Neurovascular Conflict Research Articles

Contrast-Enhanced CISS Imaging for Evaluation of Neurovascular Compression in Trigeminal Neuralgia: Improved Correlation with Symptoms and Prediction of Surgical Outcomes.

Thin-section MR imaging through the posterior fossa is frequently used for trigeminal neuralgia. Typical heavily T2-weighted imaging methods yield high anatomic detail and contrast between CSF and neurovascular structures, but poor contrast between vessels and nerves. We hypothesized that the addition of gadolinium-based contrast material to 3D-constructive interference in steady-state imaging would improve the characterization of trigeminal compression. Retrospective review of high-resolution MRIs was performed in patients without prior microvascular decompression. 3D-CISS imaging without contrast and with contrast for 81 patients with trigeminal neuralgia and 15 controls was intermixed and independently reviewed in a blinded fashion. Cisternal segments of both trigeminal nerves were assessed for the grade of neurovascular conflict, cross-sectional area, and degree of flattening. Data were correlated with symptom side and pain relief after microvascular decompression using the Fisher exact test, receiver operating curve analysis, and a paired t test. Contrast-enhanced CISS more than doubled the prevalence of the highest grade of neurovascular conflict (14.8% versus 33.3%, P = .001) and yielded significantly lower cross-sectional area (P = 8.6 × 10-6) and greater degree of flattening (P = .02) for advanced-grade neurovascular conflict on the symptoms side compared with non-contrast-enhanced CISS. Patients with complete pain relief after microvascular decompression had significantly lower cross-sectional area on contrast-enhanced CISS compared with non-contrast-enhanced CISS on preoperative imaging (P = 2.0 × 10-7). Performance based on receiver operating curve analysis was significantly improved for contrast-enhanced CISS compared with non-contrast-enhanced CISS. The addition of contrast material to 3D-CISS imaging improves the performance of identifying unilateral neurovascular compression for symptomatic trigeminal neuralgia and predicting outcomes after microvascular decompression.

Microvascular Decompression for Hemifacial Spasm Associated with Vertebral Artery: Biomedical Glue−Coated Teflon Sling Transposition Technique

Microvascular decompression is the most effective treatment for hemifacial spasm. However, when encountering hemifacial spasm associated with vertebral artery (VA), the procedure is more challenging and requires complicated operation techniques. The authors retrospectively analyzed the clinical characteristics of this group of cases and investigated reasonable transposition procedures for different anatomic classifications. We retrospectively analyzed 117 cases that underwent their first microvascular decompression for hemifacial spasm between June 2010 and December 2016, which had all associated with vertebral artery compression diagnosed by preoperational radiology examination. The study first classified offending vessels into 3 types according to operative anatomy and designed personalized decompression management according to different forms of neurovascular conflict. Curative effects and complications were assessed. The offending vessels were artificially divided into 3 types according to both arterial pattern and compression direction: 1) ipsilateral VA plus anterior inferior cerebellar artery compressing the facial nerve from the ventrolateral direction in 72 (61.5%) cases; 2) ipsilateral VA plus posterior inferior cerebellar artery compressing the facial nerve from the caudal-medial direction in 31 (26.5%) cases; 3) bilateral VA compressing the facial nerve in 14 (12.0%) cases. We selected corridors to expose the neurovascular conflict site between the suprafloccular-transhorizontal fissure approach and subtonsillar-transcerebellomedullary fissure approach. The methods of decompression consist of anteromedial and posterolateral transposition by using biomedical glue-coated Teflon sling. Sufficient decompression of the offending vessels was safely performed in all cases. All cases had total relief of symptoms immediately after their operations. Follow-up periods ranged from 16-90 months, and total recovery occurred in 110 cases (94.0%). In 7 cases (6.0%), 90% recovery occurred. Accuracy and comprehensive recognition of anatomic features of the offending vessels are crucial for the management of hemifacial spasm associated with vertebral artery compression. Appropriate approaches combined with the biomedical glue-coated Teflon sling transposition technique can allow adequate mobilization of the vertebral artery and bring complete postoperative symptom relief for most cases.

MRI Findings and Outcomes in Patients Undergoing Microvascular Decompression for Glossopharyngeal Neuralgia

Glossopharyngeal neuralgia causes extreme paroxysmal pain in the posterior pharynx, tonsillar region, base of tongue, or deep ear, that is, the distribution of the glossopharyngeal nerve. Some cases of glossopharyngeal neuralgia are associated with neurovascular conflict, usually by the posterior inferior cerebellar artery. Such symptomatic compression occurs only in proximal, centrally myelinated portions of the glossopharyngeal nerve near the brainstem. Microvascular decompression provides effective and durable pain relief for properly selected patients with medically refractory glossopharyngeal neuralgia. The purpose of this study is to describe a tailored MRI evaluation of neurovascular conflict in glossopharyngeal neuralgia to improve candidate selection for microvascular decompression. Our team developed a glossopharyngeal neuralgia imaging and evaluation protocol including a grading system for neurovascular conflict of the glossopharyngeal nerve and applied it to evaluate candidates for microvascular decompression. Our team grades neurovascular conflict as "contact" (vessel touching nerve without intervening cerebrospinal fluid) versus "deformation" (deviation or distortion of nerve from its normal course by the offending vessel). MRIs of patients with glossopharyngeal neuralgia demonstrate proximal neurovascular conflict. Postoperative MRI demonstrates separation of the glossopharyngeal nerve from the offending vessel. A tailored glossopharyngeal neuralgia imaging evaluation protocol is presented. We believe this approach has helped improve microvascular decompression outcomes and reduce unnecessary procedures at our institution. Further research may elucidate whether clinical and imaging features, including neurovascular conflict severity, predict surgical outcome for glossopharyngeal neuralgia.

Revision Microvascular Decompression for Trigeminal Neuralgia and Hemifacial Spasm: Factors Associated with Surgical Failure.

Objective To investigate risk factors for symptom recurrence in patients requiring a revision microvascular decompression (MVD) for trigeminal neuralgia (TN) or hemifacial spasm (HFS). Design Retrospective review of a prospectively maintained database. Participants Seventeen consecutive patients undergoing revision MVD at our institution between January 1993 and September 2017. Main Outcome Measures The incidence and causes for revision MVDs were recorded. Response to revision MVD for TN was tracked using the Barrow Neurological Institute (BNI) grading scale. Response to revision MVD for HFS was graded as "no improvement," "some relief," or "complete resolution" of symptoms. Results Revision MVD rate for the senior author across all MVDs performed in this period was 1.9% for TN and 9.3% for HFS. Initial MVD failure was primarily caused by active inflammation and/or scarring and adhesions in 5/17 patients, malposition/slippage of Teflon in 3/17 patients, and insufficient Teflon in 1/17 patients. Without other factors, a new site of neurovascular conflict was identified in 4/17 patients, while the same site of neurovascular conflict was found in 3/17 patients. No cause could be identified in 1/17 patients. Scarring was found primarily in the TN group and was associated with symptom persistence. Conclusion Revision MVD for recurrent TN and HFS is an effective procedure offering the prospect of a complete cure. Proper Teflon use is crucial for surgical success. Scarring after initial MVD is a negative prognostic factor requiring destructive treatment consideration. Although morbidity rates were slightly increased with revision versus original MVDs, the complications were non-disabling and resolved over time.

Is there a role for computational fluid dynamics (CFD) in neurovascular compression syndrome?

Abstract Introduction - CFD uses complex algorithms to predict flow of fluids through a tube & also predicts its impact on walls. It is increasingly being used for prediction of aneurysmal wall thickness, flow, wall shear stress and to decide clip strategy. This is an experimental study, which analyses use of CFD in neurovascular compression syndrome and probable future applications. We analysed CFD findings in 12 cases retrospectively to know fluid dynamics of vessels and its implications. Methodology - Twelve patients - 7 cases of trigeminal neuralgia and 5 of hemifacial spasm who were to be treated by MVD, were enrolled. CFD i.e. WSSv (wall shear stress vector), WSSm (magnitude), SL (stream line) and Pressure, was done in all prospectively. Results - CFD of superior cerebellar artery, anterior inferior cerebellar artery and vertebral artery was done in each case at the contact site and immediate pre + post contact location. Comparitively High WSSm correlated maximally at nerve vessel contact junction (NVCj) and also high SL at the NVCj comparing with nerve vessel contact proximal (NVCp), WSSv showed wide variations and pressure change was in-conclusive. Conclusion - At contact site, the high WSSm& SL might be a reliable indicator of a neurovascular conflict zone. To conclusively validate the findings we need large number of patients and control group.

Management of veins during microvascular decompression for idiopathic trigeminal neuralgia

Object: To summarize our experience in treating veins during microvascular decompression (MVD) procedures for idiopathic trigeminal neuralgia (TN).Methods: A total of 210 patients who underwent single MVD for idiopathic TN were retrospectively studied. The offending vessels were summarized. The treatment choices for veins during the operation were reviewed. Postoperative long-term outcomes were determined by follow-up.Results: Veins accounted for 26.7% of the total 262 offending vessels. Neurovascular conflicts were caused by veins alone in 23 patients (11.2%), and they were caused by arteries and veins together in 47 patients (22.8%). The offending veins were cut (15.7%) or saved (84.3%) during the operation. Excellent long-term outcomes were acquired in 78.3% of the patients with venous type TN.Conclusion: There are no acknowledged principles guiding the treatment of veins during MVD. Our primary treatment principle is to retain veins as often as possible.

Endoscope-assisted retrosigmoid approach in hemifacial spasm: our experience

IntroductionThe use of surgical decompression of facial hemispasm due to the loop in the internal auditory canal is not always accepted due to the risk related to the surgical procedure. Currently a new surgical technique allows surgeons to work in safer conditions. ObjectiveTo report the results with endoscope-assisted retrosigmoid approach for facial nerve microvascular decompression in hemifacial spasm due to neurovascular conflict. The surgical technique is described. MethodsWe carried out a prospective study in a tertiary referral center observing 12 (5 male, 7 female) patients, mean age 57.5 years (range 49–71) affected by hemifacial spasm, that underwent to an endoscope assisted retrosigmoid approach for microvascular decompression. We evaluated intra-operative findings, postoperative HFS resolution and complication rates. ResultsHemifacial spasm resolution was noticed in 9/12 (75%) cases within 24h after surgery and in 12/12 (100%) subjects within 45 days. A significant (p<0.001) correlation between preoperative historical duration of hemifacial spasm and postoperative recovery timing was recorded. Only 1 patient had a complication (meningitis), which resolved after intravenous antibiotics with no sequelae. No cases of cerebrospinal fluid leak, facial palsy or hearing impairment were recorded. Hemifacial spasm recurrence was noticed in the only subject where the neurovascular conflict was due to a vein within the internal auditory canal. ConclusionsThe endoscope assisted retrosigmoid approach technique offers an optimal visualization of the neurovascular conflict thorough a minimally invasive approach, thus allowing an accurate decompression of the facial nerve with low complication rates. Due to the less invasive nature, the procedure should be considered in functional surgery of the cerebellar pontine angle as hemifacial spasm treatment, specially when the procedure is performed by an otolaryngologist.

Microvascular decompression for hemifacial spasm : Surgical techniques and intraoperative monitoring

Primary hemifacial spasm with few exceptions is due to the vascular compression of the facial nerve that can be evidenced with high resolution MRI. Microvascular decompression is the only curative treatment for this pathology. According to literature review detailed in chapter “conflicting vessels”, the compression is located at the facial Root Exit Zone (REZ) in 95% of the cases, and in 5% distally at the cisternal or the intrameatal portion of the root as the sole conflict or in addition to one at brainstem/REZ. Therefore, exploration has to be performed on the entire root, from the ponto-medullary fissure to the internal auditory meatus. Because microvascular decompression is functional surgery, the procedure should be as harmless as possible and with a high probability of permanent efficacy. Besides facial palsy, main complications are hearing loss, tinnitus and gait disturbances. Causes are cochlea/labyrinth ischemia due to manipulations of their nutrient arteries and/or stretching of the eight nerve complex. To minimize the latter, the approach should not be with lateral-to-medial retraction of the cerebellar hemisphere, but along an infra-floccular trajectory, from below. In fact, most of the neurovascular conflicts are situated ventro-caudally to facial REZ at the brainstem, particularly those from a megadolicho-vertebrobasilar artery and its posterior inferior-cerebellar branch. Also, care should be taken not to cause any injury of the manipulated vessels or stretching of their perforators to brainstem. Heating from bipolar coagulation must be avoided. The inserted material used to maintain the offending vessel(s) away must not be neo-compressive. Intraoperative neuromonitoring is considered to be useful for achieving safe surgery at least until the learning curve has reached an optimal level, particularly BrainstemAuditory Evoked Potentials recordings. Increase in latency and/or decrease in amplitude of wave V warn excessive stretching or damage to the cochlear nerve, and decrease in amplitude of wave I signals possible ischemia of the cochlea. Free-running EMG of the facial muscles may warn against excessive manipulation of the facial nerve. Recording of the lateral spread responses – which are a sign of hyperexcitabilty of the facial motor system – may provide information on completeness of the decompression.

Imaging of hemifacial spasm

Almost all primary hemifacial spasms are associated with one or more neurovascular conflicts, most often at the root exit zone in the immediate vicinity of the brainstem. Imaging has first to exclude a secondary hemifacial spasm and secondly to search for and characterize the responsible neurovascular conflict(s). Magnetic resonance imaging should include high-resolution anatomical hyper T2-weighted sequences and magnetic resonance angiography by using 1.5 or even better 3 Tesla magnets. The most frequent vascular compressions are from the anterior-inferior cerebellar artery, the posterior-inferior cerebellar artery and the vertebrobasilar artery; venous conflicts are very rare. Conflicts are often multiple; also, the same vessel may compress the facial nerve in two places. Also, conflicts may be aided by particular anatomical circumstances, including arterial dolichoectasia, posterior fossa with a small volume or bony malformations.

Endoscope-assisted decompression of facial nerve for treatment of hemifacial spasm

Microvascular decompression has become the sole method for a curative treatment of primary hemifacial spasm. Finding the responsible conflicting artery is not always easy as its location can be deeply situated within the cerebellopontine/medullary fissure at the facial root exit zone. Sole or additional offending vessel(s) may be at the meatus of the internal auditory canal (5% of the cases). Identifying the compressive vessel(s) and performing decompression is in most cases possible without cerebellar retraction by classical microsurgical techniques. However, in a number of patients the neurovascular conflict may be hidden in spite of the direct illumination of the operative microscope. Therefore, assistance by endoscopy can be useful and contribute as a minimally invasive approach. The author reports his own experience in a series of 553 patients operated on over the past three decades. A total of 93.6% had complete relief of their spasm (11% after repeated surgery). Relief was delayed in 20.8% of these patients. Recurrence was rare (0.3%). There was no mortality and morbidity was low: deafness occurred in 0.6%. There was no permanent postoperative facial palsy. CSF leakage amounted to 1% in the last period of surgery. In conclusion, the author advocates combining the use of both the endoscopy for exploration and the microscope for decompression.

Absence of neurovascular conflict during microvascular decompression while treating essential trigeminal neuralgia. How to proceed? Systematic review of literature

IntroductionNeurovascular conflict is the most accepted hypothesis for the cause for trigeminal neuralgia. Microvascular decompression of the trigeminal nerve is the most common surgical treatment for these patients. However, despite advances in diagnostic techniques, neurovascular conflict is sometimes not detected during surgery. The aim of this paper is to systematically review all the options available to best manage this scenario. ResultsSeveral techniques that could be used during microvascular decompression for trigeminal neuralgia in the absence of neurovascular conflict have been described. The success rates of these techniques, pain recurrence rates and rates of complications are also reported. Finally, we provide suggestions based on our experience. ConclusionsThere is no gold standard, but several techniques could be successfully used in the absence of neurovascular conflict. The use of destructive techniques, such as PSR, should be held as treatments of last resort.

The conflicting vessels in hemifacial spasm: Literature review and anatomical-surgical implications

Since several decades, it has been established that so-called primary hemifacial spasm is linked to neuro-vascular conflicts in the facial nerve, especially its root exit zone (REZ). Based on our review of the detailed publications of literature (2489 patients), together with our own series (340 patients), the responsible vessels found at surgery were: the posterior inferior cerebellar artery in 47.2%, the anterior inferior cerebellar artery in 45.9%, the vertebro-basilar artery in 17.5%, another (smaller) artery in 11.7%. Participation of veins was very diversely estimated according to series: 4.9% on average. Multiple neuro-vascular conflicts in a same individual were frequently observed, in the order of 20 to 30% according to authors, 37% in our series. Also, abnormal conformation of the posterior fossa may play a role, such as flatness of the posterior fossa or exiguity of the cerebello-pontine angle cistern. Whatever, most neurovascular conflicts are located at brainstem and/or ventrocaudally to the facial REZ, in the order of 95% of the patients. The anatomical location and conformation of the compressive vessel(s) are crucial in determining the difficulties to identify the responsible conflict(s) and to perform effective and safe decompression. Main difficulties are encountered in cases with arteriosclerotic megadolicho-vertebrobasilar artery, at brainstem, especially when PICA and/or AICA come in association, or for neurovascular conflict(s) located at the cisternal or the intrameatal portions of the facial root. Later ones can be alone or in addition to NVC at brainstem/REZ.

Hemifacial spasm associated with other cranial nerve syndromes: Literature review

Hyperactive dysfunction may affect all cranial nerves in the posterior fossa. According to literature review and personal experience, hemifacial spasm was found to be associated not only with the most frequent cranial nerve syndromes, namely: trigeminal neuralgia, vago-glossopharyngeal neuralgia or VIIIth nerve disturbances manifested by vertigo, tinnitus, hearing decrease, but also with rarer syndromes like geniculate neuralgia, masticatory spasm etc. Also, a number of publications have pointed out the relatively high incidence of the coexistence of hemifacial spasm and systemic blood hypertension; both can be cured by vascular decompression of the ventrolateral aspect of the medulla and IX-Xth route entry zone (REZ) together with the facial REZ. Even more complex clinical presentations have been encountered, corresponding to disturbances in several cranial nerve nuclei. Some could be attributed to neurovascular conflicts from elongated arteries invaginated into the brainstem, and cured by microvascular decompression surgery. When confronted with such complex, and therefore misleading, syndrome, it is advised to search for vascular conflicts at the brainstem using high-resolution MRI exploration.

Diagnosis of primary hemifacial spasm

The diagnosis of primary hemifacial spasm (pHFS), due to a benign compression of the facial motor nerve by a vessel, within or close to its root exit zone, is often made with delay. Misdiagnosis includes psychogenic spasm, tics, facial myokymia or blepharospasm, but in fact post-facial palsy synkinesis (post-paralytic HFS) is the closest clinical condition, because it is limited to the territory of the facial nerve of a single hemiface. The differential diagnosis between these two entities, whose pathophysiological mechanisms are very different, can be made by electroneuromyographic (ENMG) examination. In addition, magnetic resonance imaging (MRI) is essential to show the offending vessel at the origin of pHFS and the absence of other causes of nerve compression. However, the diagnosis cannot be made on MRI basis alone, since a neurovascular conflict can be present in clinically asymptomatic subjects. This article reviews the clinical, MRI, and ENMG features in favour of a pHFS diagnosis as well as the various differential diagnoses of this involuntary facial movement disorder.

New insights into the pathophysiology of primary hemifacial spasm

Primary hemifacial spasm (pHFS) is due to a benign compression of the facial motor nerve by an offending vessel, leading to increased nerve excitability. Facial nerve hyperexcitability presents two different aspects. First, there is a spontaneous and ectopic generation of action potentials on the incriminated nerve and then this ectopic impulse can propagate and spread “laterally” from one facial nerve branch to another. This results in spontaneous and synkinetic spasms affecting one hemiface. Although the increase in excitability certainly concerns the nucleus of the facial motor nerve in the brainstem, it seems unlikely that the primary origin of this hyperexcitability and the associated phenomenon of lateral spreading strictly originate at the nuclear level. In fact, the mechanisms causing facial nerve hyperexcitability per se remain unknown. The leading implication of a structural nerve lesion, such as segmental demyelination, induced by vessel compression, is also unconvincing. In contrast, a functional mechanical factor increasing nerve excitability is extremely probable, that it is either due to compression or stretch resulting from the neurovascular conflict. Axonal ion channel changes are obviously associated with this mechanism. Then the lateral spreading of nerve fibre hyperexcitability probably results from an ephaptic process, the “cross-talk” between axons being located in the region of the conflict or in the transition zone between central and peripheral myelin, at the end of the facial nerve root exit zone. In any event, pHFS is due to a functional increase in facial nerve excitability triggered by an offending vessel and this clearly explains the remarkable and rapid efficacy of surgical microvascular decompression.

Reliability of MRI for predicting characteristics of neurovascular conflicts in trigeminal neuralgia: implications for surgical decision making.

The choice of microvascular decompression (MVD), among the several other surgical options, for treating refractory classical trigeminal neuralgia (TN) relies mostly on preoperative imaging, but the degree of reliability of MRI remains a matter of debate. The authors approached the question of predictability of neurovascular conflict (NVC) in a series of 100 protocolized MRI studies from patients with TN who underwent MVD, by reexamination of MR images, blinded to the clinical data and surgical findings, including the side of the neuralgia. Patients included in the study were those who underwent MVD after surgical indication had been determined based on a protocolized imagery workup (3D high-resolution T2-weighted cisternography centered on the trigeminal nerve, 3D time-of-flight angiography, and 3D gadolinium-enhanced T1-weighted imaging) performed at our institution. All MR images were blindly reexamined, and neurovascular relationships were described on both sides, noting the existence of compression, vessels involved, situation along the root, and degree of compression. The results of MRI evaluation were then compared with actual surgical findings. The extent of agreement and quality of the prediction were expressed with Cohen's kappa coefficient (κ) and receiver operating characteristic (ROC) statistics. A conflict had actually been found during surgery in 94 of 100 patients. The sensitivity of MRI to detect a conflict was 97% and the specificity was 50%. Vessel type was identified with high reliability (κ = 0.80), while the grade of the conflict and its situation along the root showed poor to average reliability (κ = 0.38 and κ = 0.40, respectively). The area under the ROC curve for predicting the presence of a conflict according to the grades of conflict seen on MRI was 0.93, which is considered very good. The positive predictive value was differentiated according to the grade of conflict, with a very high value for high grades of vascular conflict. This study shows an overall good reliability of MRI to predict the existence of an NVC. The prediction value is excellent for high grades of compression. Some apparent low-grade compressions on MRI may be revealed as false positives in surgical exploration. This raises the question of what other imaging methods might be used to determine not only the existence of a conflict but also its degree of compression. The degree of compression is of paramount importance to predict the probability of long-term pain relief, and therefore in the decision to propose MVD as the first choice of surgical treatment.

Evidências de compressão vasculonervosa na ressonância magnética do encéfalo

A compressão vasculonervosa é relacionada a inúmeras enfermidades dos nervos cranianos, sendo a ressonância magnética (RM) o exame de escolha para o adequado planejamento cirúrgico. São ilustrados quatro casos de compressão vasculonervosa na RM e sua importância como método de investigação complementar

Short-lasting unilateral neuralgiform headache with autonomic symptoms associated with idiopathic hypertrophic pachymeningitis

Short-lasting unilateral neuralgiform headache with autonomic symptoms (SUNA) is a rare form of trigeminal autonomic cephalalgia. SUNA is frequently associated with a trigeminal neurovascular conflict and rarely occurs secondary to other intracranial pathology. We report a patient with SUNA that was associated with ipsilateral meningeal inflammation caused by idiopathic hypertrophic pachymeningitis (HP). During the 9-year follow-up, she experienced multiple episodes of SUNA, most of which occurred during exacerbations of the pachymeningitis. This is the third case of SUNA associated with HP reported in the literature. Based on this observation, we suggest that in patients presenting with SUNA, besides dedicated magnetic resonance imaging (MRI) of the trigeminal nerve, gadolinium-enhanced brain MRI should be performed to rule out HP.

Trigeminal neuralgia: When does neurovascular contact turn into a conflict?

BackgroundThe most common cause for trigeminal neuralgia is contact of the trigeminal nerve with an offending vessel which is also observed routinely in many asymptomatic patients. Therefore, the aim of this study was to determine when an asymptomatic Neuro Vascular Contact (NVC) turned into a neurovascular conflict and made the patient symptomatic. MethodsAll patients who underwent Magnetic Resonance Imaging (MRI) brain with clinical diagnosis of trigeminal neuralgia formed the study group and all cases of sensorineural hearing loss formed the control group. ResultsOut of 51 cases of trigeminal neuralgia 27 were males and 24 were females. The neurovascular contact was seen in 41 (80.4%) cases and 17 (28.3%) controls. Change in caliber of trigeminal nerve was seen in 27 (52.9%) cases and only in 01 (1.66%) control. Arterial imprint on nerve was seen in 26 (50.9%) cases and 01 (1.66%) control. Distortion of the course of nerve was seen in 12 (23.5%) cases and 01 (1.66%) control. Superior cerebellar artery was commonest vessel seen in contact with nerve on affected side in 25 (61%) cases. ConclusionDemonstrating neurovascular contact alone is not enough for diagnosis of conflict as it is also present in some asymptomatic individuals, therefore it is important to identify thinning of nerve, arterial imprint or grooving and distortion in course of nerve, as these are more reliable signs of a conflict between the vessel and the nerve, and these cases are best treated surgically by Micro Vascular Decompression (MVD).

Combination of trigeminal neuralgia and cerebellopontine angle tumors. Modern approaches to diagnosis and treatment: literature review

Based on the data of world literature, the combination of cerebellopontine angle tumors (CPA) and trigeminal neuralgia (TN) caused by neurovascular conflict (NVC) is rare. TN for CPA tumors is predominantly caused by the V cranium nerve compression by tumor masses. The article presents the variants of the classification of the anatomical relationship between tumor, nerve and vessels in this pathology, as well as the recommendations on diagnostics and tactics of surgical treatment. All patients with TN should undergo MRI of the brain and least one of the modes of visualization of the cranial nerves included in the protocol of the study. Removal of CPA tumor should be combined with revision of TN root and mandatory elimination of the NVC.