Regional cerebral blood flow with age: changes in rCBF in childhood

Changes in cerebral blood flow (CBF) and regional cerebral blood flow (rCBF) throughout the entire age range including childhood were reported. The CBF in grey matter of children was markedly higher than that found in adults and showed a negative correlation with age. In contrast, the blood flow in white matter did not show a notable decrease with age. The regional distribution of CBF in children did not exhibit the frontal lobe dominance typical of adults. The rCBF pattern began to approach that of adults with growth and by 10 yr the rCBF pattern of children was similar to that of adults.     

强迫症患者局部脑血流灌注研究

目的　探讨强迫症(OCD)患者局部脑血流灌注(rCBF)特点及临床症状与rCBF的关系。方法　对2 8例符合国际疾病分类第1 0版(ICD 1 0 )强迫障碍诊断标准患者和1 5名正常人进行单光子发射计算机断层扫描(SPECT)脑显像分析。用耶鲁 布朗强迫评定量表(YBOCS)、Hamilton焦虑量表(HAMA)和Hamilton抑郁量表(HAMD)对患者临床症状进行评定。结果　OCD患者两侧丘脑、顶叶和基底神经节的平均放射性计数百分数(PMRC)显著高于正常组;右颞PMRC明显低于正常组;且正常组两侧颞叶和顶叶PMRC值差异非常显著。在强迫恐惧/洗涤、回避组,YBOCS强迫行为分量表评分与右基底PMRC显著正相关(r =0 .70 1 )。结论　OCD患者两侧丘脑、顶叶和基底神经节的血流灌注增加和功能亢进;右颞血流灌注减少和功能低下,两侧颞叶和顶叶血流灌注的不对称性与正常人显著不同,后者的不对称性非常显著;在强迫恐惧/洗涤、回避组,强迫行为与右基底节功能增强有关。     

大鼠蛛网膜下腔出血（SAH）后局部脑皮层血流量及脑水肿观察

本文研究了大鼠SAH后局部脑皮层血流量及脑组织中H2O、Na^ ,^ 含量的变化。结果表明：SAH后30min双侧大脑半球的脑血流量明显下降（P＜0．01），1h，下降至最低点，约为注血前的36％－38％，双侧大脑半球无明显区别，以后脑血流量部分恢复，低血流量状态维持48h以上，一周恢复正常，提示可能有急性脑血管痉挛的发生，SAH后4h脑组织中水含量才明显增加（P＜0．01），48h达到高峰，Na^ 的变化与水含量一致，说明有脑水肿的发生，但脑水肿出现的时间及高峰明显迟于脑血流的降低，提示SAH后脑水肿的发生、发展是脑血流量降低的继发性病理变化。     

Regional cerebral blood flow in delirium patients

The purpose of the present paper was to determine the possible mechanism of delirium by using xenon-enhanced computed tomography to measure the regional cerebral blood flow (rCBF) of the patients both during delirium and after improvement from delirium. The rCBF measurements of the frontal, temporal and occipital cortex during delirium ranged from 31.4 to 39.6 mL/100 g per min; the rCBF of the thalamus and basal ganglia ranged from 47.5 to 52.4 mL/100 g per min. After recovery from delirium the rCBF of both areas returned to normal. The findings that reduced rCBF during delirium becomes normal once delirium improves suggest that a possible cause of delirium may be the cerebral hypoperfusion.     

过度通气对重型颅脑创伤病人的脑血流和脑组织氧分压的影响

目的研究过度通气(HV)对重型颅脑创伤(sTBI)病人的颅内压(ICP)、脑血流(CBF)和脑组织氧分压(PbtO2)的影响。方法20例sTBI(GCS3～8分)病人,伤后2～5dICP超过20mmHg时,应用机械通气法使呼气末二氧化碳分压(PetCO2)维持在27～32mmHg之间30min,同时连续监测ICP、CBF和PbtO2。结果所有病人共进行了46次HV,HV可使ICP明显下降(43/46),而CBF和PbtO2对CO2的反应差异较大,其中大部分试验(38/46)CBF和PbtO2明显下降,但仍然保持在各自的缺血阈值(50AU和10mmHg)之上;5次试验CBF和PbtO2下降低于各自的缺血阈值;3次试验ICP无明显变化,CBF轻度升高,而PbtO2下降。结论HV可降低ICP,但有导致或加重脑缺血的危险,应尽量避免早期长时程应用。HV应在CBF持续监测下应用。     

Cerebral blood flow in experimental intracranlal mass lesions: Part I: The compression phase

We have shown that a rebound of intracranial pressure (ICP) occurring after decompression of an intracranial mass lesion is a threshold phenomenon dependent upon the cerebral perfusion pressure (CPP) during compression and the duration of the compression. In the present study regional cerebral blood flow (rCBF) was measured during balloon compression of a degree critical for the development of a postdecompression rebound. The effects were compared with those of hydrostatically raised pressure which under similar conditions rarely produces a rebound of ICP. Disproportionately marked reductions in flow occurred in the hemisphere ipsilateral to the balloon, especially in white matter and in cortex adjacent to the balloon with flow values of, respectively, 1.1 ± 0.9 and 6.4 ± 3.4 ml 100 g^–1 min^–1. The differences in flow between balloon and hydrostatic compression were found to be due to an increased cerebrovascular resistance (CVR) caused by a direct compressive effect by the balloon overriding the generalized vasodilation which occurs in response to the raised ICP. Thus the increase in CVR attributable to compression by the balloon added to the reduction in CPP caused by the diffuse increase in ICP. As a consequence flow in large regions of the brain was reduced below the thresholds for structural infarction and for ischaemic damage to the blood-brain barrier.     

鼠侧向液压脑损伤后脑血流量和葡萄糖利用率的改变

目的：探讨液压冲击脑损伤后脑血流量（ＣＢＦ），局部脑血流量（ｒＣＢＦ）与局部葡萄糖利用率（ｒＣＧＵ）的变化及其对神经元继发性损伤的影响。方法：应用激光多普勒流量计和定量放射自显影技术。结果：液压冲击脑损伤导致６０秒内ＣＢＦ短暂升高然后显著下降，且持续６０分钟低于正常，同侧和对侧大脑半球的ＣＢＦ相应降为正常值的７９％和９３％。外伤后１小时，损伤侧脑皮层，丘脑及海马的ｒＣＢＦ下降１２％～５９％，对侧大脑半球相应区域则下降１０％～４０％。相反，ｒＣＧＵ在冲击区周围脑皮质及同侧丘脑和海马区升高２７％～１０１％，在对侧大脑半球相应区域则升高２０％～９１％，海马区由液压冲击引起的ｒＣＢＦ和ｒＣＧＵ分离性变化十分显著，同侧海马ＣＡ１和ＣＡ２－３区存活的神经元数量在损伤后两星期时显著减少。结论：ｒＣＢＦ和ｒＣＧＵ的分离性变化是引起外伤后神经元尤其是海马区神经元继发损伤的主要因素。     

黄芪对大鼠脑缺血血脑屏障及脑血流的影响

利用大鼠局灶性脑缺血再灌流和全脑缺血再灌流损伤两种动物模型，观察黄芪注射液对脑缺血后再灌注期间血脑屏蔽及脑血流的保护作用。结果显示，与相庆对照组比较，不论是全脑缺血还是局灶性脑缺血１ｈ后再灌流３ｄ，应用黄芪的各组动物脑水肿明显减轻，血脑屏障通透性改善，大脑局部血流量显著增加。     

PETCO2监测过度通气水平对脑外伤患者脑血流、脑代谢和脑灌注的影响

目的 探讨呼吸末二氧化碳分压(PETCO2)监测下过度通气水平对颅脑外伤患者术中脑血流、脑代谢和脑灌注的影响.方法 选择东营鸿港医院神经外科自2009年1月至2012年6月急诊行脑外伤开颅去骨瓣减压血肿清除术的患者70例,按随机数字表法分为A、B2组,每组35例,A组患者PETCO2控制在20～25 mm Hg之间,动脉血二氧化碳分压(PaCO2)维持在22～25 mm Hg之间,B组患者PETCO2控制在25～30 mm Hg之间,PaCO2维持在30～45 mm Hg之间,比较手术开始去骨瓣前2组患者血气分析结果、平均动脉压、颅内压、脑氧分压、脑灌注压和脑氧供需平衡以及代谢产物神经元特异性稀醇化酶(NSE)、葡萄糖、乳酸的变化.结果 手术开始去骨瓣前A组患者的PaCO2水平、平均动脉压、颅内压、NSE、葡萄糖和乳酸水平显著低于B组,差异有统计学意义(P＜0.05);2组患者脑氧分压和脑灌注压、动脉血氧含量(CaO2)、静脉血氧含量(CjvO2)和脑氧摄取率(CERO2)比较差异无统计学意义(P＞0.05).结论 术中将PETCO2控制在20～25 mm Hg之间,能有效维持患者脑血流灌注和脑氧供需平衡,降低病理性代谢产物水平,值得临床重视.     

Stages of increased cerebral blood flow accompany stages of rapid brain growth

The existence of stages of rapid brain growth implies the existence of associated stages of increased cerebral blood flow (CBF) to supply the substances and energy needed for the added brain weight. Studies in the literature give developmental data for CBF in humans which show stages of increased cerebral blood flow at ages starting just preceding and/or coincident with the ages of the rapid brain growth stages. Confirmation of the implication for one of the earliest stages is also found in PET data. Additionally, data for rodents show a similar association of stages of increasing CBF and their brain growth stages. Thus, to the accuracy of the data, the implication is confirmed. Finding stages in cerebral blood flow predicts the existence of stages of brain growth. In addition; finding correlated blood flow stages also supports the age spans of the stages of rapid brain growth in both species. Such correlations also suggest that measurements of blood flow anywhere in the body might serve to reveal rapid growth stages in particular localities or organs if the blood flow shows significant stages. The ratio of energy consumed in brain to that in total body decreases from close to 100% at birth to the adult value of about 20% by age 18 years.     

Regional cerebral blood flow in patients with schizophrenia

Summary Regional cerebral blood flow was evaluated using Tc99m-HMPAO SPECT in 10 medicated patients with schizophrenia and 9 healthy volunteers. There were no prefrontal regions in the patient group with lower regional indices than in the control group. However, in the left hippocampal region, relative blood flow was significantly increased in the patient group compared with the control group. Furthermore, there was a relative increase in blood flow in the left basal ganglia of the patient group. A negative correlation coefficient was calculated between the relative blood flow in the left middle prefrontal cortex and the severity of the blunted affect, as well as between the relative blood flow in the left basal ganglia and the severity of the anhedonia-asociality. These findings indicate that prefrontal hypoactivity is not invariably present in all schizophrenics and that left basal ganglial hyperactivity may be associated with the effects of antipsychotic treatment and clinical improvement. Moreover, the left hippocampal hyperactivity may correspond to left limbic dysfunction in schizophrenia.     

Local cerebral blood flow after microwave exposure

Experiments were performed which demonstrate that low power, pulsed microwave exposure induces a significant increase in local cerebral blood flow within the brain of the conscious rat. Previous studies purporting to examine changes in brain vascular permeability induced by microwave radiation must be re-evaluated in the light of these observed changes in blood flow.     

Increased cerebral blood flow in idiopathic pseudotumour cerebri

Cerebral blood flow was studied in nine patients with idiopathic pseudotumour and one patient with cortical vein thrombosis in Denver, Colorado using the ¹³³Xe inhalation method. Globally elevated blood flows were found in all of the idiopathic pseudotumour patients averaging 149% of control values generated in the same setting. The patient with the cortical vein thrombosis demonstrated normal global flows. Possible pathophysiological mechanisms for these findings are discussed.     

大鼠脑出血后脑血流和脑水分含量变化的研究

研究大鼠脑出血后局部脑血流量（ｒＣＢＦ）与脑水分变化的规律及影响因素。用立体定向法自体血回注建立大鼠脑尾状核出血模型，分别在２４ｈ内不同时限用氢清除法测定ｒＣＢＦ，干湿重法测定脑水分含量，发现出血后１０ｍｉｎ同侧ｒＣＢＦ即下降，１ｈ达最低水平，出血量大时对侧半球也有明显下降；双侧脑水分含量均明显增加，其高峰期晚于ｒＣＢＦ的下降。说明脑出血后迅速出现广泛的低灌注和脑水肿     

Correlation between the clinical picture,the EEG and cerebral blood flow after partial occlusion of the middle cerebral artery in man

Summary Quantitative measurements of global and regional cerebral blood flow were performed in 18 patients 1 to 3 days after the onset of symptoms of acute cerebral ischemia due to partial occlusion of the middle cerebral artery and were repeated 21 days thereafter. The first rCBF measurement revealed either an extensive ischemic focus or an ischemic focus with simultaneous reduction of the global blood flow within the corresponding hemisphere in all patients. The later measurements indicated no change in blood flow in the ischemic focus in any case, but there was a slight increase of global cerebral blood flow in 1/3 of the cases.The measurements of cerebral blood flow were correlated with the neurological, psychopathological and EEG findings and in spite of an unaltered cerebral blood circulation, all patients showed a distinct clinical improvement. Various hypotheses for the return of neurological functions in patients with persistent cerebral ischemia are discussed.Paper read at the Kongress der Deutschen Gesellschaft für Neurologie, Hamburg 1975     

尼莫地平对脑出血患者局部脑血液、脑水肿及不同时间用药临床变化的影响

目的：动态观察尼莫地平对高血压脑出血患者局部脑血液（rCBF)、脑水肿和不同时间用药临床变化的影响。方法：随机将108例高血压脑出血患者分对照组和治疗组,并将治疗组再分为发病前12小时以内用药组和12小时以后用药组,行单光子发射断层扫描（SPECT）、临床疗效和动态观察;并随机从对照组和治疗组中分别抽出10例患者行SPCET、CT的动态观察,结果：治疗组rCBF、水肿带和临床疗效的改善显著优于对照组;12小时以内用药的临床疗效明显优于12小时以后用药。结论：早期使用尼莫地平对改善高血压脑出血后rCBF下降,提高临床疗效和减轻血肿周围水肿可能均有积极作用。     

Regional brain polyamine levels in permanent focal cerebral ischemia

Transient global cerebral ischemia has been shown to induce marked changes in the polyamine pathway with a significant increase in putrescine, the product of the ornithine decarboxylase reaction. This study examined the relationship between tissue and extracellular polyamines and regional cerebral blood flow and brain edema. Six hours of focal ischemia in cats (n=10) was produced by permanent middle cerebral artery occlusion. Extracellular polyamines were measured in extracellular fluid obtained by microdialysis. Regional cerebral blood flow using laser Doppler flowmetry and specific gravity, an indicator of brain edema, were measured in contralateral (non-ischemic), penumbra and densely ischemic brain regions. A significant increase in the tissue putrescine level was found in the penumbra but there was no difference in the putrescine levels between contralateral and densely ischemic regions. There was no significant change in the spermidine and spermine levels in the three regions. Extracellular levels of putrescine and spermidine were found to be significantly lower than the tissue levels and no change in polyamines was observed in any region. Significant edema formation was observed in densely ischemic and penumbra regions. This is the first demonstration that tissue putrescine is increased in the penumbra region, an area of incomplete ischemia that is developing brain edema.     

Regional cerebral blood flow during cortical spreading depression in rat brain: increased reactive hyperperfusion in low-flow states

The purpose of the present study was to characterize the initial vascular events accompanying cortical spreading depression (CSD) of the rat brain. Regional cerebral blood flow (rCBF) was measured during the first 1–2 min of CSD using ¹⁴C-iodoantipyrine autoradiography. The material included a reference group, and 4 groups where rCBF was altered by indomethacin treatment, hypo- or hypercapnia, or one previous episode of CSD. rCBF did not change prior to, or during the onset of CSD. Thirty seconds later, rCBF increased depending on the pre-existing level of blood flow, i.e. the rise of rCBF was pronounced at depressed flow levels, but small or absent at normal or high flow levels. The prevalent view that CSD is intimately associated with vasodilatation was accordingly not supported. The activated rCBF in normocapnic rats ranged between 93 and 175 ml/100g/min, supra normal values were the exception rather than the rule. The rCBF rise, when present, probably succeeds a period of brain hypoxia, and should be classified as a reactive hyperfusion. The results together with earlier clinical and experimental findings, support that CSD may serve as experimental migraine model.     

Depressive symptoms and regional cerebral blood flow in Alzheimer's disease

Depressive symptoms are common in patients with Alzheimer's disease (AD) and increase the caregiver burden, although the etiology and pathologic mechanism of depressive symptoms in AD patients remain unclear. In this study, we tried to clarify the cerebral blood flow (CBF) correlates of depressive symptoms in AD, excluding the effect of apathy and anxiety. Seventy-nine consecutive patients with AD were recruited from outpatient units of the Memory Clinic of Okayama University Hospital. The level of depressive symptoms was evaluated using the depression domain of the Neuropsychiatric Inventory (NPI). The patients underwent brain SPECT with 99mTc-ethylcysteinate dimer. After removing the effects of age, anxiety and apathy scores of NPI, and five subscales of Addenbrooke's Cognitive Examination-revised (ACE-R), correlation analysis of NPI depression scores showed a significant cluster of voxels in the left middle frontal gyrus (Brodmann area 9), similar to the areas in the simple correlation analysis. The dorsolateral prefrontal area is significantly involved in the pathogenesis of depressive symptoms in AD, and the area on the left side especially may be closely related to the depressive symptoms revealed by NPI.     

Laser Doppler monitoring of cerebral blood flow

Abstract

The clinical management of cerebral hemodynamic status has become more important, as well as more complex, in recent years. In response", monitoring systems for neurological patients have grown increasingly sophisticated. Unfortunately the capability of monitoring cerebral blood flow is absent in commercially available monitoring systems at this time. Various investigators have demonstrated that laser Doppler systems are capable of meeting this need. We present here a summary of laser Doppler technology and also a review of the progress in application of this technology to provide meaningful input for clinical decision making. Recent clinical experience and advances in instrumentation design suggest that laser Doppler monitoring of cerebral blood flow may soon become routine in neurological intensive care settings. [Neurol Res 1996; 18: 251–255]