Abnormal volumetric brain morphometry and cerebral blood flow in adolescents with depression

BACKGROUND Prior research has demonstrated that the brains of adolescents with depression exhibit distinct structural alterations.However,preliminary studies have documented the pathophysiological changes in certain brain regions,such as the cerebellum,highlighting a need for further research to support the current understanding of this disease.AIM To study brain changes in depressed adolescents.METHODS This study enrolled 34 adolescents with depression and 34 age-,sex-,and education-level-matched healthy control(HC)individuals.Structural and functional alterations were identified when comparing the brains of these two participant groups through voxel-based morphometry and cerebral blood flow(CBF)analysis,respectively.Associations between identified brain alterations and the severity of depressive symptoms were explored through Pearson correlation analyses.RESULTS The cerebellum,superior frontal gyrus,cingulate gyrus,pallidum,middle frontal gyrus,angular gyrus,thalamus,precentral gyrus,inferior temporal gyrus,superior temporal gyrus,inferior frontal gyrus,and supplementary motor areas of adolescents with depression showed an increase in brain volume compared to HC individuals.These patients with depression further presented with a pronounced drop in CBF in the left pallidum(group=98,and peak t=-4.4324),together with increased CBF in the right percental gyrus(PerCG)(group=90,and peak t=4.5382).In addition,17-item Hamilton Depression Rating Scale scores were significantly correlated with the increased volume in the opercular portion of the left inferior frontal gyrus(r=-0.5231,P<0.01).CONCLUSION The right PerCG showed structural and CBF changes,indicating that research on this part of the brain could offer insight into the pathophysiological causes of impaired cognition.

Characteristics of traumatic brain injury models:from macroscopic blood flow changes to microscopic mitochondrial changes

Controlled cortical impingement is a widely accepted method to induce traumatic brain injury to establish a traumatic brain injury animal model.A strike depth of 1 mm at a certain speed is recommended for a moderate brain injury and a depth of>2 mm is used to induce severe brain injury.However,the different effects and underlying mechanisms of these two model types have not been proven.This study investigated the changes in cerebral blood flow,differences in the degree of cortical damage,and differences in motor function under different injury parameters of 1 and 2 mm at injury speeds of 3,4,and 5 m/s.We also explored the functional changes and mitochondrial damage between the 1 and 2 mm groups in the acute(7 days)and chronic phases(30 days).The results showed that the cerebral blood flow in the injured area of the 1 mm group was significantly increased,and swelling and bulging of brain tissue,increased vascular permeability,and large-scale exudation occurred.In the 2 mm group,the main pathological changes were decreased cerebral blood flow,brain tissue loss,and cerebral vasospasm occlusion in the injured area.Substantial motor and cognitive impairments were found on day 7 after injury in the 2 mm group;at 30 days after injury,the motor function of the 2 mm group mice recovered significantly while cognitive impairment persisted.Transcriptome sequencing showed that compared with the 1 mm group,the 2 mm group expressed more ferroptosis-related genes.Morphological changes of mitochondria in the two groups on days 7 and 30 using transmission electron microscopy revealed that on day 7,the mitochondria in both groups shrank and the vacuoles became larger;on day 30,the mitochondria in the 1 mm group became larger,and the vacuoles in the 2 mm group remained enlarged.By analyzing the proportion of mitochondrial subgroups in different groups,we found that the model mice had different patterns of mitochondrial composition at different time periods,suggesting that the difference in the degree of damage among traumatic brain injury groups may reflect the mitochondrial changes.Taken together,differences in mitochondrial morphology and function between the 1 and 2 mm groups provide a new direction for the accurate classification of traumatic brain injury.Our results provide reliable data support and evaluation methods for promoting the establishment of standard mouse controlled cortical impingement model guidelines.

Measurements Of Cerebral Blood Flow in Postasphyxiated Newborns by Color Doppler Imaging（CDI）

Cerebral blood flow of 10 asphyxiated term newborns was continuously measured during the first 7 days of life and compared with that of 10 normal term infants by CDI. Frequency spectrum and blood flow variables in the anterior, middle and posterior cerebral arteries were studied. The results showed evidently lower systolic amplitude in patients than that in normal subjects. End diastolic amplitude was zero in part of vessels, and values of bloed flow variables were all lower in day 1 of the life as compared with the control groups. Frequency spectrum recovered to normal patterns in 9 survived infants in day 2. but blood flow variables recovered to normal by day 7. Values of resistance index (RI) rose to 1 in some vessels of moderate hypoxic ischemic encephalopathy (HIE) infants and stayed at 1 in the severe HIE infants. It is concluded that low CBF plays a key role in brain damage of post-asphyxiated newborns and RI may be an important parameter in the evaluation prognosis.

Hyperbaric oxygen therapy for cerebral blood flow and electroencephalogram in patients with acute cerebral infarction Choice for therapeutic occasion

BACKGROUND： Hyperbaric oxygen （HBO） therapy increases blood oxygen content, changes cerebral blood flow （CBF） and cerebral metabolism. Its therapeutic effects on cerebrovascular disease have been fully confirmed, but the occasion for HBO therapy is still unclear. OBJECTIVE： To observe the therapeutic effects of HBO therapy at different time on CBF and electroencephalogram （EEG） in patients with acute cerebral infarction （CI）. DESIGN： Randomized controlled trial. SETTING： Department of Neurology, Shidong Hospital, Yangpu District of Shanghai. PARTICIPANTS： Ninety-six inpatients with acute CI, admitted to Department of Neurology, Shidong Hospital, Yangpu District of Shanghai from January 2001 to December 2006, were involved in this experiment. The involved participants met the diagnosis criteria of acute CI and confirmed by skull CT or MRI. They all were patients with moderate CI （16- 30 points） according to neurologic deficit score formulated by Chinese Medical Association. Informed consents of detected items and therapeutic regimen were obtained from all the involved participants. They were randomized into two groups with 48 in each： early-stage treatment group and advanced-stage treatment group. Among the 48 patients in the early-stage treatment group, 21 male and 27 female, aged 53 -68 years, 22 patients were found with basal ganglia infarction, 10 with brain lobe infarction, 16 with multiple infarction, 27 accompanied with hypertension and 2 accompanied with diabetes meUitus. Among the 48 patients in the advanced-stage treatment group, 23 male and 25 female, aged 52 - 71 years, 25 patients were found with basal ganglia infarction, 10 with brain lobe infarction, 12 with multiple infarction, 1 with brain stem infarction, 28 accompanied with hypertension and 1 accompanied with diabetes mellitus. METHODS： After admission, patients of two groups received routine drug treatment. ① Patients in the early-stage treatment group and advanced-stage treatment group began to receive HBO therapy within one week of CI and 4 weeks after CI, respectively. The total course of treatment both was 2 weeks. EEG examination was carried out before and after therapy, and CBF was determined with ^133Xe inhalation.② Assessment criteria of curative effects： Basically cured： neurologic symptoms and body signs disappeared, could work and do housework; Markedly effective： score of neurologic deficit was decreased by over 21 points, could manage himself/herself partially; Effective： score of neurologic deficit was decreased by 8 to 12 points; Non-effective： Score was increased or decreased less than 8 points, neurologic deficit was worsened, even died. Total effective rate = （number of cured＋number of markedly effective＋number of effective）/ number of total cases ×100%. ③ t test and Chi-square test were used for comparing the difference of measurement data and enumeration data respectively, and Ridit analysis was used for comparing the difference of clinical curative effects. MAIN OUTCOME MEASURES： ① Comparison of EEG and CBF of patients from two groups before and after treatment. ②Comparison of post-treatment neurologic deficit of patients between two groups. RESULTS： All the involved 96 patients with CI participated in the final analysis. ① Clinical symptoms of patients from two groups after therapy were significantly improved as compared with those before therapy, and curative effects of early treatment group were better than those of advanced treatment group （ U = 1.99, P 〈 0.05 ） . ②After treatment, CBF in each region of brains, except for that in parietal lobe of patients in the advanced-stage treatment group, was significantly improved （P 〈 0.05 - 0.01）; The improvement of CBF of patients in the early-stage treatment group was more obvious than that in the early-stage treatment group （P 〈 0.05 - 0.01）. ③ The abnormal rate of EEF of patients from early-stage treatment group and advanced-stage treatment group before treatment was 94% and 96%, respectively. After treatment, improvement rate of EEG of patients in the early-stage treatment groulp was 95%, which was significantly different from that in the advanced-stage treatment group （82%, x^2=4.32, P 〈 0.05 ） CONCLUSION： HBO therapy both at early and advanced stages of CI （within 1 week and 4 weeks after CI attack） can improve CBF and EEG of patients with early CI, especially.

Pulsed arterial spin labeling effectively and dynamically observes changes in cerebral blood flow after mild traumatic brain injury

Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury remain poorly understood. This study sought to observe changes in cerebral blood flow in different regions after mild traumatic brain injury using pulsed arterial spin labeling. Our results demonstrate maximal cerebral blood flow in gray matter and minimal in the white matter of patients with mild traumatic brain injury. At the acute and subacute stages, cerebral blood flow was reduced in the occipital lobe, parietal lobe, central region, subcutaneous region, and frontal lobe. Cerebral blood flow was restored at the chronic stage. At the acute, subacute, and chronic stages, changes in cerebral blood flow were not apparent in the insula. Cerebral blood flow in the temporal lobe and limbic lobe diminished at the acute and subacute stages, but was restored at the chronic stage. These findings suggest that pulsed arterial spin labeling can precisely measure cerebral blood flow in various brain regions, and may play a reference role in evaluating a patient＇s condition and judging prognosis after traumatic brain injury.

A New Method for Evaluating Regional Cerebral Blood Flow Changes:Laser Speckle Contrast Imaging in a C57BL/6J Mouse Model of Photothrombotic Ischemia

The present study aimed to improve the processing of data acquired from laser speckle contrast imaging（LSCI） to provide a standardization method to explore changes in regional cerebral blood flow（r CBF） and to determine the correlations among r CBF, cerebral ischemic lesion volume and microvascular density over time in a focal ischemic region. C57BL/6J mice were subjected to focal photothrombotic（PT） ischemia. r CBF was measured using LSCI at different time points before and after PT ischemia through an intact skull. Standardized r CBF（Sr CBF）, defined as the ratio of r CBF measured in the ipsilateral region of interest（ROI） to that in the corresponding contralateral region, was calculated to evaluate potential changes. In addition, the volume of the ischemic lesion and the microvascular density were determined using Nissl staining and immunofluorescence, respectively. The relationships among the ischemic lesion volume, microvascular density and Sr CBF were analyzed over time. The results showed that the cortical r CBF measured using LSCI following PT ischemia in the C57BL/6J mice gradually increased. Changes in the cerebral ischemic lesion volume were negatively correlated with Sr CBF in the ischemic region. Changes in the microvascular density were similar to those observed in Sr CBF. Our findings indicate that LSCI is a practical technique for observing changes in murine cortical r CBF without skull opening and for analyzing the relationships among the ischemic lesion volume, microvascular density and Sr CBF following focal cerebral ischemia. Preliminary results also suggest that the use of LSCI to observe the formation of collateral circulation is feasible.

Electroacupuncture induces acute changes in cerebral cortical mi RNA profile, improves cerebral blood flow and alleviates neurological deficits in a rat model of stroke

Electroacupuncture has been shown to improve cerebral blood flow in animal models of stroke. However, it is unclear whether electroacupuncture alters mi RNA expression in the cortex. In this study, we examined changes in the cerebral cortical mi RNA profile, cerebral blood flow and neurological function induced by electroacupuncture in a rat model of stroke. Electroacupuncture was performed at Renzhong（GV26） and Neiguan（PC6）, with a frequency of 2 Hz, continuous wave, current intensity of 3.0 m A, and stimulation time of 1 minute. Electroacupuncture increased cerebral blood flow and alleviated neurological impairment in the rats. mi RNA microarray profiling revealed that the vascular endothelial growth factor signaling pathway, which links cell proliferation with stroke, was most significantly affected by electroacupuncture. Electroacupuncture induced changes in expression of rno-mi R-206-3p, rno-mi R-3473, rno-mi R-6216 and rno-mi R-494-3p, and these changes were confirmed by quantitative real-time polymerase chain reaction. Our findings suggest that changes in cell proliferation-associated mi RNA expression induced by electroacupuncture might be associated with the improved cerebral blood supply and functional recovery following stroke.

REAL-TIME MONITORING OF MITOCHONDRIAL FUNCTION AND CEREBRAL BLOOD FLOW FOLLOWING FOCAL ISCHEMIA IN RATS

Focal ischemia due to reduction of cerebral blood flow(CBF),creates 2 zones of damage:the core area,which suffers severe damage,and penumbra area,which surrounds the core and suffers intermediate levels of injury.Objectives:A novel method is introduced,which evaluates mitochondrial function in the core and in the penumbra,during focal cerebral ischemia.Methods:Wistar rats underwent focal cerebral ischemia by middle cerebral artery occlusion(MCAO)for 60 minutes,followed by 60 minutes of reperfusion.Mitochondrial function was assessed by a unique Multi-Site—Multi-Parametric(MSMP)monitoring system,which measures mitochondrial NADH using fluorometric technique,and CBF using Laser Doppler Flowmetry(LDF).Results:At the onset of occlusion,CBF dropped and NADH increased significantly only in the right hemisphere.CBF levels were significantly lower and NADH significantly higher in the core than in the penumbra.After reperfusion,CBF and NADH recovered correspondingly to the intensity of ischemia.Conclusion:Application of the MSMP system can add significant information for the understanding of the cerebral metabolic state under ischemic conditions,with an emphasis on mitochondrial function.

3D-ASL的rCBF max值在儿童后颅窝肿瘤鉴别诊断中的价值

目的:探讨三维动脉自旋标记成像(3D-ASL)参数rCBF_(max)对儿童后颅窝肿瘤的诊断价值。方法:回顾性分析2018年1月-2022年12月在本院经手术病理证实的52例后颅窝肿瘤患儿的临床和术前MRI资料(平扫、增强和3D-ASL)。其中,髓母细胞瘤28例,毛细胞星形细胞瘤11例,室管膜瘤13例。测量肿瘤实性区域的最大脑血流量(CBF_(max))值,并计算最大相对脑血流量(rCBF_(max)=CBF_(max)/CBF_(健侧正常脑灰质))。采用Kruskal-Wallis检验比较3组肿瘤的rCBF_(max)值,采用ROC曲线和约登指数来确定rCBF_(max)鉴别肿瘤病理类型的最佳阈值、敏感度、特异度和曲线下面积(AUC)。结果:室管膜瘤的rCBF_(max)值最高,为1.53(1.27,2.04),毛细胞星形细胞瘤的rCBF_(max)值最低,为0.69(0.56,0.76),髓母细胞瘤的rCBF_(max)值为0.90(0.84,1.00)。三组肿瘤的rCBF_(max)值比较,差异有统计学意义(P<0.001)。ROC曲线分析显示鉴别室管膜瘤与髓母细胞瘤的rCBF_(max)最佳阈值为1.13,相应的诊断敏感度为100%,特异度为82.1%,AUC为90.7%;鉴别髓母细胞瘤与毛细胞星形细胞瘤的rCBF_(max)最佳阈值为0.80,相应的诊断敏感度为85.7%,特异度为100%,AUC为97.1%。结论:3D-ASL定量参数rCBF_(max)对常见儿童后颅窝肿瘤的鉴别诊断具有较高的临床应用价值。

CLINICAL OBSERVATION ABOUT THE EFFECT OF BLOOD-LETTING OF JING-POINTS ON CEREBRAL BLOOD FLOW IN STROKE PATIENTS AT THE EARLY STAGE AND EXPERIMENTAL STUDY ON ITS MECHANISMS IN THE RABBIT

In this paper, the authors sum their research results about the effect of blood-letting of Jing (Well)-point on cerebral blood flow both in stroke patients and in experimental cerebral ischemia, cerebral hematoma and hypertension rabbits. In 30 cases of stroke (cerebral hemorrhage and cerebral infarction) patients, blood flow state of the anterior cerebral artery (ACA), middle cerebral artery (MCA) and the posterior cerebral artery (PCA), and the blood flow velocity of the bilateral vertebral artery (VA) and the basil artery (BA) are determined before and after pricking blood of the Twelve Jing-points. In experimental cerebral ischemia (by occlusion of the common carotid artery) rabbits, cerebral hematoma model rabbits and intravenous injection of noradrenaline induced hypertension rabbits, rheoencephalogram (REC) is detected before and after blood letting of the twelve "Jing"-points. In these 30 stroke patients, ultrasound Doppler examination’s results show that in 22 cases (73.33%) whose blood flow velocity decreases, after blood-letting of the 12 Jing-points, it increases significantly (P<0.01); in the rest 8 cases ( 26.67%) whose blood flow velocity speeds up, after treatment, it decreases evidently (P<0.01), showing a good dual-directional regulative effect of blood-letting therapy. In experimental cerebral ischemia rabbits, cerebral hematoma rabbits and hypertension rabbits whose REG lowers in the amplitude apparently (P<0.01), after blood letting stimulation of the 12 Jing-points, it increases at different degrees. Three patterns of stimulation as blood letting stimulation, pain stimulation and Jing-point stimulation, also the 3 factors of blood-letting therapy, may contribute to their effect on improvement of the cerebral blood flow. Somatic afferent nerve, sympathetic nerve of the vascular wall, central cholinergic nerve (M receptors) and adrenergic nerve (α receptors) participate in the effect of blood letting on cerebral blood flow.

Improvement of regional cerebral blood flow after oral intake of ranched-chain amino acids in patients with cirrhosis

AIM: To evaluate the effect of oral intake of branchedchain amino acids (BCAA) on brain perfusion in patients with liver cirrhosis.METHODS: Single photon emission computed tomography scans were performed in 43 patients with cirrhosis and in 15 age-matched healthy subjects.Twenty-nine out of forty-three patients were randomly treated with either BCAA granules or placebo, and single photon emission computed tomography was performed before and after the treatment. We measured the regional cerebral blood flow values using a threedimensional stereotaxic region of interest template.RESULTS: Cirrhotic patients had regions of significant hypoperfusion in the bilateral central (right P=0.039,P＜0.05; left P = 0.006 P＜0.01), parietal (right P=0.018, P＜0.05;left P=0.009, P＜0.01), angular (right P=0.039, P＜0.05;left P = 0.008, P＜0.01), and left pericallosal segments (P= 0.038 P＜0.05) as compared with healthy subjects. A significant increase in cerebral perfusion was observed 70 min after the oral intake of BCAA in the angular (right P=0.012,P＜0.05;left P=0.049, P＜0.05), temporal (right P=0.012, P＜0.05; left P=0.038, P＜0.05), pericallosal segments (right P = 0.025,P＜0.05; left P = 0.049, P＜0.05) and left precentral (P=0.044, P＜0.05), parietal (P=0.040, P＜0.05) and thalamus (P=0.033, P＜0.05). No significant change in perfusion was observed in the placebo group.CONCLUSION: Administration of BCAA rapidly improves cerebral perfusion.

Clinical Efficacy of Modified Erchen Decoction on Cervical Spondylotic Vertebral Arteriopathy with Stagnation and Blockade of Phlegm-dampness Syndrome and Effects on Cerebral Blood Flow Parameters

OBJECTIVE: To observe the effect of Modified Erchen Decoction on cervical spondylotic vertebral arteriopathy with stagnation and blockade of phlegm-dampness syndrome and effects on cerebral blood flow parameters. METHODS: A total of 80 cervical spondylotic vertebral arteriopathy(CSA) patients with stagnation and blockade of phlegmdampness syndrome admitted to our hospital from October 2016 to April 2017 were selected and randomly divided into observation group and control group, with 40 cases in each group. The observation group was treated with Modified Erchen Decoction and the control group was given conventional treatment with Western medicine. After 4 weeks of treatment, the main clinical symptoms and signs(vertigo, neck and shoulder pain, headache, psychological and social adjustment, daily life and work) and cerebral blood flow parameters [the peak values of intracranial vertebral-basal artery diastolic blood flow velocity(Vd) and systolic blood flow velocity(Vp)] were compared between the 2 groups. The total clinical effective rate and adverse reactions during treatment were also compared. RESULTS: After treatment, the total effective rate of the observation group was 90.0%, which was significantly higher than that of the control group(77.5%). The difference between the two groups was statistically significant(P < 0.05). After treatment, The scores of vertigo, neck and shoulder pain, headache, psychology and society adaptation, daily life and work were significantly increased(P < 0.05), and the above scores of the observation group were increased more obviously. The difference between the groups was statistically significant(P < 0.05). After treatment, the levels of Vd and Vp were significantly increased(P < 0.05), and the increase of the above indexes was more obvious in the observation group. The difference between the 2 groups was statistically significant(P < 0.05). There were no significant abnormalities in blood routine, urine routine, liver function and renal function. There was no significant difference in the incidence of adverse reactions between the 2 groups.(P > 0.05). CONCLUSION: The treatment of vertebral artery type cervical spondylopathy with stagnation and blockade of phlegm-dampness syndrome by Modified Erchen Decoction can effectively relieve the main clinical symptoms and signs, improve cerebral blood flow parameters, and improve the peak values of vertebral-basal artery diastolic blood flow velocity(Vd) and systolic blood flow velocity(Vp), which is safe and effective, and helps to promote the recovery of cervical function.

CEREBRAL BLOOD FLOW AND METABOLISM EVALUATION IN COMATOSE PATIENTS BY DYNAMIC SPECT

Thirty patients in coma state underwent dynamic SPECT with 133Xe, a validated technique for the quantitation of CBF by SPECT, using a new brain dedicated tomograph: CERTO-96. CMRO2 was computed by multiplying the mean CBF by AVDO2 according to the Fick’s principle. The mean values of CBF, AVDO2 and CMRO2 in patients with good outcome were significantly different from those with worse outcome. On the basis of the best "discriminant threshold", CBF and AVDO2 demonstrated an intermediate accuracy in separating the two groups, while CMRO2 showed a satisfactory accuracy.

Relationship between ultrasound parameters of the umbilical and middle cerebral arteries and intrauterine fetal distress

BACKGROUND By comprehensively analyzing the blood flow parameters of the umbilical and middle cerebral arteries,doctors can more accurately identify fetal intrauterine distress,as well as assess its severity,so that timely interventions can be implemented to safeguard the health and safety of the fetus.AIM To identify the relationship between ultrasound parameters of the umbilical and middle cerebral arteries and intrauterine distress.METHODS Clinical data of pregnant women admitted between January 2021 and January 2023 were collected and divided into the observation and control groups(n=50 each),according to the presence or absence of intrauterine distress.The ultrasound hemodynamic parameters of the uterine artery(UtA),fetal middle cerebral artery(MCA),and umbilical artery(UmA)were compared with neonatal outcomes and occurrence of intrauterine distress in the two groups.RESULTS Comparison of ultrasonic hemodynamic parameters,resistance index(RI),pulsatility index(PI),and systolic maximal blood flow velocity of UmA compared to diastolic blood flow velocity(S/D),revealed higher values of fetal MCA,PI,and S/D of UmA in pregnant women with UtA compared to controls(P<0.05),while there was no difference between the two groups in terms of RI(P<0.05)The incidence of a neonatal Apgar score of 8-10 points was lower in the observation group(66.7%)than in the control group(90.0%),and neonatal weight(2675.5±27.6 g)was lower than in the control group(3117.5±31.2 g).Further,cesarean section rate was higher in the observation group(70.0%)than in the control group(11.7%),and preterm labor rate was higher in the observation group(40.0%)than in the control group(10.0%).The incidence of fetal distress,neonatal growth restriction and neonatal asphyxia were also higher in the observation group(all P<0.05).CONCLUSION Fetal MCA,UmA,and maternal UtA hemodynamic abnormalities all develop in pregnant women with intrauterine distress during late pregnancy,which suggests that clinical attention should be paid to them,and monitoring should be strengthened to provide guidance for clinical intervention.

Optimal velocity encoding during measurement of cerebral blood flow volume using phase-contrast magnetic resonance angiography

This study investigated the effect of velocity encoding on measurement of brain blood flow and blood volume of inflow and outflow using phase-contrast magnetic resonance angiography. A single two-dimensional phase-contrast magnetic resonance angiography slice was applied perpendicular to the internal carotid artery and the vertebral artery at C2 level. For each subject, the velocity encoding was set from 30 to 90 cm/s with an interval of 10 cm/s for a total of seven settings. Various velocity encodings greatly affected blood flow volume, maximal blood flow velocity and mean blood flow velocity in the internal carotid artery, but did not significantly affect vertebral arteries and jugular veins. When velocity encoding was 60-80 cm/s, the inflow blood volume was 655 _＋ 118 mL/min, and the outflow volume was 506 _＋ 186 mL/min. The ratio of outflow/inflow was steady at 0.78-0.83, and there was no aliasing in any of the images. These findings suggest that velocity encodings of 60 80 cm/s should be selected during measurement of cerebral blood flow volume using phase-contrast magnetic resonance angiography.

Enhancing hippocampal blood flow after cerebral ischemia and vasodilating basilar arteries:in vivo and in vitro neuroprotective effect of antihypertensive DDPH

1-（2,6-Dimethylphenoxy）-2-（3,4-dimethoxyphenylethylamino）-propane hydrochloride （DDPH） is a novel antihypertensive agent based on structural characteristics of mexiletine and verapamine. We investigated the effect of DDPH on vasodilatation and neuroprotection in a rat model of cerebral ischemiain vivo, and a rabbit model of isolated basilar arteriesin vitro. Our results show that DDPH （10 mg/kg） significantly increased hippocampal blood flowin vivo in cerebral ischemic rats, and exerted dose-dependent relaxation of isolated basilar arteries contracted by histamine or KCl in thein vitro rabbit model. DDPH （3 × 10–5 M） also inhibited histamine-stimulated extracellular calcium inlfux and intracellular calcium release. Our ifndings suggest that DDPH has a vasodilative effect bothin vivo andin vitro, which mediates a neuropro-tective effect on ischemic nerve tissue.

Blood-brain barrier and cerebral blood flow: Age differences in hemorrhagic stroke

Neonatal stroke is similar to the stroke that occurs in adults and produces a significant morbidity and long-term neurologic and cognitive deficits.There are important differences in the factors,clinical events and outcomes associated with the stroke in infants and adults.However,mechanisms underlying age differences in the stroke development remain largely unknown.Therefore,treatment guidelines for neonatal stroke must extrapolate from the adult data that is often not suitable for children.The new information about differences between neonatal and adult stroke is essential for identification of significant areas for future treatment and effective prevention of neonatal stroke.Here,we studied the development of stress-induced hemorrhagic stroke and possible mechanisms underlying these processes in newborn and adult rats.Using histological methods and magnetic resonance imaging,we found age differences in the type of intracranial hemorrhages.Newborn rats demonstrated small superficial bleedings in the cortex while adult rats had more severe deep bleedings in the cerebellum.Using Doppler optical coherent tomography,we found higher stress-reactivity of the sagittal sinus to deleterious effects of stress in newborn vs.adult rats suggesting that the cerebral veins are more vulnerable to negative stress factors in neonatal vs.adult brain in rats.However,adult but not newborn rats demonstrated the stroke-induced breakdown of blood brain barrier(BBB)permeability.The one of possible mechanisms underlying the higher resistance to stress-related stroke injures of cerebral vessels in newborn rats compared with adult animals is the greater expression of two main tight junction proteins of BBB(occludin and claudin-5)in neonatal vs.mature brain in rats.

Characterization of cerebral blood flow dynamics with multiscale entropy

Based on the laser speckle contrast imaging(LSCI)and the multiscale entropy(MSE),we study in this work the blood flow dynamics at the levels of cerebral veins and the surrounding network of microcerebral vessels.We discuss how the phenylephrine-related acute peripheral bypertension is refected in the cerebral circulation and show that the observed changes are scale dependent,and they are signifcantly more pronounced in microcerebral vessels,while the macrocerebral dynamics does not demonstrate authentic inter-group distinctions.We also consider the permeability of blood-brain barrier(BBB)and study its opening caused by sound exposure.We show that alterations associated with the BBB opening can be revealed by the analysis of blood flow at the level of macrocerebral vessels.

Cerebral Blood Flow Measurement in the Assessment of Post-Traumatic Cerebral Contusions

Brain trauma (BT) is extremely common in the Western society, and has been identified as the main cause of death and disability in the under-40 age group. Many aspects of the pathophysiological mechanisms involved and the effect of changes in cerebral metabolism are unclear. The aim of this study was to establish the rela- tionship between anatomical changes and deranged cerebral perfusion in patients with cerebral contusions, using Computed Tomography (CT) and Single Proton Emission Computed Tomography (SPECT). Twenty- two (22) patients who had suffered BT were recruited. All patients underwent SPECT and CT head scans on the same day. 18 were men. Patient average age was 45.6. Patients were assessed using the Glasgow scale (average 10.6). Cause of trauma included traffic accidents (9 patients) and falls (13 patients). A 4-slice spiral CT scan was performed. For each contusion, areas of bleeding, edema, and healthy perilesional tissue were distinguished. SPECT was performed with 20 mCi of 99 mTcECD using a dual-head gamma camera (128 × 128 matrix). CT scan revealed a single lesion in 12 patients, and more than one lesion in 10. The biggest le- sions found on CT were located in the frontal region in 13 patients;temporal region in 4;and parietal region in 1;four patients had poorly defined lesions. A total absence of perfusion was visible in 18 patients in the hemorrhagic area and in 14 patients in the edema, In 7 cases SPECT showed hypoperfusion that did not cor- respond to any morphological changes on the CT scan. Quantitative of fused lesions appearing on both CT scan and SPECT revealed severe perfusion defects in the hemorrhagic area (17.8%) and in the edema (29.4%). In our study, regional cerebral blood flow add relevant information on encephalic damage in pa- tients with BT.

Role of the Peripheral Sympathetic Innervations in Controlling Cerebral Blood Flow after the Transection of Bilateral Superior Cervical Sympathetic Ganglia Two Weeks Later

Background: Cerebral blood vessels are mainly supplied by sympathetic nerves arising from the superior cervical ganglia and cerebral blood volume may be influenced by bilateral superior cervical ganglionectomy (SCG). Various stages of cerebral blood volume changes depended on the time following bilateral excision of SCG. In this study, we emphasize the subacute effect (two weeks) on the local cerebral blood flow (LCBF). Material and Methods: Sprague-Dawley rats weighing 250 ~ 400 gm (n = 20) were selected into two groups. Under the ambient temperature 20oC, the first group animals (n = 10) received sham operation and the other group animals (n = 10) underwent bilateral SCG. The LCBF and O2 delivery of 14 brain struc-tures were measured for each animal by the use of 14C-iodoantipyrine technique two weeks after the opera-tion. Results: The average of LCBF was decreased from 150 ml/100 gm/min to 129 ml/100 gm/min after bi-lateral SCG. Only the LCBF at basal ganglia was increased from 108 ml/min/100 g in the sham-operated group to 118 ml/min/100g in the SCG group. A mean of 14% reduction of LCBF was estimated. In 14 brain structures, the delivery amount of O2 was all decreased, except in basal ganglia. However, these changes of LCBF and the delivery amount of O2 at these 14 brain structures did not reach the significant differences. Conclusions: The present results show that chronic effect (two weeks) of bilateral SCG on LCBF was not only in a decrease of the LCBF, but also a decrease of local cerebral O2 delivery. However, the changes didn’t show the significant differences.