Emotion-related cerebral asymmetry: hemodynamics measured by functional ultrasound

This study assessed the use of transcranial Doppler ultrasound in detecting selective changes in cerebral blood flow velocity during emotional processes. The role of the respective hemispheres in emotional processing is controversial. Cerebral control of emotional processing has previously been investigated by analysis of patients with unilateral brain damage, experiments with selective stimulation of only one hemisphere, and more recently by imaging techniques measuring local cerebral blood flow. We investigated mean flow velocity continuously and simultaneously in both the right and left middle cerebral arteries (MCAs) in 16 healthy right-handed young subjects at rest and during the performance of three tasks: task 1: 15 slides with nonemotional content; task 2: 15 slides with negative emotional content; task 3: 15 slides with nonemotional content with different content from that in task 1. The three tasks produced significantly different effects on the right and left hemispheres. During the two nonemotional tasks the increase in mean flow velocity over basal values was similar in the two MCAs (task 1: left MCA = 3.27 ± 1.9%; right MCA = 3.63 ± 2.1%; task 3: left MCA = 2.42 ± 0.7%; right MCA = 2.56 ± 1.3%); the negative emotional task was accompanied by a significantly higher increase in the right (11.31 ± 1.6%) than in the left MCA (4.72 ± 3.7%; analysis of variance two-way interaction: side of recording x task, F = 43.6, P < 0.001). These results show the possibility of obtaining specific functional information from bilateral transcranial Doppler ultrasound and suggest the involvement of the right hemisphere in emotional processing. Received: 4 March 1999 Received in revised form: 29 June 1999 Accepted: 5 August 1999     

Compromised cerebrovascular modulation in chronic anxiety: evidence from cerebral blood flow velocity measured by transcranial Doppler sonography

Objective Cerebral autoregulation(CA) is the mechanism by which constant cerebral blood flow is maintained despite changes in cerebral perfusion pressure.CA can be evaluated by dynamic monitoring of cerebral blood flow velocity(CBFV) with transcranial Doppler sonography(TCD).The present study aimed to explore CA in chronic anxiety.Methods Subjects with Hamilton anxiety scale scores≥14 were enrolled and the dynamic changes of CBFV in response to an orthostatic challenge were investigated using TCD.Results In both the anxious and the healthy subjects,the mean CBFV was significantly lower in the upright position than when supine.However,the CBFV changes from supine to upright differed between the anxious and the healthy groups.Anxious subjects showed more pronounced decreases in CBFV with abrupt standing.Conclusion Our results indicate that cerebrovascular modulation is compromised in chronic anxiety;anxious subjects have some insufficiency in maintaining cerebral perfusion after postural change.Given the fact that anxiety and impaired CA are associated with cardiovascular disease,early ascertainment of compromised cerebrovascular modulation using TCD might suggest interventional therapies in the anxious population, and improve the primary prevention of cardiovascular disease.     

Demonstration of giant MCA aneurysm by transcranial duplex sonography and color Doppler imaging

Transcranial color Doppler sonography is a new diagnostic technique which allows real-time, colorcoded imaging of basal cerebral arteries, with simultaneous demonstration of parenchymal structures in the B-mode scan. With this technique we were able nonivasively to show a giant fusiform aneurysm of the middle cerebral artery (MCA) in an 11-year-old boy. Transcranial color Doppler sonography through the intact temporal bone demonstrated the size and location of the aneurysm and provided real-time imaging of the pulsating intra-aneurysmal flow. Additionally, duplex sonographic measurements of intravascular flow velocities within the aneurysm and the feeding and draining artery were possible. Postoperatively, patency of the MCA with reduced flow velocities after excision of the aneurysm could be shown. This is the first transcranial color Doppler report in a patient with an intracerebral aneurysm. In our opinion, transcranial color Doppler sonography offers new diagnostic possibilities in patients with cerebrovascular disorders.     

59例不同年龄段偏头痛患者经颅多普勒超声探测脑血流变化的临床意义

目的 探讨经颅多普勒超声(TCD)对偏头痛的检测价值.方法 59例偏头痛患者,按不同年龄段分成5组,在急性发作期应用TCD检测血流速度.结果 偏头痛患者不同年龄段急性发作期脑血流速度和正常人血流速度与同名动脉比较,偏头痛患者和正常人血流速度差异有统计学意义(P<0.01).结论 TCD可敏感而准确地反映偏头痛患者在急性...     

Transcranial color Doppler sonography on healthy pre-school children: flow velocities and total cerebral blood flow volume

Transcranial color Doppler sonography (TCCD) is a useful tool for intracranial investigation. Using TCCD to calculate total cerebral blood flow volume (TCBFV) can be a useful indicator for intracranial hemodynamic status. We performed a series study of TCCD on 60 healthy kindergarten students. Peak-systolic, end-diastolic, and mean blood velocities of major cerebral arteries, and depth of flow waves were measured. We also collected Gosling pulsatile index (PI) and Pourcelot resistance index (RI) of the arteries. TCBFV was calculated from the mean blood flood velocity and vessel chamber size of the internal carotid artery (ICA) and basilar artery (BA). Fifty children completed the examinations. The TCBFV was 1538+/-416 ml/min with mean cerebral blood flow volume of 571+/-241 ml/min for the ICA system and 983+/-343 ml/min for the BA system. PI, RI, and the velocities of A1, A2, M1, M2, BA, ICA, and TCBFV were not significantly different between girls and boys in this age group. In this study, we used TCCD to determine the normal data of main cerebral arteries and TCBFV of pre-school children in Taiwan. The reference data of velocities and other parameters of main cerebral arteries from our study may serve as a guide for additional pediatric cerebral hemodynamic studies.     

Predictability of intracranial pressure oscillations in patients with suspected normal pressure hydrocephalus by transcranial Doppler ultrasound

Abstract

Intracranial pressure (ICP) was monitored continuously for one night in 36 patients with suspected symptomatic normal pressure hydrocephalus (NPH) to identify patients who might benefit from subsequent shunting. In 33 of these patients middle cerebral artery (MCA) blood flow velocity by means of transcranial Doppler sonography (TCD) and ICP were recorded simultaneously. ICP B-waves always paralleled changes in the TCD signal (TCD B-wave equivalents). The relative frequency of ICP B-waves was predictable by TCD, albeit slightly underestimated due to a generally lower relative amplitude of the TCD B-wave equivalents. However; the same TCD B-wave equivalent amplitude could be accompanied by quite different ICP changes in different patients. Considering the baseline values in the absence of pressure wavesthere was no significant relationship between ICP and TCD resistance index (Pourcelot) in different patients. Raising ICP by injection of 10 ml saline into the ventricle, however was accompanied by an increased TCD resistance index in the individual patient. As the relative frequency of B-wave activity is assumed to be an indicator for shunt responsiveness, continuous TCD monitoring can be used as a screening procedure to detect the presence and the relative frequency of B-wave activity in patients with suspected NPH. However, since neither the absolute ICP nor the amplitude of spontaneous oscillations can be predicted, TCD monitoring is not suitable to replace ICP monitoring. [Neurol Res 1994; 16: 398-402]     

TCD对颈内动脉中度及重度狭窄患者脑血流动力学的评估价值

目的应用经颅多普勒超声(transcranial doppler,TCD)评价颈内动脉中度及重度狭窄患者的脑血流动力学变化。方法经数字减影血管造影(digital subtraction angiography,DSA)确诊单侧颈内动脉中度及重度狭窄的患者69例,采用TCD检测其大脑中动脉血流参数,评价其侧支循环开放情况和脑血流储备能力(CRV)。结果 TCD显示侧支循环开放者患侧收缩期峰时血流速度(Vs)、搏动指数(PI)及CVR明显高于无侧支循环开放患者(P0.05),颈内动脉中度狭窄组患侧收缩期峰时血流速度(Vs)、PI值及CVR明显高于重度组(P0.05)。结论颈内动脉狭窄时侧支开放可以改善远端血流动力学指标,但改善程度有限。TCD可检测颈内动脉狭窄患者颅内血流动力学变化,评价颅内侧支循环的建立情况,为临床治疗和评估提供可靠依据。     

Transcranial Doppler sonography in craniosynostosis

In the management of craniosynostosis, there is a need for quantitative assessment of treatment methods and outcome. Radiology and pressure studies are well documented, but so far little attention has been given to cerebral blood flow changes and their possible relevance. This paper reports our initial experience using transcranial Doppler sonography to calculate the cerebrovascular resistance and cerebral blood velocities in the major basal vessels before and after surgery for craniosynostosis. Ten patients were studied using the Scimed 2-MHz probe through the temporal and frontal windows of the skull. Measurements were taken under standard physiological conditions before, during and after surgery. Preliminary results suggest that this non-invasive technique may be helpful in predicting and assessing the outcome following surgery for craniosynostosis.     

Assessment of cerebral blood flow changes in nonconvulsive status epilepticus in comatose patients: A pathophysiological transcranial Doppler study

PurposeWe assessed the accuracy of transcranial Doppler (TCD) in helping to diagnose nonconvulsive status epilepticus (NCSE) in comatose patients admitted to the intensive care unit (ICU) for acute neurological disorders at high risk for NCSE.MethodsA 2-year prospective observational study in 38 consecutive patients requiring continuous electroencephalography (EEG) monitoring and intracranial pressure monitoring with TCD.ResultsOf the 38 patients, 10 (26.3%) had NCSE by continuous EEG monitoring. Bilateral mean and maximal systolic and diastolic TCD velocities were significantly different between patients with and those without NCSE. Areas under the receiver-operating characteristic (ROC) curves of mean and maximal systolic velocities by TCD were 0.82 (95%CI, 0.64–1.00) and 0.79 (95%CI, 0.62–0.95) with cutoffs of 95 cm/s and 105 cm/s, respectively. Areas under the ROC curves of mean and maximal diastolic velocities were 0.76 (95%CI, 0.56–0.95) and 0.78 (95%CI, 0.60–0.96) with cutoffs of 31 cm/s and 40 cm/s, respectively. For none of the velocity parameters did the areas under the ROC curves differ significantly between the left and right sides. The best performance was obtained using mean systolic (SV) and a cutoff of 95 cm/s, which yielded a positive likelihood ratio of 3.8 and a negative likelihood ratio of 0.25.ConclusionOur preliminary results showed a significant association between increased TCD velocities and NCSE in comatose patients. However, the likelihood ratios suggested a limited role for TCD in helping to diagnose seizure activity. Further studies with larger samples of NCSE patients are warranted to determine the exact contribution of TCD for NCSE detection in comatose ICU patients.     

Transcranial Doppler ultrasonic assessment of middle cerebral artery blood flow velocity changes during verbal and visuospatial cognitive tasks

Hemisphere specific changes of blood flow velocity in the right and left middle cerebral artery (MCA) induced by cognitive demands of verbal and nonverbal tasks were examined by means of a newly developed technique of simultaneous bilateral transcranial ultrasonic Doppler sonography (TCD). Thirty-one right-handed healthy volunteers served as subjects. Identical stimulus and response procedures were used with all tasks to avoid possible differential effects of these conditions on blood flow velocity. Compared to the preceding resting phase, the increase in flow velocity induced by each of the verbal tasks (sentence completion, similar or contrasting word meanings, similarities) proved to be significantly higher in the left than in the right MCA. Among the non-verbal visuospatial tasks only the “identical pictures” (perceptual speed) task led to a complementary higher increase in right MCA blood flow velocity. No such asymmetry in blood flow acceleration was observed, however, with the tasks “figure assembly” and “cube comparison” which require visualization and mental rotation of figures. The findings underline the recently emerging uncertainty in neuropsychological research with regard to the functional specialization of the right hemisphere.     

Blood flow velocity in the arteries of the anterior cerebral artery complex in patients with an azygos anterior cerebral artery aneurysm: a transcranial color-coded sonography study

Objective

It is presumed that increased blood flow through the single azygos anterior cerebral artery (Az) may contribute to the formation of an Az aneurysm. The aim of this study was to assess the blood flow velocities in the arteries of the anterior cerebral artery (ACA) complex in patients with the Az aneurysm.

Patients and methods

A series of three patients (2 men, aged: 65, 52 and 41) with an aneurysm (unruptured in two cases) of the distal Az was examined. Blood flow velocities in the Az and the A1 segment of the ACA were measured by means of a transcranial color-coded duplex sonography (TCCS) and the Az to A1 segment (Az/A1) velocity ratio was calculated. The control group consisted of 22 healthy subjects (mean age: 44 years).

Results

There was a trend toward decreased (p = 0.06) mean blood flow velocity in the Az compared to the A2 segment of the ACA of the control group. Blood velocity in the A1 segment did not differ between the study and control groups. Pulsatility and resistance indices in the Az were similar to those in the A2 segment of the control group. There were no differences between the Az/A1 ratio in the study group and the A2/A1 velocity ratio in the control group.

Conclusion

Our results suggest that Az aneurysms are not associated with increased blood flow velocity in the Az. Possibly, a hemodynamic stress related to the Az bifurcation geometry, together with a bent course of this artery around the genu of the corpus callosum, predispose to aneurysm formation.     

双焦距经颅多普勒在大脑中动脉狭窄患者检测微栓子的研究

目的 研究大脑中动脉（ＭＣＡ）狭窄患者采用ＴＣＤ检测微栓子（ＭＥＳ）的诊断价值。方法 对２１例年龄在３５￣５７岁的单侧ＭＣＡ狭窄患者,经ＣＴ／ＭＲＩ证实为脑梗死。均进行３０分钟的双焦距ＴＣＤ监测。结果 ４例（１９．０％）检测到ＭＥＳ。其中３在狭窄远端检测到,１例近,远端均检测到。均为大面积脑梗死（４／１３,３０．８％）,而腔隙性梗死未发现ＭＥＳ。结论 双焦距ＴＣＤ检测ＭＥＳ对于确定栓子来源有重要价     

Influence of biological factors on changes in mean cerebral blood flow velocity in normal ageing: a transcranial Doppler study

Analysis of the blood flow velocities in the middle cerebral artery by transcranial Doppler ultrasonography was performed in 158 healthy volunteers (aged 14-70 years; 82 men and 76 women). In a subgroup of 38 men and 21 women the end-tidal [CO₂] was also measured. The influence of biological factors such as age, sex, end-tidal [CO₂], and pulsatility and resistance indices on the mean blood flow velocity in normal ageing was investigated by multiple regression analysis. In both sex groups the measured mean blood flow velocity decreased significantly with age (P values < 0.0003 for women and < 0.0001 for men). Women had significantly higher blood flow velocities than men (P = 0.008) and the age-corrected sex difference of 5.2 cm s^–1 did not significantly depend on age (P = 0.93). The age-related linear decline of the mean blood flow velocity could not be explained by a concomitant decrease of the end-tidal [CO₂]. In a group of subjects older than 50 years, the decrease of the mean blood flow velocity was significantly related to the increase of the pulsatility or resistance index.     

Mesencephalic area measured by transcranial sonography in the differential diagnosis of parkinsonism

BackgroundTranscranial B-mode sonography (TCS) has become an important tool in the differential diagnosis of parkinsonism given that current technology enables an adequate assessment of brain structures. In this study we aimed at evaluating the usefulness of midbrain area measured by TCS in the differential diagnosis between Parkinson's Disease (PD) and Progressive Supranuclear Palsy (PSP).MethodsPatients with a diagnosis of PD or PSP according to current clinical criteria were recruited. PSP patients were classified as Richardson's syndrome and PSP-parkinsonism. TCS was performed and the mesencephalic area and third ventricle width were measured offline by an examiner blinded to clinical diagnosis.ResultsTCS was performed in 60 patients (75% PD, 25% PSP). Eight patients (13,3%) had inadequate acoustic window. Patients with PSP had a smaller mesencephalic area (3.58 cm² vs 5.28 cm², p < 0.001). A mesencephalic area ≥4.27 cm² discriminates PD from PSP with a positive predictive value 100%. Patients with PSP also had a higher third ventricle diameter (8.84 mm vs 5.11 mm, p < 0.001). Within the PSP group patients with Richardson's syndrome had a wider third ventricle than patients with PSP-Parkinsonism phenotype (9.57 mm vs 7 mm, p = 0.01), but no differences were found in the mesencephalic area between both phenotypes.ConclusionsMeasurement of the mesencephalic area and the third ventricle width by TCS is a non-invasive, easily accessible technique that is useful in the differential diagnosis between PD and PSP, at least in the late stages of the disease.     

TCD动态监测静脉窦血栓形成五例

目的评价静脉窦血栓形成患者经颅多普勒超声(TCD)检测静脉侧枝的开放和再通情况以及颅内压变化。方法用TCD 2MHz探头检测5例静脉窦血栓形成患者的颅内静脉的血流速度以及动脉频谱形态的变化。结果 5例静脉窦血栓形成患者的颅内静脉(大脑中深静脉、基底静脉)的血流速度均明显增高(139cm/s,118 cm/s,99 cm/s,103 cm/s,58cm/s),动脉频谱呈高阻力,经过治疗,随着病情的好转,颅内静脉血流速度下降,颅内动脉频谱由高阻力型恢复正常。结论 TCD能可靠无创、准确地检测颅内静脉,在病程中通过多次的TCD检查,可以评价静脉窦血栓形成静脉侧枝的开放和再通情况以及颅内压变化。     

Assessment of blood flow velocities in the ophthalmic arteries by transcranial Doppler sonography in osteopetrosis

Osteopetrosis is a rare congenital disorder of bone resorption, which causes generalized hyperostosis. One of its many complications involves the skull base and progressive encroachment of the optic nerves within their canals, resulting in optic atrophy and blindness. Management of patients with deteriorating vision may include surgical decompression of the optic canals; their selection requires careful assessment by radiology, computed tomography, visual evoked potentials, electroretinography and possibly hæmodynamic studies of the ophthalmic arteries. Postoperative changes can create difficulty in the interpretation of follow-up radiological investigations. In this study, transcranial Doppler sonography was used to assess the blood flow velocities in the ophthalmic arteries non-invasively. Pre- and postoperative studies of the Doppler parameters were done for each ophthalmic artery in a 5-month-old boy under standard physiological conditions. He presented with almost complete blindness and subsequently showed a good outcome following surgical intervention.     

经颅多普勒及彩色经颅多普勒超声与DSA对烟雾病诊断的比较分析

目的探讨经颅多普勒(TCD)及彩色经颅多普勒超声(TCCD)对烟雾病诊断的临床应用价值。方法采用TCD及TCCD探测137例烟雾病患者颅内血管血流动力学的改变,并与其DSA结果比较分析。结果 TCD探测24例,明确诊断22例,高度怀疑1例,阴性者1例,与DSA比较诊断符合率为96%。TCCD探测113例,明确诊断102例,高度怀疑8例,因无透声窗检测失败3例,与DSA比较诊断符合率为97%。结论 TCD及TCCD均能实时动态地观察颅底血管血流动力学的改变,而TCCD对颅内动脉狭窄处血流显示更敏感,更有助于准确判断血管闭塞与轻度狭窄,对烟雾病的诊断具有更高的应用价值;又因其无创,病人易接受,两者可作为烟雾病患者诊断、定期随访的首选方法。     

The cerebral hemodynamics of repetitive transcranial magnetic stimulation

Repetitive transcranial magnetic stimulation (rTMS) has been shown to be effective in the treatment of affective disorders. However, only little is known about hemodynamic physiological and safety aspects of this method. We studied the cerebral hemodynamics as measured by transcranial Doppler sonography in 20 healthy subjects during different rTMS procedures. Mean cerebral blood flow velocity (CBFBV), pulsatility index (PI), and oxygen consumption were recorded continuously and averaged directly after the rTMS procedure. RTMS did not influence blood pressure, pulse rate, or blood oxygenation. There was a maximal increase of CBFV in the middle cerebal artery (MCA) of 3.6% and 5.6% during 10 Hz and 20 Hz stimulation, respectively. This increase was only seen on the stimulated left hemisphere. The PI remained unchanged during the whole procedure. It is likely that the increase of CBFV is due to dilatation of the small resistance vessels rather than due to vasoconstriction of the MCA. In terms of cerebral hemodynamics, rTMS is a safe and well-tolerated technique with a lower increase of CBFV than that seen in electroconvulsive therapy. Received: 22 March 2000 / Accepted: 4 July 2000     

Rhythmic oscillations with a wavelength of 0.5–2 min in transcranial Doppler recordings

We have studied intracranial pressure (ICP) B-waves and their association with rhythmic changes in blood flow velocity (B-wave equivalents) by transcranial Doppler sonography (TCD) monitoring. In overnight TCD recordings in 10 normal young adults, these rhythmic changes in blood flow velocity were higher and more frequent during REM sleep and sleep stage 1 than during other sleep stages. B-wave equivalents also had a longer wavelength during REM sleep. Their relative frequency in these normal subjects over one night ranged from 35 to 73%. Peripheral resistance (assessed by the Pourcelot index) was lower and heart rate was higher at the peak of these oscillations. These results support the hypothesis that ICP B-waves are caused by vasodilation. A non-linear relationship between ICP and blood flow velocity was found during B-waves in 9 of 11 patients with suspected NPH. Our results throw doubt on the suggestion that a relative frequency of less than 80% B-wave activity can be a valid indicator for shunt responsiveness in patients with suspected normal pressure hydrocephalus (NPH). ICP recordings in suspected NPH should be accompanied by polysomnography to avoid misleading results due to variability of B-wave appearance dependant on sleep pattern.     

Biphasic cerebral blood flow velocity profile in patients with aneurysmal subarachnoid hemorrhage

Introduction: Increases in cerebral blood flow velocity (CBFV) as measured by transcranial Doppler (TCD) sonography are reflective of cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage (SAH). In serial TCD measurements, some patients exhibit CBFV temporal profiles with two peaks (biphasic). The significance of this finding remains unclear. This retrospective case-control study was conducted to investigate the characteristics and possible predictors of biphasic CBFV profiles. Methods: Biphasic CBFV profiles were identified in serial TCD examinations (every 1–2 days) of 182 consecutive patients admitted for aneurysmal SAH based on CBFV profiles of the middle cerebral artery on the side of higher maximum velocity. Patients undergoing angioplasty were excluded. Patients meeting these criteria (study patients) were compared to control patients matched for age and Hunt and Hess grade. Results: Eighteen patients (9.9%) demonstrated biphasic CBFV profiles. The first CBFV (134±11 cm/second) peak occurred on post-SAH day 6±1, and the second peak (148±12 cm/second) on day 13±1. Study patients more often exhibited focal (p<0.05) symptoms at the time of the first peak. No patient deteriorated neurologically at the time of the second peak. No correlation was observed between CBVF and mean arterial pressure or central venous pressure trends. Conclusion: Serial TCD assessment identifies patients with SAH and a biphasic CBFV temporal profile. Although the second peak usually is not associated with a worsening of symptoms, these patients were more likely to exhibit clinical symptoms during the first CBFV peak.