients died of probable myocardial infarction. No patient suffered from recurrent cerebral infarction. Three patients experienced a single ischemic event postoperatively. Neurological deficits were either unchanged (21 patients) or improved (19 patients). Postoperative angiograms showed patency in 97% of the anastomoses.
TL;DR: A nine year old girl died with a massive infarct of the right cerebral hemisphere causing transtentorial and foramen magnum herniation and a literature review of 20 pediatric cases indicates the malignant natural course of the disease.
Abstract: 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.
Journal Article•
TL;DR: A patient with transient ischemic attacks from occlusion of a left commonCarotid artery was treated with common carotid endarterectomy immediately followed by superficial temporal artery-middle cerebral artery bypass, and subsequent angiography demonstrated a pseudoaneurysm formation at the anastomotic site.
TL;DR: The clinical picture and radiological findings of 12 cases of "idiopathic" arachnoid cyst in the middle fossa which the authors have encountered during the past 12 years are described.
Abstract: This paper describes the clinical picture and radiological findings of 12 cases of "idiopathic" arachnoid cyst in the middle fossa which the authors have encountered during the past 12 years. Their results are as follows. 1) The age of the patient in 10 out of 12 cases was under 15 years of age, and 8 cases were males. The site of the cyst was on the left side in 9 cases. 2) On plain skull radiography, thinning and bulging of the temporal bone by the lesion, elevation of the lesser wing of the sphenoid, and forward projection of the greater wing of the sphenoid were observed in all cases. 3) On cerebral angiography, a characteristic elevation of the middle cerebral artery and hypoplasia of its insular and opercular portion were observed; and in the venous phase, a defect of the middle cerebral vein, backward deviation of the vein of Labbe, and elevation of the vein of Rosenthal were seen. 4) On Metrizamide (Amipaque) CT cisternography, there were two types, one which communicated and the other which did not communicate with the adjacent subarachnoid space.
TL;DR: It was concluded that angiography may be deferred if the causative aneurysm is demonstrated by CT, and the CT detection rate varied from a low of 36% for the internal carotid artery complex to a high of 76% for anterior and middle cerebral arteryAneurysms.
Abstract: Contrast enhanced computed tomography (CT) scans of 59 patients with subarachnoid hemorrhage were evaluated for intracranial aneurysms. After prospective study, the CT results were compared with angiography. Depending on the location, the CT detection rate varied from a low of 36% for the internal carotid artery complex to a high of 76% for anterior and middle cerebral artery aneurysms. It was concluded that angiography may be deferred if the causative aneurysm is demonstrated by CT.
TL;DR: This case demonstrates the feasibility of performing small vessel anastomoses in spite of low flow demand and shows the ability to clip a single branch of the middle cerebral artery for the treatment of a traumatic aneurysm.
Abstract: This case required the clipping of a single branch of the middle cerebral artery for the treatment of a traumatic aneurysm. To ensure an adequate blood supply distal to the occlusion, we anastomosed the superficial temporal artery to that branch of the middle cerebral artery (MCA) distal to the aneurysm. Despite the low flow required to irrigate only one branch of the MCA, the anastomosis remained patient. This case demonstrates the feasibility of performing small vessel anastomoses in spite of low flow demand.
TL;DR: A flow-guided, balloon-tipped microcatheter allows the radiologist to perform a reversible test occlusion of carotid-cavernous fistula, and this technique seems to have promise as another method for the obliteration of carotinine fistula.
Abstract: We report a new treatment for carotid-cavernous fistula. Using a flow-guided, balloon-tipped microcatheter, we catheterize the fistula itself, verify balloon entry into the fistula with fluoroscopy and x-ray films, and then infuse the tissue adhesive isobutyl-2-cyanoacrylate with careful fluoroscopic control. Three patients have had their fistulas occluded, with preservation of flow through the internal carotid artery. This balloon microcatheter allows the radiologist to perform a reversible test occlusion. All three patients had neurological changes during or after the procedure, and in one we inadvertently occluded several distal middle cerebral artery branches without permanent neurological deficit. No patient became blind or developed 3rd, 4th, or 6th nerve palsy from the treatment. This technique seems to have promise as another method for the obliteration of carotid-cavernous fistula.
TL;DR: A patient with a meningioma of the medial sphenoid wing underwent inadvertent intraoperative occlusion of the middle cerebral artery and Neurological deficit and infarction were presumably prevented by immediate administration of pentobarbital followed by extracranial-intracrania bypass.
Abstract: ✓ A patient with a meningioma of the medial sphenoid wing underwent inadvertent intraoperative occlusion of the middle cerebral artery. Neurological deficit and infarction were presumably prevented by immediate administration of pentobarbital followed by extracranial-intracranial bypass.
TL;DR: It is proposed that cerebral revascularization at 4 and 24 hours following a regional MCA infarct in the dog is followed by an exacerbation of the microcirculatory obstruction, cerebral edema, and infarction.
Abstract: The efficacy of cerebral revascularization by anastomosis of the superficial temporal artery (STA) to the middle cerebral artery (MCA), performed 4 and 24 hours after a regional MCA infarction had been produced by combined occlusion of the MCA and internal carotid artery, was tested in 12 dogs. To control possible intercurrent variables, seven other dogs remained untreated and five had a sham operation. Clinical and pathological changes were recorded and analyzed. An incidence of 85% infarction was obtained in the untreated control group. The severity of the clinical deficits and pathological changes for the anastomosed groups were greater than those seen in the untreated control group. The extent of the infarction was significantly greater (p less than 0.05) in the anastomosed groups than in the sham-operated and control groups. Hemorrhagic infarcts occurred in most of the dogs in the anastomosed groups, but were not present in either control group (p less than 0.05). Two dogs in the 4-hour and one in the 24-hour group improved more than any control dog, but the difference was not statistically significant (p greater than 0.05). In two dogs with occluded anastomosis the clinical deficits and the pathological changes were less than those seen in animals with patent anastomosis. The severity of the pathological and clinical changes correlated well with the reestablishment of flow in the MCA territory. It is proposed that cerebral revascularization at 4 and 24 hours following a regional MCA infarct in the dog is followed by an exacerbation of the microcirculatory obstruction, cerebral edema, and infarction. From improvement noted in three animals the authors suggest that under special conditions the revascularization could benefit some cases following acute cerebral infarction.
TL;DR: Based on the analyses of 50 random angiograms, the authors discuss the circumstances in which an anastomosis of the middle meningeal artery to a cortical branch of themiddle cerebral artery might be practical and indicated.
Abstract: ✓ A case is reported of successful anastomosis of the middle meningeal artery to a cortical branch of the middle cerebral artery. Based on the analyses of 50 random angiograms, the authors discuss the circumstances in which such an anastomosis might be practical and indicated.
TL;DR: The effects of cerebral embolism on brain monoamine metabolism appear to be different from the effects of permanent surgical occlusion of major cerebral vessels, and the bilaterality of effects after unilateral hemispheric embolisms might be related to diaschisis.
Abstract: In baboons the right cerebral hemisphere was embolised by a shower of microemboli, immediately followed by one large embolus designed to occlude the middle cerebral artery (MCA). One hour after embolism a significant, though small, reduction in blood flow and oxygen consumption of the embolised hemisphere was recorded, at which time the animals were killed and brain monoamines measured. Dopamine was reduced in the ipsilateral caudate nucleus, the reported site of maximal ischaemic damage in this model. Dopamine levels were increased in frontal and occipital grey matter sampled from areas surrounding the occluded MCA territory and in similar brain areas of the opposite non-embolised hemisphere. Noradrenaline was increased in grey matter from both cerebral hemispheres, as well as subcortical structures bilaterally. Brain 5-hydroxytryptamine levels were unaltered, but increased 5-hydroxyindoleacetic acid in cisternal cerebrospinal fluid suggested transient alteration in 5-hydroxytryptamine metabolism after embolism. The effects of cerebral embolism on brain monoamine metabolism appear to be different from the effects of permanent surgical occlusion of major cerebral vessels. The bilaterality of effects after unilateral hemispheric embolism might be related to diaschisis. The mechanisms of the observed changes, as well as their relevance to the progression of cerebral ischaemia and the complications associated with cerebral embolism, still require to be established.
TL;DR: Hypertension was produced in 8 cats by nephrectomy and wrapping the opposite kidney and subsequent occlusion of one middle cerebral artery caused ischemic infarcts that were larger than those of 8 normotensive cats.
Abstract: Hypertension was produced in 8 cats by nephrectomy and wrapping the opposite kidney. Subsequent occlusion of one middle cerebral artery caused ischemic infarcts that were larger than those of 8 normotensive cats. The larger infarcts may have been caused by increases of ischemic cerebral edema resulting from changes in the cerebral endothelial barrier induced by hypertension. In addition to increasing the likelihood of strokes, hypertension in humans may predispose toward larger cerebral infarcts.
01 Jan 1979
TL;DR: Intracranial arterial aneurysms are of considerable importance in cerebrovascular pathology and neurosurgery being the chief cause of nontraumatic subarachnoid haemorrhage (SAH), but many problems concerning their aetiology, pathophysiology and treatment are still unresolved.
Abstract: Intracranial arterial aneurysms are of considerable importance in cerebrovascular pathology and neurosurgery being the chief cause of nontraumatic subarachnoid haemorrhage (SAH) and of about 20%–25% of all intracranial haemorrhages (Heidrich, 1972; Jellinger, 1977), but many problems concerning their aetiology, pathophysiology and treatment are still unresolved.