Symptomatic vasospasm diagnosis after subarachnoid hemorrhage: evaluation of transcranial Doppler ultrasound and cerebral angiography as related to compromised vascular distribution

OBJECTIVE: To evaluate the reliability of transcranial Doppler ultrasound in detecting symptomatic vasospasm in patients after aneurysmal subarachnoid hemorrhage and monitoring response after hypertensive and endovascular treatments. DESIGN: Retrospective chart review. SETTING: Neurosciences critical care unit in a tertiary-care university hospital. PATIENTS: All patients admitted to a neurosciences critical care unit with the diagnosis of subarachnoid hemorrhage between January 1990 and June 1997. INTERVENTIONS: None MEASUREMENTS AND MAIN RESULTS: We reviewed transcranial Doppler ultrasound data of 199 patients; 55 had symptomatic vasospasm. Clinical symptoms and corresponding vascular distributions were identified, as was angiographic vasospasm (n = 35). The sensitivity and specificity of transcranial Doppler ultrasound for anterior circulation vessels were calculated by using a mean cerebral blood flow velocity criterion of >120 cm/sec. Clinical diagnosis of symptomatic vasospasm was used as the standard to determine sensitivity and specificity of transcranial Doppler ultrasound and cerebral angiography. The sensitivity of transcranial Doppler ultrasound for anterior circulation in patients with symptomatic vasospasm was 73% with a specificity of 80%. The sensitivity of cerebral angiography was 80%. For individual vessels, the sensitivity and specificity of transcranial Doppler ultrasound were middle cerebral artery, 64% and 78%; anterior cerebral artery, 45% and 84%; and internal carotid artery, 80% and 77%, respectively. The mean times for symptomatic and transcranial Doppler ultrasound signs of vasospasm presentation were 6.4 +/- 2 and 6.1 +/- 3 days, respectively. In patients without symptomatic vasospasm, the mean time for mean cerebral blood flow velocities >120 cm/sec was 7.0 +/- 3 days (p <.05). Symptomatic vasospasm also was associated with thickness of clot on head computed tomography scan and rapidly increasing mean cerebral blood flow velocities. Transcranial Doppler ultrasound signs of vasospasm improved after endovascular treatment in 30 patients. CONCLUSIONS: The reliability of transcranial Doppler ultrasound was better at detecting high mean cerebral blood flow velocities in patients with symptomatic vasospasm related to middle cerebral and internal carotid artery distributions than for anterior cerebral artery distribution. Transcranial Doppler ultrasound was as sensitive as cerebral angiography at detecting symptomatic vasospasm. High mean cerebral blood flow velocities can be apparent before the presence of symptomatic vasospasm. Daily transcranial Doppler ultrasound monitoring could provide early identification of patients with aneurysmal subarachnoid hemorrhage who are at high risk for symptomatic vasospasm and may be helpful at following success of endovascular treatment.     

经颅多普勒超声评估Willis环动脉变异

目的探讨经颅多普勒超声评估Willis环动脉变异的价值。方法152例无脑血管病患者,在行颈总动脉压迫试验时采用经颅多普勒超声(TCD)检测大脑前动脉交通前段和大脑后动脉交通前段的血流速度。结果30%患者的前交通动脉和两侧后交通动脉均开放,构成一个血流动力学完整的Willis环;95%患者的Willis环前部动脉开放,另3%前交通动脉及2%大脑前动脉交通前段缺如导致Willis环前部动脉不开放;44%Willis环后部动脉发育异常,阻碍了侧支血流从基底动脉到颈内动脉.其中36%后交通动脉缺如.8%大脑后动脉起源于颈内动脉。结论经颅多普勒超声结合颈总动脉压迫试验检测Willis环动脉变异既安全又方便,其检出率与解剖学研究一致。     

Regional cerebral blood velocity in infants. A real-time transcranial and fontanellar pulsed Doppler study

To quantitate blood velocity while maintaining the real-time ultrasound image of the intracranial vessels in infants, we used a commercial phased-array pulsed Doppler scanner and developed a transcranial technique to measure the middle cerebral artery velocity, and a fontanellar approach to measure flow velocities in the basilar, internal carotid, anterior cerebral, and the pericallosal arteries. In 22 healthy term and 25 stable preterm infants, the peak spectral systolic velocities in the internal carotid and basilar arteries in term infants were 45 +/- 3.1, and 38.8 +/- 2.5 cm/sec, (mean +/- SEM), respectively. A hierarchical pattern of velocity variation was noted between the large and small intracranial vessels in both the term and preterm infants. The velocities were 30-40% higher in the proximal than in the smaller distal, anterior cerebral, and pericallosal arteries (P less than 0.05). Although the velocities in corresponding vessels were slightly lower in preterm infants than in the term, the differences were statistically not significant. In both groups, the end diastolic velocities did not change significantly among the large and small arteries; therefore, a significant variation in Pourcelot's index (PI, the ratio of maximum systolic-end diastolic difference to the systolic velocity) was noted between the internal carotid and the pericallosal arteries: 0.88 +/- 0.01 vs. 0.76 +/- 0.02, (P less than 0.05). A nearly parabolic velocity profile was documented in the vessels studied.     

Transcranial colour coded sonography as an aid to measurement of blood flow velocity in the basal cerebral arteries

Unlike conventional transcranial Doppler, transcranial colour coded sonography allows imaging of the basal cerebral arteries. We used this technique to determine blood flow velocities, with compensation for the angle of insonation, in the anterior and posterior cerebral circulation of 60 volunteers categorised by age (20–39, 40–59, > 60 years). Successful vessel insonation declined with increasing age: 40/40 middle cerebral arteries insonated 20–39 y, 31/40 insonated >60 y. Peak, mean and end diastolic blood flow velocities also decreased with age in all arteries: 20–39 y middle cerebral artery mean VELOCITY = 72 cm/s; > 60 y middle cerebral artery mean blood flow VELOCITY = 58 cm/s; p < 0.0001. The pulsatility index increased significantly with age in the middle, posterior cerebral (P2 segment) and vertebral arteries (p < 0.05-0.005), however the resistance index increased significantly with age in all vessels (p < 0.05-0.0001).     

Age dependence of the flow velocity in the basal cerebral arteries--a transcranial Doppler ultrasound study

The age dependence of the blood flow velocities of the middle, anterior, and posterior cerebral arteries measured by the transcranial Doppler method is discussed and compared with the velocity values in the internal carotid artery. A number of 535 patients without neurological deficits but with a previous neurological event were examined. Flow velocities decrease in all examined vessels with increasing age. This is in accordance with cerebral blood flow measurements by Xenon inhalation techniques. The reasons of the decrease and its consequences on the vasospasm in patients suffering from subarachnoidal hemorrhage are discussed.     

Transcranial Doppler ultrasonic features in episodic tension-type headache

In a pilot study we used transcranial Doppler ultrasound (TCD) to measure cerebral blood flow velocities in 21 headache-free episodic tension-type headache sufferers and in the same number of age- and sex-matched control subjects. We found increased blood flow velocities in the anterior, middle and posterior cerebral arteries and a decreased pulsality index in the middle and posterior cerebral arteries in tension-type headache sufferers compared to controls. Vascular bruits were significantly more frequent in the basal cerebral arteries of the patients compared to controls. There were no significant asymmetries of blood flow velocities in corresponding arteries. The findings suggest a multifactorial pathogenesis in episodic tension-type headache including vascular abnormalities.     

Cerebral blood flow and CO2 reactivity in interictal migraineurs: a transcranial Doppler study

There is still some controversy about alterations in velocity of blood flow and in cerebral vasomotor reactivity of intracranial arteries in migraineurs during the interictal phase. By means of simultaneous bilateral transcranial Doppler ultrasonography we, therefore, assessed intracranial blood flow velocities and cerebrovascular reactivity to carbon dioxide of all three basal brain arteries in 20 migraineurs during the interictal phase and 30 nonheadache-prone control subjects. Mean blood flow velocities were higher in migraineurs than in controls in all three arteries on both sides, with a significant difference (P < 0.05) for the right anterior cerebral artery and middle cerebral artery under basal conditions and for the right posterior cerebral artery during hypercapnia. Similarly, the cerebrovascular reactivity to carbon dioxide was always higher in patients than in controls, with a significant difference for the left anterior and the right middle cerebral arteries (P < 0.05) and the right posterior cerebral artery (P < 0.01). The broad overlap of cerebrovascular blood flow velocities and CO2 reactivities in patients and controls precluded identification of values diagnostic of migraine. Nevertheless, transcranial Doppler ultrasonography offers the opportunity to noninvasively monitor cerebral blood flow parameters and, therefore, represents a valuable tool for vascular research in migraine.     

Evaluation of posterior cerebral artery blood flow with transcranial Doppler sonography: value and risk of common carotid artery compression

PURPOSE: Investigations of the posterior cerebral arteries (PCA) by transcranial Doppler sonography (TCD) may be less reliable than investigations of the anterior part of the circle of Willis. Nevertheless, a true PCA may be identified by manual compression of the proximal common carotid artery (CCA) during TCD. Therefore, we used CCA compression in clinically indicated TCD studies and assessed retrospectively its risks and prospectively its benefits for PCA evaluations. METHODS: Using the transtemporal approach, we prospectively assessed flow velocities in posteriorly located blood vessels in 180 consecutive patients before and during CCA compression. The complications of CCA compression were retrospectively reviewed in all 3,383 clinical TCD investigations performed over an 8-year period. RESULTS: Decreased flow velocities during ipsilateral CCA compression occurred in 17% of patients. A PCA-like vessel with perfusion from the carotid artery or PCA supply from the carotid circulation was unmasked. Mixed distal PCA support by the posterior communicating artery and proximal PCA could not be shown by TCD. Transient cerebral symptoms occurred in less than 0.4% of the 3,383 retrospectively reviewed TCD investigations; no other adverse effects were seen. CONCLUSIONS: TCD without CCA compression may lead to false identification of the PCA. Since transient cerebral symptoms during CCA compression are rare, CCA compression can be used when a clinical TCD investigation of intracranial collateral blood flow compensation is indicated or when the identification of a cerebral artery is uncertain.     

植物状态,闭锁综合征和脑死亡的经颅多普勒超声检查

目的：比较植物状态（ＰＶＳ）、闭锁综合征和脑死亡患者脑血流的特点。方法：用经颅多普勒超声（ＴＣＤ）检测ＰＶＳ、闭锁综合征和脑死亡患者双侧大脑中动脉（ＭＣＡ）和基底动脉（ＢＡ）的血流情况。结果：持续植物状态ＭＣＡ和ＢＡ的平均血流速分别为２９．０ｃｍ／ｓ和２３．３ｃｍ／ｓ，较正常下降４７％和２２．３％。闭锁综合征ＭＣＡ和ＢＡ的平均血流速分别为４８．０ｃｍ／ｓ和１０．３ｃｍ／ｓ，分别较正常下降８．２％和６０．０％。提示ＰＶＳ的血流速减慢以前循环为主，而闭锁综合征的血流速减慢以后循环为主。脑死亡则为特殊的双向血流、收缩期短小尖波或无血流信号，与ＰＶＳ或闭锁综合征患者的ＴＣＤ完全不同。结论：根据前后循环血流速减慢的不同及特殊的脑血流频谱，ＴＣＤ能帮助医师鉴别上述三种临床上有时易混淆的状态     

颈动脉连续波多普勒超声评估颅内侧支循环

目的探讨颈动脉连续波多普勒超声评估颅内侧支循环。方法对80例无脑供血动脉狭窄性病变患者,在行颈总动脉压迫试验时采用4 MHz连续波探头检测对侧颈内动脉起始段和同侧椎动脉寰枢段血流速度变化。并对连续波多普勒超声与经颅多普勒超声检测的侧支循环方式结果进行比较。结果颈动脉连续波多普勒超声检出前交通动脉侧支开放76例(95%),经颅多普勒超声检出前交通动脉侧支开放76例(95%)。在受检的160个后交通动脉侧支中,颈动脉连续波多普勒超声检出后交通动脉侧支开放140个(88%),经颅多普勒超声检出132个(83%)。结论颅外动脉连续波多普勒超声结合颈总动脉压迫试验检测颅内侧支循环既安全又方便,其准确率与经颅多普勒超声一致。     

New method of adult transcranial Doppler

Prior to development of better resolution duplex Doppler systems, blood flow velocities of the middle cerebral artery, anterior cerebral artery, and posterior cerebral artery were obtained in a "blind" manner, ie, the vessels were not imaged. We performed duplex transcranial Doppler examinations on 13 healthy volunteers and obtained peak velocities as well as resistive indices on all three arteries. The vessels were identified by their anatomic locations with respect to the brainstem and by the echogenic pulsating structures. This duplex transcranial Doppler examination holds promise for improving reproducibility and for detecting pathologic vascular states.     

Blood flow velocity changes in migraine attacks-a transcranial Doppler study

A pulsed Doppler device was used to measure blood flow velocities in the common carotid artery, the extracranial part of the internal carotid artery, the external carotid artery, the middle cerebral artery, and the anterior cerebral artery in 31 migraineurs without aura (n = 27) and with aura (n = 4), both during and outside an attack. The aims were to compare blood flow velocity during and between migraine attacks and to study asymmetries of the blood flow velocity. Compared with blood flow velocity values obtained in the attack-free interval, blood flow velocity was lower during attacks without aura in both common carotid arteries, but not in the other extra- and intracranial vessels which were examined. However, during attacks of migraine with aura, blood flow velocity tended to be lower in all examined vessels. There were no asymmetries of the blood flow velocity. We suggest that during migraine attacks without aura there is a dissociation in blood flow regulation in the common carotid and middle cerebral arteries.     

Ultrasonic assessment of cerebral blood flow changes during ischemia-reperfusion in 7-day-old rats

A model of ischemic brain injury in 7-day-old rat pups has been developed to study perinatal ischemia. It combines permanent occlusion of the distal left middle cerebral artery (LMCA) and transient occlusion of homolateral common carotid artery (LCCA). At removal of the clip on LCCA, reflow allowed brain reperfusion through cortical anastomoses. In 10 rat pups, we measured blood flow velocities (BFV) in main cerebral arteries with 12-MHz ultrasound imaging. At basal states, peak systolic BFV in proximal LMCA was 16.0 +/- 3.0 cm.s(-1). Occlusion of LMCA did not yield significant modifications. Occlusion of LCCA involved only a decrease in BFV to 9.5 +/- 2.6 cm.s(-1) (p < 0.001). Indeed, LMCA was then supply by the right internal carotid and the vertebral arteries through the circle of Willis. In three rat pups, release of occlusion of LCCA was followed by restoration of BFV in the left internal carotid artery and in LMCA, in seven pups, by a reversed flow in the LICA and lower BFV in LMCA (11.9 +/- 2.3, p < 0.05). BFV returned to basal values from h5 to h48 in all animals. In addition, ultrasound imaging is a useful, reproducible, non invasive, easy-to-repeat, method to assess and monitor arterial cerebral blood flow supply in small animals. It helps to characterize changes occurring during cerebral ischemia and reperfusion, particularly the depth of the hypoperfusion, as well as the variability of reflow. In preclinical studies, this method could help to identify what can be assigned to a neuroprotective treatment and what depends on changes in cerebral blood flow supply.     

健康国人年龄性别对主要脑底动脉血流速度的影响及其检测方法的探讨

应用多普勒技术探测颅外脑血管血流速度,1965年由Miyazaki等首先报告,然而,由于骨骼严重衰减超声波,故使用5～10MHz探测频率难以记录颅内血管的血流速度。1982年Aaslid报告了应用脉冲多普勒技术,通过调整取样深度,观察了颅内脑动脉的血流速度,此后,颅内主要脑底动脉的血液动力学变化,以及无创手段对频内脑血管血流速度的监测得到了广泛的研究和深入的开展。我们心功能科自1988年12月引进美国Meda Sonics经颅超声多普勒(TCD)诊断仪以来     

Transcranial measurement of blood velocities in the basal cerebral arteries using pulsed Doppler ultrasound: velocity as an index of flow

Blood velocities have been measured transcranially, at small Doppler angles, in the middle cerebral artery of normal volunteers. Cerebral blood flow was changed by varying carbon dioxide tension. In four volunteers, the relationships between arterial pCO2 and percentage change in intensity weighted mean, median, and maximum Doppler-shifted frequencies in the internal carotid and middle cerebral arteries were linear with slopes of 2.5 and 2.8% per mm Hg change in pCO2. In 38 volunteers, the relationship between end-expiratory pCO2 and time-averaged maximum Doppler frequency was linear over the range of pCO2 20-60 mm Hg with slopes of 2.5 and 2.9 percentage change per mm Hg, for internal carotid and middle cerebral, respectively. These results are very similar to those reported using direct methods of measuring cerebral blood flow. As the transcranial Doppler method is reproducible, this indicates that changes in middle cerebral blood velocity may be used to monitor changes in flow.     

Transcranial Dopplersonography. Examination technique and normal reference values

The main application of ultrasound in neurology is the examination of extracranial arteries. Recently the Doppler sonographic measurement of flow velocity in the basal cerebral arteries through the intact skull was developed using a pulsed Doppler technique and 2 MHz emitting frequency. Doppler frequencies in systole and diastole were recorded in 51 healthy subjects at 0.5 cm steps along the middle (MCA), anterior (ACA) and posterior cerebral artery (PCA) as well as the basilar artery (BA). The averaged Doppler shift in the MCA was 2.3 ± 0.4 kHz in systole and 1.15 ± 0.25 kHz in diastole, in the ACA 1.8 ± 0.35 kHz and 0.85 ± 0.22 kHz, in the PCA 1.5 ± 0.29 kHz and 0.74 ± 0.18 kHz, in the BA 1.45 ± 0.31 kHz and 0.72 ± 0.22 kHz. Separation in four age groups showed a decrease of Doppler shift in the MCA of 20% from a mean age of 17 to 67 years. Static and dynamic compression tests were evaluated to assign transcranial Doppler signals to the MCA, ACA and PCA. No compression test was necessary for the identification of the BA insonated through the occipital foramen.     

Transcranial Doppler sonography: anatomical landmarks and normal velocity values

Until recently, both the diagnosis of intracranial occlusive disease of the large brain arteries, as well as intracranial flow abnormalities due to extracranial arterial lesions, have been a "blind spot" for ultrasound techniques. With the advent of transcranial Doppler sonography (TCD), however, a broad spectrum of potential clinical and scientific applications of TCD to the intracranial vasculature has been advocated. In order to achieve an informative insonation of vessels and a correct interpretation of findings, knowledge of both anatomical landmarks within the skull and flow characteristics of distinct vessel segments are necessary. This paper presents such data elaborated from 64 carotid and 42 vertebral angiograms, 40 contrast-medium enhanced CT scans demonstrating the circle of Willis, 122 normal sagittal MRI scans of the brainstem, 40 cadaver skulls, 38 fresh cadavers, 106 normal volunteers and 59 patients with subclavian steal mechanisms. The main findings were as follows: The inner internal carotid artery bifurcation, the M1-segment of the middle cerebral artery, the C3-segment of the carotid siphon, the vertebral artery junction and the top of the basilar artery were found at insonation depths of 60.4 +/- 7, 40 +/- 8 to 60.4 +/- 7, 62 +/- 4, 84 +/- 8 and 108 +/- 8 mm, respectively. Normal mean flow velocities within the M1-segment, the posterior cerebral artery, the carotid siphon and the basilar trunk were 58 +/- 15.6, 39 +/- 9.9, 47 +/- 13.8 and 41 +/- 10 cm/s, respectively, and revealed a marked decrease with age. Intraindividual side-to-side differences were low. Vertebrobasilar data from measurements of neuroradiological material closely met in vivo findings in normals and patients. Criteria for the identification of various vessel segments are provided. On the basis of these findings, a topographical orientation within the skull should be possible in order that beginners commence TCD accurately. Normative velocity data are helpful for differentiating normal and pathological flow conditions at different ages.     

Cerebrovascular reactivity in migraineurs as measured by transcranial Doppler

Transcranial Doppler ultrasound is a relatively new diagnostic modality which allows the noninvasive assessment of intracranial circulation. A total of 10 migraine patients were studied and compared to healthy controls without headaches. Migraineurs during the headache-free interval demonstrated excessive cerebrovascular reactivity to CO2, evidenced by an increase in middle cerebral artery blood flow velocity of 47% +/- 15% compared to 28% +/- 14% in controls (p = 0.026). Differences between the two study groups revealed no significant decrease in middle cerebral artery blood flow velocity with hypocapnia. However, the differences between middle cerebral artery blood flow velocity during hyperventilation and CO2 inhalation were significantly different (p = 0.004) comparing migraineurs and controls. Instability of the baseline blood flow velocities was also noted in migraineurs during the interictal period. Characteristics which may allow differentiation of migraineurs from other headache populations could possibly be obtained from transcranial Doppler ultrasound flow studies.     

Comparison of the clinical value of transcranial Doppler ultrasound and computed tomography angiography for diagnosing ischemic cerebrovascular disease

ObjectiveTo compare the clinical value of transcranial Doppler (TCD) ultrasound and computed tomography angiography (CTA) for diagnosing ischemic cerebrovascular disease.MethodsA retrospective clinical study was conducted in 142 patients with ischemic cerebrovascular disease who were initially diagnosed by digital subtraction angiography. Under the single-blind condition, the patients were diagnosed by using TCD ultrasound and CTA independently. The accuracy of these two methods was compared.ResultsThe accuracy of diagnosing bilateral middle cerebral artery, bilateral vertebral artery and bilateral internal carotid artery lesions with a TCD examination was significantly higher than that with a CTA examination. There were no significant differences in the accuracy of diagnosing bilateral anterior cerebral artery, bilateral posterior cerebral artery or basilar artery lesions between TCD ultrasound and CTA. The accuracy of diagnosing all cerebral arterial ischemic lesions was significantly higher with a TCD examination (87.39%) than with a CTA examination (69.75%). The accuracy of diagnosing all cerebral arteries that cause ischemic encephalopathy (cerebrovascular + cervical blood vessels) was significantly higher with a TCD examination (88.03%) than with a CTA examination (69.01%).ConclusionsTCD ultrasound has several advantages over CTA. Therefore, TCD ultrasound is better for diagnosing ischemic encephalopathy than CTA.     

Ophthalmic and cerebral blood flow velocities in preterm infants: influence of ambient lighting conditions.

Doppler ultrasound was used to study ophthalmic and middle cerebral artery flow velocities at different ambient lighting conditions in 28 preterm infants in the first week of life. We found significant increases of ophthalmic and middle cerebral artery blood flow velocities when ambient light was increased from moderate to intense. Flow velocities in the ophthalmic artery increased significantly more than in the middle cerebral artery. Doppler ultrasound studies of ophthalmic blood flow velocity may assist in answering the intriguing question whether light-induced changes of ocular perfusion play a role in the development of retinopathy of prematurity.