脑出血周围组织脑血流变化CT灌注成像与早期缺血性损伤的动物实验

目的探讨血肿周围局部脑血流变化与周围组织早期缺血性损伤的关系.方法雄性SD大鼠70只,随机分为注血组和对照组,采用自体血注射法制备大鼠脑出血模型,利用GE LightSpeed螺旋CT扫描机灌注成像及计算机辅助系统制作大鼠脑CT灌注参数图,对血肿周围局部脑血流量(rCBF)、局部脑血容量(rCBV)和对比剂平均通过时间(MTT)脑血流动力学参数进行定量测量,并与大鼠脑TTC染色和HE-染色进行比较.结果血肿周围存在不同程度低灌注,低灌注梯度依色阶变化表现为多层彩色环绕带,呈"靶样"改变;血肿周围局部脑血流量呈波动性改变,血肿周围rCBF和rCBV在注血后1 h降至最低,其后逐渐回升.TTC染色血肿周围未见白色梗死区;HE-染色可见血肿周围组织疏松,细胞不同程度水肿,星形细胞肿胀,神经细胞变性.结论大鼠脑注血后血肿周围局部脑血流显著降低可引发周围组织早期缺血性损伤,CT灌注成像可在活体下显示血肿周围异常的脑血流动力学变化,可为脑出血临床救治提供有价值信息.     

Multifocal cerebral blood flow by Xe-CT and global cerebral metabolism after prolonged cardiac arrest in dogs. Reperfusion with open-chest CPR or cardiopulmonary bypass.

Using the stable xenon-enhanced computed tomography (Xe-CT) method in dogs, we studied local, regional and global cerebral blood flow (LCBF, rCBF and gCBF) in two sham experiments and nine cardiac arrest experiments. Within the same experiments without arrest, gCBF and rCBF values were reproducible and stable. LCBF values varied over time. In group I (n = 4), ventricular fibrillation cardiac arrest (no blood flow) of 10 min was reversed by open-chest cardiopulmonary resuscitation (CPR). In group II (n = 5), ventricular fibrillation cardiac arrest of 12.5 min was reversed by brief closed-chest cardiopulmonary bypass. This was followed by controlled ventilation, normotension, normoxia, normocarbia and normothermia to 4 h (n = 7) or 20 h (n = 2) postarrest. The postarrest CBF patterns were similar in both groups. Open-chest CPR during ventricular fibrillation generated near-baseline gCBF and lower LCBF ranges. During postarrest spontaneous circulation, transient diffuse hyperemia was without low-flow regions, longer in brain stem and basal ganglia than in neocortex. During delayed hypoperfusion at 1-4 h postarrest (n = 9), mean gCBF was 44-60% baseline, rCBF in primarily gray matter regions was 15-49 ml/100 cm3 per min and LCBF voxels with trickle-flow and low-flow values, in percent of CT cut area, were increased over baseline. Global CMRO2 (n = 3 of group II) recovered to near baseline values between 1 and 4 h postarrest, while gCBF and O2 delivery were about 50% baseline (mismatching of O2 uptake and O2 delivery).     

The relationship between cerebral blood flow and volume in humans

The purpose of this study was to establish the relationship between regional CBF and CBV at normal, resting cerebral metabolic rates. Eleven healthy volunteers were investigated with PET during baseline conditions, and during hyper- and hypocapnia. Values for rCBF and rCBV were obtained using 15O-labelled water and carbon monoxide, respectively. The mean value of rCBF using PET was 62 +/- 18 ml 100 g(-1) min(-1) during baseline conditions, with an average increase of 46% during hypercapnia, and a decrease of 29% during hypocapnia; baseline rCBV was 7.7 ml/100 g, with 27% increase during hypercapnia and no significant decrease during hypocapnia. A regionally uniform exponential relationship was confirmed between PaCO2 and rCBF as well as rCBV. It is shown that the theoretical implication of this is that the rCBV vs. rCBF relationship should be modelled by a power function; however, due to pronounced intersubject variability, the goodness of fit for linear and nonlinear models were not significantly different. The results of the study are applied to a numerical estimation of regional brain deoxy-haemoglobin content. Independently of the choice of model for the rCBV vs. rCBF relationship, a nonlinear deoxy-haemoglobin vs. rCBF relationship was predicted, and the implications for the BOLD response are discussed.     

应用SPECT早期诊断多发性脑梗死性痴呆的临床研究

目的:应用单光子计算机断层显像(SPECT)探讨局部脑血流(rCBF)变化与多发性脑梗死性痴呆(MID)的关系。方法:选择多发性脑梗死性痴呆组(MID组)、多发性脑梗死组(MI组)患者各20例,正常对照组20例,应用SPECT进行断层脑扫描,运用patlakplot法得出两侧大脑半球的平均血流量(mCBF),并且对大脑半球脑叶及基底核设置感兴趣区,定量测定rCBF。结果:MID组、MI组较对照组全脑mCBF均降低(P<0.01,P<0.05);额叶及基底核区域rCBF降低显著(P<0.05);MID组的额叶、颞叶皮质rCBF显著低于MI组(P<0.01,P<0.05);MID组神经心理测试MMSE评分为17.2±7.18,直线相关分析显示额叶皮质rCBF变化与MMSE呈有意义的正相关(r=0.712,P<0.05)。结论:应用SPECT对MI患者脑血流动态测定,尤其是将额叶血流低下作为敏感指标,可预测及早期发现MID病例,这对于预防MID的发生,延缓疾呆进展具有重要意义。     

Quantification of blood flow and volume in arterioles and venules of the rat cerebral cortex using functional micro-ultrasound

Relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), and blood flow speed are key parameters that characterize cerebral hemodynamics. We used contrast-enhanced functional micro-ultrasound (fMUS) imaging employing a disruption-replenishment imaging sequence to quantify these hemodynamic parameters in the anesthetized rat brain. The method has a spatial resolution of about 100μm in-plane and around 600μm through-plane, which is comparable to fMRI, and it has a superior temporal resolution of 40ms per frame. We found no significant difference in rCBV of cortical and subcortical gray matter (0.89±0.08 and 0.61±0.09 times the brain-average value, respectively). The rCBV was significantly higher in the vascular regions on the pial surface (3.89±0.71) and in the area of major vessels in the subcortical gray matter (2.02±0.31). Parametric images of rCBV, rCBF, and blood flow speed demonstrate spatial heterogeneity of these parameters on the 100μm scale. Segmentation of the cortex in arteriolar and venular-dominated regions identified through color Doppler imaging showed that rCBV is higher and flow speed is lower in venules than in arterioles. Finally, we show that the dependence of rCBV on rCBF was significantly different in cortical versus subcortical gray matter: the exponent α in the power law relation rCBV=s·rCBF(α) was 0.37±0.13 in cortical and 0.75±0.16 in subcortical gray matter. This work demonstrates that functional micro-ultrasound imaging affords quantification of hemodynamic parameters in the anesthetized rodent brain. This modality is a promising tool for neuroscientists studying these parameters in rodent models of diseases with a cerebrovascular component, such as stroke, neurodegeneration, and venous collagenosis. It is of particular import for studying conditions that selectively affect arteriolar versus venular compartments.     

The effect of i.v. L-NG methylarginine hydrochloride (L-NMMA: 546C88) on basal and acetazolamide (Diamox) induced changes of blood velocity in cerebral arteries and regional cerebral blood flow in man

The aim of this study was to estimate the effect of Nitric Oxide synthase (NOS)-inhibition (L-NMMA) on the diameter of the middle cerebral artery (MCA) and on regional cerebral blood flow (rCBF). Furthermore, to assess the effect of L-NMMA on acetazolamide induced increases in MCA blood velocity (Vmean) and rCBF. In an open crossover design 12 healthy subjects attended the laboratory twice. The first day 6 mg/kg L-LNMMA i.v. over 15 min preceded 1 g acetazolamide i.v. over 5 min. Eight days later only acetazolamide was given. V(mean) in MCA was determined with transcranial Doppler (TCD) and rCBF with Xe-133 inhalation SPECT at baseline, after L-NMMA and 25 and 55 min after acetazolamide infusion. After L-NMMA the decrease in rCBF(MCA) was 6.8% (+/- 7.4) (P < 0.019, n = 12), whereas V(mean) was not affected (P = 0.83, n = 8). The change in MCA diameter was estimated to - 1.3% (P = 0.44, n = 8). L-NMMA did not affect acetazolamide increases in Vmean (P = 0.67, n = 8) nor rCBF (P = 0.29, n = 12). The percentage increase of V(mean) was 1.5 times that of rCBF (n = 8). Our data suggest that the basal tone of human cerebral arterioles but not of conduit arteries is NO-dependent. The action of acetazolamide in man is not NO-dependent.     

Impact of L-DOPA treatment on regional cerebral blood flow and metabolism in the basal ganglia in a rat model of Parkinson's disease

Large increases in regional cerebral blood flow (rCBF) have been measured in patients with Parkinson's disease (PD) following the administration of L-DOPA, but the underlying mechanisms have remained unknown. In this study, rats with unilateral 6-hydroxydopamine (6-OHDA) lesions were used to compare patterns of rCBF and regional cerebral glucose utilisation (rCGU) in chronically L-DOPA-treated subjects following a final injection of L-DOPA or saline. The same animal model was used to the leakage of a blood-brain barrier (BBB) tracer molecule at 60 min vs. 24h following the last L-DOPA injection of a chronic treatment. All the parameters under investigation were examined with brain autoradiography following intravenous injections of specific radiotracers in awake animals ([14C]-iodoantipyrine for rCBF, [14C]-2-deoxyglucose for rCGU, and [14C]-α-aminoisobutyric acid for BBB leakage). Significant changes in rCBF and rCGU on the side ipsilateral to the 6-OHDA lesion relative to the non-lesioned side were seen at 60 min ("ON") but not 24h ("OFF") following L-DOPA administration. These changes were not seen in sham-operated rats. In the output nuclei of the basal ganglia (the entopeduncular nucleus and the substantia nigra pars reticulata) both rCBF and rCGU were elevated both in acutely L-DOPA-treated rats and chronically L-DOPA-treated rats displaying dyskinesia, but did not change significantly in chronically L-DOPA-treated non-dyskinetic cases. Acutely and chronically L-DOPA-treated rats with dyskinesia exhibited increases in rCBF "ON L-DOPA" also in the motor cortex, the striatum, and the globus pallidus, but the corresponding changes in rCGU did not show the same direction, magnitude, and/or relative group differences. The uptake of a BBB tracer (studied in the striatum and the substantia nigra reticulata in chronically L-DOPA treated rats) was significantly higher ON vs. OFF L-DOPA. The present results are the first to show that the administration of L-DOPA is followed by transient and robust increases in rCBF in the dopamine-denervated basal ganglia. This effect occurs already upon acute L-DOPA treatment and persists upon repeated drug administration in animals that develop dyskinesia. Increases in rCBF ON L-DOPA are not necessarily accompanied by enhanced glucose utilisation in the affected regions, pointing to altered mechanisms of neurovascular coupling. Finally, our results show that increases in rCBF ON L-DOPA may be accompanied by BBB hyperpermeability in the most affected regions.     

The functional anatomy of parkinsonian bradykinesia

To investigate the difficulty that patients with Parkinson's disease (PD) have in performing fast movements, we used H(2)(15)O PET to study regional cerebral blood flow (rCBF) associated with performance of a simple predictive visuomanual tracking task at three different velocities. Tracking movements in PD patients (versus tracking with the eyes alone) were associated with a general underactivation of the areas normally activated by the task (sensorimotor cortex contralateral to the moving arm, bilateral dorsal premotor cortices, and ipsilateral cerebellum). Presupplementary motor cortex (pre-SMA) ipsilateral to the moving arm had greater than normal movement-related activations. Increasing movement velocity led to increased rCBF in multiple premotor and parietal cortical areas and basal ganglia in the patients as opposed to the few cerebral locations that are normally velocity-related. The functional correlates of PD bradykinesia are: (1) impaired recruitment of cortical and subcortical systems that normally regulate kinematic parameters of movement such as velocity; and (2) increased recruitment of multiple premotor areas including both regions specialized for visuomotor control (ventral premotor and parietal cortices) and some that are not (pre-SMA). The overactivation of cortical regions observed in patients may be functional correlates of compensatory mechanisms and/or impaired suppression as a facet of the primary pathophysiology of PD.     

慢性静脉压增高状态下脑微循环的动态研究

目的 研究慢性静脉压增高状态下脑微循环的动态变化。方法 选择Wistar雄性大鼠16只,分为对照组A（n=6)和实验组B(n=10),全身麻醉下,A组单纯右颈总动脉结扎,B组右颈总动脉与右颈外静脉端端吻合。利用激光多普勒扫描技术测定吻合前、后以及2周后吻合部结扎前、后脑表25处局部脑血流（ICBF）和局部脑血流量（1CBV）的变化,区域脑血流（rCBF)和区域脑血流量（rCBV)分别用各自的25个数据的中位数表示。结果 A组的两侧大脑半球以及B组的左侧大脑半球吻合前后rCBF,rCBV的变化无统计学意义,B组的右侧大脑半球吻合前后rCBF,rCBV无统计学意义,但2周后rCBF显著降低（P＜0．05）,rCBV显著增高（P＜0．05）,吻合部结扎后rCBF即刻增高（P＜0．05）,rCBV即刻降低（P＜0．05）。结论 一侧颈总动脉一颈外静脉吻合模型对研究慢性静脉压增高状态下脑缺血的研究具有实用价值;在慢性静脉压增高状态下结扎动静脉短路后,脑灌注压迅速上升,CBF得到改善。     

三七总皂甙对急性基底节区出血患者神经功能及rCBF的影响

目的:探讨三七总皂甙(tPNS)治疗急性基底节区出血的疗效及机制。方法:选择急性基底节区出血患者32例,随机分为对照组17例和tPNS组15例,均给予基础治疗,tPNS组加用tPNS治疗14 d,观察治疗前、治疗后4、102、1 d中国卒中量表(CSS)评分的改变,及治疗前、治疗后21、90 d的Barthel指数(BI)的改变,采用单光子发射计算机成像(SPECT)和氙气CT(XeCT)观察2组治疗前后血肿周边局部脑血流量(rCBF)的变化。结果:tPNS组CSS评分在治疗4 d后即低于治疗前(P<0.05),对照组在治疗10 d后低于治疗前,2组治疗后BI比较无差异。SPECT和XeCT结果显示,治疗后2组血肿周边rCBF有所降低。结论:tPNS能促进基底节区出血患者神经功能的恢复,但不能改善血肿周边rCBF。     

多层螺旋CT脑灌注成像在急性脑缺血中的应用

目的探讨多层螺旋CT脑灌注成像在急性脑缺血中的应用价值。方法应用GE lightspeed 16层螺旋CT扫描机,对经证实的16例急性脑缺血患者先行CT平扫,选定感兴趣区行多层螺旋CT脑灌注成像,经灌注软件处理,计算出局部血容量图(rCBV)、局部血流量图(rCBF)、对比剂平均通过时间(MTT)、对比剂峰值时间(TP),并与对侧相应脑组织灌注参数进行比较。所有病例均经CT随访或经MRI证实,所有病例联合头颈部CTA扫描。结果16例患者中15例其脑缺血侧rCBF减低,MTT、TP延长,rCBV正常或轻度降低,存在半暗区;4例患者rCBV未显示病灶。1例患者rCBF减低,MTT、TP延长,rCBV明显下降,经随访证实为脑梗死。结论多层螺旋CT脑灌注成像能早期发现脑缺血灶部位和范围及推测半暗带区域、评估脑缺血预后,是一种最具潜力的脑缺血检查方法。     

99Tcm-ECD SPECT局部脑血流显像乙酰唑胺试验对抑郁症的研究

目的观察乙酰唑胺负荷试验前后抑郁症患者局部脑血流(rCBF)的变化,评价其局部脑血管储备功能.方法以18例未经抗抑郁治疗的成年抑郁症患者为研究对象,18名年龄、性别匹配的正常志愿者作为对照组,进行99Tcm-双半胱乙酯(99Tcm-ECD)SPECT脑血流灌注断层显像,用半定量分析方法测定受检者的rCBF.在第一次检查后48 h,患者口服乙酰唑胺片2克,再行SPECT脑血流显像.结果抑郁症组患者双侧上、下部额叶,双侧前、后部颞叶,双侧顶叶、左侧基底节rCBF明显降低(P＜0.01);同时,左侧顶叶rCBF灌注比对侧更低(P＜0.01).服用乙酰唑胺后,原脑内低灌注区部位的rCBF均明显增高(P＜0.01),但没能恢复到正常水平(P＞0.05).结论抑郁症患者存在着不同部位和程度的rCBF灌注减低区,乙酰唑胺脑试验可使原来呈低灌注状态的rCBF明显提高.     

脑胶质瘤MR灌注成像和病理分级对照研究

目的:本研究旨在评价相对脑血流容积(rCBV)和相对脑血流量(rCBF)在评估脑胶质瘤组织病理学分级中的价值。方法:对病理证实为脑胶质瘤的患者(低级别胶质瘤13例,高级别胶质瘤23例)行MR灌注成像及常规MRI检查。由灌注数据获取脑血流容积(CBV)图和脑血流量(CBF)图,计算出最大rCBV值和最大rCBF值。结果:高级别胶质瘤最大rCBV值及最大rCBF值分别为6.55±4.23和3.34±1.85,低级别胶质瘤分别为1.70±0.49和1.18±0.36,两组间最大rCBV值和rCBF值均有显著性差异(t检验,P<0.01);非参数相关性分析表明最大rCBV值和最大rCBF值间存在显著的相关性(r=0.812,P<0.05)。对于脑胶质瘤的定性评价,MR灌注成像结果与常规T1增强图像结果有时不吻合,不吻合率达30%。结论:MR灌注成像能有效地在术前评价脑胶质瘤的病理级别,最大rCBV值结合最大rCBF值可以更好地评估脑胶质瘤组织病理学分级。     

Assessment of hemodynamic response during focal neural activity in human using bolus tracking, arterial spin labeling and BOLD techniques

In this study, the hemodynamic response and changes in oxidative metabolism during functional activation were measured using three functional magnetic resonance imaging (fMRI) techniques: the blood oxygenation level-dependent (BOLD) technique, flow-sensitive alternating inversion recovery (FAIR), and bolus tracking (BT) of an MR contrast agent. With these three techniques we independently determined changes in BOLD signal, relative cerebral blood flow (rCBF), and cerebral blood volume (rCBV) associated with brain activation in eight healthy volunteers. In the motor cortex, the BOLD signal increased by 1.8 +/- 0.5%, rCBF by 36.3 +/- 8.2% (FAIR), and 35.1 +/- 8.6% (BT), and rCBV by 19.4 +/- 4.1% (BT) in response to simultaneous bilateral finger tapping. In the visual cortex, BOLD signal increased by 2.6 +/- 0.5%, rCBF by 38.5% +/- 7.6 (FAIR), and 36.9 +/- 8.8% (BT), and rCBV by 18.8 +/- 2.8% (BT) during flickering checkerboard stimulation. Comparing the experimentally measured rCBV with the calculated rCBV using Grubb's power-law relation, we conclude that the use of power-law relationship results in systematic underestimate of rCBV.     

急性脑出血“动态点征”区域CT灌注参数定量评估血肿扩大

目的 观察急性脑出血(AICH)"动态点征"区域CT灌注(CTP)参数定量预测血肿扩大的价值。方法 回顾性分析45例AICH首诊平扫CT、CTP原始图像、灌注参数图及24 h内复查CT,根据CTP原始图像有无"动态点征"分为阳性组(n=21)和阴性组(n=24);比较组间血肿体积变化、"点征"/密度最高区域(强化区),血肿全部区域相对脑血流量(rCBF)及相对脑血容量(rCBV)差异。绘制受试者工作特征曲线,计算曲线下面积(AUC),评价强化区灌注参数预测血肿扩大的效能;以Spearman相关性分析评估阳性组血肿体积变化与"动态点征"总出现时间的相关性。结果 首诊2组血肿体积差异无统计学意义(P＞0.05)。复查中,阳性组血肿体积明显大于阴性组(P＜0.05);阳性组17例(17/21,80.95%)、阴性组2例血肿扩大(2/24,8.33%)。阳性组强化区rCBF、rCBV及强化区与血肿区rCBF、rCBV差值均显著高于阴性组(P均＜0.05)。以rCBF=8.90 ml/(min·100 g)、rCBV=6.55 ml/100 g为截断值,预测血肿扩大的AUC分别为0.877和0.889。阳性组血肿体积变化与"动态点征"总出现时间呈正相关(r=0.628,P＜0.05)。结论 CTP"动态点征"区域灌注参数可用于预测血肿扩大;血肿体积变化与对比剂渗漏总时间呈正相关。     

用SPM分析焦虑症患者99mTc-ECD局部脑血流变化

目的：用统计参数地图（statistical parametric mapping,SPM)软件包分析焦虑症患者局部脑血流（regional cerebral blood,flow,rCBF）灌注的变化。方法：选择经CCMD－2或ICD－10诊断为焦虑症患者19例，进行脑^99mTc-ECD显像，并与23例年龄匹配的健康人作比较。用SPM软件包对脑血流图像进行组间比较，分析焦虑症患者大脑血流变化情况。结果：焦虑症患者的局部脑血流双侧颞叶，额上回，扣带回明显降低。而在中央前回，额叶眶部，左基底节血流明显升高。结论：焦虑症患者的局部脑血流有明显的变化，且与其发病机理相关。     

认知行为疗法与西酞普兰对抑郁症患者局部脑血流的影响

目的探讨认知行为疗法与喜酞普兰对抑郁症患者局部脑血流的影响。方法38例抑郁症患者分为认知行为治疗组18例和西酞普兰药物治疗20例。采用99Tcm-双半胱乙酯局部脑血流灌注单光子发射计算机断层扫描（SPECT）显像结合感兴趣区（ROI）技术,对两组患者治疗前后的局部脑血流变化和汉密尔顿抑郁量表（HAMD）评分进行比较。结果治疗后,两组患者的抑郁症状均有改善,但西酞普兰组早于认知行为治疗组;两种治疗方法均可增加右基底节血流量,认知行为治疗组亦有右边缘系统扣带回后部局部血流量增加,西酞普兰组亦有右颞叶后部局部脑血流量增加。结论两种治疗方法对抑郁症均有效,但改善脑血流的部位不同。     

黄芪注射液联合rt-PA治疗急性缺血性脑卒中的临床研究

目的探讨黄芪注射液联合重组组织型纤溶酶原激活剂(rt-PA)静脉溶栓对急性缺血性卒中患者的灌注CT检查结果以及脑梗死出血性转化(HT)发生的影响。方法对2013年5月至2014年7月因急性脑缺血性卒中发病6h内入院的54例患者进行回顾性分析,根据不同治疗方法分为rt-PA静脉溶栓治疗组(n=24)和黄芪注射液联合rt-PA组(n=30)两组。收集两组患者部分临床资料,并对所有患者溶栓前及溶栓后24h进行头部CT灌注检查计算出相对脑血流量(rCBF)、脑血容量(rCBV)、脑血管表面通透性(rPS)数值以及根据美国国立卫生研究院卒中量表(NIHSS)计算患者评分,另外收集2周内发生HT的患者例数,最后统计分析两组间治疗前后rCBF、rCBV、rPS、NIHSS评分的差值以及治疗2周内HT发生的病例数有无差别。结果黄芪注射液联合rt-PA组灌注CT参数的rCBF,CBV,rPS以及NIHSS评分治疗前后的差值均高于rt-PA组,差异有统计学意义(P0.05),但两组2周内HT的发生例数差异无统计学意义(P0.05)。结论黄芪注射液联合rt-PA能明显增加急性脑缺血卒中患者的脑部血流情况,同时减轻脑血管表面通透性,进而改善患者预后。     

Regional cerebral blood flow during hyperventilation in patients with acute bacterial meningitis

Mechanical hyperventilation is often instituted in patients with acute bacterial meningitis when increased intracranial pressure is suspected. However, the effect on regional cerebral blood flow (CBF) is unknown. In this study, we measured regional CBF (rCBF) in patients with acute bacterial meningitis before and during short‐term hyperventilation. In 17 patients with acute bacterial meningitis, absolute rCBF (in ml/100 g min^?1) was measured during baseline ventilation and hyperventilation by single‐photon emission computed tomography (SPECT) using intravenous ¹³³Xe bolus injection. Intravenous ^99mTc‐HMPAO (hexamethylpropyleneamine oxime) was subsequently given during hyperventilation. In 12 healthy volunteers, rCBF was measured by SPECT and ^99mTc‐HMPAO during spontaneous ventilation. Using standard templates to identify regions of interest (ROIs), we calculated rCBF in percentage of cerebellar (^99mTc‐HMPAO images) or mean hemispheric (¹³³Xe images) flow for each ROI, the degree of side‐to‐side asymmetry for each ROI, and the anterior‐to‐posterior flow ratio. On ¹³³Xe images, absolute rCBF decreased significantly during hyperventilation compared to baseline ventilation in all regions, but the relative rCBF did not change significantly from baseline ventilation (n=14) to hyperventilation (n=12), indicating that the perfusion distribution was unchanged. On ^99mTc‐HMPAO images (n=12), relative rCBF and the anterior‐to‐posterior flow ratio were significantly lower in patients than in controls in the frontal and parietal cortex as well as in the basal ganglia. Focal perfusion abnormalities were present in 10 of 12 patients. Regional cerebral blood flow abnormalities are frequent in patients with acute bacterial meningitis. Short‐term hyperventilation does not enhance these abnormalities.     

Hemichorea associated with gabapentin therapy with hypoperfusion in contralateral basal ganglion - a case of a paraplegic patient with neuropathic pain

Functional imaging in patients with movement disorders has suggested abnormalities of regional cerebral blood flow (rCBF). We describe a patient with thoracic cord lesion with subsequent severe neuropathic pain. Right hemichorea developed and was related to adjunctive therapy with gabapentin. The patient's hemichorea decreased gradually after cessation of gabapentin. The study of rCBF revealed hypoperfusion in the contralateral basal ganglia compared with the previous study of rCBF. Our patient is the first patient with neuropathic pain, treated with gabapentin who developed hemichorea, in the absence of brain lesions. Imaging studies of rCBF showed a perfusion defect in the contralateral basal ganglion.