Significance of different offending vessels and development of a potential screening tool for trigeminal neuralgia.

OBJECTIVES: This study was performed amongst trigeminal neuralgia (TN) patients with neurovascular contact (NVC) to 1) investigate the association of the demographic and radiologic factors/variables with TN occurrence, and 2) develop a screening tool for TN/TN-affected nerves based on the factors/variables associated with it. METHODS: Eighty-five TN patients were recruited, and 121 trigeminal nerves with NVC were derived from them. Based on MRI sequences, including balanced turbo field echo and enhanced T1 high-resolution isotropic volume excitation, radiologic factors/variables for each nerve, from the offending vessel to the presence of nerve displacement, were identified by a neuroradiologist and a neurosurgeon. Demographic and clinical data were obtained from clinical notes. Logistic regression was performed to assess the association of the factors/variables with TN occurrence (i.e., affected vs. unaffected nerves). RESULTS: Three factors/variables were significantly (p < 0.05) associated with TN occurrence amongst patients with NVC: nerve laterality, vertebral artery (VA) involvement, and the presence of nerve displacement. The nerves with VA involvement, those on the right side, and those with nerve displacement exhibited a significantly higher likelihood/odd of being affected by TN, compared to those without VA involvement, those on the left side, and those without nerve displacement, respectively. Based on these factors/variables, a screening tool/nomogram with acceptable accuracy was established (C-statistic/AUC = 0.80). CONCLUSIONS: This study revealed an association of the three radiologic factors/variables with TN occurrence. A screening tool for TN/TN-affected nerves was established based on them. The findings may lay a foundation for an improvement of the diagnosis and clinical management of TN. KEY POINTS: • VA involvement and nerve displacement could be identified using MRI, and are significantly associated with TN occurrence. • A potential objective screening tool/nomogram for TN/TN-affected nerves could be established based on the three radiologic factors/variables: VA involvement, the presence of nerve displacement, and nerve laterality. • The screening accuracy of the tool/nomogram is acceptable as the C-statistic is 0.80.

Prediction of trigeminal nerve position based on the main feeding artery in petroclival meningioma.

The trigeminal nerve is often displaced by petroclival meningioma (PCM) compression, making it difficult to locate during PCM surgery. This study investigated whether the deviated position of the trigeminal nerve could be easily predicted using the main tumor feeding artery. We retrospectively examined 32 patients who underwent surgery for primary PCM. The deviation of the trigeminal nerve was classified as either Type 1 (displacement toward the back of the cerebellar tentorium), Type 2 (toward the back of the superior petrosal sinus), Type 3 (toward the back of the petrous apex dura), Type 4 (toward the inferior aspect of the tumor), or Type 5 (toward the surface of the brain stem). The main feeding artery was determined by preoperative angiography. The trigeminal nerve was classified as Type 2 in 60% of cases where the proximal tentorial artery (TA) was the main feeding vessel. The nerve was Type 5 where the distal portion of the TA was the main feeding vessel (60% of the cases). The nerves were Type 3 and Type 4 where the proximal inferior lateral trunk (ILT) (60%) and distal ILT (75%), respectively, were the main feeding vessels. In 66.7% of the cases where the dorsal meningeal artery was the main feeding vessel, the nerve was Type 3. Type 1 classification applied in all cases where the ascending pharyngeal artery was the main feeding artery. The main feeding artery can be used to predict trigeminal nerve transposition during PCM surgery.

Computational Fluid Dynamics Analysis of the Offending Artery at Sites of Neurovascular Compression in Trigeminal Neuralgia Using Preoperative MRI Data.

This study aimed to analyze the hemodynamic features of the offending artery at sites of neurovascular compression (NVC) using computational fluid dynamics (CFD). A total of 23 patients who underwent microvascular decompression (MVD) for primary trigeminal neuralgia (TN) between January 2015 and December 2016 were enrolled in this study. The compressing vessel at the NVC site was identified microsurgically in all cases, and patients were divided into two groups based on the intraoperative findings: (1) the arterial NVC group and (2) the non-arterial NVC control group. A 3D surface model of the structures surrounding the NVC was created using preoperative magnetic resonance imaging (MRI), and CFD analysis was performed for the target artery. In addition to standard parameters, such as the wall shear stress (WSS), flow velocity, and pressure, we calculated the WSS ratio (WSSR) by dividing the WSS at the NVC by the mean WSS of the target. Arterial compression was observed intraoperatively in 13 patients. The mean WSSR of the arterial NVC group was significantly higher than that of the control group (2.36 ± 1.00 vs. 1.18 ± 0.73, P <0.05). There were no significant intergroup differences in the other calculated parameters. High WSSR, which indicates elevated WSS at the sites of NVC, was identified as a unique parameter of arterial compression that may contribute to TN. CFD could be a useful clinical tool in determining the target of MVD under preoperative conditions.

Safety profile of superior petrosal vein (the vein of Dandy) sacrifice in neurosurgical procedures: a systematic review.

OBJECTIVE Walter E. Dandy described for the first time the anatomical course of the superior petrosal vein (SPV) and its significance during surgery for trigeminal neuralgia. The patient's safety after sacrifice of this vein is a challenging question, with conflicting views in current literature. The aim of this systematic review was to analyze the current surgical considerations regarding Dandy's vein, as well as provide a concise review of the complications after its obliteration. METHODS A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A thorough literature search was conducted on PubMed, Web of Science, and the Cochrane database; articles were selected systematically based on the PRISMA protocol and reviewed completely, and then relevant data were summarized and discussed. RESULTS A total of 35 publications pertaining to the SPV were included and reviewed. Although certain studies report almost negligible complications of SPV sectioning, there are reports demonstrating the deleterious effects of SPV obliteration when achieving adequate exposure in surgical pathologies like trigeminal neuralgia, vestibular schwannoma, and petroclival meningioma. The incidence of complications after SPV sacrifice (32/50 cases in the authors' series) is 2/32 (6.2%), and that reported in various case series varies from 0.01% to 31%. It includes hemorrhagic and nonhemorrhagic venous infarction of the cerebellum, sigmoid thrombosis, cerebellar hemorrhage, midbrain and pontine infarct, intracerebral hematoma, cerebellar and brainstem edema, acute hydrocephalus, peduncular hallucinosis, hearing loss, facial nerve palsy, coma, and even death. In many studies, the difference in incidence of complications between the SPV-sacrificed group and the SPV-preserved group was significant. CONCLUSIONS The preservation of Dandy's vein is a neurosurgical dilemma. Literature review and experiences from large series suggest that obliterating the vein of Dandy while approaching the superior cerebellopontine angle corridor may be associated with negligible complications. However, the counterview cannot be neglected in light of some series showing an up to 30% complication rate from SPV sacrifice. This review provides the insight that although the incidence of complications due to SPV obliteration is low, they can happen, and the sequelae might be worse than the natural history of the existing pathology. Therefore, SPV preservation should be attempted to optimize patient outcome.

Preoperative evaluation of neurovascular relationship in trigeminal neuralgia by three-dimensional fast low angle shot (3D-FLASH) and three-dimensional constructive interference in steady-state (3D-CISS) MRI sequence.

OBJECTIVE: The purpose of the study was to evaluate the value of high-resolution three-dimensional fast low angle shot (3D-FLASH) and three-dimensional constructive interference in steady-state (3D-CISS) MRI sequence solely or the combination of both in the visualization of neurovascular relationship in patients with trigeminal neuralgia (TN). METHODS: 65 patients with unilateral TN underwent 3D-FLASH and 3D-CISS imaging were retrospectively studied. Neurovascular relationship at the intracisternal segment of trigeminal nerve was reviewed by two experienced neuroradiologist, who was blinded to the clinical details. The imaging results were compared with the operative findings in all patients. RESULTS: The accuracy and positive rates of the 3D-FLASH + CISS imaging (98.46, 92.31%) in judging the symptomatic side according to the presence of vascular contacts were higher than those of 3D-CISS (90.77%, 84.62) or 3D-FLASH (89.23, 83.08%) sequence. In addition, the statistical analysis showed the sensitivity and accuracy of 3D-FLASH + CISS imaging was higher than that of 3D-FLASH (p < 0.05). The 3D-FLASH + CISS imaging was more accurate in determining the type of offending vessel than 3D-CISS or 3D-FLASH imaging. CONCLUSION: The retrospective study demonstrates that the combination of 3D-FLASH with 3D-CISS sequence well delineates the relationship between intracisternal segment of trigeminal nerve and adjacent vessels in terms of increased positive rates and accuracy. Advances in knowledge: The study firstly dealt with the combination of 3D-CISS and 3D-FLASH imaging in TN.

Microvascular Decompression for Trigeminal Neuralgia Due to Venous Compression Alone.

Microvascular decompression (MVD) has been confirmed as an effective treatment of trigeminal neuralgia (TN); however, most previous reports just focused on MVD for TN caused by arterial conflict, there is a paucity of information about its use in venous compression causing TN. In the present study, the authors summarize 5-year experience of MVD for primary TN due to venous compression alone. Thirty-four patients with primary TN caused solely by veins underwent MVD. The presenting symptoms, key operative notes, surgical outcomes together with complications were reviewed. Of all the 34 patients, 19 (55.9%) patients occurred as typical TN. The V2 division was the most commonly affected area. Most of the venous conflicts were grade III (20/34, 58.8%). Deep superior petrosal venous system was the most frequent offending vessel (21/34, 61.8%). The venous conflicts were located at the trigeminal root entry zone in 10 (29.4%) patients, the mid cisternal zone in 18 (52.9%) patients, and the porus of Meckel's cave in 11 (32.4%) patients. At the last follow-up, excellent outcome was obtained in 26 (76.5%) patients, 7 (20.6%) patients got good outcome, fair outcome was achieved in 7 (20.6%) patients, and 1 patient unimproved (2.9%). Cerebrospinal fluid leakage was the most common complication (5.9%). In conclusion, MVD is a safe and effective surgical option for TN due to venous compression alone. It is noteworthy to explore the entire nerve and to protect veins as much as possible.

A human trigeminovascular biomarker for antimigraine drugs: A randomised, double-blind, placebo-controlled, crossover trial with sumatriptan.

Current antimigraine drugs are believed, besides their direct vasoconstrictive effect, to inhibit calcitonin gene-related peptide (CGRP) release from trigeminal nerve endings during migraine. Objective The objective of this report is to establish a biomarker for the CGRP-interfering effect of antimigraine drugs. Methods We quantified the effect of sumatriptan on the trigeminal nerve-mediated rise in forehead dermal blood flow (DBF), induced by capsaicin application (0.6 mg/ml) and electrical stimulation (0.2-1.0 mA), in a randomised, double-blind, placebo-controlled, crossover study in healthy male ( n = 11, age ± SD: 29 ± 8 years) and female ( n = 11, 32 ± 7 years) individuals. Results DBF responses to capsaicin were attenuated by sumatriptan (ΔDBF, mean ± SEM: 82 ± 18 AU, p = 0.0002), but not by placebo (ΔDBF: 21 ± 12 AU, p = 0.1026). Conclusion We demonstrated that sumatriptan inhibits increases in DBF, induced by the release of, most likely, CGRP. Thus, our model may be used as a biomarker to establish the trigeminovascular effects of (potential) antimigraine drugs, such as CGRP receptor antagonists or antibodies directed against CGRP or its receptor.

Brain white matter plasticity and functional reorganization underlying the central pathogenesis of trigeminal neuralgia.

Peripheral nerve damage does not fully explain the pathogenesis of trigeminal neuralgia (TN). Central nervous system changes can follow trigeminal nerve dysfunction. We hypothesized that brain white matter and functional connectivity changes in TN patients were involved in pain perception, modulation, the cognitive-affective system, and motor function; moreover, changes in functional reorganization were correlated with white matter alterations. Twenty left TN patients and twenty-two healthy controls were studied. Diffusion kurtosis imaging was analyzed to extract diffusion and kurtosis parameters, and functional connectivity density (FCD) mapping was used to explore the functional reorganization in the brain. In the patient group, we found lower axial kurtosis and higher axial diffusivity in tracts participated in sensory, cognitive-affective, and modulatory aspects of pain, such as the corticospinal tract, superior longitudinal fasciculus, anterior thalamic radiation, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, cingulated gyrus, forceps major and uncinate fasciculus. Patients exhibited complex FCD reorganization of hippocampus, striatum, thalamus, precentral gyrus, precuneus, prefrontal cortex and inferior parietal lobule in multiple modulatory networks that played crucial roles in pain perception, modulation, cognitive-affective system, and motor function. Further, the correlated structural-functional changes may be responsible for the persistence of long-term recurrent pain and sensory-related dysfunction in TN.

Trigeminal Neuralgia Attributable to Intraneural Trigeminocerebellar Artery: Case Report and Review of the Literature.

BACKGROUND: The trigeminocerebellar artery (TCA) is a branch of the basilar artery supplying both the trigeminal nerve root and the cerebellar hemisphere. Despite its proximity to the trigeminal nerve, only a few cases of trigeminal neuralgia (TN) caused by TCA compression of the trigeminal nerve have been reported. Moreover, TN caused by blood vessel penetration of the trigeminal nerve is very rare. CASE DESCRIPTION: We present a case of an 82-year-old female patient with typical episodes of TN. The radiologic studies showed that the offending artery was a unique branch of the basilar artery originating at a higher level than that of the usual anterior inferior cerebellar artery. During microvascular decompression surgery we were able to identify the offending vessel supplying the trigeminal nerve root and traveling between the sensory and motor root of the trigeminal nerve as an intraneural TCA. To shift the TCA away from the root entry zone, we dissected the epineurium of trigeminal nerve parallel to its axis and anchored the proximal portion of the TCA to the petrous dura. The patient's pain was completely gone immediately after the operation, with no neurologic deficits reported. CONCLUSIONS: The TCA is a potential offending vessel in TN because of trigeminal nerve compression, and the longitudinal dissection of the trigeminal nerve to make space between the vessel and the nerve roots may be an effective procedure to relieve TN caused by pressing intraneural vessels.

Neurochemical pathways that converge on thalamic trigeminovascular neurons: potential substrate for modulation of migraine by sleep, food intake, stress and anxiety.

Dynamic thalamic regulation of sensory signals allows the cortex to adjust better to rapidly changing behavioral, physiological and environmental demands. To fulfill this role, thalamic neurons must themselves be subjected to constantly changing modulatory inputs that originate in multiple neurochemical pathways involved in autonomic, affective and cognitive functions. Our overall goal is to define an anatomical framework for conceptualizing how a 'decision' is made on whether a trigeminovascular thalamic neuron fires, for how long, and at what frequency. To begin answering this question, we determine which neuropeptides/neurotransmitters are in a position to modulate thalamic trigeminovascular neurons. Using a combination of in-vivo single-unit recording, juxtacellular labeling with tetramethylrhodamine dextran (TMR) and in-vitro immunohistochemistry, we found that thalamic trigeminovascular neurons were surrounded by high density of axons containing biomarkers of glutamate, GABA, dopamine and serotonin; moderate density of axons containing noradrenaline and histamine; low density of axons containing orexin and melanin concentrating hormone (MCH); but not axons containing CGRP, serotonin 1D receptor, oxytocin or vasopressin. In the context of migraine, the findings suggest that the transmission of headache-related nociceptive signals from the thalamus to the cortex may be modulated by opposing forces (i.e., facilitatory, inhibitory) that are governed by continuous adjustments needed to keep physiological, behavioral, cognitive and emotional homeostasis.

Trigeminal neuralgia caused by a trigeminocerebellar artery.

This 31-year-old woman presented with typical right trigeminal neuralgia caused by a trigeminocerebellar artery, manifesting as pain uncontrollable with medical treatment. Preoperative neuroimaging studies demonstrated that the offending artery had almost encircled the right trigeminal nerve. This finding was confirmed intraoperatively, and decompression was completed. The neuralgia resolved after the surgery; the patient had slight transient hypesthesia, which fully resolved within the 1st month after surgery. The neuroimaging and intraoperative findings showed that the offending artery directly branched from the upper part of the basilar artery and, after encircling and supplying tiny branches to the nerve root, maintained its diameter and coursed toward the rostral direction of the cerebellum, which indicated that the artery supplied both the trigeminal nerve and the cerebellum. The offending artery was identified as the trigeminocerebellar artery. This case of trigeminal neuralgia caused by a trigeminocerebellar artery indicates that this variant is important for a better understanding of the vasculature of the trigeminal nerve root.

Neurostimulation at pterygopalatine fossa for cluster headaches and cerebrovascular disorders.

There are numerous neural structures (parasympathetic, sympathetic, and trigeminal sensory) that are compacted in a small well defined area of the pterygopalatine fossa (PPF). These targets can be readily accessed via minimally invasive neuromodulation techniques making the methods more desirable than neurosurgical deep brain or hypothalamic intervention. Recent research has shed light over the important role of the sphenopalatine ganglion (SPG), which is located within the PPF, in cerebrovascular autonomic physiology as well as in the pathophysiology of different headache disorders (cluster headache, migraine, and trigeminal autonomic cephalalgias). Accordingly, neuromodulation of the autonomic fibers (parasympathetic and sympathetic) may play a key role in the management of headaches, stroke, or cerebral vasospasm. Another important structure within the PPF is the maxillary nerve (V2), which passes through the roof of the fossa. Here the trigeminal system is accessible for a reliable neuromodulation by targeting its second branch -the maxillary nerve- and this could be utilized in various painful conditions of the head and face.

Can the neurovascular compression volume of the trigeminal nerve on magnetic resonance cisternography predict the success of local anesthetic block after initial treatment by the carbamazepine?

OBJECTIVES: Whether NVC volume on magnetic resonance (MR) cisternography might be related to the success of local anesthetic block by tetracaine (TNB) as an additional treatment after carbamazepine (CBZ) treatments in patients with trigeminal neuralgia (TN) was evaluated. STUDY DESIGN: Detectable NVC volumes were measured from MR cisternography in 65 patients with TN treated by TNB after CBZ treatments. The correlation between the success of TNB and the NVC volume or the improvement in pain by CBZ was evaluated retrospectively. RESULTS: A significant difference was found between the improvement in pain by CBZ and the success of TNB, but not between NVC volume on MR cisternography and the success of TNB. CONCLUSIONS: The present results suggest that the success of CBZ as initial treatment, but not NVC volume on MR cisternography, may be a significant predictor of the success of TNB as additional therapy in patients with TN.

Nitric oxide synthase, calcitonin gene-related peptide and NK-1 receptor mechanisms are involved in GTN-induced neuronal activation.

BACKGROUND AND AIM: Infusion of glyceryltrinitrate (GTN), a nitric oxide (NO) donor, in awake, freely moving rats closely mimics a universally accepted human model of migraine and responds to sumatriptan treatment. Here we analyse the effect of nitric oxide synthase (NOS) and calcitonin gene-related peptide (CGRP) systems on the GTN-induced neuronal activation in this model. MATERIALS AND METHODS: The femoral vein was catheterised in rats and GTN was infused (4 µg/kg/min, for 20 minutes, intravenously). Immunohistochemistry was performed to analyse Fos, nNOS and CGRP and Western blot for measuring nNOS protein expression. The effect of olcegepant, L-nitro-arginine methyl ester (L-NAME) and neurokinin (NK)-1 receptor antagonist L-733060 were analysed on Fos activation. RESULTS: GTN-treated rats showed a significant increase of nNOS and CGRP in dura mater and CGRP in the trigeminal nucleus caudalis (TNC). Upregulation of Fos was observed in TNC four hours after the infusion. This activation was inhibited by pre-treatment with olcegepant. Pre-treatment with L-NAME and L-733060 also significantly inhibited GTN induced Fos expression. CONCLUSION: The present study indicates that blockers of CGRP, NOS and NK-1 receptors all inhibit GTN induced Fos activation. These findings also predict that pre-treatment with olcegepant may be a better option than post-treatment to study its inhibitory effect in GTN migraine models.

[Intraoperative decisions and surgical efficacies of trigeminal neuralgia responsible vessels].

OBJECTIVE: To explore the types of primary trigeminal neuralgia (TN) responsible vessels and curative efficacies of microscopic vascular decompression (MVD). METHODS: A total of 162 primary TN patients underwent MVD from August 2004 to the present at our hospital.Their clinical data were collected and analyzed. There were 69 males and 93 females with an age range of 22-88 years. RESULTS: The most common responsible vessels were superior cerebellar artery (n = 65, 40.12%), anteroinferior cerebellar artery (n = 45, 27.78%), multiple vessels (n = 26, 16.05%), posteroinferior cerebellar artery (n = 16, 9.88%), veins (n = 6, 3.70%) and vertebral artery (n = 4, 2.47%). And the pressure points were at the root of trigeminal nerve (n = 139, 85.80%), distal part (n = 16, 9.88%) and root and distal part (n = 7, 4.32%). Postoperatively pain disappeared in all patients (including one case on second surgery). Postoperative follow-ups were conducted for 132 cases.Two cases recurred over 8 years and the recurrence rate was 1.52%. CONCLUSION: MVD is preferred method for primary TN non-responsive to pharmacotherapy. Identification and treatment of responsible vessels remain a key. Venous and distal pressure points should be taken care.

Importancia neuroquirúrgica del complejo venoso petroso superior / No disponible

Objetivo Conocer la anatomía microquirúrgica del complejo venoso petroso superior (CVPS).Material y métodos Se realizó estudio descriptivo y prospectivo. Se utilizaron 6 especímenes (12 lados) inyectados. Se estudió la anatomía microquirúrgica del CVPS en los encéfalos, mediante un abordaje retrosigmoideo y transpetroso anterior. Se utilizó instrumental neuroquirúrgico, endoscopio rígido de 0 grados, microscopio quirúrgico OPMI-1 con magnificación 6× a 20×. Se analizó el patrón de drenaje hacia el seno petroso superior, la formación de las venas tributarias, la relación con el nervio trigémino y las variantes del CVPS.Resultados El CVPS se encontró en todos los lados, la vena tributaria que se encontró en el 100% de los lados fue la vena de la fisura cerebelopontina. El patrón de drenaje del CVPS fue dividido en relación a la cresta suprameatal en: lateral, medial y en un punto intermedio. Se encontró el CVPS simple, formado por un tronco con sus tributarias, en 8 lados y duplicado en 4 lados. En el estudio se observó un triángulo formado por el tentorio, el CVPS y parte de la cara petrosa y tentorial del cerebelo con bordes y contenidos bien definidos, el cual se llamó triángulo petroso-tentorial. Conclusión Es necesario entender la anatomía microquirúrgica del CVPS. Así, proponemos el triángulo petroso-tentorial como corredor neuroquirúrgico para el manejo de lesiones del ángulo pontocerebeloso a la región petroclival superior (AU)

The pathophysiology of brain swelling associated with subdural hemorrhage: the role of the trigeminovascular system.

INTRODUCTION: This paper reviews the evidence in support of the hypothesis that the trigeminal system mediates brain swelling associated with subdural bleeding. The trigeminovascular system has been extensively studied in migraine; it may play an important but under-recognized role in the response to head trauma. Nerve fibers originating in trigeminal ganglion cells are the primary sensors of head trauma and, through their collateral innervation of the intracranial and dural blood vessels, are capable of inciting a cascade of vascular responses and brain swelling. The extensive trigeminal representation in the brainstem initiates and augments autonomic responses. Blood and tissue injury in the dura incite neurogenic inflammatory responses capable of sensitizing dural nerves and potentiating the response to trauma. DISCUSSION: The trigeminal system may provide the anatomo-physiological link between small-volume, thin subdural bleeds and swelling of the underlying brain. This physiology may help to explain the poorly understood phenomena of "second-impact syndrome," the infant response to subdural bleeding (the "big black brain"), as well as post-traumatic subdural effusions. Considerable age-specific differences in the density of dural innervation exist; age-specific responses of this innervation may explain differences in the brain's response to trauma in the young. An understanding of this pathophysiology is crucial to the development of intervention and treatment of these conditions. Antagonists to specific neuropeptides of the trigeminal system modify brain swelling after trauma and should be further explored as potential therapy in brain trauma and subdural bleeding.

Hemimasticatory spasm treated with microvascular decompression of the trigeminal nerve.

Hemimasticatory spasm is a very rare disorder of the trigeminal nerve characterized by paroxysmal involuntary contraction of the jaw-closing muscles. The mechanisms leading to hemimasticatory spasm are still unclear. Recently, injection of botulinum toxin has become the treatment of choice due to its excellent results. We report a case of a successful treatment of hemimasticatory spasm via microvascular decompression of the motor branch of the trigeminal nerve.

Preoperative demonstration of neurovascular relationship in trigeminal neuralgia by using 3D FIESTA sequence.

PURPOSE: The purpose of the study was to evaluate the value of high-resolution three-dimensional fast imaging employing steady-state acquisition (3D FIESTA) imaging in the visualization of neurovascular relationship in patients with trigeminal neuralgia (TN). METHODS: Thirty-seven patients with unilateral typical TN underwent 3D FIESTA imaging. Neurovascular relationship at the trigeminal root entry zone was reviewed by an experienced neuroradiologist, who was blinded to the clinical details. The imaging results were compared with the operative findings in all patients. RESULTS: In 37 patients with TN, 3D FIESTA imaging identified surgically verified neurovascular contact in 35 of 36 symptomatic nerves. Based on surgical findings, the sensitivity and specificity of magnetic resonance (MR) imaging were 97.2% and 100%, respectively. Agreement between the position (medial, lateral, superior and inferior) of the compressing vessel relative to the trigeminal nerve identified by MR imaging and surgery was excellent (K=0.81; 95% confidence interval, 0.56-1.00). A statistically significant difference was found between the site of neurovascular contact and the clinical symptom related to the trigeminal branch (Fisher's Exact Test, P<.001). CONCLUSIONS: Use of 3D FIESTA sequence enables accurate visualization of neurovascular contact in patients with TN. Anatomic relationships defined by this method can be useful in surgical planning and predicting surgical findings.