Three-dimensional transcranial Doppler in acute ischemic stroke in the territory of the middle cerebral artery: Clinical and CT correlation

We studied 34 patients with acute ischeiic stroke in the territory of the middle cerebral artery (MCA) by three-dimensional transcranial Doppler (TCD-3D). The parameters analyzed were: mean blood flow velocity, systolic and diastolic velocities; indices of pulsatility, hemisphere asymmetry and pulsatility transmission. Of the 34 patients 11 presented marked slowing of flow velocity in the MCA on the infarct side with an asymmetry index (AI) of over 40%, 8 patients with slightly reduced flow velocity in the MCA and an AI of 25–40%, 2 patients in whom there was indirect evidence of collateral circulations in the anterior cerebral artery distribution together with slowing of MCA flow; 5 patients had stenosis of the MCA, 9 patients showed no alterations of the Doppler parameters. The correlation between neurological symptom pattern and AI was significant (r=0.76). Noninvasive, easy to perform, performable at once and reliable, TCD-3D is a great improvement on traditional transcranial Doppler and is especially useful in assessing the hemodynamics of the cerebral circulation in ischemic stroke.     

Acute hemispheric stroke: Correlation between three-dimensional transcranial Doppler, MR-angiography, CT and clinical findings

We examined 50 ischemic stroke patients and 67 controls free of vascular disease, intra- or extracranial. We assessed all subjects clinically by neurological examination (quantified on the Canadian Neurological Scale or CNS), by three-dimensional transcranial Doppler sonography (TCD-3D) and by computed tomography (CT) within 24 h of the acute event, repeating CT 15 days later. 15 patients also underwent magnetic resonance angiography (MRA) and digital subtraction angiography (DSA). We used the following Doppler parameters: interhemispheric asymmetry index (AI), mean flow velocity (mV) and pulsatility index (PI) for the middle cerebral artery (MCA). The difference between patients and controls on analysis of the variance (ANOVA) in respect of AI was significant: F=50.8, p<0.0001. The CNS-AI correlation was equally valid: r=−0.56, p<0.001. The CNS-CT correlation proved to be highly significant: r=−0.72, p<0.0001. TCD-3D allowed quantitative evaluation of the hemodynamic changes and of the collateral blood supply and proved to be a sound method for the investigation of ischemic stroke, correlating well with the clinical findings, MRA and lesion size on CT. Paper presented at the National Congress at Sorrento in 1991 and selected by the Editorial Board of the Journal     

Blood flow velocities in middle cerebral artery branches after subarachnoid hemorrhage.

In a prospective study, 55 patients were examined by transcranial duplex sonography (TCCS) after subarachnoid hemorrhage (SAH) to determine whether additional transcranial duplex examination on the middle cerebral artery M2 segments would aid in the examination of the MCA stem segment. The mean blood flow velocities and pulsatility index were correlated to the occurrence of delayed ischemic neurologic deficits (DIND). Out of 47 patients included, 21 did not experience any delayed deficit (group I), 15 did (group II), and in 11 the extent to which vasospasm contributed to a neurologic deficit was unclear (group III). The highest blood flow velocity and the greatest increase of mean blood flow velocity on 1 day were significantly higher in groups II and III both in M1 and in M2. In 10 patients in group II, where the onset day of DIND was known exactly, Doppler data indicating ischemia before or at the time of DIND were observed in nine. In eight patients, Doppler of the MCA stem alone would have provided enough information to recognize the risk of symptomatic vasospasm; in one patient, only the M2 Doppler gave an indication of ischemic complication. Transcranial duplex sonography may provide additional information to TCD by accurate delineation of M1/M2 vasospasm and therefore may help plan cerebral angiography and neurointerventional treatment.     

An observational study of pre-operative transcranial Doppler examinations to predict cerebral hyperperfusion following carotid endarterectomies

The objective of this observational study was to determine whether pre-operative transcranial Doppler measurements could identify patients at risk for early cerebral hyperperfusion following carotid endarterectomies. Fifty-five patients (mean age 64.4 years) with symptomatic internal carotid artery stenosis were included. Pre-operative transcranial Doppler measurements included middle cerebral artery blood flow velocities at normocapnia, pulsatility indices and estimation of the cerebro-vascular reserve capacity ipsilateral to the internal carotid artery stenosis. The percentage change in blood flow velocities before and at the end of the procedure was calculated. Early cerebral hyperperfusion was defined as an increase of mean blood flow velocity of more than 100% at the end of the carotid endarterectomy. Early cerebral hyperperfusion was observed in 9.2%. Cerebral hyperperfusion was seen in patients with a subtotal carotid artery stenosis in combination with reduced pre-operative blood flow velocity and pulsatility. The post-operative stroke incidence in patients with an early cerebral hyperperfusion was tenfold higher compared to patients who did not experience early hyperperfusion. A prospective clinical trial is warranted to determine whether transcranial Doppler parameters can be used to indicate patients at risk for reperfusion strokes following carotid endarterectomies.     

颈动脉内膜切除术中经颅多普勒超声监测的应用

目的 应用经颅多普勒超声（trascranial Doppler,TCD）术中监测研究颈动脉内膜切除术（carotidendarterectomy,CEA）术中的脑血流变化和微栓子出现的规律。方法 应用TCD监测18例颈内动脉严重狭窄或闭塞者CEA中各期的同侧大脑中动脉（middle cerebralartery,MCA）的脑血流和微栓子信号（microembolic signal,MES）。记录CEA各期MCA收缩期血流速度（peak systolic velocity,PSV）、搏动指数（pulsitility index,PI）及微栓子的数量。结果 （1）术中1例患者出现左眼动脉颞上支栓塞,其余患者无并发症。（2）释放期和缝合期MCA的PSV及PI较基线期明显升高（P <0.01）。44.4%（8/18）的患者阻断后PSV下降>60%。术中,77.8%（14/18）的患者采取了分流措施。释放颈内动脉后33.3%（6/18）的患者PSV升高100%以上。（3）100%的患者于手术中监测到MES。患者的总MES为11～150个,平均60±42个。栓子主要集中于分流期和释放期。结论 TCD作为一项无创、实时的监测工具能够广泛应用于CEA术中监测,及时地发现围手术期的各种血流变化及MES的产生,有效预测围手术期的卒中发生,优化术中操作。     

MCA flow asymmetry is a marker for cerebrovascular disease

Abstract

Utilizing the UIC Vascular Laboratory Registry, we retrospectively analysed the significance of side to side middle cerebral artery (MCA) flow velocity differences. Side to side differences > 15% measured by transcranial Doppler were considered asymmetric. Asymmetric subjects had 5 times greater chance of having significant cervical carotid narrowing on either side on Duplex Doppler and a 3.7 times greater chance of having a stroke on brain CT or MRI. MCA flow velocity asymmetry is a marker for underlying carotid disease and stroke. [Neurol Res 1996; 18: 163–167]     

Transcranial Doppler sonography evaluation of anterior cerebral artery hypoplasia or aplasia

BACKGROUND AND PURPOSE: Transcranial Doppler (TCD) sonography is useful to evaluate intracranial arteries, however, interpretation of the TCD results in anterior cerebral artery (ACA) is difficult because of hypoplasia or aplasia. We try to define useful TCD indices and cut-off values to determine the variations of ACA. METHODS: Consecutive patients who underwent TCD and magnetic resonance angiography (MRA) were included. Patients with cerebrovascular abnormality or inadequate temporal windows were excluded. ACA status was classified as normal (NL), hypoplasia (HP), and aplasia (AP) according to MRA. TCD indices of mean flow velocity (MFV), pulsatility index (PI), ACA/middle cerebral artery (MCA) flow velocity ratio (ACA/MCA FVR), and asymmetry index (AI) of ACA were blindly compared with MRA between three groups. RESULTS: Two hundred and forty-one patients were included, and 193 patients (80%) were classified as NL, 34 (14%) as HP and 14 (6%) as AP. MFV was significantly lower in HP and AP (p<0.001), however, PI and ACA/MCA FVR were not different. AI was significantly different between NL and HP (21.5% vs. 50.4%), NL and AP (21.5% vs. 105.2%) (p<0.001). CONCLUSIONS: MFV of ACA should be interpreted with caution for its frequent anatomical variations. AI is useful to differentiate hypoplasia and aplasia from normal ACA with optimal criteria.     

Transcranial Doppler waveform blunting in severe extracranial carotid artery stenosis

OBJECTIVE: To investigate the frequency of transcranial Doppler (TCD) waveform blunting in patients with severe (80-99%) symptomatic or asymptomatic extracranial carotid artery stenosis. BACKGROUND: Severe carotid artery stenosis has been identified as a risk factor for ischemic stroke. Blunted Doppler flow waveforms (reduced systolic flow velocity and pulsatility) of the middle cerebral artery (MCA) are inferred to reflect hemodynamic impairment, possibly indicating an increased risk of stroke. METHODS: The 114 consecutive patients (mean age 72.4 years, SD 9.0 years; 37% women; 46 clinically symptomatic, 68 asymptomatic) with 80-99% stenosis of the extracranial internal carotid artery (ICA), as determined by duplex sonography, were examined with TCD. Flow velocities, pulsatility index, and spectral waveforms of the MCA distal to the ICA stenosis were assessed blinded to the clinical status of the ICA: Doppler waveform blunting was defined as loss of the characteristic systolic peak. Odds ratios with 95% confidence intervals and chi(2) statistics were used to describe the association between waveform blunting and the symptomatic status of the ICA stenosis. RESULTS: Among symptomatic patients, 23 (50%) had completed strokes, and a further 23 (50%) had transient neurologic deficits in the territory of the stenotic ICA. Blunted spectral waveform was found in 37 (80%, 95% CI 68-92%) of the symptomatic and 25 (37%; 95% CI 25-49%) of the asymptomatic patients. Symptomatic patients had significantly increased odds of having blunted TCD waveforms (OR 7.5, 95% CI 3.1-18.1, p < 0.001). CONCLUSIONS: Our findings suggest that TCD waveform blunting in the MCA as here described may be an additional risk factor in the setting of severe extracranial carotid artery stenosis. A prospectively designed study to confirm our results seems warranted.     

Transcranial Doppler in acute hemispheric brain infarction

We studied cerebrovascular anatomy using intra-arterial digital angiography, and blood flow velocity in the middle cerebral artery (MCA) using transcranial Doppler (TCD) ultrasonography in 42 patients with acute hemispheric ischemic brain infarction. We compared angiography with TCD and the clinical findings within 6 hours of the onset of symptoms. The location and extent of the chronic ischemic brain damage was assessed by CT performed 1 to 3 months after the ictus. Abnormal TCD, as manifested by either an unobtainable MCA flow signal or a significantly depressed MCA flow velocity, was highly associated with proximal MCA occlusions demonstrated by angiography. Abnormal TCD predicted both larger chronic CT lesions and more extensive ischemic change within the MCA territory. These data demonstrate that early TCD conveys useful information concerning cerebral tissue prognosis following hemispheric ischemia.     

2型糖尿病视网膜病变患者的脑血管储备研究

目的通过对2型糖尿病伴视网膜病变(DR)与糖尿病无视网膜病变(NDR)患者的眼动脉(OA)反应性对比分析,为临床提供诊断及治疗依据。方法运用TCD诊断仪,分别对20例DR和21例NDR患者行TCD检查,收集2组患者大脑中动脉(MCA)及OA的平均血流速度(Vm)、搏动指数(PI)、屏气指数(BHI)的参数进行对比分析。结果 DR组与NDR组比较:OA的Vm、屏气后平均血流速度(Vm`)、屏气后搏动指数(PI`)、BHI,MCA的Vm均比较差异有统计学意义(P<0.05)。结论通过对2型糖尿病患者OA血管反应性检测,能发现DR患者OA血流储备下降更明显,该检查有助于早期发现病变,利于及时采取更加积极的治疗,防止失明。     

Diagnosis of Moyamoya Disease with Transcranial Doppler Sonography: Correlation Study with Magnetic Resonance Angiography

BACKGROUND AND PURPOSE: Although the diagnosis of moyamoya disease may be confirmed by digital subtraction angiography, recent studies have shown the accuracy of magnetic resonance angiography. Characteristics of transcranial Doppler, a noninvasive and cost-effective method, and specific transcranial Doppler parameters reflecting distinct vascular status in moyamoya disease are explored. METHOD AND PATIENTS: Consecutive patients (> 15 years of age) diagnosed with moyamoya disease by a typical clinical history and digital sub traction angiography or magnetic resonance angiography were included. The statuses of the anterior, middle, and posterior cerebral arteries were graded as stage 1, stage 2, and stage 3 by magnetic resonance angiography. Mean flow velocity and pulsatility index were compared between these groups, and the receiver operating characteristic analysis was used to define transcranial Doppler criteria for distinct vascular status. RESULTS: Forty-five patients were included (37 women; mean age, 34.9 +/- 11.4 years). Mean flow velocity was higher and pulsatility index was lower in stage 2 (P < .01), while mean flow velocity was lower and pulsatility index was higher in stage 3 than in stage 1 (P < .01). Cutoff values reflecting stenosis or occlusion with substantial sensitivity and specificity were as follows: mean flow velocity > 85 cm/s or pulsatility index < 0.60 for stage 2, and mean flow velocity < 50 cm/s for stage 3 of middle cerebral artery; mean flow velocity > 80 cm/s or pulsatility index < 0.60 for stage 2 of anterior cerebral artery; and mean flow velocity > 60 cm/s or pulsatility index < 0.60 for stage 2 of posterior cerebral artery. CONCLUSION: Transcranial Doppler may help to refine magnetic resonance angiography findings and thus help clinicians differentiate severity or stages of moyamoya disease.     

Transcranial Doppler Markers of Diffusion-Perfusion Mismatch

BACKGROUND AND PURPOSE: During the evaluation of acute ischemic stroke with diffusion- and perfusion-weighted magnetic resonance imaging (DWI and PWI, respectively), the presence of salvageable brain tissue is suggested by the occurrence of a perfusion-diffusion "mismatch." DWI and PWI, however, are not universally available and have inherent inconveniences, which justify a search for practical diagnostic alternatives. The purpose of this study is to investigate whether there are transcranial Doppler (TCD) markers of mismatch. METHODS: Retrospective analysis of 22 patients with acute ischemic stroke affecting the middle cerebral artery (MCA) territory, who had a TCD performed within 24 hours of magnetic resonance imaging (MRI) with DWI and PWI. RESULTS: MRI and TCD were performed on average 10.8 +/- 9.2 hours apart. Time from symptom onset to MRI and TCD completion were 1.6 +/- 1.6 and 2 +/- 1.9 days, respectively. MCA and intracranial internal carotid artery (ICA) cerebral blood flow velocity (CBFV) asymmetry, together with a large ICA-to-MCA gradient, were associated with the presence of mismatch. The combined use of 2 TCD parameters (MCA CBFV asymmetry of > or = 30% and ICA-to-MCA gradient > or = 20 cm/sec) had a sensitivity of 75%, specificity of 80%, positive predictive value of 82%, and negative predictive value of 73% at detecting mismatch cases. CONCLUSIONS: Diffusion-perfusion mismatch appears to be associated with interhemispheric asymmetry between MCA and ICA CBFVs, and a large CBFV gradient between the ICA and MCA on the affected side. Prospective studies are required to verify these observations and to determine whether TCD can be used to follow patients with mismatch.     

Three-dimensional transcranial Doppler blood flow mapping in patients with cerebrovascular disorders

We investigated 60 patients with cerebrovascular disorders using a three-dimensional transcranial Doppler blood flow mapping system. A composite display of the circle of Willis is created with computer assistance, allowing accurate vessel identification and optimal data documentation of blood flow velocity and direction in the basal cerebral arteries. The basilar artery was insonated in every patient; the middle cerebral artery and the most distal internal carotid artery were found in 95% of the patients, the anterior cerebral artery in 85%, and the posterior cerebral artery in 84%. Insonation problems occurred predominantly in elderly women. Transcranial Doppler blood flow mapping showed an abnormal result in 23 of 60 patients (38%). An intracranial stenosis with greater than 50% diameter reduction or occlusion was found in 10 of 31 patients (32%) with completed stroke, reversible ischemic neurologic deficit, or transient ischemic attack. Collateral blood flow mechanisms could be demonstrated in patients with extracranial carotid artery occlusions. Intra-arterial cerebral angiography performed in 21 patients confirmed the transcranial Doppler blood flow mapping diagnosis in 19 (90.5%). In one patient an arteriovenous malformation diagnosed by transcranial Doppler blood flow mapping was confirmed by magnetic resonance imaging.     

Transcranial Doppler ultrasound in children with Sturge-Weber syndrome

Transcranial Doppler ultrasound is a noninvasive vascular assessment technique proved useful in the management of pediatric disorders predisposed to stroke and may have similar utility for Sturge-Weber syndrome. Eight children with Sturge-Weber syndrome had velocities measured in the major cerebral arteries via the Stroke Prevention Trial in Sickle Cell Anemia methodology. Velocities and pulsatility indexes were compared between the unaffected and affected sides. All subjects had reduced velocity on the affected side; the mean middle cerebral artery percentage difference was 20% (95% CI, 15%-25%). Pulsatility index was increased on the affected side; mean middle cerebral artery pulsatility index percentage difference, 34% (95% CI, 15%-53%). Six subjects also had reduced posterior cerebral artery velocity on the affected side. Side-to-side differences in middle cerebral artery and posterior cerebral artery velocities correlated with severity of MRI asymmetry (Spearman rho = 0.88, P = .02). Decreased arterial flow velocity and increased pulsatility index in the middle cerebral artery and posterior cerebral artery suggests a high resistance pattern that may reflect venous stasis and may contribute to chronic hypoperfusion of brain tissue. Further study of Transcranial Doppler in children with Sturge-Weber syndrome is indicated.     

Atrial Fibrillation,Congestive Heart Failure,and the Middle Cerebral Artery

Atrial fibrillation and congestive heart failure are risk factors for ischemic stroke usually attributed to cardiac embolism. To define potential alternative mechanisms, patients with atrial fibrillation and congestive heart failure were investigated by transcranial Doppler. Middle cerebral artery (MCA) blood flow velocities were analyzed in neurologically asymptomatic patients with nonvalvular (n = 10) and valvular (n = 13) atrial fibrillation, patients in normal sinus rhythm with congestive heart failure (n = 13), and control subjects (n = 11). Compared to patients in sinus rhythm with congestive heart failure and to control subjects, patients in both atrial fibrillation groups had significantly greater beat-to-beat variation in peak, mean, and diastolic velocities and in pulsatility index. Peak, mean, and diastolic MCA velocities in patients with atrial fibrillation and those with congestive heart failure were significantly less than those in control subjects. Patients with nonvalvular atrial fibrillation had a higher pulsatility index compared to each of the other three groups. These findings demonstrate substantial nonemboligenic alterations of the intracranial circulation associated with atrial fibrillation and congestive heart failure, and also provide an intracranial hemodynamic profile that may distinguish valvular from nonvalvular atrial fibrillation.     

Transcranial Doppler sonographic studies of cerebral autoregulation in Shy-Drager syndrome

Summary A study is reported of mean arterial blood pressure and heart rate in four patients suffering from Shy-Drager syndrome. Blood flow velocity in the middle cerebral artery (MCA) was recorded by transcranial Doppler sonography. Concomitant changes in cerebral blood flow and the effect of cerebral autoregulation were thus examined. During tilt (60°, head up) mean arterial blood pressure decreased by 40 mm Hg or 35%, while MCA blood flow velocity dropped by 14 cm/s or 28% (mean values). The lower percentage reduction in flow velocity may indicate a preserved cerebral autoregulation in central autonomic insufficiency.     

Serial Transcranial Doppler Sonography in Ischemic Strokes in Middle Cerebral Artery Territory

The changes in middle cerebral artery (MCA) blood flow velocity were serially evaluated in 31 patients with acute ischemic strokes in the MCA territory using transcranial Doppler ultrasound. In patients with a poor clinical prognosis, MCA mean velocity on the infarcted side (MV,) was significantly decreased within 48 hours after onset, compared with that on the opposite side (MV2 ) (p < 0.01 ). However, this change was not significant in patients with a good clinical prognosis. As predictors of poor clinical prognosis, an MV, of 40 cm/sec or less and an asymmetry index of - 20% or less showed positive predictive values of 93 and 88%, with sensitivities of 72 and 83% and specificities of 92 and 85%, respectively. An MV, slower than 20 cm/sec or an asymmetry index below -50% had a 100% positive predictive value and a 100% specificity, but less sensitivity (17 and 44%, respectively). Combining an MV, of 40 em/sec or less with an asymmetry index of -20% or less resulted in a 100% positive predictive value and a 100% specificity, with a relatively high sensitivity of 67%. As predictors of good clinical prognosis, an MV, faster than 40 cm/sec and an asymmetry index above -20% showed positive predictive values of 71 and 79%, with sensitivities of 92 and 85% and specificities of 72 and 83%, respectively. The clinical prognosis based on MV, seems particularly reliable for MCA territorial and cortical infarctions.     

Clinical Investigative Studies: Relationship Between Absolute Mean Cerebral Transit Time and Absolute Mean Flow Velocity on Transcranial Doppler Ultrasound After Ischemic Stroke

BACKGROUND AND PURPOSE: Previous studies of transcranial Doppler (TCD) sonography in acute stroke have used the relative difference between the symptomatic and asymptomatic arteries to assess arterial occlusion. However, a simple measure of absolute mean flow velocity might provide a direct assessment of "perfusion reserve" in acute ischemic stroke. METHODS: In a prospective study, 62 patients with ischemic stroke had TCD and a mean cerebral transit time examination within 48 hours of stroke. Absolute intracranial arterial mean flow velocities were correlated with the corresponding absolute mean transit times. RESULTS: The authors found a significant correlation between middle cerebral artery (MCA) mean flow velocity and transit time in the symptomatic (Spearman rank correlation coefficient [rho] = -0.65, P < .01) but not in the asymptomatic (rho = -0.04, P = ns) MCA territory. Equations relating absolute mean flow velocity to absolute transit time were derived. CONCLUSION: The findings suggest that in the normal hemisphere (with intact autoregulation on the horizontal portion of the autoregulation curve), flow velocity and transit time are not closely related to each other, but in the symptomatic hemisphere (on the downward slope of the autoregulation curve), flow velocity is directly proportional to the transit time and, therefore, to its inverse, perfusion reserve. The use of absolute mean flow velocity values on TCD should be further explored as a simple way of assessing "perfusion" in acute ischemic stroke.     

经颅多普勒超声脑缺血溶栓分级与阿替普酶静脉溶栓治疗急性前循环不同大动脉闭塞性脑梗死预后相关性研究

目的探讨分析经颅多普勒超声脑缺血溶栓分级与静脉溶栓治疗急性前循环不同大动脉闭塞性脑梗死患者血管再通评价与预后的相关性研究。方法选择急性前循环大动脉闭塞性脑梗死患者,对符合静脉溶栓者给予阿替普酶静脉溶栓治疗,分别于溶栓前及溶栓后24 h行床旁经颅多普勒超声(transcranial Doppler,TCD)检查并记录脑缺血溶栓分级(thrombolysis in brain ischemia,TIBI)。采用美国国立卫生研究院卒中量表(National Institutes of Health Stroke Scale,NIHSS)评分记录患者临床神经功能缺损,3个月随访时采用改良Rankin量表(modified Rankin Scale,m RS)评分评估患者预后,分析前循环不同大血管闭塞性脑梗死患者静脉溶栓前后血管再通情况及患者3个月预后。结果共入选46例患者,其中颈内动脉(internal carotid artery,ICA)闭塞患者19例,大脑中动脉(middle cerebral artery,MCA)闭塞患者27例。溶栓前与溶栓后24 h TCD监测TIBI分级提示血管再通者,ICA闭塞组5.26%,MCA闭塞组55.56%。ICA闭塞组与MCA闭塞组比较,MCA闭塞组90 d随访生活自理及良好预后的比例均高于ICA闭塞组,死亡率低于ICA闭塞组,而两组间溶栓后的症状性颅内出血发生率差异无显著性。结论急性前循环大动脉闭塞性脑梗死经静脉溶栓治疗后可获得血管再通,尤其是MCA闭塞患者;溶栓前后TIBI血流分级变化可反映大动脉血管再通情况,且有助于判断患者临床预后。     

Arterial pulsatility as an index of cerebral microangiopathy in diabetes

BACKGROUND AND PURPOSE: This study was designed to evaluate cerebral hemodynamic changes related to diabetes mellitus (DM) with transcranial Doppler ultrasonography (TCD). METHODS: We measured the flow velocities and the Gosling pulsatility index (PI) of the middle cerebral artery (MCA), extracranial internal carotid artery (ICA), and basilar artery (BA) in 56 stroke-free, normotensive patients with type 2 DM and 70 age- and gender-matched healthy volunteers. Patients were divided into 2 groups according to the presence of microvascular complications such as retinopathy, nephropathy, and neuropathy. RESULTS: Patients showed slightly lower hematocrit and higher serum fibrinogen levels than control subjects, but other clinical profiles, including stroke risk factors except for diabetes, were comparable between patients and controls. The flow velocity of the ICA but not the MCA and BA in patients regardless of the complication was significantly higher than that in controls. The PIs of the MCA and ICA were significantly higher in patients with complication than those without complication, as well as in controls. The PI of the BA was also significantly higher, even in patients without complication, than in controls. The PIs of the MCA and ICA but not the BA were closely correlated with the duration of DM (r(2)=0.46 and 0.34, respectively). CONCLUSIONS: This study defines TCD findings of diabetes-related cerebral hemodynamic changes and suggests that the PI reflects microangiopathic changes of cerebral vessels.