A single-blinded pilot study assessing neurovascular contact by using high-resolution MR imaging in patients with trigeminal neuralgia

Objective

To assess the feasibility and utility of high-resolution three-dimensional magnetic resonance angiography (3D MRA) and contrast-enhanced 3D spoiled gradient-recalled imaging (3D SPGRI) for the purpose of visualization of neurovascular contact in trigeminal neuralgia (TN) patients.

Methods

Forty-five patients (25 males, 20 females; age range, 23–82 years; and mean age, 55.67 ± 18.23 years) with unilateral typical TN and 36 control subjects (21 males, 15 females; age range, 25–85 years; mean age, 57.53 ± 19.25 years) underwent high-resolution 3D MRA and contrast-enhanced 3D SPGRI assessment. The images were reviewed by two experienced neuroradiologists who were blinded to the clinical details. The imaging results were compared with the operative findings in all the patients; additionally, the degree of neurovascular contact was compared between the two groups based on MR imaging.

Results

In 45 patients with unilateral typical TN, the use of 3D MRA in conjunction with the contrast-enhanced 3D SPGRI identified neurovascular contact in 40 of the 42 symptomatic nerves; the contact was verified surgically. Based on the surgical findings, the sensitivity and specificity of MR imaging were 95.20% and 100%, respectively. Based on MRI, the compressing vessel (artery, vein) was correctly identified in 32 of the 39 cases verified by microvascular decompression. There was good agreement (K = 0.77; 95% confidence interval, 0.54–0.99) between the position (medial, lateral, superior, and inferior) of the compressing vessel relative to the trigeminal nerve as defined by MR imaging and the surgical findings. The rates of vascular contact with the trigeminal nerve as observed on MRI were 31.94%, 48.89%, and 88.9% in the control subjects, asymptomatic, and symptomatic side of patients, respectively.

Conclusion

The combined use of high-resolution 3D MRA and contrast-enhanced 3D SPGRI is an extremely sensitive and specific technique for demonstrating vascular contact with the trigeminal nerve in TN patients.     

血管压迫性三叉神经痛责任血管的3.0T MRI研究

目的 采用3.0 T MRI显示三叉神经及周围血管的解剖关系,分析产生原发性三叉神经痛(TN)的血管压迫特点.方法 选择50例TN患者(50支TN患侧和50支TN对侧三叉神经;其中23例行微血管解压术)和50名没有面部疼痛的志愿者(100支非TN三叉神经),在3.0TMR采用三维快速稳态梯度回波序列(3D TRU-FISP)及3D 三维时间飞跃(TOF-MRA)扫描.若判断TN患者为静脉病变,并行增强3D快速小角度反转序列(3DFLASH)扫描.以上图像融合重建成虚拟脑池图,评价神经血管压迫程度分级(1级无压迫,2级静脉性压迫,3级神经与动脉接触,4级有动脉压痕,5级动脉压迫导致神经明显移位),以及血管接触神经的方位(三叉神经的上侧或其他侧)、血管神经接触点的位置(近:位于三叉神经脑池段近脑干1/3长度区域,远:位于三叉神经脑池段远脑干2/3长度区域).3D TRU-FISP序列重建的冠、矢状面图像用于测量神经长度、神经横截面及脑池面积.采用卡方检验观察2组的三叉神经:血管压迫神经引起神经切迹或移位(4级和5级)、血管神经压迫点和神经出脑干处距离、血管压迫神经的位置位于神经上侧方的发生率.采用t检验观察测量数值的统计学意义,并用Logisac回归分析三叉神经痛的发病因素.结果 两序列及融合图像可以清晰显示神经血管的关系,与23例微血管解压术中所见吻合度高,术后症状消失或明显减轻21例.血管压迫或接触三叉神经的发生率在志愿者组(1级79支,2级5支,3级8支,4级8支)、TN对侧(1级27支,2级6支,3级9支,4级8支)及TN患侧(1级4支,2级t2支,3级12支,4级7支,5级15支)分别为21.0％(21/100)、46.0％ (23/50)、92.0％ (46/50).TN患侧三叉神经较志愿者三叉神经血管受压迫程度4、5级者差异有统计学意义(x2=27.0,P ＜0.01);血管接触点的位置在TN患侧近32支、远14支,在志愿者近4支、远17支(x2=14.8,p＜0.01);压迫血管位置中,TN患侧位于神经上侧36支、其他侧10支,志愿者中位于神经上侧5支、其他侧16支(x2=18.0,P＜0.01);所在层面脑桥池面积,TN患侧为(183.9+52.5) mm2、对侧为(217.8±58.8)mm2(t=-3.04,P＜0.01);脑池段神经中点截面积,TN患侧为(6.3±1.3)mm2、对侧为(7.7±1.6) mm2(t=-4.8,P＜0.01);脑池段神经长度,TN患侧为(8.0±1.9)mm、对侧为(9.0±2.0)mm(t=-2.64,P＜0.05),差异均有统计学意义.结论 MR可以清楚显示TN患者血管与三叉神经的关系,受压迫神经位置更靠神经近端及头侧、神经所在层面脑桥池面积较小者,均是较强的手术指征.     

Patterns of neurovascular compression in patients with classic trigeminal neuralgia: A high-resolution MRI-based study

Purpose

To describe the anatomical characteristics and patterns of neurovascular compression in patients suffering classic trigeminal neuralgia (CTN), using high-resolution magnetic resonance imaging (MRI).

Materials and methods

The analysis of the anatomy of the trigeminal nerve, brain stem and the vascular structures related to this nerve was made in 100 consecutive patients treated with a Gamma Knife radiosurgery for CTN between December 1999 and September 2004. MRI studies (T1, T1 enhanced and T2-SPIR) with axial, coronal and sagital simultaneous visualization were dynamically assessed using the software GammaPlan™. Three-dimensional reconstructions were also developed in some representative cases.

Results

In 93 patients (93%), there were one or several vascular structures in contact, either, with the trigeminal nerve, or close to its origin in the pons. The superior cerebellar artery was involved in 71 cases (76%). Other vessels identified were the antero-inferior cerebellar artery, the basilar artery, the vertebral artery, and some venous structures. Vascular compression was found anywhere along the trigeminal nerve. The mean distance between the nerve compression and the origin of the nerve in the brainstem was 3.76 ± 2.9 mm (range 0–9.8 mm). In 39 patients (42%), the vascular compression was located proximally and in 42 (45%) the compression was located distally. Nerve dislocation or distortion by the vessel was observed in 30 cases (32%).

Conclusions

The findings of this study are similar to those reported in surgical and autopsy series. This non-invasive MRI-based approach could be useful for diagnostic and therapeutic decisions in CTN, and it could help to understand its pathogenesis.     

磁共振3D-TSE序列和3D-VIBE序列在诊断血管压迫性三叉神经痛中的价值

目的探讨磁共振3 D-TSE序列和3 D-VIBE序列对于血管压迫性三叉神经痛的诊断价值。方法采用3 DTSE序列和3 D-VIBE序列扫描28例临床拟诊为血管压迫性三叉神经痛的患者。经3 DMRP、MIP、min-MIP后处理图像,观察三叉神经与周围血管的关系。结果 28例患者手术证实26例存在血管神经接触或压迫,3 D-VIBE、3 D-TSE序列综合判断血管压迫性三叉神经痛的阳性预测值、阴性预测值、敏感性、手术符合率分别为92.0%(23/25)、33.3%(1/3)、92.0%(23/25)、85.7%(24/28)。而且MRI所显示的责任血管与神经的相对位置关系与术中所见具有高度的一致性(K=0.81)。结论 3 D-TSE序列和3 D-VIBE序列结合可以清楚显示脑池内血管和三叉神经的空间关系并辨认责任血管的来源,对血管压迫性三叉神经痛的术前评估具有较高的价值。     

MRI volumetry for the preoperative diagnosis of trigeminal neuralgia

To assess whether quantitative measuring methods can help improve the reliability of MRI-based evaluations of the pathological role of a neurovascular conflict between an artery and the trigeminal nerve. In a prospective study, magnetic resonance images were obtained from 62 patients with unilateral facial pain and 50 healthy test subjects. In coronal T1- and T2-weighted sequences volume measurements were performed by regions of interest and compared intraindividually (healthy versus affected side in the patient populations and right versus left side in the group of test subjects) and on the basis of the different clinical pictures (t test for dependent and independent samples, p<0.05). In patients with trigeminal neuralgia, the affected nerve showed a smaller volume than the trigeminal nerve on the healthy side (p<0.001). Such a volume difference was noted neither in the other patients nor in the healthy test subjects. Quantitative MRI measurements allow a pathological neurovascular conflict to be distinguished from a nonpathological condition where an artery is in close proximity to the trigeminal nerve. The measured volume difference between the healthy and the affected nerve in patients with neuralgia is indicative of trigeminal nerve atrophy resulting from damage to the nerve.     

面肌抽搐与三叉神经痛的MRI诊断

目的　探讨面肌抽搐及三叉神经痛患者血管压迫病因的MR表现及其诊断价值。方法　回顾性分析了 12 0例面肌抽搐及三叉神经痛患者MR表现及手术结果。结果　 (1) 6 3例面肌抽搐患者MR显示 12 6侧面听神经共发现 5 8侧存在神经血管压迫或接触 ,17侧可疑接触 ;5 7例三叉神经痛患者MR显示 114侧三叉神经共发现 4 5侧存在神经血管压迫或接触 ,12侧可疑接触。 (2 )统计学分析结果 :面肌抽搐患者症状侧和无症状侧差异有非常显著性意义 (χ2 =31 6 6 ,P <0 0 0 1) ;三叉神经痛患者症状侧和无症状侧差异有非常显著性意义 (χ2 =4 2 98,P <0 0 0 1)。 (3)根据手术结果 ,MR诊断面肌抽搐及三叉神经痛患者神经血管压迫或接触的敏感度为 94 % ,准确度为 83% ,阳性似然比为1 88。结论　MRI能清晰显示三叉神经脑池段与毗邻血管之间的关系 ,对面听神经及三叉神经血管压迫或接触的正确诊断具有较高的敏感度和准确度 ,为临床医师提供术前评估和指导治疗有极其重要的意义。     

血管压迫性三叉神经痛的MRI研究

目的 采用MR断层血管成像术对血管压迫性三叉神经痛的责任血管作深入研究。方法 235侧正常三叉神经及147侧有三叉神经痛症状的三叉神经MR三维时间飞跃（3D-TOF）扫描图像由2名医师以盲法读片，评判所见三叉神经周围有无血管及其与血管的关系，并记录所见血管的直径、血管至脑干的距离及血管的走行方向。分别进行团体t检验和卡方检验以明确有无统计学意义。结果 共有242侧三叉神经周围可以见到关系密切的血管，其中111侧为无症状组，131侧为有症状组，经统计表明有症状组三又神经所见责任血管距脑干的距离中位数为2mm，明显较无症状组（中位数为4mm）短（P〈0．01），有症状组三叉神经所见责任血管与血管夹角（89．3％，117／131）〉45。（P〈0．01）。无症状组中仅有1例（0．4％，1／235）发现三叉神经受血管推压移位，而在有症状组中有45例（30．6％，45／147），因此有症状组三叉神经受压推移率明显高于无症状组（P〈0．01）。结论 MRI对血管压迫性三叉神经痛的责任血管的评估非常有价值。责任血管距脑干的最短距离及走行与血管压迫性三叉神经痛的发病非常有关。     

三维时间飞跃对三叉神经痛的诊断价值

目的 探讨三叉神经痛神经患者的ＭＲ表现为其诊断价值。方法 应用三维时间飞跃（３Ｄ－ＴＯＦ）序列,结合ＳＥ及快速液体衰减反转恢复（ＦＬＡＩＲ）序列,回顾性分析了１０４例三叉神经痛患者ＭＲ表现及手术结果。结果 （１）１０４例三叉神经痛患者中ＭＲＩ诊断为血管压迫或接触的为７５例,术中证实有血管压迫或接触的为６９例;桥小脑角肿瘤共１４例,ＭＲＩ确诊１３例,另１例由手术确诊;血管性病变的为５例,均由微血管减     

3D-VIBE序列对血管压迫性三叉神经痛和面肌痉挛诊断价值

目的探讨3.0 T磁共振3D扰相梯度回波(3D-VIBE)序列对于三叉神经痛和面肌痉挛责任血管的诊断价值。方法利用3D-VIBE的原始图像重建,从不同的角度观察神经与血管的走行关系,发现责任血管,并与临床微血管减压术(MVD)进行比对。结果进行3D-VIBE序列扫描后发现责任血管,与术中所见基本符合。血管呈高信号,神经呈等信号,对比良好,能够直观显示血管与神经的解剖结构。三叉神经痛的症状侧的血管压迫阳性符合率为90.6%(29/32),面肌痉挛的症状侧的血管压迫阳性符合率为89.4%(17/19)。结论 3D-VIBE序列对于发现血管压迫性三叉神经痛和面肌痉挛责任血管,明确血管与神经的关系有诊断价值。     

Magnetic resonance tomographic angiography: diagnostic value in trigeminal neuralgia

A combination of MRI, MR angiography and MR tomographic angiography (MRTA) was used to study the relationship to the root exit zone of the trigeminal nerve to surrounding vascular structures in seven patients with trigeminal neuralgia (TN) and ten patients with no evidence at a lesion in this region. MRTA is the technique for showing the relationship between vessels, cranial nerves and brain stem. MRTA clearly demonstrated the presence of a vessel at the root exit zone of the trigeminal nerve in all patients with TN. In the ten other patients, examination of 20 trigeminal nerves revealed that only one nerve (5%) was in contact with a vessel at the root exit zone. This study supports vascular compression of trigeminal nerves as a cause of TN, and demonstrates the value of MRTA as noninvasive technique for demonstrating compression.     

MRI在三叉神经痛和半侧面肌痉挛病因诊断中的价值

目的 探讨MRI在诊断三叉神经痛与半侧面肌痉挛中的价值.方法 将51例三叉神经痛与23例半侧面肌痉挛患者的术前MRI资料与手术结果进行对照分析.结果 ①74例患者中,MRI诊断患侧桥小脑角胆脂瘤8例,听神经瘤7例,三叉神经瘤4例,脑膜瘤3例,患侧神经微血管压迫49例(66.21％),MRI未见异常者3例(4.05％);②手术病理结果:胆脂瘤8例,听神经瘤7例,三叉神经瘤4例,脑膜瘤3例,三叉神经或面神经根部异常血管压迫者46例(62.16％),术中未见异常者6例(8.11％).结论 MRI在三叉神经痛和半侧面肌痉挛病因诊断中具有很高价值,是术前首选的检查方法.     

The spectrum of magnetic resonance imaging findings in hypertension-related neurovascular compression

Hypertension (HTN) has been controversially related to neurovascular compression (NVC) at the rostral ventrolateral (RVL) medulla in anatomical, surgical, and radiological reports. Our objective was to investigate the association between primary HTN and signs of NVC at the medulla oblongata on magnetic resonance imaging (MRI) and to explore a new classification based on image criteria. Subjects with (n=64) and without (n=29) HTN were studied. Three-millimeter slices, with 1-mm intervals in between, were performed on T2-weighted images in axial and coronal views. Attention was focused on the relationship between the upper medulla and the surrounding arteries. The findings were divided into three categories: 1) non-NVC: absence of signs of NVC, 2) NVC type I: an artery in contact with the RVL medulla but not compressing it, and 3) NVC type II: evident compression of the RVL medulla by an artery. Signs of NVC were observed in 65.7% (42/64) of the HTN group (type I: 39.1%, 25/42 patients; type II: 26.6%, 17/42 patients). Among the normotensive subjects, 27.6% (8/29) had signs of NVC; only one (3.3%) of these had NVC type II (evident compression), and the rest were NVC type I. We conclude that the presence of NVC at the RVL medulla on MRI is related to HTN. More importantly, the finding of frank compression (NVC type II) is present almost exclusively in hypertensive subjects; only one individual (3.3% of our normotensive population) had NVC type II.     

三叉神经痛MRI序列研究及诊断价值

目的 探讨MR序列对导致三叉神经痛病变的显示能力及诊断价值.方法 回顾性分析60例三叉神经痛患者临床及MRI资料,与临床手术对照,比较不同序列MRI显示病变能力.所有患者均行常规头部MR平扫,其中9例行增强扫描,49例行桥小脑角区高分辨3D-TOF和3D-快速SE(TSE)序列扫描.利用x2检验分析3D-TOF和3D-TSE两序列的敏感度、特异度和准确度.结果 MR常规平扫及增强扫描显示6例桥小脑区肿瘤、3例三叉神经根及其周围脑膜炎,以及脑干多发硬化斑块及梗死各1例.49例为神经血管压迫所致,与手术对照3D-TOF和3D-TSE序列显示血管压迫的敏感度、特异度、准确度分别为95.3％ (41/43)、66.7％ (4/6)、91.8％ (45/49)和95.6％ (43/45)、50.0％ (2/4)、91.8％ (45/49),两者差异无统计学意义(x2值分别为0.13、0.19、0.17,P值均＞0.5).结论MRI对显示和诊断三叉神经痛病因具有重要意义.MR全脑常规扫描可以显示或排除肿瘤、炎症等病变.桥小脑角区3D-TOF和3D-TSE扫描可以敏感和准确地显示和明确神经、血管的关系.     

高危原发性三叉神经痛的介入治疗

目的 评价经皮穿刺微球囊压迫三叉神经节(PMC)治疗高危原发性三叉神经痛方法的临床效果.方法 回顾性分析从2001年1月至2007年12月采用Mullan方法治疗3053例原发性三叉神经痛患者中804例高危患者采用PMC技术治疗的临床资料.结果 对804例患者行833次手术.术后即刻成功率为97.3%.平均随访36个月,疼痛复发率为6.8%.感觉异常的发生率为3.8%,无角膜溃疡,咀嚼肌无力约占2/3,复视占0.2%.结论 PMC方法是高危原发性三叉神经痛的首选且十分有效的治疗方法之一,尤其对于疼痛累及第一支且高危的患者更有优势.     

原发性三叉神经痛的多模态MRI研究进展

原发性三叉神经痛(TN)是最常见的颅神经疾病之一,以三叉神经感觉支分布区反复发作的触电样剧烈疼痛为临床特征,病因不明。多模态MRI技术能够全面评估三叉神经脑池段与邻近血管的毗邻关系、三叉神经形态学改变、三叉神经纤维束的完整性以及相关脑区的结构与功能改变,可以为深入理解TN的发病机制、指导治疗方案的制定以及预后评估提供大量有价值信息。现就多模态MRI技术在TN研究中的技术进展和发展现状予以综述。     

磁共振体层血管造影对三叉神经痛诊断价值的研究

目的：探讨磁共振体层血管造影（MRTA）对三叉神经痛的诊断价值。方法：回顾性地分析120例经手术治疗的三叉神经痛患者的MRTA表现及手术结果。结果：120例症状侧MRTA检查有血管压迫者为79侧，接触者为28侧，共107侧，敏感性为89．17％。120例症状侧行手术治疗，手术发现有血管压迫或接触者76侧，MRTA检查诊断神经血管压迫和接触的特异性分别为96．2％和82．14％。结论：MRTA成像作为一项新的影像学检查技术，能较好地显示三叉神经根与周围血管之间的关系，从而为三叉神经痛的病因诊断及临床的治疗提供可靠的影像学依据。     

Microstructural abnormalities in the trigeminal nerves of patients with trigeminal neuralgia revealed by multiple diffusion metrics

Objective

To investigate microstructural tissue changes of trigeminal nerve (TGN) in patients with unilateral trigeminal neuralgia (TN) by multiple diffusion metrics, and correlate the diffusion indexes with the clinical variables.

Methods

16 patients with TN and 6 healthy controls (HC) were recruited into our study. All participants were imaged with a 3.0 T system with three-dimension time-of-flight (TOF) magnetic resonance angiography and fluid attenuated inversion recovery (FLAIR) DTI-sequence. We placed regions of interest over the root entry zone of the TGN and measured fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD). The mean values of FA, MD, AD and RD were compared between the affected and unaffected sides in the same patient, and to HC values. The correlation between the side-to-side diffusion metric difference and clinical variables (disease duration and visual analogy scale, VAS) was further explored.

Results

Compared with the unaffected side and HC, the affected side showed significantly decreased FA and increased RD; however, no significant changes of AD were found. A trend toward significantly increased MD was identified on the affected side comparing with the unaffected side. We also found the significant correlation between the FA reduction and VAS of pain (r = −0.55, p = 0.03).

Conclusion

DTI can quantitatively assess the microstructural abnormalities of the affected TGN in patients with TN. Our results suggest demyelination without significant axonal injury is the essential pathological basis of the affected TGN by multiple diffusion metrics. The correlation between FA reduction and VAS suggests FA as a potential objective MRI biomarker to correlate with clinical severity.     

静脉压迫性原发性三叉神经痛的 MRI 序列研究及诊断价值

目的：探讨静脉压迫性原发性三叉神经痛(PTN)患者责任静脉的最佳 MRI 序列组合。方法回顾性分析26例单独静脉压迫性 PTN 患者33支责任静脉在3D-TOF-MRA、3D-FIESTA 及 CE-3D-TOF-MRA 3种序列上的成像特点及不同序列对责任静脉的显示率。结果33支责任静脉在3D-TOF-MRA 序列上显示率15.2%(5/33);3D-FIESTA 序列与3D-TOF-MRA+3D-FIESTA 序列组合的显示率均为63.6%(21/33);CE-3D-TOF-MRA 序列上显示率100%(33/33)。CE-3D-TOF-MRA 序列较3D-TOF-MRA+3D-FIESTA 序列组合对责任静脉的显示率高且有统计学差异(P <0.005)。结论CE-3D-TOF-MRA 对责任静脉的检出率最高,联合使用3种序列,可明确诊断血管性质和压迫情况,减少责任静脉的漏诊。     

MRI Findings in Trigeminal Neuralgia without Neurovascular Compression: Implications of Petrous Ridge and Trigeminal Nerve Angles

ObjectiveTo determine the anatomical characteristics of the petrous ridge and trigeminal nerve in trigeminal neuralgia (TN) without neurovascular compression (NVC).Materials and MethodsFrom May 2017 to March 2021, 66 patients (49 female and 17 male; mean age ± standard deviation [SD], 56.8 ± 13.3 years) with TN without NVC and 57 controls (46 female and 11 male; 52.0 ± 15.6 years) were enrolled. The angle of the petrous ridge (APR) and angle of the trigeminal nerve (ATN) were measured using magnetic resonance imaging with a high-resolution three-dimensional T2 sequence. Data on the symptomatic side were compared with those on the asymptomatic side in patients and with the mean measurements of the bilateral sides in controls. Receiver operating characteristic (ROC) analysis was conducted to evaluate the performance of APR and ATN in distinguishing TN patients from controls.ResultsIn TN patients without NVC, the mean ± standard deviation (SD) of APR on the symptomatic side (98.40° ± 19.75°) was significantly smaller than that of the asymptomatic side (105.59° ± 22.45°, p = 0.019) and controls (108.44° ± 15.98°, p = 0.003). The mean ATN ± SD on the symptomatic side (144.41° ± 8.92°) was significantly smaller than that of the asymptomatic side (149.67° ± 8.09°, p = 0.003) and controls (150.45° ± 8.48°, p = 0.001). The area under the ROC curve for distinguishing TN patients from controls was 0.673 (95% confidence interval [CI]: 0.579–0.758) for APR and 0.700 (CI: 0.607–0.782) for ATN. The sensitivity and specificity using the diagnostic cutoff yielding the highest Youden index were 81.8% (54/66) and 49.1% (28/57), respectively, for APR (with a cutoff score of 94.30°) and 65.2% (43/66) and 66.7% (38/57), respectively, for ATN (cutoff score, 148.25°).ConclusionIn patients with TN without NVC, APR and ATN were smaller than those in controls, which may explain the potential cause of TN and provide additional information for diagnosis.     

Persistent trigeminal artery associated with trigeminal neuralgia: hypothesis of neurovascular compression

Introduction The aim of this study was to determine the prevalence of persistent trigeminal artery (PTA) associated with trigeminal neuralgia (TN). Methods From January 1998 to January 2004, 288 MRI scans of patients examined for trigeminal deficits were retrospectively evaluated. MRI was performed at 1.5 T. Scan protocols included cerebral TSE T2-weighted imaging, contrast enhanced SE T1-weighted imaging and thin-section 3D T2-weighted imaging of the temporal bones, 3D TOF pre- and postcontrast MR angiography. TN was defined as episodes of intense stabbing, electric shock-like pain in areas of the face supplied by the trigeminal branches. Neurovascular compression (NVC) was assumed to be present if the patient showed clinical features of TN, if there was contact between an artery and the trigeminal nerve on the affected side, and if other pathology had been excluded. The prevalence and confidence intervals were calculated (95% CI of the prevalence was based on the exact binomial distribution). Results Of 288 patients, 136 matched the criteria for TN. In this series a PTA was detected in three patients, which in all patients was on the same side as the TN. The prevalence of a PTA in patients presenting with TN was 2.2% (CI 0.005–0.06). Conclusion Previous studies have shown PTA as an incidental finding in 0.1–0.6% of cerebral angiograms. The prevalence of a PTA in patients with TN was 2.2%. With respect to the clinical significance, a PTA has to be considered in TN and the diagnosis of a PTA can easily be made using MR imaging/angiography.