Cerebral Artery Pulsatility Index Research Articles

The Impact of Aging on the Association between Aortic Stiffness and Cerebral Pulsatility Index

The central arteries dampen the pulsatile forces from myocardial contraction, limiting the pulsatility that reaches the cerebral vasculature, although there are limited data on this relationship with aging in humans. The purpose of this study was to determine the association between aortic stiffness and cerebral artery pulsatility index in young and older adults. We hypothesized that cerebral pulsatility index would be associated with aortic stiffness in older adults, but not in young adults. We also hypothesized that both age and aortic stiffness would be significant predictors for cerebral pulsatility index. This study included 23 healthy older adults (aged 62 ± 6 years) and 33 healthy young adults (aged 25 ± 4 years). Aortic stiffness was measured using carotid‐femoral pulse wave velocity (cfPWV), while cerebral artery pulsatility index in the internal carotid arteries (ICAs), middle cerebral arteries (MCAs), and basilar artery were assessed using 4D Flow MRI. Cerebral pulsatility index was calculated as (maximum flow – minimum flow) / mean flow. In the combined age group, there was a positive association between cfPWV and cerebral pulsatility index in the ICAs (r = .487; p < 0.001), MCAs (r = .393; p = 0.003), and basilar artery (r = .576; p < 0.001). In young adults, there were no associations between cfPWV and cerebral pulsatility index in any of the arteries of interest (ICAs: r = .253; p = 0.156, MCAs: r = ‐.059; p = 0.743, basilar artery r = .171; p = 0.344). In contrast, in older adults there was a positive association between cfPWV and cerebral pulsatility index in the MCAs (r = .437; p = 0.037) and basilar artery (r = .500; p = 0.015). However, the relationship between cfPWV and cerebral pulsatility index in the ICAs of the older adults did not reach the threshold for significance (r = .375; p = 0.078). In conclusion, age and aortic stiffness are significant predictors of cerebral artery pulsatility index in healthy adults. This study highlights the importance of targeting aortic stiffness in our increasingly aging population to reduce the burden of age‐related changes in cerebral hemodynamics.

Short-Term Volume Loading Effects on Estimated Intracranial Pressure in Human Volunteers.

BACKGROUND: Short-term fluid loading is used as part of post-spaceflight medical procedures and clinical treatment in hospitals. Hypervolemia with hemodilution induced by rapid fluid infusion reportedly impaired dynamic cerebral autoregulation. However, the effects on intracranial pressure (ICP) remain unknown. Therefore, we estimated ICP noninvasively (nICP) to examine whether rapid fluid infusion would raise ICP.METHODS: Twelve healthy male volunteers underwent two discrete normal saline (NS) infusions (15 and 30 ml · kg-1 stages, NS-15 and NS-30, respectively) at a rate of 100 ml · min-1. The cerebral blood flow (CBF) velocity (CBFv) waveform from the middle cerebral artery obtained by transcranial Doppler ultrasonography was recorded, as was the arterial blood pressure (ABP) waveform at the radial artery obtained by tonometry. We then used these waveforms to calculate nICP, cerebral artery compliance, and the pulsatility index (PI) in an intracranial hydraulic model.RESULTS: nICP increased significantly in both infusion stages from preinfusion (preinfusion: 7.6 ± 3.4 mmHg; NS-15: 10.9 ± 3.3 mmHg; NS-30: 11.7 ± 4.2 mmHg). No significant changes were observed in cerebral artery compliance or PI. Although ABP did not change in any stage, CBFv increased significantly (preinfusion: 67 ± 10 cm · s-1; NS-15: 72 ± 12 cm · s-1; NS-30: 73 ± 12 cm · s-1).DISCUSSION: Hypervolemia with hemodilution induced by rapid fluid infusion caused increases in nICP and CBFv. No changes were observed in cerebral artery compliance or PI related to cerebrovascular impedance. These findings suggest that rapid fluid infusion may raise ICP with increased CBF.Kurazumi T, Ogawa Y, Takko C, Kato T, Konishi T, Iwasaki K. Short-term volume loading effects on estimated intracranial pressure in human volunteers. Aerosp Med Hum Perform. 2022; 93(4):347-353.

The Impact of Aging on the Association Between Aortic Stiffness and Cerebral Pulsatility Index.

The central arteries dampen the pulsatile forces from myocardial contraction, limiting the pulsatility that reaches the cerebral vasculature, although there are limited data on this relationship with aging in humans. The purpose of this study was to determine the association between aortic stiffness and cerebral artery pulsatility index in young and older adults. We hypothesized that cerebral pulsatility index would be associated with aortic stiffness in older adults, but not in young adults. We also hypothesized that both age and aortic stiffness would be significant predictors for cerebral pulsatility index. This study included 23 healthy older adults (aged 62 ± 6 years) and 33 healthy young adults (aged 25 ± 4 years). Aortic stiffness was measured using carotid-femoral pulse wave velocity (cfPWV), while cerebral artery pulsatility index in the internal carotid arteries (ICAs), middle cerebral arteries (MCAs), and basilar artery were assessed using 4D Flow MRI. Cerebral pulsatility index was calculated as (maximum flow – minimum flow) / mean flow. In the combined age group, there was a positive association between cfPWV and cerebral pulsatility index in the ICAs (r = 0.487; p < 0.001), MCAs (r = 0.393; p = 0.003), and basilar artery (r = 0.576; p < 0.001). In young adults, there were no associations between cfPWV and cerebral pulsatility index in any of the arteries of interest (ICAs: r = 0.253; p = 0.156, MCAs: r = −0.059; p = 0.743, basilar artery r = 0.171; p = 0.344). In contrast, in older adults there was a positive association between cfPWV and cerebral pulsatility index in the MCAs (r = 0.437; p = 0.037) and basilar artery (r = 0.500; p = 0.015). However, the relationship between cfPWV and cerebral pulsatility index in the ICAs of the older adults did not reach the threshold for significance (r = 0.375; p = 0.078). In conclusion, age and aortic stiffness are significant predictors of cerebral artery pulsatility index in healthy adults. This study highlights the importance of targeting aortic stiffness in our increasingly aging population to reduce the burden of age-related changes in cerebral hemodynamics.

Evaluation of cardiac sphericity index among intrauterine growth restriction and normal fetuses

Foetal growth restriction (FGR) describes the pregnancy complications of pathological reduced foetal growth, leading to significant perinatal mortality and morbidity, and subsequent long-term cardiovascular outcomes. This prospective case-control study was performed on pregnant women referred to the hospitals of Tehran University of Medical Sciences in 2017–2019. All pregnant women underwent ultrasound scan and doppler sonography. FGR was defined as a sonographic estimation of foetal weight below the tenth percentile for a given gestational age. Cardiac sphericity index, including basal-apical length (BAL), transverse length (TL), global sphericity index (GSI), umbilical artery pulsatility index (PI), middle cerebral artery (MCA) PI and cerebroplacental ratio (CPR) were assessed. Mean gestational age in FGR and control groups were 233.90 ± 22.00 days and 229.00 ± 25.02 days, respectively. Foetal size index and estimated foetal weight in FGR foetuses were significantly lower than the control group (p < .05). BAL, TL and GSI were significantly affected by FGR (p = .0001, p = .018 and p = .0001, respectively). Abnormal GSI, MCA PI, umbilical artery PI and CPR were significantly more prevalent among FGR foetuses (p = .017, p = .0001, p = .0001 and p = .0001, respectively). Cardiac sphericity index, as well as uterine PI, MCA PI and CPR, were the determinants of FGR in foetuses with normal Doppler and abnormal GSI. IMPACT STATEMENT What is already known on this subject? Foetal growth restriction (FGR) describes the foetus that does not grow to its expected biological potential in utero, and is a relatively common complication of pregnancy. FGR is accosted with negative birth outcomes and long-term cardiovascular outcomes. One of the indicators of FGR is cardiac sphericity. What do the results of this study add? The findings of this study revealed that the cardiac sphericity index as well as umbilical PI, MCA PI and CPR ratio change in FGR foetuses. What are the implications of these findings for clinical practice and/or further research? It is recommended that more studies be performed to follow FGR foetuses longitudinally and evaluate the long-term cardiac abnormalities in infancy and childhood and compare it between FGR foetuses and normal foetuses.

Ratio of umbilical and cerebral artery pulsatility indices in assessment of fetal risk: numerator and denominator matter.

Ratio of umbilical and cerebral artery pulsatility indices in assessment of fetal risk: numerator and denominator matter.

Maternal Central Blood Pressure Is Associated with Fetal Middle Cerebral Artery Dopplers.

Cardiovascular adaptations to pregnancy involve physiological mechanisms that increase cardiac output, decrease total vascular resistance, and decrease both systolic and diastolic blood pressure (BP). These maternal hemodynamic changes modulate uteroplacental blood flow and fetal-placental Doppler indices. Our objective was to create maternal cardiac profiles of pregnant women using non-invasive measurements of central BP to identify changes in maternal-fetal hemodynamics as a surrogate to fetal status. This was a prospective cohort study of all singleton pregnancies in a perinatal referral center between January and April 2018. Central BP was measured non-invasively using the BP+ device. The BP+ device is a supra-systolic oscillometric central BP device, which measures BP waveforms peripherally and calculates central BP. We compared various BP+ values for peripheral BP with central BP and stratified by gestational age. We investigated the correlations between peripheral BP, central BP, estimated fetal weight (EFW), and the pulsatility indices (PI) of Doppler velocimetry and demonstrate that both central systolic and diastolic BP correlated to peripheral systolic and diastolic BP. Linear regression analysis confirmed that central BP predicts the middle cerebral artery (MCA) PI. The MCA PI correlated with EFW, specifically higher central systolic BP is associated with a lower MCA PI, implying a possible etiology of fetal brain shunting with poor placental perfusion. Future studies using predictors and markers of fetal outcomes from maternal cardiac parameters should consider maternal cardiovascular measurements to peripheral arterial BP.

Routine assessment of cerebroplacental ratio at 35–37 weeks’ gestation in the prediction of adverse perinatal outcome

Third-trimester studies in selected high-risk pregnancies have reported that low cerebroplacental ratio, due to high pulsatility index in the umbilical artery, and or decreased pulsatility index in the fetal middle cerebral artery, is associated with increased risk of adverse perinatal outcomes. To investigate the predictive performance of screening for adverse perinatal outcome by the cerebroplacental ratio measured routinely at 35-37 weeks' gestation. This was a prospective observational study in 47,211 women with singleton pregnancies undergoing routine ultrasound examination at 35+6 to 37+6 weeks' gestation, including measurement of umbilical artery-pulsatility index and middle cerebral artery-pulsatility index. The measured umbilical artery-pulsatility index and middle cerebral artery-pulsatility index and their ratio were converted to multiples of the median after adjustment for gestational age. Multivariable logistic regression analysis was used to determine whether umbilical artery-pulsatility index, middle cerebral artery-pulsatility index, and cerebroplacental ratio improved the prediction of adverse perinatal outcome that was provided by maternal characteristics, medical history, and obstetric factors. The following outcome measures were considered: (1) adverse perinatal outcome consisting of stillbirth, neonatal death, or hypoxic-ischemic encephalopathy grades 2 and 3; (2) presence of surrogate markers of perinatal hypoxia consisting of umbilical arterial or venous cord blood pH ≤7 and ≤7.1, respectively, 5-minute Apgar score <7, or admission to the neonatal intensive care unit for >24 hours; (3) cesarean delivery for presumed fetal compromise in labor; and (4) neonatal birthweight less than the third percentile for gestational age. First, the incidence of adverse perinatal outcome, presence of surrogate markers of perinatal hypoxia, and cesarean delivery for presumed fetal compromise in labor was greater in pregnancies with small for gestational age neonates with birthweight <10th percentile compared with appropriate for gestational age neonates; however, 80%-85% of these adverse events occurred in the appropriate for gestational age group. Second, low cerebroplacental ratio <10th percentile was associated with increased risk of adverse perinatal outcome, presence of surrogate markers of perinatal hypoxia, cesarean delivery for presumed fetal compromise in labor, and birth of neonates with birthweight less than third percentile. However, multivariable regression analysis demonstrated that the prediction of these adverse outcomes by maternal demographic characteristics and medical history was only marginally improved by the addition of cerebroplacental ratio. Third, the performance of low cerebroplacental ratio in the prediction of each adverse outcome was poor, with detection rates of 13%-26% and a false-positive rate of about 10%. Fourth, the detection rates of adverse outcomes were greater in small for gestational age than in appropriate for gestational age babies and in pregnancies delivering within 2 weeks rather than at any stage after assessment; however, such increase in detection rates was accompanied by an increase in the false-positive rate. Fifth, in appropriate for gestational age neonates, the predictive accuracy of cerebroplacental ratio was low, with positive and negative likelihood ratios ranging from 1.21 to 1.82, and0.92 to 0.98, respectively; although the accuracy was better in smallfor gestational age neonates, this was also low with positive likelihood ratios of 1.31-2.26 and negative likelihood ratios of 0.69-0.92. Similar values were obtained in fetuses classified as small for gestational age and appropriate for gestational age according to the estimated fetal weight. In pregnancies undergoing routine antenatal assessment at 35-37 weeks' gestation, measurement of cerebroplacental ratio provides poor prediction of adverse perinatal outcome in both small for gestational age and appropriate for gestational age fetuses.

Different vasodilatation characteristics among the main cerebral arteries in fetuses with congenital heart defects

To observe Doppler changes in the three main cerebral arteries in fetuses with congenital heart defects (CHDs). The pulsatility index (PI) values of the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) were prospectively compared in 78 CHD fetuses and 78 normal control fetuses. Correlations between the cerebral artery PIs and the neurodevelopment scores (psychomotor development index [PDI] and mental development index [MDI]) were assessed. The MCA-PI was decreased significantly in fetuses with hypoplastic left heart syndrome (HLHS). The ACA-PI was reduced significantly in fetuses with HLHS, fetuses with left-sided obstructive lesions (LSOLs) and fetuses with transposition of the great arteries. The PCA-PI was significantly smaller in fetuses with HLHS and fetuses with LSOLs. More fetuses presented signs of cerebral vasodilatation of the ACA than the MCA for certain types of CHD (P < 0.05). The ACA-PI was positively correlated with the PDI and MDI scores in fetuses with CHDs (r2 = 0.26, 0.20, P < 0.01). The MCA-PI was only positively correlated with the PDI scores (r2 = 0.15, P < 0.01). The ACA exhibited signs of vasodilatation more frequently and severely than the MCA. The ACA-PI appears to be more sensitive for predicting abnormal neurodevelopmental outcomes than the MCA-PI.

Color Doppler Imaging of Cerebral-Umbilical Pulsatility Ratio in Intrauterine Growth Retardation

Background: Intrauterine growth retardation (IUGR) refers to a condition in which a fetus is unable to achieve its genetically determined potential size. IUGR may also be defined as growth at the 10th or less percentile for weight of the all fetuses at that gestational age. It has long been recognized that impaired fetoplacental perfusion is associated with intrauterine growth retardation. Ultrasonography with Color Doppler has provided a new tool for this purpose.Objective: To evaluate the role of Color Doppler ultrasonography in the diagnosis of IUGR.Materials and Methods: This prospective study was carried out in the department of Radiology &amp; Imaging of Dhaka Medical College Hospital within a period of January 2010 to September 2011 on 90 patients aged between 17?35 years who were clinically suspected as cases of IUGR or previously USG diagnosed cases of IUGR.Results: The highest incidence of IUGR was found in the age group between 21?25 years. The mean gestational age at birth was 33.2 ± 3.5 weeks and mean birth weight 1.3 ± 6.2 kg in case of abnormal cerebral-umbilical (C/U) ratio group. According to cerebral-umbilical pulsatility index (PI) value 65 cases (72.2%) were diagnosed as abnormal and 25 (27.8%) as normal flow pattern. Perinatal findings showed that 67 were small for gestational age (SGA) and 23 had normal birth weight. The validity of cerebral-umbilical PI ratio for diagnosis of IUGR was studied by calculating sensitivity, specificity, accuracy, PPV and NPV.Conclusion: In this study Color Doppler findings of cerebral-umbilical vessels and the validity tests reveal that Color Doppler evaluation of middle cerebral artery (MCA) and umbilical artery (UA) PI ratio is an useful modality in diagnosis of IUGR.J Enam Med Col 2017; 7(3): 140-145

P25.03: Fetal umbilical/middle cerebral artery pulsatility indices and the cerebroplacental ratio (CPR) normograms at 16–40 weeks of gestation by polynomial regression analysis

P25.03: Fetal umbilical/middle cerebral artery pulsatility indices and the cerebroplacental ratio (CPR) normograms at 16–40 weeks of gestation by polynomial regression analysis

Abstract WP187: Subclinical Macro and Microvascular Disease in Stroke-free Subjects With Nonsustained Atrial Fibrillation

Introduction: Prevalence of nonsustained atrial fibrillation (NSAF), described as irregular atrial runs lasting shorter than 30-seconds, is higher in patients with ischemic stroke compared to stroke-free controls. Nonetheless, its role in causality of stroke and future cerebrovascular risk is still not established. Subclinical atherosclerotic burden and vascular stiffness are more prevalent, and have been shown to modify future risk of vascular events in patients with atrial fibrillation (AF). We aimed to determine the relationship between NSAF and subclinical atherosclerosis, vascular dysfunction and cerebral microvascular disease. Methods: Sonographic carotid distensibility metrics, carotid intima-media thickness (IMT), carotid plaque burden score (Ten Cate’s), middle cerebral artery (MCA) pulsatility index (PI) and cerebral white matter disease burden (Fazekas’ periventricular and subclinical scores) were studied in 263 stroke-free control subjects. 24-hour Holter monitoring documented NSAF in 27% of study population. Abnormality limits were set as mean±standard deviation. Results: Compared to those without NSAF (age 62±8 yr, 43% male), subjects with NSAF (age 67±9 yr, 31% male) had significantly higher total carotid plaque burden score (p=0.009) and significantly lower common carotid artery carotid distensibility (p=0.019). Maximum and averaged IMT, carotid stiffness and elastic modulus, and asymptomatic significant (≥50%) carotid artery stenosis were numerically higher. Patients with NSAF had significantly higher MCA PI (p=0.007) and numerically higher white matter disease scores. Regression analysis models showed that NSAF is one independent predictors of abnormal carotid distensibility (p=0.026) and presence of carotid plaque (p=0.023); but not for carotid plaque burden score (&gt;4), MCA PI (&gt;1.1) and IMT max (&gt;0.966). Conclusions: The presence of a significant relationship between NSAF and presence of carotid artery plaque and decreased cervical artery distensibility raises the possibility that NSAF might be a reflection of subclinical atherosclerotic burden. This crosstalk between surrogate markers might explain the higher prevalence of NSAF in ischemic stroke patients.

Evaluation of fetal middle cerebral artery Doppler indices in pregnancies with intrauterine growth restriction: A cross-sectional study

Background: Doppler velocimetry studies of placental and fetal circulation can provide important information regarding fetal well-being providing an opportunity to improve fetal outcome. Aims and Objective: The aim of this study to evaluate the role of color Doppler velocimetry of the fetal middle cerebral artery (MCA) velocity waveforms, systolic/diastolic ratio (S/D), pulsatility index (PI), and resistance index (RI) in intrauterine growth restriction (IUGR) pregnancies in II and III trimesters. Materials and Methods: This was a cross-sectional study. The control and study groups were studied in II and III trimesters. They were first subjected to ultrasonography biometry and then to MCA Doppler sonography. The statistical analysis was performed by “unpaired” and “paired” t-test. Results: In both control and study groups, the values of S/D ratio, PI, and RI in MCA decline during II to III trimester. The values were lower in the study group as compared to the control group. Thus that the present study predicts were; (a) lower PI values were suggestive of fetal hypoxia, (b) The lower values are due to vasodilatation due to hypoxia to supply more blood to the brain to protect it from the damaging effects of hypoxia. Thus, the brain is spared from damage. Conclusion: Doppler can be considered as one of the important non-invasive techniques to assess the fetomaternal and uteroplacental circulations. The MCA indices were valuable for predicting the outcome of IUGR pregnancies.

EP17.04: Pulsatility index of the uterine and cerebral arteries at 41 weeks of pregnancy

EP17.04: Pulsatility index of the uterine and cerebral arteries at 41 weeks of pregnancy

OP16.03: The influence of a standard breakfast meal on fetal middle cerebral and umbilical artery pulsatility indices

OP16.03: The influence of a standard breakfast meal on fetal middle cerebral and umbilical artery pulsatility indices

Abstract WP435: Changes in Pulsatility and Resistance Indices of Cerebral Arteriovenous Malformation Feeder Arteries After Embolization and Surgery

Introduction: Embolization reduces flow in cerebral arteriovenous malformations (AVMs) before surgical resection, but changes in pulsatility and resistance indices (PI, RI) are unknown. Here, we measure PI, RI in AVM arterial feeders pre- and post-embolization/surgery. Methods: Records of patients who underwent AVM embolization and surgical resection at our institution between 2007-2014 and had PI, RI, and flows obtained using quantitative magnetic resonance angiography were retrospectively reviewed. PI = [(systolic - diastolic flow velocity)/mean flow velocity] and RI = [(systolic - diastolic flow velocity)/systolic flow velocity]. Hemodynamic parameters were compared between the feeder and contralateral artery pre- and post-embolization/surgery. Results: 32 patients with 48 feeder arteries underwent embolization (mean 1.3 sessions). 32 patients with 49 feeder arteries had surgery with/without preoperative embolization. Before any treatment, flow volume rate and mean, systolic, diastolic flow velocities were significantly higher in feeders versus contralateral counterparts ( P &lt;0.001 for each parameter), and PI, RI were significantly lower in feeder compared to contralateral vessels ( P =0.003, P =0.002). After embolization, flow velocities within feeders were significantly higher than in the normal contralateral vessels, but PI, RI did not change significantly (Table). However, after surgery flow velocities within feeders decreased significantly and PI, RI normalized to match the indices of their contralateral counterparts (Table). Conclusions: Following partial AVM embolization, PI, RI are unchanged and flow velocities in feeder arteries increase significantly likely due to redistribution of flow through residual nidus. Complete surgical resection results in normalization of PI, RI and a concomitant decrease in flow velocities. Table: Changes in PI, RI after embolization and surgery.

Diffusion Tensor Imaging, Intracranial Vascular Resistance and Cognition in Middle-Aged Asymptomatic Subjects

Background: The contribution of traditional vascular risk factors to cognitive impairment and dementia is well known. However, in order to obtain possible targets for prevention of vascular cognitive impairment (VCI), it may be important to identify other early and noninvasive markers in asymptomatic middle-aged adults. The calculation of middle cerebral artery-pulsatility index (MCA-PI) is an ultrasonologic, noninvasive, validated and easily reproducible technique to assess increased distal resistance to blood flow. This study aims to assess the relationship between MCA-PI, microstructural white matter (WM) integrity and cognition in a middle-aged asymptomatic population. Methods: Ninety-five participants from the Barcelona-Asymptomatic Intracranial Atherosclerosis (AsIA) neuropsychology study were included. Subjects were 50-65 years old, free from dementia and without history of vascular disease. Transcranial color-coded duplex ultrasound examination was performed to assess MCA-PI as a measure of vascular resistance. WM integrity was evaluated by fractional anisotropy (FA) measurements of diffusion tensor images (DTI) acquired on a 3T-MRI. The neuropsychological battery was specifically selected to be sensitive to VCI, and included tests that were grouped into six cognitive domains: executive functioning, attention, verbal fluency, memory, visuospatial skills and psychomotor speed. A multivariate linear regression model adjusted for age, gender, years of education, diabetes and hypertension was performed. Results: MCA-PI was significantly associated with WM disintegration in different tracts (fornix, corticospinal and anterior thalamic), all p < 0.05 uncorrected. Both mean MCA-PI and mean FA of those significant tracts were independently associated with poor performance in attention, psychomotor speed, and visuospatial skills after adjustment for age, gender, years of education, and vascular risk factors (all p < 0.05). MCA-PI was independently associated with lower scores in all cognitive domains, except for visuospatial skills. Conclusions: Our data suggest that MCA-PI may be related to WM disintegration and early vascular cognitive impairment in middle-aged subjects. Although further prospective studies are needed to provide evidence for its validity in longitudinal studies, our results support the proposal of including MCA-PI as part of clinical assessment in order to identify targets for VCI prevention.

Plasma Total Homocysteine Level Is Associated with the Pulsatility Index of Cerebral Arteries in Lacunar Infarction

PurposeThe pulsatility index (PI), measured by transcranial Doppler (TCD), is a surrogate marker for distal vascular resistance in cerebral arteries, and elevated plasma total homocysteine (tHcyt) is regarded as a cause of ischemic stroke, including lacunar infarction. We investigated the relationship between the PI of cerebral arteries and plasma tHcyt in patients with lacunar infarction.Materials and MethodsPlasma tHcyt level and TCD examination were performed in 94 patients with lacunar infarction. Mean flow velocity (MFV) and PI were assessed at the ipsilateral middle cerebral artery (MCA) and contralateral MCA, relative to the infarction, and the basilar artery (BA). Multivariate regression analysis was conducted between log-transformed tHcyt levels (logHcyt) and the PI of individual arteries.ResultsThere was a significant correlation between logHcyt and the PI in all tested arteries (ipsilateral MCA: r=0.21, p=0.03; contralateral MCA: r=0.21, p=0.04; BA: r=0.35, p=0.01). In multivariate regression analysis, this significance remained unchanged after adjusting for vascular risk factors, creatinine, hematocrit and platelet count (ipsilateral MCA: β=0.26, p=0.01; contralateral MCA: β=0.21, p=0.04; BA: β=0.39, p=0.001). There was no significant association between logHcyt and MFV of individual arteries.ConclusionA significant association between plasma tHcyt and the PI of cerebral arteries indicates that homocysteine plays a role in the increase of distal arterial resistance in lacunar infarction.

Behavioural problems at the age of eleven years in preterm-born children with or without fetal brain sparing: A prospective cohort study

Background In severe intrauterine growth restriction (IUGR) due to placental insufficiency a haemodynamic adaptation occurs, resulting in preferential blood flow to the fetal brain (brain sparing). With Doppler ultrasound an increased ratio between the umbilical and the cerebral artery pulsatility index (U/C ratio) can be demonstrated. IUGR is associated with impaired neurodevelopmental outcome. Objective Evaluation of the effect of fetal brain sparing on behavioural problems at eleven years in premature born children. Methods Prospective cohort study in premature children born in 1989, with a gestational age of 26 0/7 to 33 0/7 weeks. An U/C ratio > 0.72 was defined as brain sparing. Behavioural problems were assessed with the parent-reported Child Behaviour Check List (CBCL) and the Teacher's Report Form (TRF). T scores > 60 for total problem score and subscales of internalizing and externalizing behaviour, were considered abnormal. Results Ninety-eight of the 116 survivors were assessed, of which 31 with antenatally established fetal brain sparing. According to the CBCL-total problem score 23.3% of the premature born babies in the brain sparing group had behavioural problems compared with 22.8% of those without brain sparing. According to the TRF-total problem score the percentages were 21.4% and 20.0%, respectively. Logistic regression analysis failed to show a significant association of U/C ratio with behavioural problems. In this model oxygen dependency at 28 days, IQ < 85 at five years, cranial ultrasound abnormalities, fetal growth ratio < 0.80, Apgar scores < 7 after 5 min and birth weight < p10 contributed significantly. Conclusion In this cohort brain sparing itself has no significant association with behavioural problems at eleven years.

Longitudinal brain perfusion changes in near-term small-for-gestational-age fetuses as measured by spectral Doppler indices or by fractional moving blood volume

The objective of this study was to compare the temporal sequence of fetal brain hemodynamic changes in near-term small-for-gestational-age fetuses as measured by spectral Doppler indices or by fractional moving blood volume. Cerebral tissue perfusion measured by fractional moving blood volume, cerebroplacental ratio, anterior cerebral artery, and middle cerebral artery pulsatility indices were weekly performed in a cohort of singleton consecutive small-for-gestational-age fetuses with normal umbilical artery delivered after 37 weeks of gestation. A total of 307 scans were performed on 110 small-for-gestational-age fetuses. Mean gestational age at diagnosis and at delivery was 35.7 and 38.6 weeks, respectively. The proportion of fetuses with abnormal fractional moving blood volume, cerebroplacental ratio, anterior cerebral artery-pulsatility index, and middle cerebral artery-pulsatility index values was 31.3%, 16.8%, 17.2%, and 10.8% at 37 weeks of gestation and 42.7%, 23.6%, 20.9%, and 16.4% before delivery. The presence of brain redistribution in small-for-gestational-age fetuses was detected earlier and in a higher proportion of fetuses using cerebral tissue perfusion rather than spectral Doppler indices.

Homocysteine and Pulsatility Index of Cerebral Arteries

A pulsatility index (PI) represents vascular resistance distal to an examined artery. The purpose of the present study was to evaluate an association between plasma total homocysteine (tHcy) and PIs of the cerebral arteries in patients with ischemic stroke. Consecutive patients with ischemic stroke referred to a neurovascular ultrasound laboratory were evaluated from March 2007 to February 2008. PI was defined as (peak systolic velocity-end-diastolic velocity)/mean flow velocity as recommended. Transcranial Doppler was examined in both middle cerebral arteries and vertebral arteries, and basilar arteries. All patients with ischemic stroke were subdivided according to the presence of proximal internal carotid arterial steno-occlusion (ICS). The numbers of patients enrolled for the present analysis as ischemic stroke without and with ICS were 272 and 92, respectively. PIs measured in the cerebral arteries did not show a significant difference in the two groups, in spite of the fact that mean flow velocities of both basilar arteries and vertebral arteries were significantly elevated in the patients with ICS. Plasma tHcy was found to be independently associated with graded increases of PIs in all cerebral arteries in the patients without ICS, even adjusted for the potential confounders. However, there was no association between tHcy and PI in the patients with ICS. Plasma tHcy was directly associated with increased cerebral arterial resistance. But in clinical situations when the cerebral arterial hemodynamics were altered as in the patients with ICS, the effect of tHcy on arterial remodeling could be obscured.