椎动脉复合体的显微神经外科解剖及临床意义

行经枕下区域的椎动脉复合体集中于椎动脉的V3 段 ,其范围从枢椎横突孔至椎动脉穿入硬膜处 ,由椎动脉的血管袢、分支以及周围的纤维环、神经和静脉等结构组成。V3 又可分为水平段 (V3 h)及垂直段 (V3 v)两部分。对于此部位各层组织结构显微解剖的研究 ,阐明其生理及病理条件下的功能和特点 ,在临床上具有重要的指导意义。     

远外侧入路的解剖学基础

目的 通过显微外科解剖学方法探讨寰枕区解剖结构的特点,为深入理解和施行远外侧入路手术提供解剖学基础.方法 观察6具(12侧)尸头寰枕区枕动脉走行与位置、椎动脉与枕后肌肉三角的关系,以及小脑后下动脉的起始位置;并于导航系统引导下测量寰枕关节磨除程度与手术视野显露的关系和后组脑神经在切口处的位置.结果 经远外侧入路手术时,倒"U"形切口显露清晰、手术视野优于直线切口.6具(12侧)尸头枕动脉均走行于头夹肌的下方和头最长肌的上方;在枕后肌肉三角内均有椎动脉走行并于硬膜外发出肌支和硬膜支;11侧小脑后下动脉起源于硬膜内椎动脉,1侧起源于硬膜外椎动脉.寰枕关节磨除至根部可清楚地显露硬膜内小脑后下动脉起始部及第Ⅸ(舌咽神经)、X(迷走神经)和Ⅺ对(副神经)脑神经,但距第Ⅻ对脑神经(舌下神经)的距离较远[(7.20±2.33)cm];磨除寰枕关节后1/3,至舌下神经和脑干腹侧的手术距离明显缩短[(6.50±2.31)cm];二者比较差异有统计学意义(t=4.743,P=0.008).结论 经远外侧入路施行延髓腹侧和腹外侧病变手术可清楚地显露下斜坡邻近区、延髓腹侧和小脑后下动脉起始部.手术中应注意保护枕后肌肉三角内的椎动脉或起源于椎动脉硬膜外段的小脑后下动脉.对于舌下神经外侧病变无需磨除寰枕关节,需要时以磨除后1/3为宜,进一步磨除寰枕关节只能减少手术视野的深度而不能扩大显露范围.     

椎动脉V1段迂曲的危险因素分析

目的 探讨椎动脉V1段迂曲的危险因素及其与后循环缺血的相关性.方法 收集临床205例已行全脑血管DSA检查的患者,记录患者的临床资料,观察并记录患者椎动脉V1段形态,探讨椎动脉V1段迂曲的危险因素.结果 205例入组患者,124例(60.5％)(迂曲组)存在椎动脉V1段迂曲,无迂曲者81例(39.5％)(对照组)；398支椎动脉中,椎动脉V1段迂曲者166支(42％)；迂曲组年龄显著高于对照组,差异具有统计学意义(P＜0.01)；迂曲组患者女性比率以及患有高血压病的比率显著高于对照组,差异具有统计学意义(P＜0.01)；迂曲组与对照组在糖尿病、吸烟史、血脂水平方面差异无统计学意义(P＞0.05),多元logistic回归分析显示女性、高龄及高血压病是椎动脉v1段迂曲的危险因素(P＜0.05).结论 女性、高龄、高血压病病史是发生椎动脉V1段迂曲的危险因素.     

远外侧入路手术中椎动脉颅内段的显微解剖应用研究

目的 对椎动脉颅内段进行观察和测量,探讨远外侧人路手术中如何保护椎动脉颅内段和小脑后下动脉. 方法 手术显微镜下对20例带颈成人头颅标本模拟远外侧人路开颅,到达颈静脉孔区,显露椎动脉颅内段及其主要分支,观察其走形特点和形态,并测量相关数据. 结果椎动脉颅内段穿寰枕筋膜后在基底动脉沟与对侧椎动脉合成基底动脉.椎动脉与舌下神经关系密切,本组30侧椎动脉穿经舌下神经根的腹侧达桥脑延髓沟,8侧椎动脉穿舌下神经根丝之间,2侧椎动脉经舌下神经根丝的背侧.70%的椎动脉与舌下神经有接触,其中30%的椎动脉对舌下神经造成压迫.椎动脉颅内段主要分支有小脑后下动脉、脊髓前动脉、脑膜后动脉和一些穿动脉.小脑后下动脉是椎动脉最大的分支,本组全部发自椎动脉颅内段,行程多为袢状并同后组颅神经关系密切.小脑后下动脉的起始点因人而异,同一标本左右也不一致,大多起自椎动脉颅内段的中上1/3.本组未见小脑前下动脉起源于椎动脉.脊髓前动脉均起于双侧椎动脉的末段,在中线吻合成一单干,沿脊髓前正中裂迂曲下降供应脊髓. 结论 熟悉椎动脉颅内段及其分支的走形特点和解剖变异有助于远外侧入路到颈静脉孔区手术中识别和保护椎动脉颅内段的主要分支.     

彩色多普勒超声诊断椎动脉夹层的价值分析

目的探讨彩色多普勒血流显像(CDFI)检测椎动脉夹层(VAD)患者的血管内径、血管内回声及血流动力学变化,评价其诊断椎动脉夹层的临床价值。方法经超声检查、数字减影血管造影(DSA)证实椎动脉夹层患者14例,研究其超声影像学特征、血流动力学参数变化。结果根据血管结构特征分为双腔型、壁内血肿型及夹层动脉瘤型,14例椎动脉夹层患者中,壁内血肿型9例(累及V1段4例,累及V2段3例,累及V1、V2段2例),双腔型5例(累及V1段3例,累及V2段1例,累及V1、V2段1例),患侧椎动脉病变部位原始管腔明显增宽,真腔内径变窄且小于原始管腔内径1/2以上时,峰值流速(PSV)和搏动指数(PI)明显高于健侧,差异有统计学意义(P0.05)。结论彩色多普勒超声可以根据患侧椎动脉二维声像图及血流动力学特征初步筛查椎动脉夹层,为临床早期诊断和治疗提供可靠信息。     

寰枕融合患者椎动脉走行的CT血管成像研究及其临床意义

目的观察先天性寰枕融合患者椎动脉走行的解剖学特征及其在颅颈交界区后路内固定手术中的临床意义。方法回顾自2007年1月-2010年10月施行CT血管造影检查的48例先天性寰枕融合患者诊断与治疗经过,观察分析其椎动脉解剖走行特点。结果根据椎动脉分支和行程,48例患者96侧椎动脉共分为5种类型:Ⅰ型,椎动脉单干,走行于枕骨化的寰椎后弓和枢椎椎板之间,共19侧(19.79%);Ⅱ型,椎动脉单干,走行于寰椎与枕骨之间的骨孔,共43侧(44.79%);Ⅲ型,椎动脉单干,走行于枕骨与寰椎后弓之间,共29侧(30.21%);Ⅳ型,椎动脉开窗,一支走行于枕骨化的寰椎后弓下方,一支走行于寰椎和枕骨之间,入硬脑膜后重新汇合成椎动脉,共3侧(3.1 3%);V型,椎动脉发育细小或缺如,共2侧(2.08%)。结论先天性寰枕融合患者,椎动脉解剖走行变异较大。对于Ⅰ型和Ⅳ型椎动脉患者,神经外科手术显露时损伤椎动脉的风险较高;而Ⅱ型和Ⅲ型椎动脉患者,遵守严格的骨膜下分离操作原则可降低椎动脉损伤风险。手术前行CT血管造影并结合骨性结构融合特点,能够明显降低手术损伤的风险。     

寰枢段椎动脉在远外侧入路中的应用显微解剖研究

目的 为颅颈交界区手术入路提供解剖学参数,帮助神经外科医生安全、准确地暴露手术靶区.方法 应用10％甲醛固定的汉族成人尸头标本10例20侧;漂白干颅骨及寰枢椎10例20侧.模拟手术入路逐层解剖,并对解剖结构进行精确测量和拍照.结果 寰枢段椎动脉在颅颈交界区形成比较恒定的五个生理弯曲,平均直径(4.3±0.5) mm,角度多变.寰椎后弓外侧半距(19.3±4.7)mm.结论 熟悉寰枢段椎动脉五个生理弯曲的定位方法,有助于提高颅颈交界区手术入路的安全性.     

椎动脉型颈椎病与椎动脉V2段狭窄性病变的相关性

目的探讨临床诊断为椎动脉型颈椎病与经脑血管造影证实椎动脉V2段狭窄性病变的相关性。方法随机选取椎动脉型颈椎病患者116例,经数字减影血管造影(DSA)检查,分为临床诊断椎动脉型颈椎病但DSA证实未发现椎动脉V2段狭窄性病变组,和临床诊断为椎动脉型颈椎病同时DSA证实发现椎动脉V2段狭窄性病变组,并对两组的结果进行统计分析。结果 116例椎动脉型颈椎病患者中,经DSA检查证实有椎动脉V2段狭窄的患者只有32例,指标无统计学意义(P 0. 05)。结论椎动脉型颈椎病与椎动脉V2段狭窄性病变无相关性。     

椎动脉狭窄颈部CTA与DSA诊断差异及支架治疗疗效观察

目的 探讨颈部CTA检查在椎动脉狭窄诊断中的重要作用以及应用血管内支架成形术治疗症状性椎动脉狭窄的可行性及安全性.方法 回顾性分析自2007年5月至2011年4月在广州市第一人民医院神经内科住院的椎动脉系统脑梗死患者,所有患者均完善颈部CTA及颅脑MRA检查,若筛选发现可能存在椎动脉狭窄,则行DSA检查.经DSA确诊为椎动脉狭窄的患者在个体评估并知情同意后行椎动脉支架成形术.结果 颈部CTA检查发现38例椎动脉狭窄后循环脑梗死患者,均经DSA证实并予椎动脉支架成形术治疗.29例患者颈部CTA发现有＞50％椎动脉狭窄共38处,其中V4段狭窄8处,V1段狭窄30处;DSA证实仅4处V4段狭窄和28处V1段狭窄超过50％.另有9例颈部CTA示椎动脉V1段显示不清,而DSA明确其狭窄＞50％.38例患者共置入椎动脉支架41枚,支架成形术成功率100％,术后平均狭窄率(11.6％±8.9％)较术前(65.0％±11.2％)明显降低.术后随访6～25个月,1例发生脑干腔隙性梗死,1例脑干梗死呈闭锁状态,1例椎动脉V4段狭窄患者发生蛛网膜下腔出血.结论 颈部CTA检查对椎动脉狭窄的诊断能提供较大帮助.血管内支架成形术是治疗症状性椎动脉狭窄安全、有效的方法.     

2型糖尿病后循环缺血(PCI)患者DSA椎动脉狭窄分析

目的通过数字减影血管造影(digital substraetion angiography,DSA)方法,评价2型糖尿病后循环缺血(PCI)患者椎动脉狭窄的临床特点。方法选择2型糖尿病后循环缺血患者115例行CTA检查,筛查出65例椎动脉狭窄患者,均行DSA检查,以数字(V1-V4)顺血流方向标记椎动脉全程,评价2型糖尿病后循环缺血(PCI)患者椎动脉狭窄的临床特点。结果 (1)糖尿病后循环缺血患者以椎动脉V1段狭窄率发生最高,占73.07%,其次是V2和V4段,V3段狭窄最少见;(2)合并糖尿病的后循环缺血患者以轻度狭窄最常见,占41.54%,其次是重度和中度狭窄。结论 2型糖尿病后循环缺血(PCI)患者以椎动脉V1段狭窄最常见。狭窄程度以轻度狭窄最常见,重度和中度狭窄次之。     

乙状窦前迷路后入路中岩斜区应用解剖研究

目的通过对乙状窦前迷路后入路应用解剖研究,为中岩斜区显露提供显微外科解剖学基础。方法在10例(20侧)国人成人尸头(经10%甲醛固定并血管经彩色乳胶灌注)上模拟乙状窦前迷路后入路,观察中岩斜区神经血管走行分布特点、神经和血管间关系,测量相关重要数据。结果中岩斜区显微结构主要包括三叉神经(Ⅴ)、外展神经(Ⅵ)、面听神经(Ⅶ、Ⅷ)、基底动脉(BA)及小脑前下动脉(AICA)。三叉神经颅内段长度、出颅部至正中矢状面距离、矢状面角度分别为(13.82±1.84)mm,(12.90±2.02)mm,19.1°±8.0°,外展神经分别为(16.86±3.22)mm,(10.04±1.78)mm,25.6°±12.6°,面听神经分别为(14.84±2.30)mm,(23.88±2.90)mm,70.2°±5.5°。结论乙状窦前迷路后入路适用于中岩斜区显露。中岩斜区显微解剖研究及相关测量数据可为提高该区手术安全度和成功率提供参考。     

前交通动脉复合体临床解剖学的3D-DSA研究

目的探讨前交通动脉复合体的3D-DSA的特点,为前交通动脉瘤治疗提供参考。方法回顾性分析30例全脑3D-DSA检查阴性患者的影像学资料,测量大脑前动脉A1和A2段、回返动脉直径,以及大脑前动脉A1段与颈内动脉、大脑前动脉A1段与A2段夹角。结果左、右侧大脑前动脉A1段直径分别为(1.91±0.36)mm和(1.81±0.36)mm,长度分别为(13.0±1.60)mm和(14.0±2.28)mm;左、右侧大脑前动脉A2段直径分别为(1.88±0.38)mm和(1.69±0.36)mm;左侧和右侧回返动脉直径分别为(0.50±0.15)mm和(0.42±0.13)mm;右侧大脑前动脉A1段与A2段夹角为(94.13±23.59)度,左侧大脑前动脉A1段与A2段夹角为(97.74±25.19)度,右侧大脑前动脉A1段与右侧颈内动脉夹角为(89.14±16.61)度,左侧大脑前动脉A1与左侧颈内动脉夹角为(82.30±21.06)度。结论前交通动脉复合体存在较多的变异,充分了解其解剖学3D-DSA的特点对处理前交通动脉瘤具有重要意义。     

颅眶手术入路双容积融合影像的临床应用解剖学研究

目的 探讨双容积融合影像解剖学对颅眶手术的临床应用价值。方法 收集100例DSA检查无异常发现的病人,利用其三维脑血管成像及三维颅骨成像数据,在Siemens双C臂机Syngo后处理工作站,进行三维数据融合,获得3D-DSA/3D-CT的融合影像,选择颅眶区手术入路的步骤,对血管影像与颅骨相关及毗邻关系进行观察并测量与手术入路相关的数据,在三维静态（冠状位、矢状位、轴位及与手术相关的角度）与连续动态融合影像模拟手术入路步骤进行操作。结果 观察发现多数眼动脉起始部位于颈内动脉床突段内侧,沿视神经管外下方走行。颅骨左右径平均（143.89±5.78）mm,颅骨前后径平均（173.14±5.68）mm,双侧眼动脉起始处至视神经管上壁距离平均（7.32±2.42）mm,视神经孔到眶上裂距离平均（2.42±0.69）mm。在三维融合影像中发现2例眼动脉未经视神经管入眶的变异。结论 颅眶手术入路双容积融合影像,与单一影像相比,可显示手术入路的相互比邻解剖关系,对手术有更精准的参考价值。应用手术对象的融合影像显示手术入路,可达到标准化、个体化,对手术参考价值更大,更符合手术真实情况。     

Rete mirabile bei segmentaler Agenesie der A. carotis interna

The term carotid rete mirabile refers to an anatomic structure common in several lower mammals (e.g., swine). The blood supply for the intracranial arteries originates from branches of the external carotid artery, predominantly the ascending pharyngeal and internal maxillary arteries. In these animals the intracranial internal carotid artery forms from a dense network of numerous converging, small-caliber vessels. An analogous structure is rarely found in humans. Associated with segmental agenesis of the internal carotid artery, so-called carotid rete mirabile can be observed. In it numerous tortuous vessels with a diameter of 1-2 mm are found along the expected course of the internal carotid artery and coming from branches of the external carotid artery. These vessels converge to the intradural paraclinoid segment of the internal carotid artery, which shows a normal diameter. This rare pattern of collateral supply to the brain is illustrated here on the basis of two clinical case histories. Both patients presented with aneurysmal subarachnoid hemorrhage. In one, histological examination of a vessel biopsy revealed medial fibromuscular dysplasia. In both patients the rete mirabile was found in only one carotid system. The affected carotid canal in the skull base was hypoplastic. Human carotid rete mirabile probably has no inherent pathologic significance, but its frequent association with other intra- and extracranial vascular pathologies should be kept in mind.     

小脑梗死的分型与后循环血管病变

目的 研究有无大血管病变患者小脑梗死灶的特征,探讨小脑梗死分型与后循环血管病变的关系。 方法 收集我科自2006年1月～2008年3月期间住院的小脑梗死患者共35例,所有患者均同时具备颅脑磁共振成像（magnetic resonance imaging,MRI）和血管造影检查,包括计算机断层摄影血管造影（computed tomographic angiography,CTA）、磁共振血管造影（magnetic resonance angiography,MRA）和数字减影血管造影（digital subtraction angiography,DSA）检查。根据血管造影检查的结果将入组患者分为两组：大血管病变组20例,小血管病变组15例,分析两组小脑梗死的分型和后循环血管病变（包括狭窄或闭塞）的关系。 结果 ⑴大血管病变组20例中,颅内血管（椎动脉颅内段或基底动脉）病变最多见（10例,50%）,梗死类型多为分水岭梗死（7例,70%）;其次为颅外血管合并颅内血管（椎动脉颅外段合并颅内段或基底动脉）病变（8例,40%）,梗死灶多为小脑后下动脉（PICA）供血区的区域性梗死（7例,87.5%）;单独颅外血管（椎动脉颅外段）病变最少见（2例,10%）,梗死分布无明显倾向性。⑵小血管病变组15例中,梗死灶亦多位于分水岭区（9例,60%）。 结论 由于小脑血液供应特点,小脑梗死中分水岭梗死和腔隙性梗死较区域性梗死更为常见。小梗死灶（直径≤2cm）可能存在后循环大血管的狭窄或闭塞,应予积极的治疗和干预,以防病情加重。     

椎动脉起始位置与穿出颈椎横突孔高度关系的三维CT血管成像研究

目的通过三维CT血管成像(CTA)探讨椎动脉起始位置与穿出颈椎横突孔高度的关系。方法回顾性分析2017年3月至2019年3月河北医科大学第二医院神经外科行头颈上胸部CTA检查的480例患者的临床资料。将图像传输至图像后处理工作站进行骨质和血管重建,观察双侧椎动脉的起源、走行及穿出颈椎横突孔的高度。对于右侧椎动脉起源正常者,根据穿出颈椎横突孔的高度分为C₄、C₅、C₆组,每组随机选取10例分别测量右侧椎动脉起始位置至右侧颈总动脉起始的距离(L1)和右侧甲状颈干的距离(L₂),以L₁/(L₁+L₂)×100%计算椎动脉起始的相对位置。结果480例患者中,457例(95.2%)双侧椎动脉起源位置正常,均起源于锁骨下动脉,另23例(4.8%)起源异常,其中左侧椎动脉起源于主动脉弓19例、左侧颈外动脉1例;右侧椎动脉起源于右侧颈总动脉3例,且均合并迷走右锁骨下动脉。480例患者中,405例(84.4%)双侧椎动脉经C₆横突孔穿出;另75例(15.6%)穿出高度异常,其中左侧34例,经C₃、C₄、C₅、C₇横突孔穿出的分别有1、4、24、4例,直接入枕骨大孔1例;右侧41例,经C₃、C₄、C₅横突孔穿出的有1、14、26例。椎动脉起源异常的患者,左侧椎动脉起自主动脉弓的占比最高(19/20),且多数穿出颈椎横突孔的高度异常(18/19);右侧椎动脉均起自右侧颈总动脉合并迷走右锁骨下动脉(3/3),且穿出颈椎横突孔的高度均异常(3/3)。椎动脉起源正常的患者,96.7%(445/460)的左侧椎动脉穿出颈椎横突孔的高度正常,92.0%(439/477)的右侧椎动脉穿颈椎横突孔高度正常。3组右侧椎动脉起源正常的患者椎动脉起始的相对位置的差异有统计学意义[C₄组:(24.3±2.1)%、C₅组:(47.9±6.6)%、C₆组:(77.7±1.7)%,H=20.178,P<0.001]。结论椎动脉起始位置异常时,其穿出颈椎横突孔的高度多异常。右侧椎动脉的起始相对位置越靠近右侧颈总动脉时,穿出颈椎横突孔的高度越高;而越靠近右侧甲状颈干,穿出颈椎横突孔的高度越低。     

The V2 segment of the vertebral artery in anterior and anterolateral cervical spinal surgery: a cadaver angiographic study

OBJECTIVE: The second segment of the vertebral artery is under the risk of injury during anterior and anterolateral cervical spine procedures. To avoid such a risk, one needs to be familiar with the regional anatomy. The aim of this study was to measure the distance between the vertebral artery and the uncinate process, midline, and the medial side of the longus colli muscle using vertebral artery angiograms at the level of C6, C5, C4, and C3 vertebrae. MATERIALS AND METHODS: In 12 human cadavers, the vertebral arteries were first irrigated with water. Then the arteries were filled with silicon and barium, and finally their angiographic images were obtained. RESULTS: The transverse diameter of the vertebral artery was measured at C6, C5, C4, C3, and C2 level. The values on the left were bigger than the values on the right (p>0.05). The distance between the vertebral artery and the midline decreased from C6 (17.2+/-5.6mm on the right, 17.2+/-2.3mm on the left) to C3 (15.8+/-5.3mm on the right, 13.8+/-2.1mm on the left) (p>0.05). The distance between the apex of the uncinate process and the medial side of the vertebral artery was found to be longer at C4 (2.7+/-1.0 mm on the right, 2.2+/-1.0mm on the left) and C5 (2.5+/-1.1mm on the right, 2.5+/-1.0mm on the left) vertebra levels on the right side (p=0.339 at C4, p=0.862 at C5). The distance between the medial side of the longus colli muscle and the medial side of the vertebral artery was measured as 9.7+/-2.7 mm (9.5+/-2.9 mm on the right, 9.8+/-2.6mm on the left) at C6 level, 9.2+/-2.6mm (8.6+/-2.4mm on the right, 9.8+/-3.1mm on the left) at C5, 9.4+/-1.9 mm (9.2+/-2.1mm on the right, 9.5+/-2.0mm on the left) at C4, and 10.4+/-2.7 mm (10.5+/-3.0mm on the right, 10.1+/-2.6mm on the left) at C3 vertebra level. No significant difference was found between the right and the left (p>0.05). The angle between the vertebral artery and the midline was measured as 4.0+/-1.9 degrees on the right and 2.2+/-1.4 degrees on the left side (p=0.030). CONCLUSION: It was considered that the values obtained could be useful in anterolateral and anterior cervical approaches in terms of evaluating the position of the vertebral artery and its relation to vertebral structures. It is also concluded that the risk of injury in upper subaxial cervical spine is higher than in the lower part of the subaxial cervical spine.     

Extracranial vertebral artery dissections: a review of 13 cases

Clinical and radiologic findings in 13 patients (11 women, 2 men) with extracranial vertebral artery dissection are reported. Dissection was spontaneous in 8 patients, occurred after neck manipulation in 2 and after a potential minor injury to the neck in 3. Six had a history of common migraine, 4 were using oral contraceptives at the time of dissection, and 3 had fibromuscular dysplasia. Dissection was bilateral in 8 patients and associated with carotid dissection in 3. It usually presented with neck or occipital pain preceding basilar ischemic symptoms by a few minutes to 1 month. In 3 patients, transient ischemic attacks were the only manifestation of basilar ischemia, and in 1 patient there was no symptom of basilar ischemia despite bilateral vertebral dissection. In 19 of the 21 dissected vertebral arteries, the angiographic appearance was that of an irregular stenosis, which was associated in 6 arteries with pseudoaneurysmal formation. In 2 patients, 1 vertebral artery was occluded but the contralateral artery showed the typical irregular stenosis. The dissection involved only the third segment in 33%, only the second segment in 24%, and 2 or more segments in 38%. Eleven patients were treated with anticoagulants and 2 with aspirin; 11 recovered without sequelae and 2 had residual deficit. No recurrence was observed (mean follow-up 34 months). At control angiography (n = 12) or ultrasonic study (n = 1), 63% of dissected vertebral arteries had returned to normal, 26% showed marked improvement, and 11% were occluded. Our patient characteristics are compared with those of previously published cases. The validity of the distinction between spontaneous dissection and dissection associated with minor trauma is discussed.     

Color-coded duplex ultrasonography of the origin of the vertebral artery: normal values of flow velocities.

The introduction of color-coded duplex ultrasonography has improved the ease of performing ultrasound investigations of the vertebral arteries. So far, normal values of flow velocities have been reported only for the intertransverse region of the vertebral artery (V2 segments). Atherosclerotic disease at the origin of the vertebral arteries (V0 segment) is frequent and is one of the risk factors for vertebrobasilar ischemic disease. Normal values of flow velocities of the vertebral artery origin are needed to assess pathologic findings, such as vertebral artery origin stenosis or dissection. The aim of this study was to describe the normal flow velocities of vertebral artery origin (V0 segment) and the pre- (V1 segment) and intertransverse (V2 segment) part in 50 age-matched neurologic patients (mean age 54) without ischemic cerebral disease. The V0 segment could be visualized in 46 persons (92%) on the right side and in 43 (86%) on the left. The peak systolic blood velocity ranged from 30 to 100 cm/s (mean 63.6 +/- 17.5 cm/s), and end-diastolic blood velocity ranged from 10 to 35 cm/s (mean 16.1 +/- 5.1 cm/s). Analysis of side-to-side differences showed no significant differences of flow velocities in all subjects. It is concluded that color duplex ultrasonography is a feasible method to insonate the origin of the vertebral artery, and that nomogram data could be established. It is suggested that color-coded duplex ultrasonography of the vertebral artery origin should be performed in all patients with clinical symptoms or signs of vertebrobasilar ischemic disease. Nevertheless, further studies are needed to determine the normal and pathologic values of flow velocities of the vertebral artery origin and their reproducibility.