Magnetic Resonance Tomographic Angiography Research Articles

A novel 3D multimodal fusion imaging surgical guidance in microvascular decompression for primary trigeminal neuralgia and hemifacial spasm

BackgroundNeurovascular compression (NVC) is a primary etiology of trigeminal neuralgia (TN) and hemifacial spasm (HFS). Despite Magnetic Resonance Tomographic Angiography (MRTA) being a useful tool for 3D multimodal fusion imaging (MFI) in microvascular decompression (MVD) surgery planning, it may not visualize smaller arterial vessels and veins effectively. We validate a novel computed tomography angiography and venography (CTA/V) - diffusion tensor tractography (DTT) -3D-MFI to enhance the MVD surgical guidance.MethodsIn this prospective study, 80 patients with unilateral primary TN or HFS who underwent MVD surgery were included. Imaging was conducted using CTA/V-DTT-3D-MFI compared with CT-MRTA-3D-MFI in predicting the responsible vessel and assessing the severity of NVC. Surgical outcomes were subsequently analyzed. Neurosurgery residents were provided with questionnaires to evaluate and compare the two approaches.ResultsCTA/V-DTT-3D-MFI significantly improved accuracy in identifying the responsible vessel (kappa = 0.954) and NVC (kappa = 0.969) compared to CT-MRTA-3D-MFI, aligning well with surgical findings. CTA/V-DTT-3D-MFI also exhibited higher sensitivity in identifying responsible vessels (98.0%) and NVC (98.7%) than CT-MRTA-3D-MFI. Additionally, CTA/V-DTT-3D-MFI showed fewer complications, shorter operation times, and lower recurrence after one year (all p < 0.05). Resident neurosurgeons emphasized that CTA/V-DTT-3D-MFI greatly assisted in formulating precise surgical strategies for more accurate identification and protection of responsible vessels and nerves (all p < 0.001).ConclusionCTA/V-DTT-3D-MFI enhances MVD surgery guidance, improving accuracy in identifying responsible vessels and NVC for better outcomes. This advanced imaging plays a crucial role in safer and more effective MVD surgery, as well as in training neurosurgeons.

Comparative study of CTA/CTV and MRTA for preoperative simulation of microvascular decompression in neurovascular compression syndromes.

Neurovascular compression syndrome (NVCS), characterized by cranial nerve compression due to adjacent blood vessels at the root entry zone, frequently presents as trigeminal neuralgia (TN), hemifacial spasm (HFS), or glossopharyngeal neuralgia (GN). Despite its prevalence in NVCS assessment, Magnetic Resonance Tomographic Angiography (MRTA)'s limited sensitivity to small vessels and veins poses challenges. This study aims to refine vessel localization and surgical planning for NVCS patients using a novel 3D multimodal fusion imaging (MFI) technique incorporating computed tomography angiography and venography (CTA/CTV). A retrospective analysis was conducted on 76 patients who underwent MVD surgery and were diagnosed with single-site primary TN, HFS, or GN. Imaging was obtained from MRTA and CTA/CTV sequences, followed by image processing and 3D-MFI using FastSurfer and 3DSlicer. The CTA/CTV-3D-MFI showed higher sensitivity than MRTA-3D-MFI in predicting responsible vessels (98.6% vs. 94.6%) and NVC severity (98.6% vs. 90.8%). Kappa coefficients revealed strong agreement with MRTA-3D-MFI (0.855 for vessels, 0.835 for NVC severity) and excellent agreement with CTA/CTV-3D-MFI (0.951 for vessels, 0.952 for NVC). Resident neurosurgeons significantly preferred CTA/CTV-3D-MFI due to its better correlation with surgical reality, clearer depiction of surgical anatomy, and optimized visualization of approaches (p < 0.001). Implementing CTA/CTV-3D-MFI significantly enhanced diagnostic accuracy and surgical planning for NVCS, outperforming MRTA-3D-MFI in identifying responsible vessels and assessing NVC severity. This innovative imaging modality can potentially improve outcomes by guiding safer and more targeted surgeries, particularly in cases where MRTA may not adequately visualize crucial neurovascular structures.

Trigeminal neuralgia secondary to osteoma and vascular compression: illustrative case.

Trigeminal neuralgia (TN) is a common neurosurgical issue that has a detrimental impact on patients' quality of life. Osteoma at the petrous apex is a rare etiology of TN. Here, the authors present a case involving the co-occurrence of petrous osteoma and a vascular loop around the trigeminal nerve. Both exerted pressure or compression on the exit of the trigeminal nerve. A 46-year-old male presented with a 3-year history of persistent severe pain in the right side of his face. Magnetic resonance tomographic angiography of the trigeminal nerve revealed an abnormal signal in the right prepontine cistern, along with a vascular loop accompanying the right trigeminal nerve. A computed tomography scan of the skull indicated a nodular calcified density. The combined anterior transpetrosal approach for petrous osteoma and microvascular decompression (MVD) for the offending vessel were successfully performed. The patient was discharged without any complications or facial pain. Although extremely rare, TN simultaneously secondary to petrous osteoma and offending vessels should be considered in the diagnosis. In this case, the combined surgical removal of petrous osteoma and MVD for the offending vessels proved to be an effective treatment for TN secondary to osteoma and vascular compression.

Application of Virtual Endoscopy in Microvascular Decompression of Trigeminal Neuralgia.

The main purpose of this study is to evaluate the accuracy of virtual endoscopy (VE) in microvascular decompression (MVD) for the treatment of trigeminal neuralgia (TN). A total of 30 TN patients aged 42 to 70 years were recruited from January 2015 to January 2019, and all patients were confirmed to have severe neurovascular compression (NVC) (≥degree 2) by magnetic resonance tomographic angiography (MRTA). Preoperative MRTA and enhanced CT were performed, and the data were imported into Stlview software for VE simulation of MVD. The reliability of VE, real endoscopy, and MRTA in evaluating the degree and position of MVD in TN patients was compared. Virtual endoscopy is more reliable than MRTA in evaluating the degree of NVC, but both of them are reliable in determining the position of NVC in TN patients. Virtual endoscopy can be used in MVD for the treatment of TN, including preoperative diagnosis and risk evaluation, intraoperative guidance, and postoperative evaluation.

Sensitivity of magnetic resonance tomographic angiography for detecting the degree of neurovascular compression in trigeminal neuralgia

PurposeNeurovascular compression (NVC) is hypothesized to be the main pathogenic factor of trigeminal neuralgia (TN). Microvascular decompression (MVD) has become a popular surgery for TN, and the success rate depends on the degree of NVC. As the routine examination before MVD, magnetic resonance tomographic angiography (MRTA) shows high sensitivity for detecting NVC. However, there are no reports on the sensitivity of MRTA for assessing the degree of NVC.MethodsThis study aimed to evaluate the sensitivity of MRTA for determining the degree of NVC by comparing preoperative MRTA and intraoperative endoscopy findings. A total of 480 patients who suffered from TN and underwent MVD were included. Their preoperative MRTA and intraoperative endoscopy findings were reviewed. The kappa test was used to identify similarities between the MRTA and endoscopy findings.ResultsThe degree of NVC on preoperative MRTA was similar to that on endoscopy (kappa = 0.770). The number of offending vessels according to preoperative MRTA was coincident with that according to endoscopy (kappa = 0.722).ConclusionMRTA had high sensitivity for detecting not only the presence of NVC but also the degree of NVC.

Correlation between cerebellar retraction and hearing loss following microvascular decompression for hemifacial spasm

Objective To investigate the relationship between cerebellar retraction and postoperative hearing loss of microvascular decompression (MVD) for hemifacial spasm (HFS). Methods The study included 130 patients clinically diagnosed as primary HFS who underwent MVD at Neurosurgery Department of Rui Jin Hospital, Shanghai JiaoTong University School of Medicine from March to September of 2016. The cerebellar retraction (retraction depth and distance) were quantitatively measured on preoperative MRTA (magnetic resonance tomographic angiography). Pre- and postoperative auditory functions were assessed by pure tone average (PTA). Postoperative hearing dysfunction was defined as the postoperative PTA >50 dB combined with a decrease of PTA ≥15 dB compared with preoperative conditions. Correlation of cerebellar retraction with postoperative hearing loss was analyzed by uni- and multivariate statistical methods. Results HFS was completely disappeared in 112 (86.2%) patients, spasm of musculus facialis was occasionally appeared in 10 (7.7%) patients, HFS was partly alleviated in 8 (6.1%) patients. Among those 130 cases, 12 (9.2%) patients developed hearing dysfunction post MVD. Univariate analysis showed that the retraction depth in hearing loss group was significantly greater than that in cases without hearing loss (P 0.05). Multivariate logistic regression analysis showed that cerebellar retraction depth was significantly associated with the incidence of postoperative hearing loss (P=0.001). Conclusions The results have suggested the correlation between cerebellar retraction depth and likelihood of hearing loss following MVD for HFS. In addition, cerebellar retraction depth could be considered as a useful tool for risk prediction of hearing loss post MVD. Key words: Hemifacial spasm; Microvascular decompression; Hearing loss; Cerebellar retraction

Efficacy of stereotactic gamma knife surgery and microvascular decompression in the treatment of primary trigeminal neuralgia: a retrospective study of 220 cases from a single center.

ObjectivesA retrospective study was undertaken to compare the efficacy of stereotactic gamma knife surgery (GKS) and microvascular decompression (MVD) in the treatment of primary trigeminal neuralgia (TN) at a single center. The study included the evaluation of clinical outcomes of pain relief and pain recurrence and complications associated with GKS and MVD.MethodsThe study included 202 patients with primary TN and was conducted between January 2013 and December 2014; about 115 patients were treated with GKS and 87 patients were treated with MVD. TN pain was evaluated using the Barrow Neurological Institute and the visual analog scale scoring systems. Preoperative magnetic resonance tomographic angiography was performed for all patients. Microscope-assisted MVD used the suboccipital retrosigmoid sinus approach. GKS targeted the trigeminal nerve root entry zone with a margin radiation dose of 59.5 Gy, and brainstem dose <12 Gy. Posttreatment follow-up was for 2 years.ResultsPostoperative Barrow Neurological Institute scores for patients treated with GKS and MVD were significantly improved compared with preoperative scores (P<0.01). Reduction in postoperative pain following MVD (95.4% patients) was significantly greater than that following GKS (88.7% patients) (P<0.01). Postoperative visual analog scale scores of the MVD group were significantly reduced compared with those of patients treated with GKS at the same postoperative time points (P<0.01). Patients treated with GKS had a significantly increased rate of loss of corneal reflex compared with patients treated with MVD (P=0.002).ConclusionBoth GKS and MVD are safe and effective first-line and adjunctive treatment options for patients with TN. The clinical outcomes of pain relief and reduction of pain recurrence were better with MVD. For GKS, this study showed that the optimal radiation therapeutic dose range was 70–90 Gy, but brainstem radiation protection is recommended.

Analysis of magnetic resonance tomographic angiography false negatives in trigeminal neuralgia before microvascular decompression

Objectives The aim of this study was to clarify the reason for the high rate of false-negative cases for offending vessels determined by magnetic resonance tomographic angiography (MRTA) in trigeminal neuralgia (TN) patients before microvascular decompression (MVD).

Application of electrophysiological methodsand magnetic resonance tomographic angiography in the differentiation between hemifacial spasm and Meige syndrome.

Bilateral hemifacial spasm and Meige syndrome can be easily confused due to their similar clinical manifestation. Here, we aimed to investigate the application of electrophysiological methods and magnetic resonance tomographic angiography (MRTA) in the differentiation between hemifacial spasm and Meige syndrome. 10 patients with bilateral hemifacial spasm and 9 patients with Meige syndrome received electrophysiological monitoring of nerves. There were two males and eight females with bilateral hemifacial spasm, aged 16-58years with a course of 5-54months. For the patients with Meige syndrome, there were three males and six females, aged 51-68years with a course of 12-36months. All patients received conventional MRTA of the brain blood vessels before decompression. We found that all patients with Meige syndrome showed synchronous contraction of bilateral orbicularis oculi muscles and (or) burst discharge from orbicularis oris muscles in surface electromyography (sEMG). However, those with hemifacial spasm presented with bilaterally asynchronous burst discharge. Electromyography for patients with Meige syndrome did not record abnormal muscle response (AMR), but recorded AMR for those with bilateral hemifacial spasm. The offending vessels were compressed in patients with hemifacial spasm in MRTA, while MRTA results were generally negative for those with Meige syndrome. Combining sEMG and AMR detection in EMG and MRTA, bilateral hemifacial spasm can be differentiated from Meige syndrome with a reduction of misdiagnosis rate.

Preoperative evaluation of the neurovascular compression using magnetic resonance tomographic angiography: our radiologic indications for microvascular decompression to treat trigeminal neuralgia.

The aim of this study was to introduce our classification of the neurovascular compression (NVC) in trigeminal neuralgia and the radiologic indications for microvascular decompression (MVD) based on magnetic resonance tomographic angiography. From 2003 to 2011, 322 patients with primary trigeminal neuralgia were treated with MVD. The score of NVC was from 0 to 3. Three scores, separately from axial, oblique sagittal, and coronal images, were added together. The degree of NVC was classified as follows: grade 0 (0-1), grade 1 (2-3), grade 2 (4-6), and grade 3 (7-9). In summary, 88.3% (182/206) patients with absolute indication, 78.3% (65/83) patients with relative indication, and 90.9% (30/33) without indication showed excellent results. Among the 27 patients with good result, 13 patients (48.1%) were in grade 1, and 3 (11.1%) were in grade 0. Among the 18 patients with poor result, 5 patients (27.8%) were in grade 1 preoperatively. Five patients with severe complications were all in grade 0 with vague NVC. The patients with grades 2 and 3 (absolute indications) NVC were recommended with MVD.

Microvascular decompression for recurrent trigeminal neuralgia

Recurrence of trigeminal neuralgia (TN) symptoms after microvascular decompression (MVD) is a challenge for neurosurgeons. This study evaluates the indication, efficacy and safety of re-do MVD. We retrospectively reviewed consecutive patients who underwent MVD for TN from January 2000 to June 2012. The parameters of study interest were pre-operative magnetic resonance tomographic angiography (MRTA) findings and operative findings. Pain outcome was scored using the Barrow Neurological Institute (BNI) grading scale. Twelve patients underwent re-do MVD following recurrence of pain. Vascular compression was detected on pre-operative MRTA images in eight patients, a small mass was found in two patients, and pre-operative imaging was negative in two patients. Of the eight patients with a positive finding of arterial conflict, a vascular loop was identified intra-operatively in five patients (62.5%); in two (25.0%) a small granuloma filled with Teflon fibers was found compressed the trigeminal nerve; and in one patient (12.5%) only dense arachnoid adhesions were found around the trigeminal nerve. For the two patients with mass compression on MRTA images, a granuloma was found during operation. Neurovascular compression was found in the two patients with negative preoperative MRTA images. Re-do MVD is a safe and effective treatment for recurrent TN when indicated by a prolonged pain-free period following the first surgery.

Etiologic exploration of magnetic resonance tomographic angiography negative trigeminal neuralgia

Our objective was to explore the etiologic factors involved in trigeminal neuralgia with negative magnetic resonance tomographic angiography (MRTA) results. Clinical data from 341 patients with idiopathic trigeminal neuralgia who were treated with neurovascular decompression between March 2003 and December 2011 were retrospectively analyzed. The etiologic causes of preoperative MRTA-negative trigeminal neuralgia were categorized based on comparisons between preoperative MRTA and intraoperative endoscopic images. MRTA was highly sensitive (92.4%, 291/315) to neurovascular compression, whereas its specificity was 65.4% (17/26). Among the 24 false-negative cases, there were nine patients with petrosal vein compression, 12 with superior cerebellar artery compression, two with superior cerebellar arterial branch compression, and one patient with anterior inferior cerebellar artery compression. Among the 17 true-negative cases, three patients had arachnoid adhesions, one had a protruding temporal eminence, five had micro-cholesteatomas, and eight patients exhibited no compression. The factors responsible for the MRTA-negative results included small-diameter arterial vessels, veins with slow blood flow, arachnoid adhesions, protruding temporal eminences, micro-cholesteatomas, and other pathologies such as multiple sclerosis. Preoperative diagnoses of MRTA-negative patients need to integrate the MRI results from multiple sequences to discriminate between arteriolar compression, venous compression, and small compressive lesions. When narrow cerebellopontine angles are shown in MRTA, arachnoid adhesion and temporal eminence compression should be considered.

Predicting the Outcome of Microvascular Decompression for Primary Trigeminal Neuralgia by the Use of Magnetic Resonance Tomographic Angiography

Microvascular decompression (MVD) has been the available method to cure trigeminal neuralgia (TN), and several factors have been discussed as significant predictors of excellent outcome after MVD. This study aimed to find out the value of magnetic resonance tomographic angiography (MRTA) in predicting the outcome of MVD for TNs. A total of 157 cases of TNs who underwent MVD have taken MRTA preoperatively and postoperatively and then were followed up for 5 years. The possible prognostic factors were analyzed by χ(2) test and Kaplan-Meier survival analysis. Five years after MVD, 83.4% (131 cases) gave excellent, 10.2% (16 cases) gave good, and 6.4% (10 cases) gave poor results. A significant difference was found between the severity of postoperative neurovascular compression (χ(2) = 16.307, P < 0.01)/the relief rate of neurovascular compression (NVC) (χ(2) = 17.221, P < 0.01) and the outcome after MVD. However, no significant correlation was found between the severity of preoperative NVC and the outcome (χ(2) = 6.275, P = 0.329). The Kaplan-Meier survival curves showed that lower degree of postoperative NVC severity group and higher relief rate group had better pain relief after MVD. Postoperative MRTA can help us predict the outcome of MVD; less severity of postoperative NVC and more relief of compression could be possible prognostic factors.

Correlation of MR tomographic findings and microvascular decompression treatment of the neurovascular compressions of the cranial nerves

Objective To explore the correlation of the operation effects of the miorovascular decompression(MVD) and the findings on magnetic resonance tomographic angiography(MRTA) in patients of neurovascular compression of the cranial nerves.Methods Two hundred and twenty three patients treated with the microvascular decompression were analyzed retrospectively.They were grouped and graded according to the vessel compression on the cranial nerves.The compression were grouped as none, moderate and severe, and the operation effects were graded as Ⅰ ( complete relief), Ⅱ ( partial relief) and Ⅲ ( no relief).The operation effects grades were correlated according to the compression groups by Kruskal-Wallis test and the operation effects between each two of the groups were compared using Nemenyi test.P < 0.05 was defined as statistic significant.Results Of the 53 cases of non-compression group, 31 cases were graded as Ⅰ , 13 cases were graded as Ⅱ and 9 cases were graded as Ⅲ, according to the operation-effects of the decompression.Of the 110 cases of moderate group,95 cases were grade as Ⅰ , 11 cases were graded as Ⅱ and 4 cases were graded as Ⅲ.Of the 60 cases of severe group, 48 cases were graded as Ⅰ, 7 cases were graded as Ⅱ and 5 cases were graded as Ⅲ.There were statistic significance among the three groups,where χ2= 16.84 and P <0.05.The mean rank of the non-compression, the moderate and the severe group was 134.21,102.37 and 110.4 ,respectively.The difference of the mean ranks between the non-compression group and the moderate group was 31.84, and between the non-compression and the severe group was 24.17, respectively, where P < 0.05 both.Conclusions There was close relationship between the findings on magnetic resonance tomographic angiography and the operation effects of the MVD.The operation effects of patients with moderate and severe vessel compression were much better than the non-compression group.MRTA is helpful for MVD surgical indication and its prognosis. Key words: Trigeminal neuralgia; Decompression,surgical ; Magnetic resonance imaging

Hemifacial spasm patient with ipsilateral total absence of common carotid artery, vertebral artery and aneurysm of the contralateral internal carotid artery

We present a case of a 45-year-old male patient with left hemifacial spasm for 6 years. Magnetic resonance tomographic angiography confirmed that there were small vessels adjacent to the left facial nerve root entry zone, but the left internal carotid artery (ICA) was absent. Magnetic resonance angiography using three-dimensional time of flight technique showed the absence of the left ICA and vertebral artery, But the presence of a 6-mm aneurysm in the bifurcation of the right internal carotid artery. These abnormal arterial structures were further confirmed by angiogram. Aortic arch angiogram revealed a right-sided aortic arch and the Subclavian steal phenomenon. The left common carotid artery and the left Subclavian artery were absent. Right vertebral angiography showed retrograde filling of the left vertebral artery. The left upper limb was fed by this artery. The aneurysm was successfully clipped. Post-operatively, the hemifacial spasm was weakened. However, the operation did not change the neurovascular positional relationship, thus we advised follow-up visits. Cerebral artery anomalies should be taken into consideration when performing imaging and surgical corrections in patients with hemifacial spasm.

Predicting the Outcome of Microvascular Decompression for Trigeminal Neuralgia Using Magnetic Resonance Tomographic Angiography

To investigate the role of preoperative magnetic resonance tomographic angiography (MRTA) in predicting the clinical outcomes of trigeminal neuralgia (TN) patients following microvascular decompression (MVD). Preoperative MRTA imaging was performed on 167 consecutive patients with TN. The characteristics of offending vessels were determined by MRTA prior to MVD. The relationship of neurovascular contact was classified into 3 types: positive, negative, and contralateral positive, which were compared with the surgical findings and clinical outcomes. MRTA showed obvious neurovascular compression in accordance with surgical findings in 144 patients. Among the remaining 23 patients with negative finding on preoperative MRTA images, neurovascular compression (vein alone or in combination with artery) were found in 16, no definite vascular compression in 7. The sensitivity of MRTA on the symptomatic side was therefore 90%, the specificity was 100% in our series. A correlation was found between clinical outcomes and preoperative findings on MRTA. In 144 MRTA-positive patients, 136 achieved "excellent" or "good" outcomes after MVD and were significantly better than the MRTA-negative group (P < .01). The outcomes of patients with a single artery compression were significantly better than those with venous compression, vein in combination with artery compression, or without obvious neurovascular contact (P < .01). Seven of 23 MRTA-negative patients obtained poor outcomes after operation, venous compression were identified intraoperatively in 4 of them, no definite offending vessel was found in 3 patients. This study suggests that the curative rate of TN following MVD is higher in the MRTA-positive group. Venous compression and no neurovascular contact that were negative on MRTA image are poor prognostic factors for surgical outcome of TN. Thus, preoperative MRTA serves as a useful tool in patient selection and outcome prediction.

Clinical manifestations and imaging features of peripheral vestibular paroxysmia: a report of 7 cases

To investigate the clinical manifestations and imaging features of peripheral vestibular paroxysmal (PVP). The clinical data, including magnetic resonance tomographic angiography (MRTA), of 7 PVP patients, 1 male and 2 females, aged 40-72, were retrospectively analyzed. (1) All 7 patients had non-specific cochleovestibular symptoms, e.g., recurrent vertigo and continuous dizziness. (2) The predominant symptom was transient vertigo or dizziness with the sudden change of head position. (3) MRTA showed cross of the cochleovestibular nerve (CNV) and blood vessel in all patients. (4) Carbamazepine and sibelium succeeded to relieve the symptoms. Compression of the cranial nerve VIII by crossing vessel thereon may be the mechanism of PVP which can be identified and diagnosed clinically.

Neurovaskularna kompresija (konflikt)

Since Dandy first reported vascular compression of the trigeminal nerve, the concept of neurovascular compression syndrome for trigeminal neuralgia and hemifacial spasm (HFS) has been accepted, and neurovascular decompression has been performed for this condition. The further investigations indicated that some other clinical syndromes such as glossopharyngeal neuralgia, disabling positional vertigo, tinnitus, geniculate neuarlgia, spasmodic torticolis, essential hypertension, cyclic oculomotor spasm with paresis and superior oblique myokymia also may be initiated by vascular compression of the glossopharyngeal, cochleovestibular, intermediate, accessory, oculomotor and trochlear nerves or the ventrolateral medulla oblongata. In this study several hypotheses regarding the development of cranial nerves vascular compression syndromes are presented. It is alsoemphasized the value of high-resolution magnetic resonance tomographic angiography for visualization of vascular compression. The most frequent clinical syndromes caused by vascular compressionof the cranial nerves are discussed regarding the pathogenesis, symptomes and therapy. We present our series of 124 patients with preoperative evidently positive finding of vascular compression to the trigeminal nerve (MRI). Microvascular decompression (MVD) was performed in all of them. Initial postoperative result was excellent in 110/124 (89%) patients,while in 11/124 (9%) patients the pain relief was satisfactory. In the remaining three patients MVD failed. Recurrence of pain after two years reached 19%. Complications were related to diplopia associated with transient fourth nerve dysfunction in 5 (4%) patients, facial motor dysfunction in 4 (3%) patients, transient facial hypesthesia in 27 (22%) patients and partially hearing loss in 4 (3%) patients. Cerebellar hemorrhagic infarction occurred in 1 (0.8%) patient and cerebrospinal fluid leaks appeared in two (1.6%) cases. There was no lethal outcome.

Treatment of atypical trigeminal neuralgia with microvascular decompression

To explore the methods for achieving pain relief in patients with atypical trigeminal neuralgia (TN) using microvascular decompression (MVD). Retrospective study of 26 patients treated during the years 2000 to 2004. Twenty-six patients in whom vascular compression of the trigeminal nerve was identified by high definition magnetic resonance tomographic angiography (MRTA) were treated with MVD for atypical TN in our department. Clinical presentations, surgical findings and clinical outcomes were analyzed retrospectively. In this study, single trigeminal division was involved in only 2 patients (8%) and two or three divisions in the other 24 patients (92%). Of prime importance is the fact that in 46.2% of the patients, several conflicting vessels were found in association. Location of the conflicts around the circumference of the trigeminal root was supero-medial to the root in 53.5%, supero-lateral in 30.8% and inferior in 15.7%. MVD for atypical TN resulted in complete pain relief in 50% of the patients with complete decompression, partial pain relief in 30.8% and poor pain relief or pain recurrence in 19.2% of the patients without complete decompression postoperatively. Complete decompression of the entire trigeminal root plays an important role in achieving pain relief in patients with atypical TN with MVD.

Demonstration of neurovascular compression in trigeminal neuralgia and hemifacial spasm with magnetic resonance imaging: Comparison with surgical findings in 60 consecutive cases

Background Until recently, it has been impossible to demonstrate vascular compression at the root entry or exit zone (REZ) of the trigeminal nerve and facial nerve in patients with trigeminal neuralgia (TN) and hemifacial spasm (HFS) preoperatively, although surgical findings have revealed apparent neurovascular compression and its correction has resulted in a good outcome in most cases. Revealing the anatomic correlation between nerves and vessels at the REZ preoperatively would be useful to predict operative findings. Methods To assess whether the vascular contact of the nerve at the REZ could be demonstrated preoperatively, high-resolution magnetic resonance tomographic angiography (MRTA) was performed in 21 patients with TN and 39 with HFS. Neuroradiological findings were compared with the operative findings in all patients. Contralateral asymptomatic nerves were evaluated as a control. Results MRTA correctly identified offending vessels in 14 (67%) of the 21 TN and 34 (87%) of the 39 HFS patients. Failure to identify neurovascular contact was noted in the cases with compression by veins or small arteries, thickened arachnoid, or distal compression. Neurovascular contact was also observed in 15% of the asymptomatic nerves. The deformity of the nerve seemed to be a more important factor for determining operative indication. Conclusions MRTA could demonstrate offending vessels in TN and HFS at a high rate and was useful to predict operative findings. MRTA gave supportive evidence of surgical indications in patients with TN and HFS, although attention should be paid to the fact that MRTA did not necessarily detect all of the offending vessels.