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Surgical Treatment of Secondary Trigeminal Neuralgia Induced by Cerebellopontine Angle Tumors: A Single-Center Experience

Introduction. Classical trigeminal neuralgia is caused by the compression of the trigeminal nerve root and often requires surgical intervention due to the maladaptive intense pain syndrome. Both arteries and veins are considered compressing vessels, however, the role of venous compression in the development of neuralgia remains undefined. The aim of the study was to investigate the effectiveness of microvascular decompression in the treatment of trigeminal neuralgia caused by venous compression, considering the use of various surgical tactics. Material and methods. A retrospective analysis of surgical outcomes in 70 patients who underwent microvascular decompression for trigeminal neuralgia at the Federal Neurosurgical Center (Novosibirsk, Russia) between 2017 and 2021 was conducted. The study included 46 women and 24 men aged 23–82 years with unilateral facial pain. Brain MRI was performed preoperatively to evaluate neuroimaging picture and to clarify the relationships between the trigeminal nerve root and adjacent vessels. The surgical results were assessed during follow-up using the Barrow Neurological Institution (BNI) scale. Results. The study showed that venous neurovascular compression is frequently found in trigeminal neuralgia patients undergoing microvascular decompression in 26.9 % of cases. Various operative strategies were used when venous compression was detected, with high short-term success rates and lower recurrence rates. Long-term monitoring indicated pain relief in 71.4 % of cases (BNI I–II) and pain recurrence in 28.6 % of cases (BNI III, IV, V). Conclusion. This study highlights the effectiveness of microvascular decompression in treating classical trigeminal nerve neuralgia caused by venous compression and emphasizes the importance of individual surgical tactics based on the characteristics of the adjacent veins to achieve optimal results.

The aim of this study was to prospectively evaluate atrophic changes in trigeminal nerves (TGNs) using measurements of volume (V) and cross-sectional area (CSA) from high-resolution 3-T MR images obtained in patients with unilateral trigeminal neuralgia (TN), and to correlate these data with patient and neurovascular compression (NVC) characteristics and with clinical outcomes. Anatomical TGN parameters (V and CSA) were obtained in 50 patients (30 women and 20 men; mean age 56.42 years, range 22-79 years) with classic TN before treatment with microvascular decompression (MVD). Parameters were compared between the symptomatic (ipsilateralTN) and asymptomatic (contralateralTN) sides of the face. Twenty normal control subjects were also included. Two independent observers blinded to the side of pain separately analyzed the images. Measurements of V (from the pons to the entrance of the nerve into Meckel's cave) and CSA (at 5 mm from the entry of the TGN into the pons) for each TGN were performed using imaging software and axial and coronal projections, respectively. These data were correlated with patient characteristics (age, duration of symptoms before MVD, side of pain, sex, and area of pain distribution), NVC characteristics (type of vessel involved in NVC, location of compression along the nerve, site of compression around the circumference of the root, and degree of compression), and clinical outcomes at the 2-year follow-up after surgery. Comparisons were made using Bonferroni's test. Interobserver variability was assessed using the Pearson correlation coefficient. The mean V of the TGN on the ipsilateralTN (60.35 ± 21.74 mm(3)) was significantly smaller (p < 0.05) than those for the contralateralTN and controls (78.62 ± 24.62 mm(3) and 89.09 ± 14.72 mm(3), respectively). The mean CSA of the TGN on the ipsilateralTN (4.17 ± 1.74 mm(2)) was significantly smaller than those for the contralateralTN and controls (5.41 ± 1.89 mm(2) and 5.64 ± 0.85 mm(2), respectively). The ipsilateralTN with NVC Grade III (marked indentation) had a significantly smaller mean V than the ipsilateralTN with NVC Grade I (mere contact), although it was not significantly smaller than that of the ipsilateralTN with NVC Grade II (displacement or distortion of root). The ipsilateralTN with NVC Grade III had a significantly smaller mean CSA than the ipsilateralTN with NVC Grades I and II (p < 0.05). The TGN on the ipsilateralTN in cured patients had a smaller mean CSA than that on the ipsilateralTN of patients with partial pain relief or treatment failure (p < 0.05). The same finding was almost found in relation to measurements of V, but the p value was slightly higher at 0.05. Results showed that TGN atrophy in patients with TN can be demonstrated by high-resolution imaging. These data suggest that atrophic changes in TGNs, which significantly correlated with the severity of compression and clinical outcomes, may help to predict long-term prognosis after vascular decompression.

Trigeminal neuralgia (TN) is a common cause of facial pain. To answer the following questions: 1) In patients with TN, how often does routine neuroimaging (CT, MRI) identify a cause? 2) Which features identify patients at increased risk for symptomatic TN (STN; i.e., a structural cause such as a tumor)? 3) Does high-resolution MRI accurately identify patients with neurovascular compression? 4) Which drugs effectively treat classic and symptomatic trigeminal neuralgia? 5) When should surgery be offered? 6) Which surgical technique gives the longest pain-free period with the fewest complications and good quality of life? Systematic review of the literature by a panel of experts. In patients with trigeminal neuralgia (TN), routine head imaging identifies structural causes in up to 15% of patients and may be considered useful (Level C). Trigeminal sensory deficits, bilateral involvement of the trigeminal nerve, and abnormal trigeminal reflexes are associated with an increased risk of symptomatic TN (STN) and should be considered useful in distinguishing STN from classic trigeminal neuralgia (Level B). There is insufficient evidence to support or refute the usefulness of MRI to identify neurovascular compression of the trigeminal nerve (Level U). Carbamazepine (Level A) or oxcarbazepine (Level B) should be offered for pain control while baclofen and lamotrigine (Level C) may be considered useful. For patients with TN refractory to medical therapy, Gasserian ganglion percutaneous techniques, gamma knife, and microvascular decompression may be considered (Level C). The role of surgery vs pharmacotherapy in the management of TN in patients with MS remains uncertain.

Trigeminal neuralgia (TN) is a complex orofacial neuropathic pain condition with limited understanding of underlying mechanisms and therapeutic options. Emerging evidence suggests the involvement of the brain in persons with TN including widespread brain changes when employing a widely used brain aging biomarker that estimates a predicted brain age difference or brain age gap. The aim of the present cross-sectional study was to assess the predicted brain age difference (brain-PAD) or brain age gap across two TN subtypes (classical TN, and secondary/idiopathic TN) in comparison with age-and sex-matched pain-free controls and its association with several clinical and psychological characteristics. Thirty-four individuals diagnosed with Classical TN, 17 diagnosed with secondary/idiopathic TN were age- and sex-matched to pain-free controls (n=54). All participants underwent a T1 brain MRI and completed clinical and psychological measures. There were significant differences in brain-PAD among TN subtypes (ANCOVA p=0.0078, effect size f2=0.282), with individuals diagnosed with Classical TN having a brain-PAD significantly greater than the controls by 3.87years (p=0.01, Bonferroni-corrected). There were no significant brain-PAD differences between secondary/idiopathic TN and pain-free controls. Brain-PAD had a significant positive association with both pain catastrophizing (p<0.05) and pain-related anxiety (p<0.05), but no significant association with disease duration (p<0.05) or usual pain intensity (p<0.05) in persons with classical TN. The results were similar using a second brain aging biomarker. We report here accelerated brain aging processes in individuals with classical TN, but not in persons diagnosed with secondary/idiopathic TN. Our study replicates previous findings and adds to the literature that accelerated brain aging may not occur across all TN subtypes. Given the increased use of MRI for TN diagnostics, combined with our own recent work deriving brain aging biomarkers from clinical-grade scans, future studies within clinical settings are feasible and may help understand this debilitating condition.

Classical trigeminal neuralgia (TN) is a chronic pain disorder that has been described as one of the most severe pains one can suffer. The most prevalent theory of TN etiology is that the trigeminal nerve is compressed at the root entry zone (REZ) by blood vessels. However, there is significant evidence showing a lack of neurovascular compression (NVC) for many cases of classical TN. Furthermore, a considerable number of patients who are asymptomatic have MR evidence of NVC. Since there is no validated animal model that reproduces the clinical features of TN, our understanding of TN pathology mainly comes from biopsy studies that have limitations. Sophisticated structural MRI techniques including diffusion tensor imaging provide new opportunities to assess the trigeminal nerves and CNS to provide insight into TN etiology and pathogenesis. Specifically, studies have used high-resolution structural MRI methods to visualize patterns of trigeminal nerve-vessel relationships and to detect subtle pathological features at the trigeminal REZ. Structural MRI has also identified CNS abnormalities in cortical and subcortical gray matter and white matter and demonstrated that effective neurosurgical treatment for TN is associated with a reversal of specific nerve and brain abnormalities. In conclusion, this review highlights the advanced structural neuroimaging methods that are valuable tools to assess the trigeminal system in TN and may inform our current understanding of TN pathology. These methods may in the future have clinical utility for the development of neuroimaging-based biomarkers of TN.

ObjectivesBrain structural and functional abnormalities have been separately reported in patients with classic trigeminal neuralgia (CTN). However, whether and how the functional deficits are related to the structural alterations remains unclear. This study aims to investigate the anatomical and functional deficits in patients with CTN and explore their association.MethodsA total of 34 patients with CTN and 29 healthy controls (HCs) with age- and gender-matched were recruited. All subjects underwent structural and resting-state functional magnetic resonance imaging (fMRI) scanning and neuropsychological assessments. Voxel-based morphometry (VBM) was applied to characterize the alterations of gray matter volume (GMV). The amplitude of low-frequency fluctuation (ALFF) method was used to evaluate regional intrinsic spontaneous neural activity. Further correlation analyses were performed between the structural and functional changes and neuropsychological assessments.ResultsCompared to the HCs, significantly reduced GMV was revealed in the right hippocampus, right fusiform gyrus (FFG), and temporal-parietal regions (the left superior/middle temporal gyrus, left operculo-insular gyrus, left inferior parietal lobule, and right inferior temporal gyrus) in patients with CTN. Increased functional activity measured by zALFF was observed mainly in the limbic system (the bilateral hippocampus and bilateral parahippocampal gyrus), bilateral FFG, basal ganglia system (the bilateral putamen, bilateral caudate, and right pallidum), left thalamus, left cerebellum, midbrain, and pons. Moreover, the right hippocampus and FFG were the overlapped regions with both functional and anatomical deficits. Furthermore, GMV in the right hippocampus was negatively correlated with pain intensity, anxiety, and depression. GMV in the right FFG was negatively correlated with illness duration. The zALFF value in the right FFG was positively correlated with anxiety.ConclusionOur results revealed concurrent structural and functional changes in patients with CTN, indicating that the CTN is a brain disorder with structural and functional abnormalities. Moreover, the overlapping structural and functional changes in the right hippocampus and FFG suggested that anatomical and functional changes might alter dependently in patients with CTN. These findings highlight the vital role of hippocampus and FFG in the pathophysiology of CTN.

Trigeminal nerve atrophy and neurovascular compression (NVC) are frequently observed in classical trigeminal neuralgia (CTN). To determine whether nerve characteristics contribute to Gamma Knife (Elekta AB, Stockholm, Sweden) surgery (GKS) outcomes in unilateral CTN without previous surgery. From 2006 to 2012, 67 patients with unilateral CTN without previous surgery received GKS with a maximal dose of 90 Gy delivered to the trigeminal nerve juxta brainstem. Two evaluators, blinded to the side of pain, analyzed the magnetic resonance images before GKS to obtain the parameters, including nerve cross-sectional area (CSA), vessel type of NVC, and site of NVC along the nerve. Correlations of the parameters with pain relief (Barrow Neurological Institute [BNI] grades I-IIIb) and recurrence (BNI grades VI-V) were made by using Cox regression and Kaplan-Meier analyses. The median CSA of the symptomatic nerves was significantly smaller than that of the asymptomatic nerves (4.95 vs 5.9 mm2, P<.001). After adjustment for age and sex, larger nerve CSA was associated with lower initial pain relief (hazard ratio 0.81, P=.03) and lower pain recurrence after initial response (hazard ratio 0.58, P=.02). Patients with nerve atrophy (CSA of≤4.4 mm2 after receiver operating characteristic curve analysis) had a lower 5-yr probability of maintaining pain relief after initial response than those without nerve atrophy (65% vs 86%, P=.04). Trigeminal nerve atrophy may predict pain recurrence in patients with initial post-GKS relief of CTN. Arterial and proximal NVC are not predictive of GKS outcomes. Future studies are required to determine optimal treatments for long-term pain relief in patients with CTN and trigeminal nerve atrophy.

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Classical trigeminal neuralgia (CTN) and the short-lasting unilateral neuralgiform headache attacks (SUNHA) are clinically similar. The SUNHAs include short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA). Shared clinical signs with CTN include severe, unilateral trigeminal pain that is often triggered by innocuous stimuli and accompanied by a dull persistent background pain. Recent reports on trigeminal neuralgia cases with atypical features such as autonomic signs and prolonged attack duration further blur the clinical distinction between CTN and SUNHAs. Are the similarities greater than their differences? If so, this may reflect a spectrum of disease ranging from typical CTN attacks to typical SUNHAs with a mixed phenotype in the middle. In this review they will summarize the overlap between these entities and contrast the pathophysiology and treatment approach.

Background: Novel magnetic resonance (MR) imaging techniques prompted the emergence of T1-w/T2-w images or “myelin-sensitive maps (MMs)” to measure myelin in vivo. However, acquisition-related variations in MR intensities prevent meaningful quantitative comparisons between MMs. We propose an improved pipeline to standardize MMs that is applied to patients with classic trigeminal neuralgia (CTN) and trigeminal neuralgia secondary to multiple sclerosis (MSTN). Methods: 3T scanner was used to obtain T1-w and T2-w images for 17 CTN and 17 MSTN patients. Template images were obtained from ICBM152 database. MS plaques and normal-appearing white matter (NAWM) were labelled. A Gaussian curve-fit was applied to the histogram of the intensity distribution of each patient image, and transformed to match the Gaussian curve-fit of the template image. Results: MM intensities were decreased within MS plaques, compared to NAWM in MSTN patients (p&lt;0.001) and its corresponding regions in CTN patients (p&lt;0.001). Qualitatively, the standardized patient image and its histogram better resembled the ICBM152 template. Conclusions: MM analysis revealed reduced myelin content in MS plaques compared to corresponding regions in CTN patients and surrounding NAWM in MSTN patients. The standardized MM serves as a non-invasive, clinical tool for quantitative analyses of myelin content between different brain regions and different patients in vivo.

Introduction/purpose Facial pain is a debilitating disease with 15,000 new TN cases and 500 GPN cases reported each year, and is often refractory to medical treatment. Minimally invasive rhizotomy is an excellent treatment but requires reaching a deep skull base target with a needle for radiofrequencey (RF) treatment. In this report, we highlight a combined flat panel dynaCT and fluoroscopic guidance system to target the V3 through foramen ovale, V2 through foramen rotundum, and glossopharyngeal nerve adjacent to the styloid process for RF-based therapies, with step-by-step instruction as highlighted by representative cases. Materials and methods Eighteen patients with Trigeminal Neuralgia (TN) and 2 patients with classical Glossopharyngeal Neuralgia (GPN) were enrolled. Among the 18 TN patients, 15 presented with atypical Trigeminal Neuralgia (ATN) and 3 presented with classical Trigeminal Neuralgia (CTN). Numeric Rating Scale (NRS) scores for facial pain pre-treatment, immediate post-treatment, post procedure day 1, and months 1 and 3 were recorded documenting primary clinical outcome (pain relief with 50% or more reduction in NRS) and adverse clinical outcome (hematoma, facial numbness, masticatory weakness, corneal involvement, and difficulty swallowing). Results The technical success rate is 100%, confirmed by dynaCT and electrostimulatory testing in awake patients. GPN and CTN groups show excellent immediate and sustained pain relief (2/2 (100%) and 3/3 (100%) with NRS reduction >50% up to 3 months). The ATN group is variable, with 6/15 (40%) having good immediate and sustained pain relief, while the other 9 (60%) patients experienced sub-optimal response (NRS reduction Conclusion We present a step-by-step method using representative examples targeting V3, V2, and the glossopharyngeal nerve, as well as our single-center experience with dyna-CT guided RF ablation of chronic facial pain. Using this multidisciplinary approach, we demonstrate 100% technical success with needle guidance to difficult locations. Treatment results are excellent for CTN and GPN (100% NRS reduction >50% up to 3 months), with more variable results in ATN (40% NRS reduction >50% up to 3 months), which is known to be more refractory to therapies. Disclosures N. Telischak: None. J. Heit: None. O. Choudhri: None. H. Do: None. X. Qian: None.

ObjectiveThis study aimed to explore the central mechanism of classical trigeminal neuralgia (CTN) by analyzing the static amplitude of low-frequency fluctuation (sALFF) and dynamic amplitude of low-frequency fluctuation (dALFF) in patients with CTN before and after a single-trigger pain.MethodsThis study included 48 patients (37 women and 11 men, age 55.65 ± 11.41 years) with CTN. All participants underwent 3D-T1WI and three times resting-state functional magnetic resonance imaging. The images were taken before stimulating the trigger zone (baseline), within 5 s after stimulating the trigger zone (triggering-5 s), and in the 30th minute after stimulating the trigger zone (triggering-30 min). The differences between the three measurements were analyzed using a repeated-measures analysis of variance.ResultsThe sALFF values of the bilateral middle occipital gyrus and right cuneus gradually increased, and the values of the left posterior cingulum gyrus and bilateral superior frontal gyrus gradually decreased in triggering-5 s and triggering-30 min. The values of the right middle temporal gyrus and right thalamus decreased in triggering-5 s and subsequently increased in triggering-30 min. The sALFF values of the left superior temporal gyrus increased in triggering-5 s and then decreased in triggering-30 min. The dALFF values of the right fusiform gyrus, bilateral lingual gyrus, left middle temporal gyrus, and right cuneus gyrus gradually increased in both triggering-5 s and triggering-30 min.ConclusionsThe sALFF and dALFF values changed differently in multiple brain regions in triggering-5 s and triggering-30 min of CTN patients after a single trigger of pain, and dALFF is complementary to sALFF. The results might help explore the therapeutic targets for relieving pain and improving the quality of life of patients with CTN.

Classic trigeminal neuralgia is a clinical condition with pathognomonic acute and sporadic episodes of pain. Atypical trigeminal neuralgia manifests more dull, constant, and chronic with occasional acute burning or stabbing pain as experienced in classic trigeminal neuralgia. There have been reports of trigeminal neuralgia developing after cervical insults, positing a cervical source of orofacial pain. We report a patient with chronic, bilateral atypical trigeminal neuralgia symptoms due to a cervical cavernous malformation who underwent a C3-C6 laminectomy with cavernous malformation resection and had subsequent seroma-induced bilateral classic trigeminal neuralgia. Therapist-led cervical exercises improved his symptoms. His quality of life and function independence improved and his medications were titrated down. In conclusion, trigeminal neuralgia does not always present as classic paroxysmal, electrical pain and can occur from a cervical insult distal to the C2 spinal level.

Surgical Strategy for Petroclival Meningioma-Related Trigeminal Neuralgia: The Role of Porus Trigeminus Opening