Radiological and intraoperative findings of a rare case of vestibular paroxysmia.

Vestibular paroxysmia (VP) is a rare condition. The pathogenesis is linked to a neurovascular conflict (NVC) between an abnormal arterial loop and the VII/VIII cranial nerve complex in the cerebello-pontine angle. Due to its rarity, intraoperative findings are only anecdotally reported. Here we reported on a case of VP, showing the radiological images and the intraoperative surgical video of microvascular decompression (MVD). Further we discussed our findings considering the pertinent literature. We think that in case of VP the concordance between the side of tinnitus/hypoacusia and the side of NVC on magnetic resonance imaging should be always looked for before considering MVD as a therapeutic option.

Assessment of prevalence of vascular contact of the facial nerve in asymptomatic patients using three-dimensional constructive interference in steady-state (3D CISS) MRI acquisition.

Purpose: To evaluate the prevalence of vascular contact of the facial nerve in patients without hemifacial spasm or facial palsy using magnetic resonance imaging (MRI). Material and methods: Our radiology database was accessed to find a series of consecutive adult patients who underwent MRI of the brain during the study period, excluding those with a history of hemifacial spasm (HFS), facial palsy, traumatic brain injury, intracranial tumour, intracranial surgery, trigeminal neuro-vascular compression, brain radiation therapy, and studies with poor image quality. A total of 112 (224 sides) MRIs of the posterior fossa were independently reviewed by 2 radiologists for neurovascular contact involving the facial nerve. The presence of neuro-vascular contact, the number of points of contact, the location of contact along the intracranial course of the facial nerve, the culprit vessel, and the severity of compression were recorded in the CISS MRI sequence in the cohort of patients without HFS and facial palsy. Results: The prevalence of neurovascular contact involving the facial nerve can be as high as 51% in patients asymptomatic for HFS and facial palsy. It is frequently caused by the anterior inferior cerebellar artery and commonly involves the cisternal portion with mild to moderate severity. Conclusions: In asymptomatic patients, the pulsatile neurovascular contact of the intracranial segment of the facial nerve typically occurs at one point, involving the distal portion with milder severity in contrast to patients with HFS. These results in the asymptomatic cohort should be considered when evaluating the candidacy of HFS patients for microvascular decompression.

Sex differences in trigeminal neuralgia: a focus on radiological and clinical characteristics.

BACKGROUND: It is well established that trigeminal neuralgia is more prevalent in females than in males. Neurovascular compression with morphological changes of the trigeminal root represents the most recognized etiological factor. However, other factors may play a role in the framework of a multi-hit model. The primary aim of this study was to investigate sex differences in radiological and clinical characteristics of trigeminal neuralgia to better understand the multifactorial origin of this peculiar neuropathic pain condition. METHODS: In this cross-sectional study patients with a definite diagnosis of primary trigeminal neuralgia were consecutively enrolled. Each patient underwent 3T MRI with sequences dedicated to the study of neurovascular compression. Major morphological changes of the trigeminal root were quantitatively assessed. Clinical characteristics were systematically collected through a dedicated questionnaire. A logistic regression model was implemented to predict radiological and clinical characteristics based on sex. RESULTS: A total of 114 patients with classical (87) or idiopathic trigeminal neuralgia (27) were enrolled. Female sex was predictive for idiopathic trigeminal neuralgia. Male sex was predictive, among the comorbidities and clinical characteristics, for hypertension, the involvement of the left side and the second trigeminal division, alone or with the ophthalmic division. DISCUSSION: The preponderance of TN in the female sex and the association between idiopathic TN and the female sex suggest the role of additional etiological factors in the framework of a multi-hit model. The identification of clinical variables predicted by sex suggests the possibility that distinct phenotypes, with peculiar pathophysiological and therapeutic aspects, may occur in females and males.

Microvascular decompression for trigeminal neuralgia: a single-center experience with 516 cases, including 32 patients with multiple sclerosis.

BACKGROUND AND OBJECTIVES: To evaluate the effectiveness and long-term pain relief of microvascular decompression (MVD) for "typical" trigeminal neuralgia (TN), including patients affected by multiple sclerosis (MS). METHODS: Between January 2011 and December 2022, 516 consecutive patients presenting with trigeminal neuralgia and a diagnosed neurovascular conflict at MRI underwent microvascular decompression surgery in our neurosurgery department. Ten surgeons with different ages and experiences performed the surgical procedures. Pain improvement, re-operation rate, and complication rates were retrospectively collected and analyzed. RESULTS: 516 patients were included (214 males 302 females, ranging from 12 to 87 years), including 32 patients with multiple sclerosis. Neurovascular compression was found in all cases during surgery. Barrow Neurological Institute pain intensity scale with a score of I was achieved in 404 patients (78,29%), a score II or III was obtained in 100 cases (19,37%) and a score of IV and V in 12 patients (2,32%). In the multiple sclerosis subset of patients, a BNI score of I was achieved in 21/32 (65.62%). The pain recurrence rate of our series was 15.11%. The follow-up for all patients was at least of 13 months, with a mean follow-up of 41.93 months (± 17.75 months, range 13-91 months). Neither intraoperative mortality nor major intra-operative complications occurred in the analyzed series. The re-operation rate was 12.98%. Thermorhizotomy, percutaneous balloon compression, cyber-knife radiosurgery, or new MVD were the surgical techniques utilized for re-operations. CONCLUSIONS: MVD may be considered an effective and safe surgical technique for TN, and in patients affected by multiple sclerosis, it may be proposed even if a less favorable outcome has to be expected with respect to classic TN patients. Larger studies focusing on the relation of multiple sclerosis with neurovascular compression are required.

Outcome after microvascular decompression for trigeminal neuralgia in a single center-relation to sex and severity of neurovascular conflict.

BACKGROUND: Trigeminal neuralgia (TN), a severe type of facial pain, is mainly caused by a neurovascular conflict (NVC). The severity of the NVC seems associated with the outcome following microvascular decompression (MVD) surgery. This study aimed to investigate the outcome after MVD and whether it is affected by NVC severity and sex. METHODS: TN patients (n = 109) were followed for 5 to 10 years after MVD. Barrow Neurology Index (BNI), Patients Global Impression of Change (PGIC), complications, and time to relapse were evaluated. The NVC severity was retrospectively reviewed from presurgical MRI. Demographic and clinical factors and NVC severity were analyzed for potential association with outcome after MVD. RESULTS: The success rate (BNI ≤ 2) was 80% after 5 to 10 years follow-up for TN patients with severe NVC (grade 2-3) and 56% for TN patients with mild NVC (grade 0-1, P = 0.003). No sex difference was observed in outcome for patients with both mild (P = 0.924) and severe NVC (P = 0.883) respectively. Three patients (2.8%) during the hospital stay, and two patients (1.8%) at 6 weeks, experienced a complication requiring invasive treatment. At long-term 52/109 patients (47.7%) reported some type of persistent adverse event, of which the majority were mild and required no treatment. CONCLUSIONS: MVD offers an 80% probability of long-term pain relief in TN patients with severe NVC, with low frequency of serious complications. NVC severity significantly affects outcome after MVD, while no sex differences in outcome were found. In consistency with previous work, the results stress the importance of adequate neuroradiological assessment of the NVC for preoperative patient selection.

Neurovascular conflict and sudden unilateral sensorineural hearing loss: coincidence or coexistence?

OBJECTIVE: To study the association between neurovascular conflict (NVC) of the 8th cranial nerve (CN8) and unilateral sudden sensorineural hearing loss SSNHL (SSNHL). METHODS: A systematic literature search of "MEDLINE" via "PubMed," "Embase," and "Google-Scholar" was conducted. Meta-analysis of pooled data was performed for NVC prevalence of SSNHL affected ears versus controls. RESULTS: The literature search identified 941 publications, of which, 9 included in qualitative synthesis (1030 ears) and 5 in quantitative synthesis (484 ears). NVC was as prevalent as 0.8-69% for affected ears and as 19-57% for controlled ears. No association between MRI protocol and NVC prevalence was proved. An odds ratio of 1.05 (95% confidence interval = 0.79-1.39) was calculated for association of NVC in unilateral SSNHL ears versus controls. CONCLUSION: The prevalence of NVC of CN8 in unilateral SSNHL affected ears is not significantly bigger than controls. Hence, NVC of CN8 is probably NOT associated with unilateral SSNHL.

[Early results of intraoperative neurophysiological monitoring in surgical treatment of hemifacial spasm]. / Analiz blizhaishikh rezul'tatov intraoperatsionnogo neirofiziologicheskogo monitoringa pri khirurgicheskom lechenii gemifatsial'nogo spazma.

BACKGROUND: Neurophysiological monitoring in surgery for hemifacial spasm has been used since the 1990s, when Moller et al. demonstrated the effectiveness of intraoperative assessment of lateral spread response (LSR) regarding postoperative outcomes. Currently, there are conflicting data on effectiveness and feasibility of this technique. Widespread hemifacial spasm determines the relevance of neurophysiological monitoring in surgical treatment of these patients. OBJECTIVE: To evaluate the effectiveness of various methods of intraoperative neurophysiological monitoring in surgical treatment of hemifacial spasm regarding early postoperative outcomes. MATERIAL AND METHODS: The study group included 43 patients (8 men and 35 women) aged 26-68 years. We assessed severity of hemifacial spasm using the SMC Grading Scale. All patients underwent vascular decompression of the facial nerve under neurophysiological control: monitoring of transcranial motor evoked potentials from facial muscles (m. orbicularis oculi, m. orbicularis oris, m. mentalis) and recording unilateral LSR. The control group included 23 patients (4 men and 19 women) aged 29-83 years. In this group, facial nerve decompression was performed without neurophysiological control. The effect of neurophysiological monitoring on postoperative outcomes (in-hospital period and 3 postoperative months) after vascular decompression of the facial nerve was assessed using the SMC Grading Scale. We considered severity and incidence of spasms. RESULTS: Thirty-one (72%) patients in the main group had no spasms of mimic muscles at discharge. In the control group, there were no spasms in 15 patients (65%). At the same time, there were fewer Grade I patients in the control group (12%) compared to the main group (26%). Moreover, 27 (66%) and 12 (52%) patients were free from episodes of hemifacial spasm in both groups, respectively. Patients with hemifacial spasm grade I-II comprised 29% in the main group and 34% in the control group. The number of relapses within three months increased in the control group (13%). CONCLUSION: Intraoperative monitoring of transcranial motor evoked potentials from the facial muscles and LSR during vascular decompression of the facial nerve increases the efficiency of surgery for hemifacial spasm in early postoperative period. Less number of relapses and lower intensity of hemifacial spasm necessitate neurophysiological monitoring in neurosurgical treatment of these patients.

Clinical outcome after microvascular decompression for trigeminal neuralgia: a systematic review and meta-analysis.

Microvascular decompression (MVD) is considered an effective treatment for trigeminal neuralgia (TN). However, the anatomical and clinical variables associated with a better outcome are not fully examined. The authors performed a systematic review and meta-analysis of the literature investigating the immediate and long-term clinical results of MVD for TN, and the impact of the anatomical features of the neurovascular conflict on the outcome. The systematic search of three databases was performed for studies published between January 1990 and November 2021. PRISMA guidelines were followed. Random-effects meta-analysis was used to pool the analyzed outcomes, and random-effect meta-regression was used to examine the association between the effect size and potential confounders. A funnel plot followed by Egger's linear regression was used to test publication bias. A total of 9 studies were included in this analysis, including 2102 patients with trigeminal neuralgia. The immediate post-operative rate of BNI I was 82.9%, whereas surgical failure (BNI IV-V) was reported in approximately 2.6% of patients. CSF leak was the most common postoperative complication (2.4%). The rate of BNI I at last follow up was 64.7% (p < 0.01), showing a significant negative correlation after multiple meta-regression with the rate of patients with isolated venous conflict (p < 0.01). On the other hand, the evidence of an arterial conflict proved is positive association with a favorable outcome (p < 0.01). At the last follow-up, BNI IV-V was reported in 19.2% (95% CI 8.9-29.5%, p < 0.01, I2 = 97.3%). This meta-analysis confirms the safety and efficacy of MVD for TN. The occurrence of serious postoperative complications is very low. The long-term outcome is associated with the type of vascular structure involved, being pure venous conflict associated with a higher risk of surgical failure. These findings should be considered when planning surgery for patients with TN.

Microvascular decompression for hemifacial spasm involving the vertebral artery.

OBJECTIVE: Microvascular decompression (MVD) has become an accepted treatment modality for the vertebral artery (VA)-involved hemifacial spasm (HFS). The aim of this retrospective study was to evaluate clinical and surgical outcomes of HFS patients undergoing MVD and surgical and cranial nerve complications and investigate reasonable transposition procedures for two different anatomic variations of VA. METHODS: Between January and December 2018, 109 patients underwent first MVD for HFS involving VA at Nanjing Drum Tower Hospital. Based on whether the VA could be moved ventrally at the lower cranial nerves (LCNs) level, patients were assigned to Group A (movable VA, n = 72) or B (unmovable VA, n = 37), and clinical and surgical outcomes and complications on the day of post-surgery and during follow-up were assessed. All patients were followed up ranging from 17 to 24 months with a mean follow-up period of 21 months. RESULTS: After a mean follow-up of 21 months, the total cure rate significantly decreased in all patients compared to that achieved on the day of surgery, and Group A patients exhibited a higher cure rate versus Group B (93.1% vs. 75.7%, P = 0.015). Group B patients with unmovable VA revealed both higher incidence of surgical complications (45.9% vs. 15.3%, P = 0.001) and frequency of bilateral VA compression (27% vs. 8.3%, P = 0.009) versus Group A. No significant difference was observed in long-term cranial nerve complications. CONCLUSIONS: VA-involved HFS can benefit from MVD strategies after preoperative assessment of VA compression. HFS patients with movable VA may receive better long-term efficacy and fewer complications. A Teflon bridge wedged between the distal VA and medulla gives rise to adequate space for decompression surgery.

Internal neurolysis: 'nerve combing' for trigeminal neuralgia without neurovascular conflict - early UK outcomes.

INTRODUCTION: Internal neurolysis (INL) is a surgical procedure where trigeminal nerve fibres are separated between the pons and porus trigeminus to relieve trigeminal neuralgia (TN). We report pain and functional outcomes to evaluate its safety and efficacy. MATERIALS AND METHODS: Prospective cohort of all patients undergoing retrosigmoid craniotomy and INL between 2015 and 2017 at University Hospital Southampton. Patients with type I (6) or type II (2) refractory TN and no clear neurovascular conflict were offered INL as an alternative to partial sensory rhizotomy. Barrow Pain Intensity Scale (BNI) and Brief Pain Inventory Facial scores (BPI-Facial) were assessed. Minimum follow-up was 2 years'. RESULTS: Eight patients (7F:1M) underwent INL. Two had MS. Pre-operatively, all had severe pain (BNI grade V) and the median BPI-Facial score was 115 (range 79-123).. There were no unexpected complications. On last follow-up, six (75%) had no pain (BNI grade I), while two (25%) had recurred (at 5 and 27 months). Median BPI-Facial score for all patients on the last follow-up was 20 (range 18-91) reflecting dramatically improved quality of life and activities. CONCLUSIONS: INL is a potentially safe and effective treatment for refractory TN. Long-term efficacy is unknown, but early results are promising.

Topography of the pain in classical trigeminal neuralgia: insights into somatotopic organization.

Trigeminal neuralgia is defined by its clinical characteristics of paroxysmal unilateral facial pain in a well-defined territory. Distribution of the pain may be in one or several of the cutaneous and/or mucous territories of the three divisions with V2 pain being the most frequent territory followed by V3 and V1. Factors determining the distribution of pain have not yet been systematically investigated. It is now well recognized that vascular compression factor is a predominant aetiology of classical trigeminal neuralgia. In this study we aimed to find whether there is a relation between the location of the vascular compression and the peripheral distribution of the pain. Patients with classical trigeminal neuralgia in whom microvascular decompression was performed were included. Data recorded pertained to the nature of the conflict, its degree and, most importantly, location around the root: supero-median, supero-lateral or inferior. Equally, clinical data for the distribution of pain were recorded. Most of the patients 318 (89.3%) had the compression coming from above, i.e. 220 (61.7%) had compression from a supero-medial direction and 98 (27.5%) from a supero-lateral direction; inferior compression was present in 38 patients (10.7%). Distribution of the pain was significantly different according to the location of the conflict (P = 0.0005, Fisher Exact test). Odds ratios were computed for each location of compression and painful territory involved. According to the overall distribution of pain, patients with supero-medial compression had an odds ratio of 2.7 [95% confidence interval (CI) 1.66-4.41] of manifesting with V1 pain. Conversely V3 pain was less likely to occur with supero-median compression than the other types of pain (odds ratio 0.53, 95% CI 0.34-0.83). Inferior compression on the other hand was more likely to manifest with V3 pain with an odds ratio of 2.56 (95% CI 1.21-5.45). Overall V2 pain had an odds ratio close to 1 regardless of the type of compression. These findings suggest an association between the location of the neurovascular conflict with its resulting insult and the distribution of pain supporting a somatotopic view of the organization of the trigeminal root and a role of the conflict in the clinical manifestation of trigeminal neuralgia.

Improving the accuracy of pre-operative evaluation of neurovascular conflict in trigeminal neuralgia using magnetic resonance subtraction.

PURPOSE: To investigate the ability of magnetic resonance (MR) subtraction to evaluate neurovascular conflict (NVC) and to compare it with conventional MR protocols. METHODS: This prospective study included 82 patients with trigeminal neuralgia who underwent microvascular decompression for NVC. All patients had a pre-operative examination using 3T MRI. The MRI protocols used comprised 3D balanced (B)-fast field echo (FFE), 3D steady-state magnetic resonance angiography (MRA), and 3D T1-FFE sequences. MR subtraction images were obtained by subtracting native images from B-FFE and steady-state MRA. NVC evaluation was performed using subtraction images (MR subtraction) and combination images (conventional MR protocols using B-FFE and T1-FFE in combination). Clinical assessment of the degree of compression, the type of compressing vessel, and the location of conflict were undertaken by two independent observers. The two methods were then compared using surgical criteria. RESULTS: MR subtraction exhibited greater accuracy than the conventional method in terms of the estimated severity of conflict (87.80% vs. 57.32%, p < 0.05), and demonstrated better consistency with surgical findings (k = 0.794 vs. k = 0.365, p < 0.05). For the type of compressing vessel and the location of conflict, both methods were highly accurate and agreed to a similar extent with surgical findings (p = 0.987, compressing vessel; p = 0.665, location of conflict). CONCLUSION: MR subtraction proved reliable in NVC pre-operative evaluation, with increased accuracy when estimating severity. This result strongly supports the wider use of MR subtraction as the preferred choice in clinical application.

Virtual reality-based evaluation of neurovascular conflict for the surgical planning of microvascular decompression in trigeminal neuralgia patients.

OBJECTIVE: Trigeminal neuralgia (TN) is a lightning bolt of violent, electrifying, and stinging pain, often secondary to the neurovascular conflict (NVC). The vessels involved in NVC are mostly arteries and rarely veins. Evaluation of NVC in the deep infratentorial region is inseparably connected with cranial imaging. We retrospectively analyzed the potential influence of three-dimensional (3D) virtual reality (VR) reconstructions compared to conventional magnetic resonance imaging (MRI) scans on the evaluation of NVC for the surgical planning of microvascular decompression in patients with TN. METHODS: Medical files were retrospectively analyzed regarding patient- and disease-related data. Preoperative MRI scans were retrospectively visualized via VR software to detect the characteristics of NVC. A questionnaire of experienced neurosurgeons evaluated the influence of VR visualization technique on identification of anatomical structures involved in NVC and on surgical strategy. RESULTS: Twenty-four patients were included and 480 answer sheets were evaluated. Compared to conventional MRI, image presentation using 3D-VR modality significantly influenced the identification of the affected trigeminal nerve (p = 0.004), the vascular structure involved in the NVC (p = 0.0002), and the affected side of the trigeminal nerve (p = 0.005). CONCLUSIONS: In patients with TN caused by NVC, the reconstruction of conventional preoperative MRI scans and the spatial and anatomical presentation in 3D-VR models offers the possibility of increased understanding of the anatomy and even more the underlying pathology, and thus influences operation planning and strategy.

Migrainous facial palsy (MFP): the introduction of a new concept of neurovascular conflict and its preliminary clinical evidence.

BACKGROUND: Facial palsy and migraine have frequently been reported to occur in conjunction. We report a case series and propound a theory to explain the same. AIMS AND OBJECTIVES: To postulate an anatomico-pathophysiological association in the causative factor of lower motor neuron type of facial palsy in cases with migraine without aura. MATERIALS AND METHODS: Preliminary experiences and observations in 12 cases suffering from facial palsy following an attack of migraine without aura, mainly in the occipital and posterior auricular region, are elaborated. RESULTS: Facial palsy occurred on the ipsilateral side as the headaches in a majority of the cases (83.33%) and in rare cases of bilateral headaches (16.67%), it lateralised to the side the headaches were more severe. In most of these cases (75%), a complete clinical recovery was noted within 6 months. CONCLUSION: We concluded that neurogenic inflammation of the facial nerve trunk caused by its proximity to the dilated posterior auricular/stylomastoid/occipital and superficial temporal arteries during a migraine attack leads to a temporary lower motor neuron type of paresis of the muscles supplied by the facial nerve. SIGNIFICANCE: This pathophysiological understanding of the disease mechanism could open new avenues as to the treatment of this condition. This proposition indicates in clearer light than before, a possible mechanism to explain the higher incidence and risk of facial palsy in migraineurs.

[Hypertensive crisis in a 3-year-old boy - neurovascular conflict?] / Przelom nadcisnieniowy u 3-letniego chlopca ­ konflikt naczyniowo-nerwowy?

Hypertensive crisis is a sudden rise in blood pressure with accompanying clinical symptoms. The disease is extremely rare in small children and is always a complication of secondary hypertension. CASE REPORT: 3-year-old boy (spontaneous delivery, 37 week of gestation, birth weight 2170g, 10 AS, unremarkable family history) was admitted to a hospital because of weight loss (1.5 kg, i.e. approx. 15% in 6 months), anorexia, abdominal and limb pain and lethargy. On admission, very high blood pressure values (190/150 mm Hg), lean subcutaneous tissue, frequent blinking, height 88 cm (<3c), body weight 9.5 kg (<3c). In additional tests: blood morphology, parameters of renal function, ions, gasometry, catecholamine urinary excretion, steroid profile and daily cortisol profile were within normal limits. Elevated plasma renin activity was found. In imaging studies kidneys, adrenal glands and renal arteries were normal. Normotension was not obtained on two antihypertensive drugs - metoprolol and amlodipine. In angio-CT tortuous right vertebral artery, extending to the left on the anterolateral surface of the medulla oblongata - possible compression of the vessel of the left side of medulla - was found. Diagnosis of neurovascular conflict was made. The patient was consulted by neurosurgeon who declare no possibility of surgical treatment of anomalies. In the treatment, according to the literature, a drug blocking the renin-angiotensin-aldosterone-enalapril system was used, which normalized blood pressure. At the same time, intensive nutritional treatment was used. Resolution of symptoms and weight gain was observed. In further follow-up patients' parents withdrew enalapril lawlessly, which did not lead to recurrent rise in blood pressure. The latter may suggest other, transient cause of hypertensive crisis e.g. intoxication. CONCLUSIONS: Severe hypertension in pediatric patients can give symptoms as weight loss and behavioral disorders. In the diagnostic of hypertensive crisis in children, neuroimaging studies and toxicological tests should be performed.

Arachnoiditis as an outcome factor for microvascular decompression in classical trigeminal neuralgia.

BACKGROUND: Neurovascular conflict is considered a key element of classical trigeminal neuralgia (TN) and consequently, microvascular decompression (MVD) is an effective treatment. Nevertheless, failures of MVD are described by many authors. In some patients, the arachnoid membranes surrounding the trigeminal nerve and neighbouring vessels may be thickened and adhesive. Here we analyse the impact of such focal arachnoiditis on outcome after MVD for TN. METHODS: A cohort of prospectively followed patients after their MVD was reviewed for intraoperative, imaging and clinical data if findings of arachnoiditis during MVD were described. Long-term outcome assessment was the main endpoint. RESULTS: We reviewed data from 395 MVD procedures, performed for TN from 2001 to 2014. Intraoperative evidence of focal arachnoiditis, as described by the surgeon, has been noted in 51 patients (13%). In 35 (68.6%), neuralgia was typical and in the other 17 (31.4%) it was atypical. As expected by definition, neurovascular conflict was found in 49 interventions (96%); it was predominantly arterial in 27 (52.9%). Accompanying arachnoiditis was encountered: mild in 20 interventions (39.2%), severe in 31 (60.8%). A successful result (BNI I or II) was achieved in 29 patients (56.9%). The other 22 patients (43.1%) had persistence or recurrence of pain. Overall KM probability of being pain free at 15 years was 72%. CONCLUSIONS: Intraoperative finding of arachnoiditis during MVD for classical trigeminal neuralgia is associated with poorer outcome than that of classical trigeminal neuralgia in general. This is particularly true for low grades of conflict.

Symptomatic medulla compression by vertebral artery.

OBJECTIVE: Vertebral artery medulla compression syndrome (VAMCS) is a very rare condition manifesting as different neurological focal deficits. The case of a 36-year-old male with symptomatic brainstem compression by vertebral artery (VA) treated by means of microvascular decompression (MVD) and a review of the literature is presented. CASE REPORT: On admission, a 36-year-old patient presented with hypoalgesia, hypothermesthesia and hemiparesis on the left side. Magnetic resonance imaging (MRI) of the head disclosed the right VA loop compressing the ventrolateral medulla and excluded other entities such as brain tumor, stroke and multiple sclerosis. Since displacement and significant compression of the right pyramidal tract was confirmed by diffusion tensor imaging (DTI), neurovascular compression syndrome was diagnosed. The patient underwent MVD of the medulla using a Gore-Tex implant as a separating material via the right far-lateral approach. The left hemiparesis and hemisensory loss remitted rapidly after the procedure. The post-procedural neurological improvement was maintained at one year follow-up. Based on a review of the literature, a total of 33 cases of surgically treated VAMCS has been reported so far. CONCLUSION: VAMCS should be considered as the cause of neurological deficits when other pathological entities are ruled out. In symptomatic conflict of the VA with the medulla, microvascular decompression using a Gore-Tex implant can be an effective method of treatment. Nevertheless, a statistical analysis on all reported cases showed favorable results using the VA repositioning technique when compared with MVD (success rate 91% vs. 58%, p<0.05).

Nerve atrophy in trigeminal neuralgia due to neurovascular compression and its association with surgical outcomes after microvascular decompression.

BACKGROUND: Idiopathic trigeminal neuralgia (TN) is caused by neurovascular compression and is often related to morphological changes in the trigeminal nerve. The aim of this study was to quantitatively measure atrophic changes of trigeminal nerves in patients with TN, and to further investigate whether nerve atrophy affected the efficacy of microvascular decompression (MVD). METHODS: We conducted a prospective case-control study of 60 consecutive patients with TN and 30 sex- and age-matched healthy controls. All subjects underwent high-resolution three-dimensional MRI. The volume of the cisternal segment of trigeminal nerves was measured and compared using 3D Slicer software. Patients with TN underwent primary MVD and regular follow-up for at least 2 years. Associations of nerve atrophy with patient characteristics and operative outcomes were analyzed. RESULTS: The mean volume of the affected trigeminal nerve was significantly reduced in comparison to that of the nonaffected side (65.8 ± 21.1 versus 77.9 ± 19.3 mm3, P = 0.001) and controls (65.8 ± 21.1 versus 74.7 ± 16.5 mm3, P = 0.003). Fifty-two patients (86.7%) achieved complete pain relief without medication immediately after surgery, and 77.6% of patients were complete pain relief at the 2-year follow-up. The Spearman correlation test showed that there was a positive correlation (r = 0.46, P = 0.018) between the degree of trigeminal nerve indentation and nerve atrophy. In multivariate logistic regression analysis, two factors, indentation on nerve root (OR = 2.968, P = 0.022) and degree of nerve atrophy (OR = 1.18, P = 0.035), were associated with the long-term outcome. CONCLUSIONS: TN is associated with atrophy on the affected nerve. Furthermore, greater nerve atrophy is associated with more severe trigeminal nerve indentation and better long-term outcome following MVD.

Painful spasms in facial, masticatory, and motor ocular muscles reversed after microvascular decompression of a neurovascular conflict at brainstem.

The authors present a case of a 42-year-old female admitted for disabling complex and atypical bilateral facial spasms associated with painful masticatory and motor ocular dystonic movements, difficult to fit in the definition of any known cranio-facial dyskinesias. MRI showed a left PICA loop invaginated into the brainstem, considered responsible of an hyperactive disorder of the brainstem nuclei neighboring the conflict. After microvascular decompression, the patient made a full recovery with complete disappearance of the paroxystic phenomena. Such a type of image should be searched for, in an intra-axial brainstem location, in the absence of conflict in the cistern at root entry/exit zone (REZ).

Trigeminal neuralgia due to venous neurovascular conflicts: outcome after microvascular decompression in a series of 55 consecutive patients.

BACKGROUND: Implication of veins as neurovascular conflict (NVC) in the genesis of trigeminal neuralgia (TN) remains a matter of debate. Few reports dealing with venous NVC have been published. The objective of this study is to describe the outcome in a historical cohort of consecutive patients with classical TN due to venous compression. METHODS: All patients with TN treated by microvascular decompression (MVD) from 2005 to 2013 were included if a marked venous compression was found at the surgery either alone or accompanied by an artery. Patients were evaluated for clinical presentation, operative findings and the long-term outcome. Outcome was considered favourable if patients were classed as BNI I or II (i.e. not requiring any medication). Kaplan-Meier analysis was used to determine probability of a favourable outcome at 10 years of follow-up. RESULTS: Out of the overall series of 313 patients having been treated by MVD and considered for the study, in 55 (17.5 %) a vein was the main compressive vessel; in 26 (8.3 %) it was the only compressive vessel. Probability of relief with no need for medication at 10 years was 70.6 %. The patients with focal arachnoiditis had a poor long-term outcome, i.e. BNI III-V, in 85.7 % compared with 20.8 % without arachnoiditis (p = 0.0037 Fisher's exact test). No differences in outcome were found between patients presenting with purely venous compression and patients with mixed compression. Outcome was similarly good for patients with atypical neuralgia when compared to patients with typical clinical presentation. CONCLUSIONS: Venous NVC as a cause of TN is far from rare. MVD with complete liberation of the entire root in cases with clear-cut venous compression on imaging studies gives a good probability of long-term pain relief, thus encouraging to propose surgery for such patients.