Medulla and cervical cord contrast-induced encephalopathy detected by neuromonitoring during coil embolization of posterior circulation aneurysms.

Understanding the risks of contrast-induced encephalopathy (CIE), a serious complication of contrast agents, is crucial in endovascular treatment. We present the case of a 73-year-old woman who developed CIE in the medulla and cervical cord during coil embolization for unruptured left basilar-superior cerebellar artery and basilar artery tip aneurysms. The CIE was identified via neuromonitoring. In this case, spinal cord ischemia might have occurred due to reduced perfusion pressure after inserting the distal access catheter (DAC) in the vertebral artery. Multiple injections of contrast medium via the DAC during coil embolization likely contributed to an unusual form of CIE. Extreme caution is warranted during endovascular treatments involving the posterior circulation, due to the relatively high incidence of contrast-mediated encephalopathy, which can lead to severe consequences such as perforator infarction. Neuromonitoring is very useful for the early detection of neurological changes, particularly because intraoperative angiography may not reveal all irregularities.

Dissecting and fusiform aneurysms of the superior cerebellar artery: anatomy, clinical presentation, and treatment outcomes.

The management of superior cerebellar aneurysms is still controversial. Although several techniques are available, the deep localization of the lesion and the limited number of cases increase the complexity of decision-making for optimal treatment. Only a few cases of dissecting and fusiform aneurysms of the superior cerebellar artery (SCA) are described in the literature, many of which are without long follow-ups. The study aims to offer an exhaustive retrospective analysis of patients affected by SCA fusiform and dissecting aneurysms treated at our institution from 2008 to 2023, highlighting outcomes and complications. Moreover, a comprehensive narrative review was performed. A total of seven patients were treated at our institution. After a title and abstract screen, fifty-five papers met the criteria for inclusion in the review. In our case series, conservative treatment was proposed as the first therapeutic option in four cases (57.1%), while endovascular treatment (EVT) was in three cases (42.9%). A good recovery was observed in 66% of patients presenting with subarachnoid hemorrhage (SAH), while every patient without SAH achieved a good clinical outcome. A poor outcome was observed only in one patient with a dissecting aneurysm causing SAH, who also suffered a pontine infarction. In the literature review, conservative treatment was proposed as a first therapeutic option in eleven cases (16.6%), open microsurgical techniques in 19 patients (28.8%), and EVT in 31 patients (46.9%). Fatal outcome was documented in five patients (7.5%), all characterized by the rupture of the vascular lesion, while 6.1% of cases had non-fatal poor outcomes.

A large vertebral artery fenestration involving the distal segments associated with bilateral duplication of the superior cerebellar artery: a case report.

PURPOSE: The aim of our study is to report a case of a large fenestrated vertebral artery (FVA) and bilateral duplication of the superior cerebellar artery (SCA) incidentally diagnosed using Computed Tomography Angiography (CTA) and Digital Subtraction Angiography (DSA). CASE PRESENTATION: A 63-year-old female patient presenting to the neurology clinic with complaints of dizziness and balance disorder. CTA and DSA revealed a large FVA involving the V3 and V4 segments. Additionally, we observed bilateral duplicated SCAs originating from the distal basilar artery. DISCUSSION: FVA is a rare anomaly resulting from fusion failure during the embryological period, with a reported incidence of 0.1%. FVA is often (70%) detected in the extracranial region, but it can also occur intracranially at a frequency of approximately 30%. Although various nomenclatures are used in the literature, we identified only two reports of a single fenestration encompassing the V3 and V4 segments, i.e., involving both the extracranial and intracranial regions. While duplication of the SCA is relatively common, bilateral duplication of SCA occurs at a rate of 0.9-5%. CONCLUSION: This case report describes an unusual case of VA fenestration involving both extracranial and intracranial segments, along with bilateral duplication of the SCAs. While rare, these findings highlight the importance of recognizing such vascular anomalies, which could be relevant for planning surgical or endovascular procedures in the posterior circulation.

Anatomy of the pontine arteries and perforators of the basilar artery in humans.

Cerebral blood flow constitutes a critical area of interest for neurologists, neurosurgeons, and interventional radiologists as a social burden related to ischemic stroke, hemorrhagic stroke, and vascular dementia is expected to intensify. There is a great need to develop new and effective therapies, therefore deepening understanding of cerebrovascular anatomy, physiology, and pathology is crucial. The main aim of the study was to develop a comprehensive classification of the pontine arteries considering their typology, relations to the cranial nerves, branching schemes, and superficial pontine blood supply areas. We prepared 100 anatomical specimens of the human brainstem with the basilar artery, the pontine arteries, and the terminal perforating arteries. With the use of microsurgical microscope, we analyzed morphometry of the basilar artery, origins, courses, and branching patterns of the pontine arteries as well as distribution of the terminal perforators in relation to pontine superficial vascular areas and the cranial nerves. Additionally, we studied presence of pontine branches of the superior cerebellar artery (SCA) and anterior inferior cerebellar artery (AICA). Repetitive branching patterns, origins, and courses led us to distinguish five types of the pontine arteries: type 1-the paramedian branches, type 2-the short circumflex branches, type 3-composition of the paramedian and the short circumflex branches, type 4-long circumflex branches, and type 5-median branches penetrating the pons along the basilar sulcus. Types 1, 2, and 4 were described in the literature previously, but the classification did not include the median branches (the most prevalent branches) and frequently occurring combinations of the types 1 and 2. There were seven pontine arteries on both sides on average that presented the following general pattern: the first pontine artery below the SCA is a type 4 vessel called the posterolateral pontine artery and it is followed by a type 2 vessel-the superolateral pontine artery; the next three arteries represent the types 1, 2, and 3 and supply most of the ventral pontine surface; the sixth artery-the anterolateral pontine artery-is a short circumflex branch and the seventh artery, originating below the AICA, represents long circumflex arteries. Occlusion of each of the abovementioned vessels relates to a specific pontine vascular syndrome. As explained by the phylogenesis and ontogenesis of the central nervous system, the pontine arteries are subject to variability. The SCA and the AICA took part in the pontine blood supply in 2.5% and 12.5% of cases, respectively, therefore neurovascular interventions involving the SCA, or the AICA may lead to pontine ischemia. Contact of the pontine arteries with the cranial nerves depends on the vessel type and origin location.

Persistent trigeminal artery-superior cerebellar artery segmental fusion diagnosed using magnetic resonance angiography.

PURPOSE: To describe a case of persistent trigeminal artery (PTA)-superior cerebellar artery (SCA) segmental fusion incidentally diagnosed on magnetic resonance (MR) angiography. CASE REPORT: A 53-year-old woman with a history of facial pain underwent cranial MR imaging and MR angiography. MR angiography showed a left lateral-type PTA arising from the precavernous portion of the left internal carotid artery (ICA). PTA branched into the left distal SCA and showed segmental fusion with the proximal SCA at the distal part of the PTA. We also diagnosed an unruptured cerebral aneurysm at the junction between the left ICA and PTA. DISCUSSION: PTA is the most frequent type of carotid-vertebrobasilar anastomosis. The reported prevalence rate is 0.2% by angiography and 0.34% by MR angiography. There are two types of PTA-lateral (usual) and medial (intrasellar). SCA arising from the lateral-type PTA has rarely been reported. Further, a PTA from which the distal SCA branches and segmentally fuses with the proximal SCA at the distal part of the PTA has not been reported. CONCLUSION: Using MR angiography, we diagnosed a rare type of PTA that fused segmentally with SCA. No similar case has been reported in relevant English-language literature.

Duplicated superior cerebellar arteries, one of which was supplied by a persistent trigeminal artery variant diagnosed by magnetic resonance angiography.

PURPOSE: The purpose of the study was to describe a case of duplicated superior cerebellar arteries (SCAs), whose caudal branch was supplied by a persistent trigeminal artery (PTA) variant, diagnosed by magnetic resonance (MR) angiography. CASE REPORT: A 74-year-old woman with a history of cerebral infarction underwent cranial MR imaging and MR angiography. MR imaging revealed chronic-stage left cerebellar and right basal ganglionic infarctions. MR angiography showed no steno-occlusive lesions in the intracranial arteries; however, duplicated left SCAs were observed and the caudal branch arose from the precavernous segment of the left internal carotid artery, which is indicative of a PTA variant. DISCUSSION: Variations of the SCA (e.g., duplication, early bifurcation, and common trunk of the posterior cerebral artery and SCA) are frequently seen. A cerebellar artery arising from the precavernous segment of the internal carotid artery without connection to the basilar artery is regarded as a PTA variant. According to a meta-analysis, the prevalence is reported to be 0.2%. The majority of PTA variants are classified as the anterior inferior cerebellar artery type. PTA and PTA variants are frequently associated with other cerebral variations. A case of duplicated posterior inferior cerebellar artery, in which one of the branches was supplied by a PTA variant, was reported previously. However, the combination of duplicated SCA and PTA variants has not been reported. CONCLUSION: Using MR angiography, the author diagnosed a case of duplicated SCA, whose caudal branch was supplied by a PTA variant. No similar case has been reported in the relevant English-language literature.

Bilateral duplicated hypoplastic superior cerebellar arteries one of which originates from a full-type fetal posterior cerebral artery.

PURPOSE: The association of bilateral duplication of the superior cerebellar artery with an origin from the posterior cerebral artery is rare but of great interest to anatomists, radiologists, and surgeons. This article reports bilateral duplicated hypoplastic superior cerebellar arteries, one of which arises from a full-type fetal cerebral artery. MATERIAL AND METHOD: A 59-year-old woman admitted to the neurosurgery department for a subarachnoid hemorrhage underwent a brain CTA with 3D reconstruction using «3D slicer 4.11¼ software. Brain CTA and the 3D model were used to analyze the configuration of the posterior circulation. RESULTS: CTA images and the 3D model showed an unusual configuration of the posterior circulation. The basilar artery prolonged the left vertebral artery, while the right vertebral artery ended in the right posterior inferior cerebellar artery. On both sides, a full-type fetal posterior cerebral artery and duplicated hypoplastic superior cerebellar artery were observed. Three cerebellar arteries arose from the basilar artery, while the fourth one emerged from the right fetal posterior cerebral artery. CONCLUSION: Knowledge of such a configuration of the posterior circulation and others is necessary before radiological and surgical procedures. It helps to understand hemodynamic events, and neurovascular conflicts, improve revascularization procedures, and avoid surgical arterial and nervous injuries.

Unreported branching pattern of the triplicated anterior cerebral artery associated with multiple bilateral variants of the superior cerebellar artery detected by computed tomography angiography and 3D modeling.

A 26-year-old patient underwent a successful ablation of Grade 2 diffuse astrocytoma of the right parietal lobe. The postoperative computed tomography angiography with 3D modeling revealed a residual avascular porencephalic cyst. Otherwise, multiple arterial variants have been encountered. First, the left A1 segment was fenestrated, and three A2 segments arose from the anterior communicating artery. The middle A2 segment was dominant and supplied left callosomarginal and both pericallosal territories. The right A2 segment supplied the right callosomarginal territory, while the left A1 was limited to the left orbitofrontal and frontopolar territories. This configuration represents a triplicated anterior cerebral artery with an unusual branching pattern not included in the classification of Baptista. In addition, on both sides, superior cerebellar artery duplication was present, with one arising from the basilar artery and the other from the P1 segment of the ipsilateral posterior cerebral artery. The left lower superior cerebellar artery was early bifurcated. It is the first time such a cerebrovascular configuration has been reported. Because of the several clinical and surgical applications of the anterior cerebral artery and superior cerebellar artery variants, this case report is of utmost interest to anatomists, radiologists, and neurosurgeons.

Advantages of petrosectomy for superficial temporal artery to superior cerebellar artery bypass based on three-dimensional distance measurements using cadaver heads.

Superficial temporal artery (STA) to superior cerebellar artery (SCA) bypass is usually performed via the subtemporal approach (StA), anterior transpetrosal approach (ApA), or combined petrosal approach (CpA), but no study has yet reported a quantitative comparison of the operative field size provided by each approach, and the optimal approach is unclear. The objective of this study is to establish evidence for selecting the approach by using cadaver heads to measure the three-dimensional distances that represent the operative field size for STA-SCA bypass. Ten sides of 10 cadaver heads were used to perform the four approaches: StA, ApA with and without zygomatic arch osteotomy (ApA-ZO- and ApA-ZO+), and CpA. For each approach, the major-axis length and the minor-axis length at the anastomosis site (La-A and Li-A), the major-axis length and the minor-axis length at the brain surface (La-B and Li-B), the depth from the brain surface to the anastomosis site (Dp), and the operating angles of the major axis and the minor axis (OAa and OAi) were measured. Shallower Dp and wider operating angle were obtained in the order CpA, ApA-ZO+, ApA-ZO-, and StA. In all parameters, ApA-ZO- extended the operative field more than StA. ApA-ZO+ extended La-B and OAa more than ApA-ZO-, whereas it did not contribute to Dp and OAi. CpA significantly decreased Dp, and widened OAa and OAi more than ApA-ZO+. ApA and CpA greatly expanded the operative field compared with StA. These results provide criteria for selecting the optimal approach for STA-SCA bypass in light of an individual surgeon's anastomosis skill level.

Oculomotor nerve segment between proximal posterior and superior cerebellar arteries: an MRI study.

PURPOSE: No study has documented the oculomotor nerve (OMN) segment lying between the posterior cerebral (PCA) and superior cerebellar (SCA) arteries adjacent to the brainstem. The present study aimed to characterize it. METHODS: A total of 71 patients underwent thin-sliced, sagittal T2-weighted magnetic resonance imaging for analysis. RESULTS: The OMN segments lying between the PCA and SCA were identified in all patients. The OMN segment in relation to the PCA and SCA was classified into five types. Of them, the PCA-OMN contact type was the most frequent and found in 35.2% of 71 sides on the right and 39.4% on the left. Also, the PCA-OMN compression type was identified in 12.7% on the right and 15.5% on the left. In these types, the mean distance between the brainstem and contact/compression sites were measured 4.4 ± 2.3 mm on the right and 4.4 ± 1.6 mm on the left. In more than forty percent, the sites were located at the level of the pontomesencephalic junction. CONCLUSIONS: The OMN may be frequently in contact with the PCA near the brainstem. The site located more distal than the central-peripheral myelin junction of the OMN can attribute to a low frequency of neurovascular compression syndrome of the nerve.

Multiple cerebral arterial variations incidentally detected by magnetic resonance angiography: a case report.

We herein report a case of multiple variations, including (1) anterior communicating artery duplication, (2) accessory anterior cerebral artery (ACA), (3) distal origin right accessory middle cerebral artery (MCA) with bifurcation, (4) proximal origin left accessory MCA with bifurcation, (5) right superior cerebellar artery (SCA) duplication, and (6) left SCA early bifurcation. These variations were found incidentally by magnetic resonance (MR) angiography. Volume-rendering images of MR angiography were more useful than maximum-intensity-projection images for identifying these variations, especially bilateral accessory MCAs, which were superimposed with the A1 segment of the ACAs and the M1 segment of the MCAs.

Superficial temporal artery-superior cerebellar artery bypass and trapping of a fusiform aneurysm using intradural anterior petrosectomy: technical case report and anatomical study.

Aneurysms at the distal portion of the superior cerebellar artery (SCA) are very rare. Because of the deep location and a propensity for nonsaccular morphology, aneurysm trapping or endovascular occlusion of the parent artery are the usual treatment options, which are associated with varying risks of ischemic complications. The authors report on a 60-year-old woman who had a 3.5-mm unruptured aneurysm in the lateral pontomesencephalic segment of the SCA with a significant interval growth to 8 mm. Direct surgical intervention comprising trapping of the aneurysm through a subtemporal approach and intradural anterior petrosectomy combined with revascularization of the distal SCA using the superficial temporal artery (STA) was performed. This approach provided sufficient space for the bypass instruments to be introduced into the deep surgical field at a more favorable angle to enhance microscopic visualization of the anastomosis with minimal retraction of the temporal lobe. The patient was discharged with no neurological deficit. Preservation of the blood flow in the distal SCA should be attempted to minimize the risk of ischemic injury, particularly when the aneurysms arise in the anterior or lateral segment of the SCA. The authors demonstrate the safety and effectiveness of the intradural anterior petrosectomy for STA-SCA bypass along with a relevant anatomical study.

Multimaterial and multicolor 3D-printed model in training of transnasal endoscopic surgery for pituitary adenoma.

OBJECTIVE: The aim of the present study was to investigate the practical value of a multimaterial and multicolor 3D-printed model in anatomical teaching, surgical training, and preoperative planning of transnasal endoscopic surgery for pituitary adenoma. METHODS: Multimodality neuroimaging data were obtained in a 42-year-old healthy male volunteer and a 40-year-old female patient with an invasive nonfunctional pituitary adenoma. Three 3D-printed models were produced: a monomaterial and monocolor model, a monomaterial and multicolor model, and a multimaterial and multicolor model. The effects on anatomical teaching and surgical training for exposing the vidian nerve were assessed by 12 residents, and the training effect was validated on cadavers. The practical values for preoperative planning were evaluated by 6 experienced neurosurgeons. All evaluations were based on 5-point Likert questionnaires. RESULTS: The multimaterial and multicolor model was superior to the monomaterial models in surgical training for exposing the vidian nerve (Fisher test; p < 0.05). In addition, the multimaterial and multicolor model was superior to the monomaterial models in anatomical teaching and preoperative planning (Friedman test; p < 0.05). CONCLUSIONS: Multimaterial and multicolor 3D printing technology makes it convenient and efficient to produce a practical model for simulating individualized and complex anatomical structures in the sellar region. Furthermore, the multimaterial model can provide a more realistic manipulative experience for surgical training and facilitate the preoperative planning.

Analysis of cerebrovascular aneurysm treatment cost: retrospective cohort comparison of clipping, coiling, and flow diversion.

OBJECTIVE With the continuous rise of health care costs, hospitals and health care providers must find ways to reduce costs while maintaining high-quality care. Comparing surgical and endovascular treatment of intracranial aneurysms may offer direction in reducing health care costs. The Value-Driven Outcomes (VDO) database at the University of Utah identifies cost drivers and tracks changes over time. In this study, the authors evaluate specific cost drivers for surgical clipping and endovascular management (i.e., coil embolization and flow diversion) of both ruptured and unruptured intracranial aneurysms using the VDO system. METHODS The authors retrospectively reviewed surgical and endovascular treatment of ruptured and unruptured intracranial aneurysms from July 2011 to January 2017. Total cost (as a percentage of each patient's cost to the system), subcategory costs, and potential cost drivers were evaluated and analyzed. RESULTS A total of 514 aneurysms in 469 patients were treated; 273 aneurysms were surgically clipped, 102 were repaired with coiling, and 139 were addressed with flow diverter placements. Middle cerebral artery aneurysms accounted for the largest portion of cases in the clipping group (29.7%), whereas anterior communicating artery aneurysms were most frequently involved in the coiling group (30.4%) and internal carotid artery aneurysms were the majority in the flow diverter group (63.3%). Coiling (mean total cost 0.25% ± 0.20%) had a higher cost than flow diversion (mean 0.20% ± 0.16%) and clipping (mean 0.17 ± 0.14%; p = 0.0001, 1-way ANOVA). Coiling cases cost 1.5 times as much as clipping and flow diversion costs 1.2 times as much as clipping. Facility costs were the most significant contributor to intracranial clipping costs (60.2%), followed by supplies (18.3%). Supplies were the greatest cost contributor to coiling costs (43.2%), followed by facility (40.0%); similarly, supplies were the greatest portion of costs in flow diversion (57.5%), followed by facility (28.5%). Cost differences for aneurysm location, rupture status, American Society of Anesthesiologists (ASA) grade, and discharge disposition could be identified, with variability depending on surgical procedure. A multivariate analysis showed that rupture status, surgical procedure type, ASA status, discharge disposition, and year of surgery all significantly affected cost (p < 0.0001). CONCLUSIONS Facility utilization and supplies constitute the majority of total costs in aneurysm treatment strategies, but significant variation exists depending on surgical approach, rupture status, and patient discharge disposition. Developing and implementing approaches and protocols to improve resource utilization are important in reducing costs while maintaining high-quality patient care.

Endovascular management of fusiform aneurysms in the posterior circulation: the era of flow diversion.

Fusiform aneurysms are uncommon compared with their saccular counterparts, yet they remain very challenging to treat and are associated with high rates of rebleeding and morbidity. Lack of a true aneurysm neck renders simple clip reconstruction or coil embolization usually impossible, and more advanced techniques are required, including bypass, stent-assisted coiling, and, more recently, flow diversion. In this article, the authors review posterior circulation fusiform aneurysms, including pathogenesis, natural history, and endovascular treatment, including the role of flow diversion. In addition, the authors propose an algorithm for treatment based on their practice.

Postprocedural, midterm, and long-term results of cerebral aneurysms treated with flow-diverter devices: 7-year experience at a single center.

OBJECTIVE Flow diversion has emerged as a viable treatment option for selected intracranial aneurysms and recently has been gaining traction. The aim of this study was to evaluate the safety and effectiveness of flow-diverter devices (FDDs) over a long-term follow-up period. METHODS The authors retrospectively reviewed all cerebral aneurysm cases that had been admitted to the Division of Neurosurgery of the Università degli Studi di Napoli between November 2008 and November 2015 and treated with an FDD. The records of 60 patients (48 females and 12 males) harboring 69 cerebral aneurysms were analyzed. The study end points were angiographic evidence of complete aneurysm occlusion, recanalization rate, occlusion of the parent artery, and clinical and radiological evidence of brain ischemia. The occlusion rate was evaluated according to the O'Kelly-Marotta (OKM) Scale for flow diversion, based on the degree of filling (A, total filling; B, subtotal filling; C, entry remnant; D, no filling). Postprocedural, midterm, and long-term results were strictly analyzed. RESULTS Complete occlusion (OKM D) was achieved in 63 (91%) of 69 aneurysms, partial occlusion (OKM C) in 4 (6%), occlusion of the parent artery in 2 (3%). Intraprocedural technical complications occurred in 3 patients (5%). Postprocedural complications occurred in 6 patients (10%), without neurological deficits. At the 12-month follow-up, 3 patients (5%) experienced asymptomatic cerebral infarction. No further complications were observed at later follow-up evaluations (> 24 months). There were no reports of any delayed aneurysm rupture, subarachnoid or intraparenchymal hemorrhage, ischemic complications, or procedure- or device-related deaths. CONCLUSIONS Endovascular treatment with an FDD is a safe treatment for unruptured cerebral aneurysms, resulting in a high rate of occlusion. In the present study, the authors observed effective and stable aneurysm occlusion, even at the long-term follow-up. Data in this study also suggest that ischemic complications can occur at a later stage, particularly at 12-18 months. On the other hand, no other ischemic or hemorrhagic complications occurred beyond 24 months.

Clipping of ipsilateral posterior communicating and superior cerebellar artery aneurysms.

The case is a 55-year-old female who presented with dizziness as the chief complaint. She has a family history of two relatives with subarachnoid hemorrhage. Digital subtraction angiography revealed the presence of a left-sided posterior communicating artery aneurysm and an ipsilateral superior cerebellar artery (SCA) aneurysm. Due to the smaller nature of the SCA, a decision was made to proceed with surgical clipping of both lesions through a pterional approach. A narrated video with illustrations depicts the intraoperative management of these lesions with postoperative angiography results. The video can be found here: http://youtu.be/HCHToSsXv-4 .

Rupture of an aneurysm of the superior cerebellar artery feeding a dural arteriovenous fistula.

We experienced a very rare case of bleeding from an aneurysm of a branch of the superior cerebellar artery, which feeds a dural arteriovenous fistula (DAVF) of the posterior fossa. The aneurysm was not detected on initial angiography and 2 episodes of rebleeding resulted in deterioration of the patient's condition. Although rare, aneurysms of the pial feeding arteries should be considered as a cause of bleeding in cases of DAVF.

Fully endoscopic microvascular decompression for trigeminal neuralgia: technique review and early outcomes.

OBJECT: Fully endoscopicmicrovascular decompression (E-MVD) of the trigeminal nerve was initially described more than 1 decade ago, but has not yet gained wide acceptance. The authors present the experience of their first 47 consecutive E-MVDs for trigeminal neuralgia (TN). METHODS: All surgeries were performed by a single surgeon (J.Y.K.L.) at the Pennsylvania Hospital at the University of Pennsylvania. Patients prospectively completed pain scales before and after surgery by using the Brief Pain Inventory-Facial outcomes tool. All patients were called on the telephone, and the same outcome tool was administered without reference to their preoperative pain status. RESULTS: Forty-seven patients (17 men) were identified and enrolled. Forty (85%) had Burchiel Type 1 TN. Vascular compression was observed at surgery in 42 patients (89%). No surgery was aborted or converted to microscope. One patient suffered permanent hearing loss, for a permanent neurological morbidity rate of 2%. Overall improvement in pain outcomes was excellent, with a median maximum pain intensity preoperatively of 10 and postoperatively of 0 (p< 0.0001). The mean interference with global function scores were 6.2 preoperatively and reduced to 1.0 at last follow-up (p < 0.0001). The mean interference with facial function was 7.3 preoperatively and reduced to 1.2 at last follow-up (p < 0.0001). The mean follow-up period after surgery was 15 ± 8 months. CONCLUSIONS: In experienced hands, E-MVD offers superb visualization and illumination and is both safe and effective, at least in the short term. Further longer-term study is needed to compare E-MVD to traditional microscopic MVD.

The anatomy of vascular compression in trigeminal neuralgia.

The etiological basis of trigeminal neuralgia (TN) is unknown but vascular (arterial and venous) compression of the trigeminal nerve roots has emerged as the likely cause in most cases. Here we examine the evidence for the "brain sagging/arterial elongation hypothesis" with reference to the cerebral arteries and veins believed to cause the compression. Most often implicated are the superior cerebellar artery, the anterior and posterior inferior cerebellar arteries, and the superior petrosal vein including several of its tributaries. The reviewed data suggest that the theoretical support for a vascular compressive etiology of TN is weak, albeit the surgical outcome data are relatively convincing.