抑郁症患者局部脑血流变化的SPECT研究

目的用SPECT测定抑郁症患者的局部脑血流(rCBF),比较乙酰唑胺脑负荷试验后脑血流灌注变化,观察抑郁症患者脑血管的调节能力,以及是否存在潜在缺血灶。方法以18例未经抗抑郁治疗的抑郁症患者为研究对象,19名正常人作为对照组,行单光子发射计算机断层扫描(SPECT)检查。抑郁症患者48h后口服乙酰唑胺2g,再行SPECT检查。观察服用乙酰唑胺前后脑内血流的变化。结果抑郁组患者双侧额叶、颞叶的rCBF显著下降(P<0.01～0.05),左顶叶、右基底节rCBF也明显降低(P<0.05);同时,抑郁症患者局部脑血流低灌注存在不对称性,左侧灌注更低。服用乙酰唑胺后,原脑内各血流灌注下降部位恢复正常血供,未发现潜在缺血病灶。结论抑郁症患者某些特定部位存在脑血流灌注下降;乙酰唑胺脑负荷SPECT试验未发现抑郁症患者存在潜在缺血部位,而且使其局部脑血流低灌注状态恢复正常。     

尼莫地平负荷SPECT脑血流灌注显像在急性非致残性脑血管病中的诊断价值

目的分析尼莫地平负荷脑血流灌注显像在急性非致残性脑血管病中的诊断价值。方法选取2017-01-01-2017-11-01在厦门大学附属第一医院就诊的35例急性非致残性脑血管病患者,行MRI、99Tcm-ECD静息及尼莫地平负荷SPECT脑血流灌注显像。分别在双侧额叶、颞叶、顶叶、枕叶、基底节区、小脑、脑干对称部位勾画感兴趣区(regions of interests,ROI),并记录各个ROI平均放射性计数,分析负荷前后SPECT图像及局部脑血流量(regional cerebral blood flow,rCBF),观察负荷前后脑血流灌注的变化情况,比较MRI、静息及尼莫地平负荷SPECT脑血流灌注显像对急性非致残性脑血管病责任病灶诊断阳性率的差异。采用卡方检验分析数据。结果在急性非致残性脑血管病中,MRI、静息及尼莫地平负荷SPECT脑血流灌注显像诊断阳性率分别为45.7%(16/35)、71.4%(25/35)、91.4%(32/35)。负荷前后rCBF变化的4种类型情况:A型:静息显像rCBF正常,负荷后rCBF减低5个;B型:静息rCBF减少,负荷后rCBF降低无明显改善11个;C型:静息rCBF减少,负荷后rCBF降低更明显8个;D型:静息时rCBF降低,负荷后rCBF改善11个。结论联合尼莫地平负荷前后SPECT脑血流灌注显像可明显提高急性非致残性脑血管病病灶诊断阳性率,且能够有效评估脑血管储备功能。     

血管性痴呆患者SPECT脑血流灌注显像特点

目的　探讨血管性痴呆 (VD)患者 SPECT局部脑血流灌注显像特点 ,为 VD的早期诊断和痴呆严重程度的评估寻找客观的生物学指标。方法　分别对 45例 VD、3 0例卒中无痴呆 (SWD)和 3 0例正常对照者 (NC)3组进行 SPECT局部脑血流灌注显像 ,半定量分析各脑区血流灌注情况。结果　 VD组额叶、顶叶、颞叶和基底节局部脑血流灌注比 SWD组减少 (P<0 .0 5 ) ;并以额叶、颞叶血流灌注的减少最为显著 (P<0 .0 1)。与 NC组相比 ,SWD组额叶、顶叶、颞叶和基底节局部脑血流灌注均减低 (P<0 .0 5 )。额叶、颞叶血流灌注减低与 MMSE评分间存在正相关关系 (r=0 .75 5 ,P<0 .0 1)。结论　 VD患者存在明显的脑血流灌注减低 ,以额叶、颞叶最为显著 ,且与MMSE评分间存在正相关 ,SPECT脑血流灌注显像有助于 VD的诊断和病情评估     

高血压脑出血应用甘露醇和尼莫地平后脑血流动力学参数变化

目的研究高血压脑出血患者应用甘露醇注射液联合尼莫地平注射液后脑血流动力学参数的变化。方法将254例脑出血患者随机分为2组,对照组126例选择20%甘露醇注射液常规治疗,实验组128例在对照组基础上联合应用尼莫地平治疗。监测2组病患者治疗后1d、7d和14d的脑血流动力学参数,包括患侧平均血流速度和搏动指数,并观察2组治疗后14d的脑血肿体积、脑水肿面积和临床疗效。结果治疗后2组Vm和PI比治疗前明显改善(P<0.05),以实验组更佳(P<0.05);治疗后14d脑血肿体积、脑水肿面积均较对照组更少(P<0.05)。结论甘露醇注射液联合应用尼莫地平能促进脑血流动力学参数进一步改善。     

单光子发射型计算机断层显像在颅内外动脉搭桥手术中的应用价值

目的 采用单光子发射型计算机断层显像（single photon emission computed tomography,SPECT）观察缺血性卒中患者颞浅动脉-大脑中动脉搭桥手术前后脑血流灌注变化,了解SPECT在颅内外动脉搭桥手术中的应用价值。方法 对12例缺血性卒中患者手术前后脑血流灌注显像结果进行对比分析,并分别比较手术前和手术后有无侧支代偿患者脑血流灌注显像。结果 12例患者额、颞叶病变侧与对侧相应区域放射性计数比值手术前后有统计学差异（P <0.05）,而顶、枕叶、基底节及丘脑手术前后无统计学异（P >0.05）。手术前或手术后有无侧支代偿患者上述各部位病变侧与对侧相应区域放射性计数比值无统计学差异（P >0.05）。结论 搭桥手术可改善脑循环代偿不足脑组织的血流灌注,以额、颞叶血流灌注改善明显。     

大脑中动脉狭窄患者脑血流灌注与脑血流储备的相关性研究

目的通过CTA(CT Angiography,脑血管成像)及CTP(CT Perfusion,脑灌注成像)筛选大脑中动脉狭窄导致血流灌注下降的患者。用TCD(Transcranial Doppler Ultrasound,经颅多普勒超声)评估大脑中动脉狭窄导致血流灌注下降患者的CVR(Cerebral Vascular Reserve,脑血流储备),研究脑灌注与CVR的关系。方法收集2008年10月～2010年6月北京友谊医院神经内科住院患者中完成头颅CTA,CTP及CO2吸入试验者共31例。按单侧大脑中动脉狭窄大于50%以及脑灌注参数下降20%为参考标准分为患者组(15例)及对照组(16例)。在颞窗固定探头记录CO2激发试验前,试验后1 min,2 min大脑中动脉血流速度并得出最大血管反应性,用血管反应性作为CVR参考指标,采用独立样本t检验比较两组的CVR值,用线性相关分析评估CTP与CVR的关系。结果吸入试验前后脑血流速度出现显著差异,脑血流速度会在一过性降低后升高。脑灌注减低组和对照组之间的CVR有显著差异(P<0.05)。CVR与灌注参数中CBF(Cere-bral Vascular Flow,脑血流量)呈正相关(r=0.747,P<0.05)。结论大脑中动脉狭窄的患者脑灌注受损时会出现CVR的下降,CVR与CBF有着较高的一致性,CVR或许可以作为一种相对简易的指标来观察患者脑灌注的改变。     

阿尔茨海默病的脑血流灌注研究

目的探讨AD患者脑血流灌注的特征性变化。方法选择20例确诊AD患者和10例认知正常者,对所有入组对象行SPECT脑血流灌注显像检查,对所得图像进行视觉分析和半定量分析,比较两组对象各脑区血流灌注情况的差异,并比较AD患者左、右脑叶脑血流灌注的差异。结果 (1)视觉分析结果显示,AD组以颞叶或顶叶脑血流灌注减低为主,各占55%,其中双侧颞顶叶血流灌注减低者占15%,单侧颞顶叶血流灌注减低占20%。正常认知组SPECT影像学表现各异,额叶、颞叶、顶叶、枕叶、丘脑、基底节血流灌注减少情况均存在,各占10%。但无双侧颞顶叶血流灌注减少者,40%表现完全正常。(2)半定量分析结果显示,AD组在右额叶、双侧颞顶叶、右枕叶血流灌注显著低于正常认知组(P<0.05),以右侧颞叶血流灌注降低最明显,左右颞顶叶血流低灌注程度对比无显著性差异。结论 AD患者的SPECT特征性表现为双侧对称性颞顶叶血流低灌注,其中右侧颞叶血流灌注下降最严重。     

关于急性脑梗死患者在头高斜位下脑血流变化的临床研究

目的观察急性脑梗死患者在头高斜位时脑血流变化。方法对照组为11名健康支援者,急性脑梗死患者31例,采用双通道经颅多谱勒超声技术和心电监护仪观察从0°到60°头高斜位时心率、血压、脑血流速度的变化。结果从0°到60°,对照组脑血流速度、血压无明显变化;脑梗死组分为亚组1(12例,收缩压下降>20mmHg)、亚组2(19例,收缩压下降<20mmHg)。亚组1脑血流速度减慢、血压下降均明显(P<0.05),与对照组对比有明显统计意义(P<0.05);亚组2脑血流速度减慢,血压升高(P>0.05),但与对照组比较无显著性差异。结论在头高斜位时,有些脑梗死患者脑血流速度明显减慢,血压明显下降;脑血流自动调节功能损害明显。     

体外循环心内直视手术时脑血流速度改变的研究

目的研究体外循环心内直视手术期间脑血流速度的变化和影响因素。方法在１７例患者心内直视手术时应用双通道经颅多普勒于术中动态监测大脑中动脉血流速度的变化。结果在体外循环转流期间，脑血流速度降低并随平均动脉压的改变有一定波动，血流频谱呈锯齿状。结论ＴＣＤ动态监测脑血流速度在体外循环心脏手术过程中对了解脑灌注的改变有一定价值     

偏头痛与脑白质变性

目的探讨偏头痛与脑白质变性的关系及其可能形成机制。方法偏头痛患者(n=55)行头颅MRI检查,部分行脑ECT脑血流灌注显像。同期本院非神经系统疾病并行头颅MRI检查的内科住院病人作为对照组(n=51)。结果偏头痛组中,头颅MRI显示16例脑白质内见小点片样等T1或稍长T1,长T2异常信号,以多发性为主;对照组仅3例患者可见大脑半球白质内异常信号,两者之间差异有显著性意义。偏头痛组中3例患者做头颅ECT脑血流灌注显像检查,在单侧或双侧的额、颞部的脑局部血流灌注下降。对照组中4例行头颅ECT,未见脑局部血流灌注下降。结论反复偏头痛发作可能同脑白质变性具有相关性,其形成机制可能与脑血管舒缩功能异常等有关。     

Cerebral blood flow and CO2 reactivity in patients with transient ischemic attack]

To elucidate the changes in cerebral blood flow (CBF) and CO2 reactivity in patients with transient ischemic attack (TIA), 10 patients with TIA and 5 healthy adults (controls) underwent two consecutive CBF measurements (i.e. the first measurement during room air inhalation and the second measurement during 5%CO2 inhalation). Hemispheric mean CBF was determined by each CBF measurement using 133Xenon inhalation method. CO2 reactivity was evaluated by analysing delta CBF (= mean CBF during hypercapnea-mean CBF at rest) and delta CBF/delta PaCO2. The resting mean CBF values in the bilateral hemispheres (i.e. both of the affected and unaffected hemispheres) were significantly lower in TIA patients than controls (p less than 0.05). Inhalation of 5%CO2 significantly increased mean CBF in TIA patients bilaterally, however the mean CBF value during hypercapnea was again significantly lower in TIA patients than controls (p less than 0.05). CO2 reactivity in TIA patients was not significantly different from controls (p greater than 0.05). The result demonstrated that TIA patients have a chronic and global cerebral oligemia with normal CO2 reactivity. The chronic and global cerebral oligemia may develop a transient ischemic neurological symptom by being superimposed with local decrease of CBF.     

Cerebrovascular reactivity to acetazolamide in carotid artery disease: Enhancement of side-to-side CBF asymmetry indicates critically reduced perfusion pressure

Cerebral blood flow (CBF), measured with a mobile 10 detector unit and non-invasive Xenon-133 technique, was investigated before and after cerebral vasodilation with acetazolamide (Diamox) in 78 patients prior to carotid endarterectomy. The change in side-to-side CBF asymmetry from baseline to Diamox study, the Diamox asymmetry enhancement, was compared with the intraoperatively measured cerebral perfusion pressures. Asymmetry enhancement exceeded the methodological variation in 14 patients, 13 of whom had a perfusion pressure below 65 mmHg, Insignificant asymmetry enhancement was found in 64 patients: 52 with unilateral and 12 with bilateral disease. Of these two and four patients, respectively, had perfusion pressures below 65 mmHg. Enhancement of CBF asymmetry following a potent cerebral vasodilator stimulus is a reliable predictor, in unilateral carotid artery disease, of critically reduced cerebral perfusion pressure.     

Cerebrovascular reactivity to acetazolamide in carotid artery disease. Enhancement of side-to-side CBF asymmetry indicates critically reduced perfusion pressure

Cerebral blood flow (CBF), measured with a mobile 10 detector unit and non-invasive Xenon-133 technique, was investigated before and after cerebral vasodilation with acetazolamide (Diamox) in 78 patients prior to carotid endarterectomy. The change in side-to-side CBF asymmetry from baseline to Diamox study, the Diamox asymmetry enhancement, was compared with the intraoperatively measured cerebral perfusion pressures. Asymmetry enhancement exceeded the methodological variation in 14 patients, 13 of whom had a perfusion pressure below 65 mmHg. Insignificant asymmetry enhancement was found in 64 patients: 52 with unilateral and 12 with bilateral disease. Of these two and four patients, respectively, had perfusion pressures below 65 mmHg. Enhancement of CBF asymmetry following a potent cerebral vasodilator stimulus is a reliable predictor, in unilateral carotid artery disease, of critically reduced cerebral perfusion pressure.     

Evaluation of the cerebral vasodilatory capacity by the acetazolamide test before EC-IC bypass surgery in patients with occlusion of the internal carotid artery

Cerebral blood flow (CBF) was measured by xenon-133 inhalation tomography in 18 patients with cerebrovascular disease before and 4 months after extracranial-intracranial bypass surgery. Only patients who showed a reduced CBF in areas that were intact on the CT scan and relevant to the clinical and angiographical findings were operated. The majority of the patients had suffered a minor stroke with or without subsequent transient ischemic attacks. They were studied at least 6 weeks following the stroke. All patients had an occlusion of the relevant internal carotid artery. To identify preoperatively the patients with a compromised collateral circulation and hence reduced CBF due to reduced perfusion pressure, a cerebral vasodilatory stress test was performed using acetazolamide (Diamox). In normal subjects, Diamox has been shown to increase tomographic CBF without change of the flow distribution. In the present series 9 patients showed a significant redistribution of flow in favor of the non-occluded side ("positive" Diamox test). Two of these 9 patients showed even a paradoxical decrease in focal CBF preoperatively, i.e., a "steal" effect. These 2 patients were the only patients who improved in focal CBF after shunting. The remaining 9 patients all showed uniform flow responses ("negative" Diamox test), and none of these increased in focal CBF postoperatively. The finding of an unchanged flow map postoperatively confirmed that the low flow areas were not due to restricted flow via collateral pathways. However, an increase in the regional vasodilatory capacity was observed postoperatively in the majority of patients.     

Cerebral haemodynamics and long-term prognosis after extracranial-intracranial bypass surgery.

The effectiveness of extracranial-intracranial arterial (EC-IC) bypass surgery for haemodynamic stroke remains controversial. In this study correlation of presurgical and postsurgical cerebral haemodynamics with long term prognosis was evaluated. Twenty eight patients (25 men, three women: mean age 61.4 (SD 8.2) years) with reduced cerebrovascular reserve due to steno-occlusive cerebral vascular disease formed the study group. Measurement of mean hemispheric cerebral blood flow (mCBF) and the cerebral vasodilatory capacity (% mCVR) with an intravenous acetazolamide injection were performed by a xenon-133 inhalation method and SPECT. Patients were treated with EC-IC bypass surgery and measurements of mCBF and % mCVR were made again about one month after surgery. The patients were then observed for a long period (range 27-115 months). During the observation period, four patients experienced subsequent ischaemic strokes. The presurgical and the postsurgical resting mCBF for the affected hemisphere were significantly reduced in the patients with strokes during follow up compared with the values in patients without strokes during follow up (P < 0.03 and 0.01 respectively). The % mCVR of the affected hemisphere was significantly raised after surgery in all patients except one (P < 0.01). The postsurgical change in resting mCBF was not unidirectional. In conclusion, resting mCBF was unchanged and % mCVR was improved after EC-IC bypass surgery in patients with reduced cerebrovascular reserve. The group of patients with a reduced presurgical and postsurgical resting mCBF continue to be a high risk group for subsequent ischaemic stroke seen after EC-IC bypass surgery.     

Study of Regional Cerebral Blood Flow in West Syndrome

Summary: Focal cortical disturbances are frequent sequelae in West syndrome (WS) even though it is a generalized epileptic syndrome. Functional neuroimaging was used to determine whether focal perfusion abnormalities exist at WS onset and change during evolution. We studied regional cerebral blood flow (rCBF) at different stages of WS. Mean CBF (mCBF) and rCBF were measured using SPECT (single photon emission computed tomography) and ¹³³Xe in 13 WS patients: at onset (20 cases), just after steroids (17 cases), and after a mean follow-up of 2 years (26 cases). At WS onset, interictal mCBF was increased as the result of foci of hyper- and hypoperfusion, which were, respectively, mainly located in the frontal and posterior cortex. Just after steroid therapy, mCBF decreased without any focal predominance. During follow-up, hypoperfused foci remained unchanged whereas the frontal hyperperfused foci decreased after spasm control. Our results show that focal abnormalities are present at WS onset. Focal hypoactivity could reflect a cortical lesion responsible for WS and focal hyperactivity could play a role in the persistence of generalized epilepsy.     

Evaluation of the regional cerebral vasodilatory capacity before carotid endarterectomy by the acetazolamide test

To estimate the regional perfusion pressure and possibly the stump pressure during carotid endarterectomy, cerebral blood flow (CBF) measurements including a vasodilatory test were performed preoperatively. CBF was measured by ¹³³Xe inhalation and emission tomography. An intravenous dose of 1g acetazolamide (Diamox) was used as cerebral vasodilator. Thirty-six patients with a clinical history of previous strokes (9 cases) or transient ischaemic attacks (27 cases) were studied. Nine of the patients showed occlusion of the contralateral internal carotid artery (ICA). The percent flow increase induced by Diamox in the ipsilateral hemisphere correlated to the ICA pressure was measured before clamping (n = 32, r = 0.55, p < 0.001). In 12 of the 36 patients, Diamox caused a significant change in the flow distribution indicating a restricted regional vasodilatory capacity and a reduced regional perfusion pressure. In addition, these 12 patients showed a low stump pressure (<50 mmHg). However, 8 additional patients had uniform CBF increases at the Diamox test, but showed low stump pressures. It is concluded, that preoperative tests of the cerebral vasodilational capacity can be used to identify most patients with a low ICA pressure, and a substantial fraction of patients that will develop a low stump pressure upon ICA clamping during operation. In these patients with abnormal Diamox tests surgical reconstruction is particularly indicated, but, at the same time the perioperative risks are presumably highest in this group.     

Quantitative regional cerebral blood flow measured by Tc-99m HMPAO SPECT in mood disorder

Depressed (n = 14) and remitted (n = 9) patients with mood disorder, patients with depressive disorder not otherwise specified (NOS; n = 10) and normal subjects (n = 8) underwent non-invasive and quantitative measurement of cerebral blood flow using HMPAO and SPECT in a resting state. The mean and regional cerebral blood flow (CBF) in twelve ROIs were compared among the four groups and correlations between CBF and the depressive symptoms were studied. The CBF was computed using graphical analysis on the SPECT console after a bolus injection of Tc-99m HMPAO and radionuclide angiography. The depressed group had significantly lower mCBF in the bilateral hemisphere and rCBF in all except one of the ROIs that the NOS and normal group. Significant negative correlations were found between the Hamilton scale for depression and rCBF in the bilateral lower frontal cortex after correcting for age in the mood disorder. Parallel analysis using both the quantitative and semiquantitative methods revealed that the former provided more global reduction of CBF in mood disorder. These results indicate that mean and regional CBF measured by this non-invasive method contributes to the objective evaluation of depressive symptoms. Negative correlations between HRSD and rCBF in the frontal regions indicate that frontal hypoactivity is closely related to depressive symptoms.     

Cerebral blood flow and common carotid flow in neurologically asymptomatic carotid endarterectomy patients

To define subgroups in 50 neurologically asymptomatic patients with carotid stenosis (mean diam. of stenosis 81.1 +/- 12.5%) regional cerebral blood flow (rCBF) and common carotid artery flow were measured by means of the intravenous Xenon-133 technique and a Doppler flowmeter, respectively. The rCBF studies were performed both at rest and after administration of acetazolamide (Diamox). In this asymptomatic cohort of 50 patients we found subgroups with significant hemispheric baseline asymmetry (BA) (five patients; BA = 7.2 +/- 1.8%) and/or pathological Diamox asymmetry enhancement (DAE) (five patients; DAE = 8.8 +/- 1.3%). Carotid endarterectomy in these cases resulted in a significant reduction of hemispheric differences of rCBF (postoperative BA = 0.4 +/- 3.4, postoperative DAE = 1.7 +/- 3.8). Measurements of common carotid flow revealed significantly higher flow rates in the postoperative period and compensation of intercarotid flow asymmetry. In pathophysiologically defined preclinical subgroups of cerebrovascular disease with hemispheric rCBF differences and/or impairment of the cerebral vascular reserve capacity surgical procedures might be useful.     

Cerebral blood flow and common carotid flow in neurologically asymptomatic carotid endarterectomy patients

To define subgroups in 50 neurologically asymptomatic patients with carotid stenosis (mean diam. of stenosis 81.1 ± 12.5%) regional cerebral blood flow (rCBF) and common carotid artery flow were measured by means of the intravenous Xenon-133 technique and a Doppler flowmeter; respectively. The rCBF studies were performed both at rest and after administration of acetazolamide (Diamox). In this asymptomatic cohort of 50 patients we found subgroups with significant hemispheric baseline asymmetry (BA) (five patients; BA = 7.2 ± 1.8%) and/or pathological Diamox asymmetry enhancement (DAE) (five patients; DAE = 8.8 ± 1.3%). Carotid endarterectomy in these cases resulted in a significant reduction of hemispheric differences of rCBF (postoperative BA = 0.4 ± 3.4, postoperative DAE = 1.7 ± 3.8). Measurements of common carotid flow revealed significantly higher flow rates in the postoperative period and compensation of intercarotid flow asymmetry. In pathophysiologically defined preclinical subgroups of cerebrovascular disease with hemispheric rCBF differences and/or impairment of the cerebral vascular reserve capacity surgical procedures might be useful.