Trigeminal Neuralgia Patients Research Articles

Functional alterations of the brain default mode network and somatosensory system in trigeminal neuralgia

Mapping the localization of the functional brain regions in trigeminal neuralgia (TN) patients is still lacking. The study aimed to explore the functional brain alterations and influencing factors in TN patients using functional brain imaging techniques. All participants underwent functional brain imaging to collect resting-state brain activity. The significant differences in regional homogeneity (ReHo) and amplitude of low frequency (ALFF) between the TN and control groups were calculated. After familywise error (FWE) correction, the differential brain regions in ReHo values between the two groups were mainly located in bilateral middle frontal gyrus, bilateral inferior cerebellum, right superior orbital frontal gyrus, right postcentral gyrus, left inferior temporal gyrus, left middle temporal gyrus, and left gyrus rectus. The differential brain regions in ALFF values between the two groups were mainly located in the left triangular inferior frontal gyrus, left supplementary motor area, right supramarginal gyrus, and right middle frontal gyrus. With the functional impairment of the central pain area, the active areas controlling memory and emotion also change during the progression of TN. There may be different central mechanisms in TN patients of different sexes, affected sides, and degrees of nerve damage. The exact central mechanisms remain to be elucidated.

Utility and Prognostic Value of Intraoperative Blink Reflex in Trigeminal or Facial Nerve Monitoring in Skull Base Surgeries: A Systematic Review

Blink reflex (BR) is an oligosynaptic reflex that involves the ophthalmic branch of the trigeminal nerve (TN), ipsilateral main sensory and trigeminospinal nuclei, bilateral facial nuclei, and the facial nerves (FN). Theoretically, as it tests the function of both TN and FN simultaneously, it is an ideal tool for monitoring the status of TN and FN during skull base surgeries. Nevertheless, it is only recently utilized in surgeries as the use of anesthesia limits its use. Two authors inputted the search terms: [(Blink Reflex) AND (Intraoperative Neuromonitoring OR Neuro Intraoperative Monitoring OR Intraoperative OR NIOM OR IONM) AND (skull base surgery OR Facial Nerve OR Trigeminal Nerve OR Microvascular Decompression OR Hemifacial Spasm)] in Medline through its Pubmed interface and other search engines. Papers that fulfilled the inclusion and exclusion criteria were obtained and scrutinized. Only 7 observational papers with a total of 437 participants were included in the current systematic review. All studies (n=5) involving the use of BR in FN surgery noted that IOBR is beneficial, safe, sensitive, specific, and predictive of outcomes while all 2 papers involving trigeminal neuralgia patients recommended BR's use in microvascular decompression (MVD) of TN. IOBR is a sensitive, specific and safe monitoring technique that has good predictability of facial paresis and paresthesia among patients undergoing MVD for trigeminal neuralgia and primary hemifacial spasm and those who are for cerebellopontine angle tumor resection.

Efficacy and safety of Dyna CT-assisted percutaneous balloon compression in the treatment of tumor-related trigeminal neuralgia: A single-center retrospective analysis

BackgroundPercutaneous balloon compression (PBC) has been widely used in the treatment of trigeminal neuralgia (TN). Patients with tumor-related TN are typically treated by tumor resection. However, when craniotomy is not feasible, PBC may serve as a simple and effective method for pain relief. Currently, there is limited literature on the use of this technique in treating patients with tumor-related TN. In this study, we aim to evaluate the efficacy and safety of Dyna CT-assisted PBC in the treatment of tumor-related TN. MethodsFrom January 2018 to December 2023, a total of 19 patients with tumor-related TN underwent Dyna CT-assisted PBC at our institution. The modified Barrow Neurological Institute Pain Intensity Grading Scale and sensory reduction scores were employed to assess treatment outcomes. A retrospective analysis was conducted on the clinical characteristics, surgical efficacy, postoperative complications, and follow-up results of all patients. ResultsImmediate and complete pain relief was observed in 18 patients following PBC, with one patient experiencing delayed recovery. Follow-up periods ranged from 4 to 62 months, revealing only 4 patients with pain recurrence at the last follow-up, and tumor-related TN patients with involvement of Meckel's cave were more prone to recurrence. No severe complications occurred throughout the follow-up period. Although facial numbness was reported in all 15 patients, jaw weakness in 8 patients, and postoperative headache in 7 patients, these symptoms resolved within a short period. There were no statistically significant differences in postoperative facial numbness and jaw weakness between tumor-related TN patients with or without Meckel's cave involvement. However, patients with Meckel's cave involvement were more likely to experience postoperative headaches. Patient satisfaction scores indicated a significant improvement in postoperative quality of life. ConclusionFor patients with tumor-related TN, when craniotomy is not feasible, Dyna CT-assisted PBC proves to be a safe and effective alternative treatment. Additionally, we observed varying postoperative clinical outcomes based on the different sites of tumor compression on the trigeminal nerve. Patients with tumor-related TN not involving Meckel's cave exhibited more enduring clinical efficacy compared to those with Meckel's cave involvement.

A novel indicator to predict the outcome of percutaneous stereotactic radiofrequency rhizotomy for trigeminal neuralgia patients: diffusivity metrics of MR-DTI

A novel indicator to predict the outcome of percutaneous stereotactic radiofrequency rhizotomy for trigeminal neuralgia patients: diffusivity metrics of MR-DTI

Effectiveness and complication of low-dose trigeminal nerve block with alcohol in idiopathic trigeminal neuralgia

Background: Trigeminal nerve block with alcohol was introduced long ago as a treatment method for trigeminal neuralgia. However, very little information is available in the literature regarding trigeminal nerve block with alcohol, and therefore, we evaluated the efficacy and related complications of an alcohol block of the trigeminal nerve for the treatment of indiopathic trigeminal neuralgia.Subjects and methods: Longitudinal and retrospective study in 38 idiopathic trigeminal neuralgia patients with low-dose trigeminal nerve block with alcohol from January 2019 to July 2022. Results: 38 patients were analyzed who received absolute alcohol injections in the management of trigeminal neuralgia (TN) from January 2019 to July 2022. There are 30 cases were injected with 0,3 ml of absolute alcohol and 8 cases with a greater 0,3 ml dose. The visual analogue scale (VAS) was used for pain improved with moderate level (18 cases) and severe level (12 cases) before, 24 patients had marked improvement of pain with mild level or free from pain. 30 patients (100%) who initially became free from pain experienced a recurrence of pain at least 1 year. Using the Barrow Neurologic Institude pain scale (BNI-PS), after 2 weeks there were only 2 patients (6,7%) experienced recurrent pain with BNI-PS IV, 2 patients (6,7%) with BNI-PS IV after 12 months and 5 patient (17,2%) with BNI-PS IV, 1 patient with BNI-PS V (3,4%) after more than 12 months. No serious complications were reported. Facial numbness was reported in 16 cases (53,3%) with 0,3 ml of absolute alcohol and 8 cases (87,5%) with a greater 0,3 ml dose. Other complications included: keratitis in 4 cases (13,3%) with 0,3 ml of absolute alcohol and 1 cases (25%) with a greater 0,3 ml dose, masseter muscle weakness in 7 cases (23,3,%) with 0,3 ml of absolute alcohol and 2 cases (25,5%) with a greater 0,3 ml dose.

Causal interactions in brain networks predict pain levels in trigeminal neuralgia

Trigeminal neuralgia (TN) is a highly debilitating facial pain condition. Magnetic resonance imaging (MRI) is the main method for generating insights into the central mechanisms of TN pain in humans. Studies have found both structural and functional abnormalities in various brain structures in TN patients as compared with healthy controls. Whereas studies have also examined aberrations in brain networks in TN, no studies have to date investigated causal interactions in these brain networks and related these causal interactions to the levels of TN pain. We recorded fMRI data from 39 TN patients who either rested comfortably in the scanner during the resting state session or tracked their pain levels during the pain tracking session. Applying Granger causality to analyze the data and requiring consistent findings across the two scanning sessions, we found 5 causal interactions, including: (1) Thalamus → dACC, (2) Caudate → Inferior temporal gyrus, (3) Precentral gyrus → Inferior temporal gyrus, (4) Supramarginal gyrus → Inferior temporal gyrus, and (5) Bankssts → Inferior temporal gyrus, that were consistently associated with the levels of pain experienced by the patients. Utilizing these 5 causal interactions as predictor variables and the pain score as the predicted variable in a linear multiple regression model, we found that in both pain tracking and resting state sessions, the model was able to explain ∼36 % of the variance in pain levels, and importantly, the model trained on the 5 causal interaction values from one session was able to predict pain levels using the 5 causal interaction values from the other session, thereby cross-validating the models. These results, obtained by applying novel analytical methods to neuroimaging data, provide important insights into the pathophysiology of TN and could inform future studies aimed at developing innovative therapies for treating TN.

Evaluation of the Effectiveness of Using Pulse Dose Radiofrequency for Treatment of Trigeminal Neuralgia

Trigeminal neuralgia has an incidence of 4-13 per 100000 people per year. The incidence of this disease increases in the elderly, and it is known to cause severe shock-like pain. Pharmacological therapy is the first-line treatment of trigeminal neuralgia. If pharmacological therapy fails, then different procedures are available. Pulse-dose radiofrequency is one such procedure. In this study, we evaluated Pulse dose radiofrequency's efficacy as a method in which pulse amplitude and width are considered essential variables. This research was conducted as a cross-sectional study on trigeminal neuralgia patients referred to the pain clinic of Amir A’lam Hospital in 2020. Conservative therapy has failed; therefore, the clinician decided to use pulse dose radiofrequency to reduce their pain. Among the 29 patients registered during this period, 15 (51.8%) were women and 14 (48.3%) were men. The mean (±SD) age of the patient was 57.07(±14.26) years. The tow route was interrupted in 7 (24.1%) patients. A significant difference was observed between the pain scores before and after the operation (P<0.001). Pulse-dose radiofrequency is a safe and effective therapy for treating trigeminal neuralgia and can be considered a new way to develop the pulse radiofrequency method.

352 Outcomes After Microvascular Decompression for Sole Arterial Versus Venous Compression in Trigeminal Neuralgia

INTRODUCTION: In most cases of trigeminal neuralgia (TN), the trigeminal nerve is compressed by the arterial vasculature. METHODS: We retrospectively reviewed all patients undergoing microvascular decompression at our institution, identifying patients with either sole arterial or venous compression. We dichotomized patients into arterial or venous groups and obtained demographics and postoperative complications for each case. Barrow Neurological Index (BNI) pain scores were collected preoperatively, postoperatively, and at final follow-up, as well as recurrence of pain. Differences were calculated via Chi-squared tests and t-tests. Ordinal regression was used to account for variables known to influence TN pain. Kaplan-Meier analysis was used to determine recurrence-free survival. RESULTS: Of 1044 patients, 642 (61.7%) had either sole arterial or venous compression. 472 of these cases demonstrated arterial compression, and 170 displayed sole venous compression. Patients in the venous compression group were significantly younger (p < 0.001). Patients with sole venous compression demonstrated worse preoperative (p = 0.04) and final follow-up (p < 0.001) pain scores. Patients with sole venous compression had significantly higher rate of pain recurrence (p = 0.02) and BNI score at pain recurrence (p = 0.04). On ordinal regression, venous compression was found to independently predict worse BNI pain scores (OR = 1.66, p = 0.003). Kaplan-Meier analysis demonstrated a significant relationship between sole venous compression and increased risk of pain recurrence (p = 0.03). CONCLUSIONS: TN patients with sole venous compression demonstrate worse pain outcomes following MVD compared to those with only arterial compression.

External assessment of preoperative scores for predicting outcome after microvascular decompression for trigeminal neuralgia.

Recently, two scoring systems have been developed for predicting pain-free outcomes after microvascular decompression (MVD). Evaluation of these scores on large external datasets has been limited. In this study, the authors aimed to evaluate the performance of published MVD scoring systems in predicting pain-free outcome. A total of 458 patients who underwent MVD for trigeminal neuralgia (TN) between 2007 and 2020 and had at least 6 months of follow-up were included in this study. Hardaway and Panczykowski scores were retrospectively computed for each patient and compared with postoperative pain recurrence and pain-free duration. The mean ± SD area under the receiver operating characteristic curve for predicting any pain recurrence after MVD was 0.567 ± 0.081 using the Hardaway score and 0.546 ± 0.085 using the Panczykowski score. On log-rank tests and Kaplan-Meier analysis, the patients with Hardaway scores of 0-2 had significantly shorter pain-free survival times after MVD than did those with a score of 3. Patients with a Panczykowski score of 1 had a significantly shorter pain-free duration after surgery compared with both patients with scores of 2-3 and patients with scores of 4-5. Patients with Panczykowski scores of 2-3 also had significantly shorter pain-free duration compared with patients with scores of 4-5. Both the Hardaway and Panczykowski scores may be useful for predicting postoperative pain-free duration in TN patients, and their utility may be greatest when scores are clustered. Continued refinement of both scoring systems will help to improve our ability to predict patient outcomes after MVD.

Long-term outcome of microvascular decompression for typical trigeminal neuralgia with autologous muscle: an analysis of 1025 patients from a developing country.

The objective was to evaluate the long-term outcome of microvascular decompression (MVD) utilizing autologous muscle for trigeminal neuralgia (TGN). A retrospective review was performed of all first-time MVD patients for typical classic TGN without prior surgical intervention who were treated between 2000 and 2019 at a tertiary supraregional neurosurgery practice. Demographic characteristics, surgical findings, operative results, complications, and recurrence rates at 1 year, 5 years, and last follow-up were collected. Pain outcome was assessed using the Barrow Neurological Institute (BNI) pain score. The chi-square test with continuity correction was used to compare categorical variables, and Kaplan-Meier curves and Cox regression were used to identify factors associated with recurrence. In total, 1025 patients were studied with a median (interquartile range [IQR]) (range) follow-up of 8 (5-13) (3-20) years. In the immediate postoperative period, 889 patients (86.7%) had complete pain relief and 106 (10.3%) had partial pain relief; neither group required medication, and 30 patients (2.9%) had no relief. One hundred forty-one recurrences (13.8%) occurred over a median (IQR) of 3 (2-6) years after surgery. The proportion of patients without recurrence was 97% at 1 year, 90% at 5 years, 85% at 10 years, 82% at 15 years, and 81% at 20 years. There was no significant difference in the probability of recurrence between patients with complete (114/907 [12.6%] recurrences) or partial (19/106 [17.9%] recurrences) postoperative pain relief (p = 0.124, log-rank test). Patients with venous compression (n = 322) had a significantly higher rate of MVD failure (n = 16 [5%]) compared to those with arterial compression (14/703 [2%]) (p = 0.015, chi-square test). In the Cox proportional hazards model, venous compression and lack of immediate postoperative pain relief had hazard ratios of 1.62 (95% CI 1.16-2.27) and 2.65 (95% CI 1.45-4.82) for recurrence, respectively. One hundred twenty-four (12.1%) complications were documented, including facial numbness (44 [4.3%]), facial nerve palsy (37 [3.6%]), CSF leak (13 [1.3%]), and diplopia (5 [0.5%]), which resolved in all patients. MVD with autologous muscle provides long-lasting pain relief in TGN patients with vascular compression with minimum morbidity and is a viable alternative to synthetic materials.

Altered trends of local brain function in classical trigeminal neuralgia patients after a single trigger pain.

To investigate the altered trends of regional homogeneity (ReHo) based on time and frequency, and clarify the time-frequency characteristics of ReHo in 48 classical trigeminal neuralgia (CTN) patients after a single pain stimulate. All patients underwent three times resting-state functional MRI (before stimulation (baseline), after stimulation within 5s (triggering-5s), and in the 30th min of stimulation (triggering-30min)). The spontaneous brain activity was investigated by static ReHo (sReHo) in five different frequency bands and dynamic ReHo (dReHo) methods. In the five frequency bands, the number of brain regions which the sReHo value changed in classical frequency band were most, followed by slow 4 frequency band. The left superior occipital gyrus was only found in slow 2 frequency band and the left superior parietal gyrus was only found in slow 3 frequency band. The dReHo values were changed in midbrain, left thalamus, right putamen, and anterior cingulate cortex, which were all different from the brain regions that the sReHo value altered. There were four altered trends of the sReHo and dReHo, which dominated by decreased at triggering-5s and increased at triggering-30min. The duration of brain function changed was more than 30min after a single pain stimulate, although the pain of CTN was transient. The localized functional homogeneity has time-frequency characteristic in CTN patients after a single pain stimulate, and the changed brain regions of the sReHo in five frequency bands and dReHo complemented to each other. Which provided a certain theoretical basis for exploring the pathophysiology of CTN.

A nomogram based on radiomics and clinical information to predict prognosis in percutaneous balloon compression for the treatment of trigeminal neuralgia.

To develop a clinical-radiomics nomogram based on clinical information and radiomics features to predict the prognosis of percutaneous balloon compression (PBC) for the treatment of trigeminal neuralgia (TN). The retrospective study involved clinical data from 149 TN patients undergoing PBC at Zhongnan Hospital, Wuhan University from January 2018 to January 2022. The free open-source software 3D Slicer was used to extract all radiomic features from the intraoperative X-ray balloon region. The relationship between clinical information and TN prognosis was analyzed by univariate logistic analysis and multivariate logistic analysis. Using R software, the optimal radiomics features were selected using the least absolute shrinkage and selection operator (Lasso) algorithm. A prediction model was constructed based on the clinical information and radiomic features, and a nomogram was visualized. The performance of the clinical radiomics nomogram in predicting the prognosis of PBC in TN treatment was evaluated using the area under the receiver operating characteristic curve (AUC) and decision curve analysis (DCA). A total of 149 patients were eventually included. The clinical factors influencing the prognosis of TN in univariate analysis were compression severity score and TN type. The lasso algorithm Max-Relevance and Min-Redundancy(mRMR) was used to select two predictors from 13 morphology-related radiomics features, including elongation and surface-volume ratio. A total of 4 predictors were used to construct a prediction model and nomogram. The AUC was 0.886(95% confidence interval (CI), 0.75 to 0.96), indicating that the model's good predictive ability. DCA demonstrated the nomogram's high clinical applicability. Clinical-radiomics nomogram constructed by combining clinical information and morphology-related radiomics features have good potential in predicting the prognosis of TN for PBC treatment. However, this needs to be further studied and validated in several independent external patient populations.

A Single Center Retrospective Study: Evaluation of Demographic Structure, Pain Characteristics, Early and Late Results, and Complications in 214 Trigeminal Neuralgia Patients Treated with Radiofrequency Thermocoagulation

A Single Center Retrospective Study: Evaluation of Demographic Structure, Pain Characteristics, Early and Late Results, and Complications in 214 Trigeminal Neuralgia Patients Treated with Radiofrequency Thermocoagulation

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

ObjectivePetroclival (PC) meningiomas invade Meckel's cave through the porus trigeminus, leading to secondary trigeminal neuralgia (TN). Microsurgery and stereotactic radiosurgery (SRS) are the typical treatment options. This study investigated symptom control, outcomes, and surgical strategies for PC meningioma-induced TN. MethodsWe retrospectively analyzed 28 TN patients with PC meningiomas who underwent microsurgical nerve decompression between January 2021 and February 2023. In all patients undergoing a transpetrosal approach, the porus trigeminus was opened to enable the removal of the entire tumor within Meckel’s cave. Clinical outcomes were assessed using the Barrow Neurological Institute (BNI) pain intensity scale. Risk factors for poor TN outcomes and poor facial numbness were analyzed. ResultsAmong 28 patients, 21 (75%) underwent the transpetrosal approach, 5 (17.9%) underwent the retrosigmoid approach, and 2 (7.1%) underwent the Dolenc approach. Following microsurgery, 23 patients (82.1%) experienced TN relief without further medication (BNI I or II). TN recurrence occurred in 2 patients (7.1%), and 3 patients (10.7%) did not achieve TN relief. Cavernous sinus invasion was significantly correlated with poor TN outcomes (p=0.047). A history of previous SRS (p=0.011) and upper clivus type tumor (p=0.018) were significantly associated with poor facial numbness. ConclusionsMicrosurgical nerve decompression is effective in improving BNI scores in patients with TN associated with PC meningiomas. Considering the results of our study, the opening of the porus trigeminus can be considered as a suggested procedure in the treatment of PC meningiomas, especially in cases accompanied by TN.

A prospective cohort study on perioperative percutaneous balloon compression for trigeminal neuralgia: safety and efficacy analysis.

With the recent emergence of percutaneous balloon compression (PBC) as a promising treatment for trigeminal neuralgia (TN), there is a growing need for research on its safety and efficacy. This study was designed to evaluate the safety and efficacy of PBC in the treatment of TN patients during the perioperative period. This study involved a total of 400 TN patients who were selected and treated with PBC at our institution. The clinical data and short-term outcomes were analyzed based on sex, initial PBC treatment for TN, and subsequent PBC treatment for recurrent TN after previous PBC or microvascular decompression (MVD) or radiofrequency thermocoagulation (RFT). No statistically significant difference was found when comparing postoperative pain relief between male and female patients with TN. Nevertheless, female patients were found to be more vulnerable than male patients to abnormal facial sensations (P = 0.001), diplopia (P = 0.015), postoperative headache (P = 0.012), and hyposmia (P = 0.029). Additionally, it was observed that there was no substantial difference in the postoperative pain relief rate between the first-time PBC group and PBC for recurrent TN patients postoperatively following procedures such as PBC, MVD, and RFT. In conclusion, this study has shown that PBC treatment is effective in managing TN in both males and females, regardless of whether the treatment was administered as a primary intervention or following prior surgical procedures such as PBC, MVD, or RFT. Nonetheless, it is noted that the risk of postoperative complications appears to be higher in female patients compared to male patients.

Whole Blood Transcriptome Analysis in Patients with Trigeminal Neuralgia: a Prospective Clinical Study.

Trigeminal neuralgia (TN) brings a huge burden to patients, without long-term effective treatment. This study aimed to explore the differentially expressed genes (DEGs) and related enrichment pathways in patients with TN. This was a study of transcriptome sequencing and bioinformatics analysis of human samples. Whole blood samples were collected from the TN patients and pain-free controls. RNA was extracted to conduct the RNA-sequencing and the subsequent bioinformatics analysis. DEGs between the two groups were derived. Kyoto encyclopedia of genes and genomes (KEGG) and Gene ontology (GO) was used to find the enrichment pathways of DEGs. Protein protein interaction (PPI) network was used to depict the interaction between DEGs and find the most important gene, hub gene. Compared with the control group, there were 117 up-regulated DEGs and 103 down-regulated DEGs in the whole blood of patients in the TN group. Pathway enrichment analysis showed that DEGs were mainly enriched in the neuroimmune and metabolic pathways. The PPI network demonstrated that colony stimulating factor 2 (CSF2) was the most important hub gene in the whole blood of TN patients. This study shows the expression of the transcriptome in the whole blood samples of TN patients. The neuroimmune responses and key hub gene CSF2 in the whole blood cells play a vital role in the occurrence of TN. Our research provides a theoretical basis for the diagnosis and treatments of TN. This study was registered at clinicaltrials.gov in June 2021 (No. NCT04923399).

Bilateral brain microstructural alterations in patients with left-sided classic trigeminal neuralgia: a diffusion kurtosis imaging study.

White matter microstructural abnormalities in patients with classic trigeminal neuralgia (TN) have been observed. However, the impact of classic TN in both hemispheres, the difference and extent of alterations in bilateral hemispheres, and the relationship between the impaired area and pain conduction are not fully understood. The purpose of this study was to investigate brain microstructural alterations and compare the bilateral hemispheres in patients with unilateral classic TN, as well as to explore their clinical implications. The authors performed a cross-sectional study of 36 patients with left classic TN (TN group; age 40-66 years) and 36 healthy controls (HC group; age 40-66 years). Diffusion kurtosis imaging (DKI; b-values = 0, 1250, and 2500 sec/mm2) was performed in all patients using a 3T MRI scanner. The FMRIB Software Library with tract-based spatial statistics was used to analyze intergroup differences in both hemispheres. Atlas-based region of interest analysis was conducted in fiber tracts and gray matter structures. Decreased fractional anisotropy (FA) and increased mean diffusivity in 2.70% and 5.34% of white matter regions, such as the corona radiata, corpus callosum, internal capsule, superior longitudinal fasciculus, and cingulum, were detected in the TN group compared with the HC group (p < 0.05, family-wise error correction). Reduced mean kurtosis (MK), axial kurtosis, and radial kurtosis were detected in the bilateral thalamus in TN patients. The FA and MK values decreased asymmetrically in both cerebral hemispheres. Atlas-based region of interest analysis revealed more pronounced FA and MK reductions in the left thalamus and posterior corona radiata. There were negative associations of disease duration and pain intensity with the MK values in the thalamus, internal capsule, and superior corona radiata. The authors concluded that unilateral TN could have asymmetrical microstructural alterations in bilateral hemispheres, which might be due to the compromised fiber tract integrity and abnormal neurons and synapses. The thalamus could be an important relay station in the pain conduction and modulation pathway and could have microstructural abnormalities in both the left and right sides. DKI could provide important information on the CNS pathophysiology of TN and assist in prognostic evaluation.

The relevance of biologically effective dose for pain relief and sensory dysfunction after Gamma Knife radiosurgery for trigeminal neuralgia: an 871-patient multicenter study.

Recent studies have suggested that biologically effective dose (BED) is an important correlate of pain relief and sensory dysfunction after Gamma Knife radiosurgery (GKRS) for trigeminal neuralgia (TN). The goal of this study was to determine if BED is superior to prescription dose in predicting outcomes in TN patients undergoing GKRS as a first procedure. This was a retrospective study of 871 patients with type 1 TN from 13 GKRS centers. Patient demographics, pain characteristics, treatment parameters, and outcomes were reviewed. BED was compared with prescription dose and other dosimetric factors for their predictive value. The median age of the patients was 68 years, and 60% were female. Nearly 70% of patients experienced pain in the V2 and/or V3 dermatomes, predominantly on the right side (60%). Most patients had modified BNI Pain Intensity Scale grade IV or V pain (89.2%) and were taking 1 or 2 pain medications (74.1%). The median prescription dose was 80 Gy (range 62.5-95 Gy). The proximal trigeminal nerve was targeted in 77.9% of cases, and the median follow-up was 21 months (range 6-156 months). Initial pain relief (modified BNI Pain Intensity Scale grades I-IIIa) was noted in 81.8% of evaluable patients at a median of 30 days. Of 709 patients who achieved initial pain relief, 42.3% experienced at least one pain recurrence after GKRS at a median of 44 months, with 49.0% of these patients undergoing a second procedure. New-onset facial numbness occurred in 25.3% of patients after a median of 8 months. Age ≥ 63 years was associated with a higher probability of both initial pain relief and maintaining pain relief. A distal target location was associated with a higher probability of initial and long-term pain relief, but also a higher incidence of sensory dysfunction. BED ≥ 2100 Gy2.47 was predictive of pain relief at 30 days and 1 year for the distal target, whereas physical dose ≥ 85 Gy was significant for the proximal target, but the restricted range of BED values in this subgroup could be a confounding factor. A maximum brainstem point dose ≥ 29.5 Gy was associated with a higher probability of bothersome facial numbness. BED and physical dose were both predictive of pain relief and could be used as treatment planning goals for distal and proximal targets, respectively, while considering maximum brainstem point dose < 29.5 Gy as a potential constraint for bothersome numbness.

Complementary and Integrative Medicine for the Treatment of Trigeminal Neuralgia and Trigeminal Autonomic Cephalalgia.

Trigeminal neuralgia (TN) and trigeminal autonomic cephalalgias (TACs) are both painful diseases which directly impact the branches of the trigeminal nerve, which supply the face. Patients who have experienced adverse effects, have not responded to mainstream treatments, or have a personal preference for nonmedication options, often turn to complementary and integrative medicine (CIM). The aim of this review is to discuss the efficacy and safety of CIM therapies available for the treatment of TN and TACs. Not only are there limited therapeutic options for TN and TAC patients, but also is there a proportion of patients who are intolerant to standard medical treatments. Recent findings have illustrated that 86% of patients with headache disorders utilize CIM modalities in combination with mainstream medical therapy. CIM modalities can be helpful for these diseases and have primarily been studied in combination with standard medical therapy. There is limited evidence for CIM and behavioral therapies in managing these conditions, and more research is needed to confirm which therapies are safe and effective.

Repeat Gamma Knife radiosurgery for recurrent trigeminal neuralgia in patients with multiple sclerosis: a single-center retrospective study.

Gamma Knife radiosurgery (GKRS) has emerged as an effective treatment option for trigeminal neuralgia (TN) in patients with multiple sclerosis (MS). To date, the outcomes of repeat GKRS for patients with TN and MS with recurrent pain have been investigated in a few patients. This study aims to report the outcomes and predictive factors of pain reduction for MS patients undergoing repeat GKRS for recurrent TN. Eighteen patients with MS underwent repeat GKRS for recurrent TN. A retrospective chart review and telephone interviews were conducted to determine background medical history, dosimetric data, and outcomes of the procedure. Facial pain and sensory function were evaluated using the Barrow Neurological Institute (BNI) scales. Fifteen patients achieved a BNI pain score of IIIa or better, indicating pain reduction, within a median period of 21 days after repeat GKRS. The maximum dose for repeat GKRS ranged from 70 to 85 Gy. Pain recurred in 5 patients after a median period of 12 months after GKRS. Percentages of patients with pain reduction at 1, 2, 3, 5, and 7 years were 60%, 60%, 50%, 50%, and 50%, respectively. Older age at repeat GKRS predicted sustained pain reduction (P = 0.01). Seven patients developed facial sensory disturbances, which were bothersome in two patients. Repeat GKRS may be used as an effective treatment modality for prolonging the duration of pain reduction time in patients with MS and TN. After repeat GKRS, facial sensory disturbances are common; however, they are often not bothersome.