• Journal of Korean Neurosurgical Society
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• 제29권12호
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• pp.1563-1569
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• 2000

Objective : Delayed ischemic neurologic deficit(DIND) is one of the major complications following aneurysmal subarachnoid hemorrhage(SAH). However, the correlation between angiographic vasospasm(AV) and DIND after SAH is not precisely known. The authors investigated the timing, incidence, characteristics of DIND, and analyzed correlation between AV and DIND. Patients and Methods : A series of 126 patients with SAH and performed cerebral angiography which, confirmed anterior circulation aneurysm, admitted to between January 1996 to December 1998, were studied retrospectively. A comparative analysis between group 1(G1) in which AV patients presented with DIND, and group 2(G2) patients did not DIND, were done. AV was graded according to location, distribution and degree. Location of vasospasm was classified as basal type(BT), distal type(DT). BT was involved horizontally and include the bilateral carotid systems, proximal middle cerebral artery(MCA) and proximal anterior cerebral artery(ACA). DT was involved vertically and include the MCA branches as they become vertically or posteriorly oriented and the ACA distal to the anterior communicating artery. BT and DT all defined ether as localized type(LT) or combined type(CT). Distribution of vasospasm was classified as type I, type II and type III. Type I represents the involvement of bilateral carotid systems and bilateral anterior cerebral artery, type II was designed as one carotid system without involving anterior cerebral artery, and type III when only some portions of the anterior cerebral artery were involved, bilaterally. Degree of vasospasm was classified as mild(less than 25%), moderate(between 25-50%), severe(greater than 50%), and those were determined by comparing the caliber of the artery in vasospasm to that of the nearest area of apparently normal vessel. Results : The incidence of AV & DIND was 57/126(45.2%), 29/126(23.0%), and timing of DIND was 9 days(${\pm}4.1$) after initial hemorrhage. As for the location, BT was seen in 12 cases(40.0%), DT 11 cases(36.7%) and CT 7 cases (23.3%), respectively. Where as G1, BT was seen 5 cases(18.5%), DT 5 cases(18.5%) and CT 17 cases(63.0%), respectively in G2. CT AV was more correlated with DIND than LT AV(p<0.05). For distribution, type I was seen in 16 cases(59.2%), type II 4 cases(14.8%), type III 7 cases(25.9%) in G1 where as type I was seen in 7 cases(23.3%), type II 10 cases(33.3%), type III 13(43.3%) in G2. Type I AV was well correlated with DIND unlike to type II or type III(p<0.05). As for the degree, mild was seen in 4 cases(14.8%), moderate 14 cases(51.9%), severe 9 cases (33.3%) in G1, and mild 16 cases(18.5%), moderate 11 cases(36.7%) and severe 3 cases(10.0%) in G2. Moderate to severe type AV was well correlated with DIND(p<0.05). Conclusion : These results indicate that it may be possible to predict DIND according to careful analysis of location, distribution, degree of AV in patients with aneurysmal SAH.

• 대한신경과학회지
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• 제36권4호
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• pp.350-353
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• 2018

Ischemic stroke caused by the cerebral vasculopathy is a rare complication of polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome. We present a case of recurrent ischemic strokes caused by cerebral vasculopathy in a patient with POEMS syndrome. A 34-year-old man presented with gait disturbance and dizziness. Brain magnetic resonance imaging demonstrated acute ischemic stroke in the middle cerebral artery-anterior cerebral artery (MCA-ACA) border zones of bilateral hemispheres. Repeated angiographic studies showed progressive worsening of the left distal internal carotid artery, ACA, and MCA stenoses, along with sustained steno-occlusion of right MCA.

• 대한핵의학회지
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• 제26권2호
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• pp.251-256
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• 1992

Regional cerebral blood flow were measured in 10 patients with Parkinson's disease and 12 normal persons using $^{99m}Tc-HMPAO$ SPECT. Reconstructed images were interpreted qualitatively and were compared with those findings of CT. For the quantitative analysis, six pairs of region of interest matched with the perfusion territories of large cerebral arteries and cerebellar hemisphere were determined. From the count values, indices showing the degree of asymmetry between right and left cerebral or cerebellar hemisphere, cerebral asymmetry index (ASI) and percent index of cerebellar asymmetry (PIA), and an index showing change of each region, region to cerebellum ratio (RCR) were obtained. ASI of normal persons and patients were $0.082{\pm}0.033$ and $0.108{\pm}0.062$, respectively and PIA were $-0.4{\pm}0.7%$ and $-0.7{\pm}1.0%$, respectively, which showed no statistically significant difference between normal persons and patients. Among 10 RCR's, those of both regions of basal ganglia and both regions of anterior cerebral artery were significantly reduced. We concluded that the most significant reduction of regional cerebral blood flow in patients with Parkinson's disease was observed in the regions of basal ganglia and in the regions of anterior cerebral artery, and the degree of change in hemispheric blood flow was similar in both hemisphere.

• 한국가시화정보학회지
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• 제20권2호
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• pp.45-54
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• 2022

We analyzed the low wall-shear stress area in the intracranial aneurysm that occurred at an anterior communicating artery with a special emphasis on vortical structures close to the wall. We reconstructed the aneurysm model from patient CTA data. We assumed blood as an incompressible Newtonian fluid and treated the blood vessel as a solid wall. The pulsatile boundary condition was applied at the inlet of the anterior cerebral artery. From the instantaneous flow field, we computed the histogram of the wall-shear stress over the aneurysm wall and found the low wall-shear stress event (< 0.4 Pa). This extreme event was due to the low wall-shear stress area that occurred at the daughter sac. We found that the merging of two vortices induced the low wall-shear stress area; one arises from the morphological characteristics of the daughter sac, and the other is formed by a jet flow into the aneurysm sac. The latter approaches the daughter sac, which ultimately leads to the strong ejection event near the daughter sac.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• 제25권4호
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• pp.462-467
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• 2023

Thrombectomy procedures following intra-aneurysmatic lesions are extremely rare, and few cases have been reported. This article describes a microsurgical intra-aneurysmatic thrombectomy (MIaT) for a distal anterior cerebral artery (DACA) aneurysm. We present the case of a 48-year-old female that was admitted to the emergency room, showing neurologic deterioration with focal deficits. A computed tomography angiography (CTA) scan revealed an aneurysm located in the distal segment of the left anterior cerebral artery. During the surgical procedure, after clipping, a well-formed clot was visualized through the aneurysm's wall obstructing the left DACA flow. We proceeded to open the aneurysm's dome to remove the thrombus and clip the aneurysm neck, re-establishing the flow of the left DACA. Intra-aneurysmatic thrombosis can occur as a complication during clipping, obstructing the distal flow of vital arteries and causing fatal results in the patient's postoperative status. MIaT is a good technique for restoring the flow of the affected vessel and allows a secure aneurysm clipping after thrombus removal.

• Journal of Korean Neurosurgical Society
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• 제29권3호
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• pp.330-335
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• 2000

Objective : The purpose of this report is to assess the morbidity and mortality associated with clipping of intracranial unruptured aneurysms. Methods : At the authors' institution between May 1989 and December 1998, a total of 128 unruptured aneurysms in 110 patients were treated with surgical clippings. The medical records and neuroimaging studies of the patients were reviewed retrospectively. Results : The main locations of the aneurysms were : middle cerebral artery 31%, internal carotid-posterior communicating artery 28%, anterior communicating artery 16%, paraclinoid 6.5%, internal carotid-anterior choroidal artery 7%, posterior circulation 7%. Forty three percent of the aneurysms were symptomatic and 57% asymptomatic. The overall outcome of the surgery was : Glasgow outcome scale(GOS) I 86%, GOS II 6%, GOS III 4.3%, GOS IV 0% and GOS V(death) 3.5%. The operative risk is higher for large to giant aneurysms, and for aneurysms in posterior circulations. Patients with non-giant aneurysm in anterior circulation showed no mortality, but morbidity of 8.2%, and in posterior circulation : 25% of mortality and 75% of morbidity. Patients with giant anterior circulation aneurysm have 22% of mortality and 22% of morbidity. For patients with giant posterior circulation aneurysm, mortality and morbidity were 25% and 25%, respectively. The postoperative deaths were related to occlusion of the major parent artery in 3 cases(75%). The postoperative morbidity was related to occlusion of artery(9/13), intraoperative rupture(3/13), and cranial nerve injury(1/13). Conclusion : This report documents 3.5% mortality and 13% of morbidity in the clipping surgery for unruptured intracranial aneurysms, and the relatively low risk of surgical clipping in non-giant and those located in anterior circulation. The natural history, especially risk of bleeding, of the unruptured intracranial aneurysms is still controversial. However, with respect to surgical results, unruptured non-giant aneurysm located in anterior circulation should be operated in patients with low risk.

• 한국전산유체공학회지
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• 제16권4호
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• pp.64-71
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• 2011

Cerebral aneurysm mostly occurs at a bifurcation of the circle of Willis. When the cerebral aneurysm is ruptured, a disease like subarachnoid hemorrhage and stroke is caused and this can be even deadly for patients. Generally it is known that causes of the intracranial aneurysm are a congenital deformity of the artery and pressure or shear stress from the blood flow. A blood flow pattern and the geometry of the blood vessel are important factors for the aneurysm formation. Research for several hemodynamic indices has been performed and these indices can be used for the prediction of aneurysm initiation and rupture. Therefore, the numerical analysis was performed for hemodynamic characteristics of the blood flow through the cerebral artery applying the various bifurcation angle and flow rate ratio. We analyze the flow characteristics using indices from the results of the numerical simulation. In addition, to investigate the flow pattern in the aneurysm according to the bifurcation angle and the flow rate ratio, we performed the numerical simulation on the supposition that the aneurysm occurs.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.161-168
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• 2011

Cerebral aneurysm mostly occurs at a bifurcation of the circle of Willis. When the cerebral aneurysm is ruptured a disease like subarachnoid hemorrhage and stroke is caused and this can be even deadly for patients. Generally it is known that causes of the intracranial aneurysm are a congenital deformity of the artery and pressure or shear stress from the blood flow. A blood flow pattern and the geometry of the blood vessel are important factors for the aneurysm formation. Research for several hemodynamic indices has been performed and these indices can be used for the prediction of aneurysm initiation and rupture. Therefore, the numerical analysis was performed for hemodynamic characteristics of the blood flow through the cerebral artery applying the various bifurcation angle and flow rate ratio. We analyze the flow characteristics using indices from the results of the numerical simulation. In addition, to investigate the flow pattern in the aneurysm according to the bifurcation angle and the flow rate ratio, we performed the numerical simulation on the supposition that the aneurysm occurs.

• 대한한방내과학회지
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• 제28권4호
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• pp.709-716
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• 2007

Objective : We present reference values of flow velocities of intracranial and extracranial cerebral arteries and relation with change factor. Method : We checked transcranial Doppler ultrasonography on mean velocity, systolic velocity, pulsatility index, and resistance index of 252 patients. We also compared differences of change factor. Result : The result showed a difference by sex and age and relevance between vessels besides mean velocity of vessels related with past history and social history. Conclusion : According to the above results, females showed higher velocity of all vessels. With advancing age, subjects showed reduction in velocity and increase in pulsatility index and resistance index. Anterior cerebral, middle cerebral, and posterior cerebral artery increased in proportion to velocity of internal carotid artery and basilar artery. Vessel velocity correlated with diabetes mellitus, hypertension and hyperlipidemia.

• Journal of Yeungnam Medical Science
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• 제14권1호
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• pp.77-84
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• 1997

55명의 미숙아를 대상으로 이중 도플러 초음파 검사를 실시하여 대천문을 통한 전 뇌동맥의 혈류속도 및 혈류형태를 조사하였다. 미숙아에서 뇌 혈류속도 및 pulsatility index는 재태기간, 출생 체중, 및 미숙아의 나이 등의 증가에 따라 비례하여 증가하였으나 resistive index는 감소하였다. 뇌실 출혈이 있는 환아 군에서는 특징적인 resistive index의 증가가 보였지만 혈류속도 및 plusatility index는 불규칙하였다. 정상 미숙아의 뇌혈류 관찰 및 환아 군에서의 뇌혈류 검사에서 이중 도플러 초음파 검사는 비침습적이고 재현성도 뛰어나 선별검사로 유용한 방법이라고 생각한다.