Usefulness of transcranial color-coded sonography in the diagnosis of cerebral vasospasm

BACKGROUND AND PURPOSE: The noninvasive diagnosis of cerebral vasospasm with the use of conventional transcranial Doppler ultrasonography (TCD) is based on a velocity study of the middle cerebral artery (MCA). The authors report a prospective comparative study between transcranial color-coded sonography (TCCS), conventional transcranial Doppler (TCD), and angiography in the diagnosis of cerebral vasospasm after surgical treatment for aneurysm. METHODS: Thirty consecutive patients underwent routine angiography after surgical treatment for intracranial aneurysm. The distribution of vasospasm was determined after a prospective calculation of the angiographic diameter of the MCA, internal carotid artery (ICA), and anterior cerebral artery (ACA). The blood flow velocities (systolic and maximum) of the MCA, ICA, and ACA were evaluated by TCCS and TCD. RESULTS: The correlation between mean maximum velocity and angiographic diameter was significant for the MCA (r=-0.637, P<0.0001), ICA (r=-0.676, P<0.0001), and ACA (r=-0.425, P<0.01). TCCS sensitivity and specificity were higher than those for TCD for MCA (100% and 93%, respectively) and ICA (100% and 96.6%, respectively). For ACA, the sensitivity and specificity were 71.4% and 84.8%, respectively. CONCLUSIONS: The authors suggest that TCCS is useful for accurate monitoring of cerebral vasospasm in the MCA and ICA. In the ACA, TCCS monitors the hemodynamic state of the anterior part of the circle of Willis, which could expose the patient to a delayed ischemic deficit.     

经颅多普勒监测蛛网膜下腔出血后脑血管痉挛的临床观察

目的总结应用经颅多普勒(TCD)监测蛛网膜下腔出血(SAH)后脑血管痉挛的临床价值。方法对2015-06—2016-05本院收治的78例SAH患者进行回顾性分析,均进行TCD监测,同时对患者进行数字减影血管造影(DSA)检查,观察各个时间段患者颅内血管血流速度变化,并以DSA检查结果作为标准判断TCD诊断颅内血管痉挛的价值。结果在7~10d时间段,患者的MCA、ACA、VA、BA血流速度达到峰值,后逐渐下降,颅内血管痉挛现象逐渐缓解;SAH患者MCA、ACA、VA、BA血流速度在7d、7~10d、10~14d三个时间段比较差异均具有统计学意义(P0.05);78例SAH患者,TCD诊断发生颅内血管痉挛59例,DSA诊断发生率颅内血管痉挛62例,TCD诊断SAH患者发生颅内血管痉挛的灵敏度为93.55%、特异度为93.75%、漏诊率为6.45%、误诊率为6.25%,TCD诊断颅内血管痉挛与DSA的一致性Kappa=0.816,P0.05。结论 TCD检查诊断SAH后出现颅内血管痉挛具有准确性高、无创等优点,值得临床推广应用。     

The influence of ruptured cerebral aneurysm localization on the blood flow velocity evaluated by transcranial Doppler ultrasonography

The relationship between changes of blood flow velocities in cerebral arteries measured by transcranial Doppler ultrasonography and aneurysm localization was investigated in a group of 165 patients after aneurysmal subarachnoid hemorrhage (SAH). Mean blood flow velocities (MFV) in the middle cerebral artery (MCA) and anterior cerebral artery (ACA) were registered. In patients with aneurysm of internal carotid artery and MCA (group A) statistically significant higher values of MFV from the 1st to the 5th day and on the 12th, 13th, 14th, 15th, and 19th day after SAH were found compared to patients with aneurysm of the anterior communicating artery, ACA, and pericallosal artery (group B). Pathological values of MFV exceeding 120 cm sec-1 in MCA were registered during 14 days in group A and during eight days in group B. Blood flow velocities in ACA were statistically significantly higher in group B on the 2nd, 7th, 9th and 11th day compared to group A. Pathological values of MFV exceeding 90 cm sec-1 in ACA were registered during nine days in both groups. MFV differences between group A and group B in 38 patients subjected to delayed surgery were not observed. The influence of aneurysm localization was observed between the 7th and 14th day after SAH. Critical MFV values for vasospasm in the MCA should be 120 cm sec-1 and in the ACA 90 cm sec-1.     

The relation between cerebral blood flow velocities as measured by TCD and the incidence of delayed ischemic deficits. A prospective study after subarachnoid hemorrhage

Patients (n = 127) with aneurysmal subarachnoid hemorrhage (SAH) were examined by transcranial Doppler ultrasonography (TCD) in a prospective study to follow the time course of the posthemorrhagic blood flow velocity in both the middle cerebral artery (MCA) and in the anterior cerebral artery (ACA). Results were analysed to reveal their relationship and predictive use with respect to the occurrence of delayed ischemic deficits. Mean flow velocities (MFV) higher than 120 cm sec(-1) in MCA and 90 cm sec(-1) in ACA were interpreted as indicative for significant vasospasm. In 20 of our 127 patients (16%) a delayed ischemic deficit (DID) was subsequently diagnosed clinically (DID+ group). Patients in the DID+ group can be characterized as those individuals who presented early during the observation period post-SAH with highest values of MFV, a faster increase and longer persistence of pathologically elevated MFV-values (exceeding 120 cm sec(-1) in MCA and 90 cm sec(-1) in ACA). They also show a greater difference in MFV-values if one compares the operated to the nonoperated side. Differences in MFV-values obtained in MCA or ACA were statistically significant (p < 0.05) for DID+ and DID- patients. The daily maximal increase of MFV was found between days 9 and 11 after SAH. In the DID+ group, the maximal MFV was 181 +/- 26 cm sec(-1) in MCA and 119 +/- 14 cm sec(-1) in ACA. In contrast to this, patients in the DID- group were found to present with MFV of 138 +/- 11 cm sec(-1) in MCA and 100 +/- 7 cm sec(-1) in ACA respectively. Delayed ischemic deficits appeared three times more often in DID+ patients than in patients with MFV < 120 cm sec(-1), if they showed a MFV > 120 cm sec(-1) in MCA. If pathological values were obtained in ACA, this ratio increases to about four times, if DID + patients presented with MFV > 90 cm sec(-1) versus patients with MFV < 90 cm sec(-1). Daily monitoring of vasospasm using TCD examination is thus helpful to identify patients at high risk for delayed ischemic deficits. This should allow us to implement further preventive treatment regimens.     

Continual Transcranial Doppler in the Monitoring of Hemodynamic Change following Aneurysmal Subarachnoid Hemorrhage

Aims: To analyze and compare the value of different treatment methods for acute aneurysmal subarachnoid hemorrhage (aSAH)‐related vasospasm. Cerebral hemodynamic variables’ changes were evaluated by transcranial Doppler (TCD) in aSAH patients within 14 days after onset. Methods: Thirty aSAH patients were enrolled in the study within 72 h after onset. Baseline CT and TCD were used for assessment. Patients were divided into three groups according to SAH severity and patients’ discretion: nonsurgical group, endovascular coiling, and neurosurgical clipping. TCD hemodynamic parameters were measured and Lindegaard index was calculated daily from onset to 14th day after SAH. The group mean cerebral blood velocity (MBFV) and Lindegaard index were compared using repeated measures analysis of variance (reANOVA). Least Significant Difference (LSD) test was used for post hoc comparison. All 30 patients were followed for 90 days after onset for outcome assessment. Results: The values of MBFV and Lindegaard index of anterior cerebral artery (ACA)/middle cerebral artery (MCA) from high to low is nonsurgical group, clipping and coiling (ACA: P= 0.0001/P= 0.006; MCA: P= 0.243/P= 0.317). Conclusions: These results indicate that both neurosurgical clipping and endovascular coiling management may relieve the severity of cerebral vasospasm in acute aSAH.     

Value of repeat-angiography in cases of unexplained subarachnoid hemorrhage (SAH)

Purpose – To investigate the rate of false negative initial cerebral angiography in spontaneous SAH and to ascertain why aneurysms remain undetected. Furthermore to validate CCT in predicting the presence and site of an angiographically missed aneurysm. Methods – Forty-two patients with spontaneous SAH were investigated, in whom initial cerebral angiography did not reveal any bleeding cause. Repeat-angiography was performed in all patients 5 to 55 days (mean 15 days) after the bleeding event. All patients underwent CCT scans within 48h after the ictus. Results – In 8 of 42 patients (19%) repeat-angiography revealed an aneurysm missed on initial angiography. The aneurysms were located on the AcomA (n = 2), the MCA (n = 2), the ACA (n= 1), the PICA (n = 2) and the junction of ICA and PcomA (n = 1). Presumable reasons for missing an aneurysm were spasms detected in four of eight cases on initial angiography and thrombosis of the aneurysm found in two cases at surgery. In two cases, multiple additional views just revealed the aneurysm appearing different in size and shape on repeat-angiography. CCT blood distribution pattern in four cases indicated presence and site of an aneurysm, while blood distribution was non-specific in the other four cases. Conclusion – Repeat-angiography plays an important role in defining the site of an initially occult aneurysm and should be performed in all cases of unexplained SAH. It is of particular importance if vasospasm has compromised the initial angiogram or if one part of the vascular tree is not optimally seen.     

Detection of Vasospasm by Transcranial Doppler Sonography

Little information exists on the utility of transcranial Doppler sonography (TCD) in detecting anterior (ACA) and posterior cerebral artery (PCA) vasospasm following subarachnoid hemorrhage. During the period at risk for vasospasm, 53 patients with subarachnoid hemorrhage who had technically adequate TCD performed within 24 hours of cerebral angiography, allowing evaluation of 87 ACAs and 84 PCAs, were studied. ACA and PCA vasospasm were defined by mean blood flow velocities of at least 120 cm/ sec and at least 90 em/sec, respectively. For detection of ACA vasospasm, sensitivity was 18% and specificity was 65%. For PCA vasospasm, sensitivity was 48% and specificity was 69%. False-positive findings for occlusion accounted for 12 (92 %) of 13 ACA false-positive results and 7 (37%) of 19 PCA false-positive results, and were most often due to anatomical factors and operator error or inexperience. After exclusion of both true-positive and false-positive findings for occlusion and changes in the diagnostic criterion to at least 130 cm/sec for ACA vasospasm and at least 110 cm/sec for PCA vasospasm, specificity improved for both types of vasospasms (100 and 93%, respectively). However, the sensitivity of TCD to detect ACA and PCA vasospasm is limited by a variety of anatomical, technical, and other factors. It is concluded that TCD is highly specific in detecting both ACA and PCA vasospasm in arteries that can be insonated.     

蛛网膜下腔出血后脑血管痉挛实验研究

目的　在兔蛛网膜下腔出血 (SAH)模型上 ,尝试建立经颅多普勒超声 (TCD)及血管造影 ,监测椎基动脉脑血管痉挛 (CVS)的新方法。方法　兔枕大池一次性注血 ,同时行逆行颈总动脉插管椎基动脉造影及开骨窗TCD监测。结果　逆行性脑血管造影能清晰显示椎基底动脉系统 ,注血前后血管直径差异明显 (P <0 .0 5 ) ,平均血流速度注血后明显增快 ,但中、重度痉挛之间基底动脉血流速度变化无明显差异。结论　一侧颈总动脉逆行插管椎基动脉造影 ,操作简便 ,结果可靠。采取开骨窗以提高TCD超声频率的方法 ,可获得兔基底动脉稳定的频谱图并易于重复。     

动脉瘤夹闭术可能缩短急性动脉瘤性蛛网膜下腔出血相关脑血管痉挛持续时间

目的   比较不同治疗方法对动脉瘤性蛛网膜下腔出血（aneurysmal subarachnoid hemorrhage,aSAH）后的血流动力学变化,并分析对aSAH后血管痉挛的影响。 方法  连续选取2008年4月～2009年10月首都医科大学附属北京天坛医院神经病学中心急诊入院的45例发病在72?h内的aSAH患者,收集基线资料、计算机断层扫描（computed tomography,CT）、经颅多普勒超声（transcranial Doppler,TCD）及90?d改良Rankin量表评分。根据患者接受的治疗分为保守组、填塞组和夹闭组。使用TCD连续测定14?d之内大脑中动脉及大脑前动脉血流速度,计算Lindegaard指数,比较3组的处理平均血流速度、Lindegaard指数及血管痉挛持续时间。 结果  大脑前动脉/大脑中动脉的平均血流速度及Lindegaard指数由高到低依次为保守组、夹闭组及填塞组［大脑前动脉：平均血流速度为（74.60±5.84）cm/s、（70.00±5.24）cm/s、（65.70±6.03）cm/s,P=0.0001;Lindegaard指数分别为3.87±0.32、3.82±0.31、3.65±0.36,P=0.006;大脑中动脉：平均血流速度分别为（101.2±9.1）cm/s、（87.0±6.2）cm/s、（76.2±9.2）cm/s,P=0.004;Lindegaard指数分别为5.50±0.65、4.15±0.46、3.81±0.55,P=0.005］。夹闭组患者脑血管痉挛持续时间较保守组短［（3.30±1.87）d vs?（7.29±2.23）d,P=0.035］。保守组患者90?d预后较差（P=0.028）。 结论  神经外科夹闭术和血管内动脉瘤填塞术均能缓解急性aSAH后脑血管痉挛的严重程度;外科夹闭术可缩短脑血管痉挛持续时间。     

The relation between cerebral blood flow velocities as measured by TCD and the incidence of delayed ischemic deficits. A prospective study after subarachnoid hemorrhage

Abstract

Patients (n = 127) with aneurysmal subarachnoid hemorrhage (SAH) were examined by transcranial Doppler ultrasonography (TCD) in a prospective study to follow the time course of the posthemorrhagic blood flow velocity in both the middle cerebral artery (MCA) and in the anterior cerebral artery (ACA). Results were analysed to reveal their relationship and predictive use with respect to the occurrence of delayed ischemic deficits. Mean flow velocities (MFV) higher than 120 cm sec^-1 in MCA and 90 cm sec^-1 in ACA were interpreted as indicative for significant vasospasm. In 20 of our 127 patients (16%) a delayed ischemic deficit (DID) was subsequently diagnosed clinically (DID+ group). Patients in the DID+ group can be characterized as those individuals who presented early during the observation period post-SAH with highest values of MFV, a faster increase and longer persistence of pathologically elevated MFV-values (exceeding 120 cm sec^-1 in MCA and 90 cm sec^-1 in ACA). They also show a greater difference in MFVvalues if one compares the operated to the nonoperated side. Differences in MFV-values obtained in MCA or ACA were statistically significant (p < 0.05) for DID+ and DID- patients. The daily maximal increase of MFV was found between days 9 and 11 after SAH. In the DID+ group, the maximal MFV was 181 ± 26 cm sec^-1 in MCA and 119 ± 14 cm sec^-1 in ACA. In contrast to this, patients in the DID- group were found to present with MFV of 138 ± 11 cm sec^-1 in MCA and 100 ± 7 cm sec^-1 in ACA respectively. Delayed ischemic deficits appeared three times more often in DID+ patients than in patients with MFV < 120 cm sec^-1, if they showed a MFV > 120 cm sec^-1 in MCA. If pathological values were obtained in ACA, this ratio increases to about four times, if DID+ patients presented with MFV > 90 cm sec^-1 versus patients with MFV < 90 cm sec^-1. Daily monitoring of vasospasm using TCD examination is thus helpful to identify patients at high risk for delayed ischemic deficits. This should allow us to implement further preventive treatment regimens. [Neurol Res 2002; 24: 582-592]     

不同浓度尼膜同灌洗对实验性脑血管痉挛的治疗作用

目的通过动物实验,采用不同浓度尼膜同灌洗给药,探讨其防治脑血管痉挛的最佳药物浓度和效应时间,为临床直用提供可靠的实验依据。方法采用颞部开窗置管注血法建立兔脑血管痉挛动物模型,分成4组,在注血后第3天打开颞部切口,分别用不同浓度的尼膜同液术野灌冼,A组:1:20尼膜同液;B组:1:10尼膜同液;C组:1:5尼膜同液;D组:5%乙醇生理盐水对照组,用TCD监测大脑中动脉在用药后5min、15min、30min、60min时的血流速度,14d后处死动物,光镜下观察大脑中动脉周围脑组织及海马病理变化。结果B组在用药后60min大脑中动脉血流速度显著下降;C组用药后15min大脑中动脉血流速度显著下降(P<0.05),30min和60min下降更显著(P<0.01)。大脑中动脉周围脑组织及海马病理检查细胞结构未见异常。结论1:5和1:10尼膜同液在术野中灌洗后能显著解除脑血管痉挛,提示在颅脑手术中采用适量尼膜同液冲冼,对防治术后脑血管痉挛安全、有效。     

Early cerebral hemodynamic alternations in patients operated on the first, second and third day after aneurysmal subarachnoid hemorrhage

Surgery timing after aneurysmal subarachnoid hemorrhage (SAH) may influence the risk of vasospasm after early surgical procedure and is correlated with SAH extensiveness. A group consisting of 127 patients with aneurysmal SAH was studied. The changes of mean flow velocity (MFV) were measured in middle cerebral artery (MCA) and in anterior cerebral artery (ACA) by transcranial Doppler sonography (TCD) in three groups of patients divided according to the surgery timing (on the first, second and third day after SAH). Changes of MFV values in MCA and in ACA were similar in all groups. MFV values in the group of patients operated on the third day were the lowest and the pathologic values lasted for the shortest time. In patients with massive SAH (Fisher IV group) and mild SAH (Fisher II group), the lowest MFV values were observed, if patients were operated within 24 hours after SAH. In patients without SAH (Fisher I group), the MFV values were the lowest, if they were operated on the third day after SAH. In patients with severe SAH (Fisher III group), the lowest risk of vasospasm was observed, if they were operated on the second day after SAH; however, the highest risk was found in patients operated on the first day after SAH. Our study suggests: (1) in patients with severe SAH operated on the second day, the lowest risk of vasospasm was observed, and the highest risk of vasospasm was observed if those were operated on the first day; (2) the highest risk of vasospasm was observed in patients operated within 24 hours with mild and massive SAH and in patients without SAH operated on the third day after SAH.     

Transcranial Doppler sonography in subarachnoid hemorrhage

Ten patients presenting a subarachnoid hemorrhage (SAH) due to rupture of a middle cerebral or an anterior communicating aneurysm are presented. Transcranial Doppler (TCD) values are obtained at different time intervals after SAH. The correlation of TCD values, vasospasm and clinical course is discussed.     

Sensitivity and specificity of transcranial Doppler ultrasonography in the diagnosis of vasospasm following subarachnoid hemorrhage

Vasospasm is the leading cause of death and disability in patients with aneurysmal subarachnoid hemorrhage (SAH). Transcranial Doppler ultrasonography (TCD) can detect the arterial narrowing noninvasively, but the sensitivity and specificity of this technique have not been reported in a population of patients with a high frequency of angiographic vasospasm. In this study, 34 consecutive patients with SAH undergoing angiography during the period of risk for vasospasm had technically adequate TCD examinations within 24 hours of the angiogram. Using a mean flow velocity of 120 cm/sec and above as indicative of vasospasm, TCD correctly detected angiographic vasospasm in 17 patients; there were no false positives. It correctly determined that 5 patients did not have vasospasm, whereas there were 12 false negatives. False negatives were frequently due to angiographic vasospasm involving vessels not assessable by TCD. The correlation between mean flow velocity and the angiographic residual lumen diameter of the middle cerebral artery was statistically significant. These data suggest that TCD is a highly specific (100%), but less sensitive (58.6%) test for the detection of angiographic vasospasm following SAH. Confirmatory angiography may be avoided if the TCD study is positive, but additional studies may be necessary if the clinical picture is suspicious and the TCD study is negative.     

Doppler ultrasound measurement of blood flow volume in the extracranial internal carotid artery for evaluation of brain perfusion after aneurysmal subarachnoid hemorrhage

Monitoring of cerebral blood flow (CBF) is an essential part in the early diagnosis of cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH). Several methods have been established to monitor cerebral perfusion in these patients. During last few years, a new sonographic approach has been introduced, the so called 'angle independent ultrasound system' for monitoring volume flow in the internal carotid artery (ICA). The angle independent Doppler ultrasound system Quantix ND (Cardiosonix Ltd, Israel) determines the diameter of the ICA as well as the velocity of blood flow in the extracranial part of this vessel. Thus, a determination of the global CBF in the anterior circulation can be achieved. Aim of our study was to compare the Quantix ND system and the commonly used transcranial Doppler sonography (TCD) in patients suffering from aneurysmal SAH. We included 11 patients (eight female and three male; Hunt and Hess I-V) and performed post-operatively/post-interventionally daily measurement of blood flow volume in the ICA, and determined the blood flow velocity in middle and anterior cerebral artery (MCA and ACA) with TCD. Six patients post-operatively/post-interventionally developed cerebral vasospasm, resulting in ischemia and territorial infarction. Three patients were chosen as case studies. In contrast to the TCD, we found a strong significant correlation of blood flow volume with Quantix ND in the ICA and the occurrence of cerebral infarction (p<0.001). These preliminary data justify further investigation of this angle independent Doppler ultrasound device. We postulate that this new tool might be effective for monitoring the CBF in the critical post-operative/post-interventional interval following aneurysmal SAH.     

Arteriovenous differences of oxygen and transcranial Doppler sonography in the management of aneurysmatic subarachnoid hemorrhage.

After subarachnoid hemorrhage (SAH) the detection of hemodynamically significant vasospasm is frequently difficult, especially in comatose patients. Most clinicians use transcranial Doppler sonography (TCD) to detect increasing mean blood flow velocities in the basal arteries as markers of cerebral vasospasm, without accounting for the effects of sedation and variations in blood pressure or pCO(2). This study was conducted to test the hypothesis that the arteriovenous difference of oxygen (avDO(2); in terms of % volume) could also be useful for the evaluation of vasospasm. A total of 22 SAH patients (M : F = 1 : 1.75, age 58+/-10 years, median Hunt and Hess grade 4) were prospectively enrolled. All patients were sedated with continuous doses of midazolam/fentanyl and/or propofol. TCD studies and avDO(2) measurements were conducted at the same time or in close succession. The blood flow velocity of the middle cerebral artery was recorded. A cranial CT scan was conducted if the avDO(2) increased by at least 0.8%. Overall, 82 measurements were recorded in 22 patients between days 1 and 13 after SAH. TCD mean flow velocities increased as expected. In contrast, avDO(2) decreased until post-hemorrhage day 4 before it increased again. Overall, after SAH, avDO(2) was significantly lower than in normal individuals. Cerebral infarction occurred primarily in patients with a maximal change of avDO(2) of more than 1%. TCD velocities alone are poor indicators of the severity of vasospasm. In contrast, daily avDO(2) seems to be a more robust parameter. However, collection of additional metabolic information is warranted.     

Tissue at risk concept for endovascular treatment of severe vasospasm after aneurysmal subarachnoid haemorrhage

OBJECTIVE: To report a case of severe vasospasm after subarachnoid haemorrhage (SAH) where "tissue at risk" was identified by magnetic resonance imaging (MRI), and to demonstrate the haemodynamic consequences with either resolution of the perfusion-diffusion mismatch by balloon angioplasty or evolution of an infarct. METHODS: A 45 year old women with SAH underwent surgical treatment of a ruptured middle cerebral artery (MCA) aneurysm. On day 3 she became obtunded and developed a right hemiparesis. Diffusion weighted (DWI) and perfusion weighted (PWI) imaging were done before and after transluminal balloon angioplasty (TBA) of multifocal proximal vasospasm. RESULTS: The initial MRI revealed no DWI lesion but PWI showed a severe perfusion deficit of 6.7 to 16.4 seconds in the complete left MCA territory. Digital subtraction angiography confirmed severe segmental narrowing of left C1 and M1. The spastic segments were successfully dilated by TBA. Follow up MRI showed that the PWI-DWI mismatch resolved in the anterior and middle MCA territory with no tissue infarction, whereas in the terminal dorsal MCA territory a severe mismatch remained and cerebral infarction evolved. CONCLUSIONS: PWI/DWI can identify tissue at risk for infarction in severe vasospasm following SAH. This may allow selection of patients for angioplasty and the monitoring of treatment effects.     

A case of symmetrical aneurysms at the bilateral middle cerebral arteries associated with the deep seated arteriovenous malformation in the midline]

A case of symmetrical aneurysms at the bilateral middle cerebral arteries (MCA) associated with the deep seated arteriovenous malformation (AVM) in the midline was presented. Because symmetrical aneurysms at the MCA are 1.17% of all aneurysms, and those associated with the deep seated AVM in the midline are very rare. A 75-year-old female suffered from a sudden onset of a severe headache and a loss of consciousness, and was admitted to our department on June 14, 1996. Computed tomography(CT) showed a subarachnoid hemorrhage (SAH) in the right sylvian fissure (Fisher's Group 4). Bilateral symmetrical MCA's aneurysms and the deep seated AVM were clarified by angiography. The symmetrical aneurysms stood out anterior lateral side and the right aneurysm had bleb. On the other hand, the afferent vessels of the AVM were the branches of bilateral posterior cerebral arteries, and the efferent vessel was the vein of Galen. So we determined SAH due to right MCA aneurysm, and performed the neck clipping of the ruptured aneurysm. The symmetrical aneurysms at the MCA associated with AVM in midline have not been reported. Each parent's artery was not connected each other. These origins, therefore, are suggested to be related not only to acquired factors like hypertension, hemodynamic stress etc, but also to a congenital factor. The origin of the saccular aneurysm is suggested congenital either but it isn't definite.     

Bedside-microdialysis for early detection of vasospasm after subarachnoid hemorrhage. Case report and review of the literature

Continuous monitoring of cerebral metabolism would be desirable for early detection of vasospasm in SAH patients. Bedside-microdialysis, a new technique for on-line monitoring of cerebral metabolism, may reflect changes seen in cerebral vasospasm diagnosed by transcranial Doppler sonography (TCD). This report represents the first case of combined TCD monitoring and on-line microdialysis from the brain extracellular fluid in a SAH patient. A 48-year-old woman suffered subarachnoid hemorrhage grade IV according to Hunt and Hess. Angiography revealed an aneurysm of the left carotid artery. The aneurysm was clipped 45 hours after bleeding. The microdialysis catheter was inserted after aneurysm clipping into the white matter of the left temporal lobe. Sampling of microdialysates started immediately, analyzing time for glucose, lactate, pyruvate and glutamate was four minutes. Postoperatively, the patient was doing well and microdialysis and TCD parameters remained within normal range. On the third postoperative day a shift to anaerob metabolism (decrease of glucose, increase of lactate and the lactate-pyruvate ratio up to pathological levels) and an increase in glutamate was observed suggesting insufficient cerebral perfusion. The patient progressively deteriorated clinically. Vasospasm was diagnosed by TCD monitoring 36 hours after onset of ischemic changes monitored by microdialysis. After elevation of mean arterial blood pressure, TCD values and metabolic parameters normalized. Interestingly, the pathological changes in on-line microdialysis preceded the typical increase in blood flow velocity by TCD and the clinical deterioration. Our case suggests, that bedside-microdialysis may be useful for early detection of vasospasm and continuous surveillance of treatment and may be a new guide to treat ischemic neurological deficits following SAH.     

Distribution of cerebral microembolism in the anterior and middle cerebral arteries

BACKGROUND AND PURPOSE: Cerebral infarcts occur more frequently along the middle (MCA) than the anterior cerebral artery (ACA) territory. The reason(s) for this difference remains speculative. The objective of this study was to investigate the distribution of cerebral microemboli as detected by transcranial Doppler ultrasound (TCD) along the MCA and ACA territories. METHODS: Records of consecutive patients examined for the presence of cerebral microembolism during a 32-month period at the Neurovascular Laboratory were reviewed. Of the original 375 TCD studies in 268 patients, 28 studies in 24 patients demonstrated microembolic signals (MES) and monitored the MCA and ACA on the same side. TCD studies were performed on TC-2000 or TC-2020 instruments. MES positive studies were saved and off-line reviewed. MES satisfied previously established criteria. RESULTS: MES were more frequent in the MCA than the ACA in 85.7% (24/28) of studies (P < 0.01). Of the total number of MES (n = 979), 29.6% (n = 290) were detected in the ACA and 70.4% (n=689) in the MCA (P<0.01). The mean (+/- SD) intensity of MCA MES of 12.2 (+/- 2.4) dB was significantly lower than that of ACA MES of 14.8 (+/-3.2) dB (P=0.05). The mean (+/-SD) duration of MCA MES of 38.1 (+/- 45.3) ms was longer than that of ACA MES of 30.7 (+/-34.0) ms (P=0.05). CONCLUSIONS: Cerebral microembolism occurs more frequently in the MCA than the ACA, which may explain the uneven distribution of cerebral infarcts along these arterial territories. Furthermore, there are significant differences in the characteristics of ACA and MCA MES.