Treatment Modalities For Trigeminal Neuralgia Research Articles

Microsurgical posterior fossa re-exploration for recurrent trigeminal neuralgia after previous microvascular decompression: common grounds—scarring, deformation, and the “piston effect”

ObjectiveMicrovascular decompression (MVD) is a well-accepted treatment modality for trigeminal neuralgia (TN) with high initial success rates. The causes for recurrence of TN after previously successful MVD have not been fully clarified, and its treatment is still a matter of debate. Here, we present the surgical findings and the clinical outcome of patients with recurrent TN after MVD who underwent posterior fossa re-exploration.MethodsMicrosurgical posterior fossa re-exploration was performed in 26 patients with recurrent TN (mean age 59.1 years) who underwent MVD over a period of 10 years. The trigeminal nerve was exposed, and possible factors for recurrent TN were identified. Arachnoid scars and Teflon granulomas were dissected meticulously without manipulating the trigeminal nerve. Outcome of posterior fossa re-exploration was graded according to the Barrow Neurological Institute (BNI) pain intensity score. Follow-up was analyzed postoperatively at 3, 12, and 24 months and at the latest available time point for long-term outcome.ResultsThe mean duration of recurrent TN after the first MVD was 20 months. Pain relief was achieved in all patients with recurrent TN on the first postoperative day. Intraoperative findings were as follows: arachnoid scar tissue in 22/26 (84.6%) patients, arterial compression in 1/26 (3.8%), venous contact in 8/26 (30.8%), Teflon granuloma in 14/26 (53.8%), compression by an electrode in Meckel’s cave used for treatment of neuropathic pain in 1/26 (3.8%), evidence of pulsations transmitted to the trigeminal nerve through the Teflon inserted previously/scar tissue (“piston effect”) in 15/26 (57.7%), and combination of findings in 18/26 (69.2%). At long-term follow-up (mean 79.5 months; range, 29–184 months), 21/26 (80.8%) patients had favorable outcome (BNI I-IIIa). New hypaesthesia secondary to microsurgical posterior fossa re-exploration occurred in 5/26 (19.2%) patients.ConclusionsPosterior fossa re-exploration avoiding manipulation to the trigeminal nerve, such as pinching or combing, may be a useful treatment option for recurrent TN after previously successful MVD providing pain relief in the majority of patients with a low rate of new hypaesthesia.

Fluoroscopic Landmark to Optimize the View of the Foramen Ovale Using the Neighboring Structure

Radiofrequency thermocoagulation (RFT) via trans-oval approach is effective treatment modalities for trigeminal neuralgia. Clear identification of the foramen ovale (FO) is the most important initial step for successful percutaneous procedures. The purpose of this study was to verify whether the medial end of the temporomandibular joint and the distance between the mandibular angle and the occipital inner line can be used as a fluoroscopic landmark to determine the proper angulation of the C-arm. Analysis of previously saved fluoroscopic FO images during RFT was performed. As a fluoroscopic landmark to guide a proper lateral and axial oblique rotation of the C-arm, the position of the medial end of the temporomandibular joint and the vertical distance between the mandibular angle and the occipital inner line were evaluated. When the FO was located at the most central point within the H-figure, the medial end of TMJ was always located within the mandibular notch. The maximum view of the FO was defined when the FO showed maximal short axis to long axis ratio. The FO showed the best view when the vertical distance between the mandibular angle and occipital inner line was 20.04 (5.1) mm. This study demonstrated that the medial end of the temporomandibular joint and the vertical distance between the mandibular angle and occipital inner line as a fluoroscopic landmark for obtaining the optimal view of the FO.

Efficacy of transcutaneous electrical nerve stimulation (TENS) in the management of trigeminal neuralgia: A systematic review and meta-analysis.

Trigeminal Neuralgia is one of the most painful disorders known to man. So making patient pain free and to achieve a better quality of life in TN patients is one of the biggest challenge. Non-invasive procedures like Transcutaneous electrical nerve stimulation (TENS) have been tried clinically for Trigeminal neuralgia. Aim: The systematic review and meta-analysis aimed to compare and evaluate the efficacy of transcutaneous electric nerve stimulation in the management of trigeminal neuralgia. The present review has been registered with PROSPERO - An international prospective register of systematic review CRD42021254136. An electronic search was done in PubMed, Cochrane Library, Science Direct, Google Scholar, EBSCOHOST. The assessments of articles were done using selection criteria and PRISMA guidelines Only prospective clinical trials like Randomized clinical trials (RCTs) and clinical trials were included in this review. A total of three studies were included in the meta -analysis. The proportion of total number of patients after TENS therapy across studies with p-value < 0.0001 for each which showed statistically significance. The overall difference in two groups was significant with standardize mean difference of 3.03 [95% CI: 2.50, 3.56]. TENS can be an effective treatment modality for trigeminal neuralgia in reducing the pain intensity with no reported side effects for patients with trigeminal neuralgia alone or even in combination with other first line drugs. Key words:TENS, TN, TENS, TN, Transcutaneous electrical nerve stimulation.

Cervical Spinal Cord Stimulation for Trigeminal Neuralgia: a Narrative Review.

Trigeminal neuralgia (TN) is a chronic neuropathic pain condition affecting one or more divisions of the fifth cranial (trigeminal) nerve. TN is defined by recurrent unilateral electric shock-like pain that is abrupt in both onset and termination. The pain is triggered by innocuous sensory stimuli and is classified as either classic TN, related to vascular compression; secondary TN, due to a tumor along the trigeminal nerve or an underlying disease like multiple sclerosis; or idiopathic TN. Among the various therapies available for TN, carbamazepine remains the first-line treatment. Newer medications have demonstrated efficacy in patients who do not respond to or cannot tolerate carbamazepine. When medical management and neuroablative procedures fail, spinal cord stimulation (SCS) serves as a promising and popular option, with an estimated 34,000 SCS procedures performed annually worldwide. SCS employs the implantation of electrical leads in the epidural space to manage pain. A review of literature was conducted to explore the use of cervical spinal cord stimulation (SCS) for the treatment of trigeminal neuralgia. A MEDLINE/PubMed search using the search terms "spinal cord stimulation" and "trigeminal neuralgia" was employed to find any case reports and research studies (retrospective studies, double-blinded studies, observational studies) on the topic. No date limiters were used for the search. The initial search resulted in 76 non-duplicate entries from the database. After application of the search criteria, 58 studies were excluded because they were not relevant to the study. A further detailed review of the included articles was conducted by all the reviewers. During this phase of the review, additional 6 studies were excluded. A total of 11 studies were included: 7 case reports and 4 retrospective review studies. In the review, we discuss 7 different case reports on the use of cervical SCS for trigeminal neuralgia and an additional 4 retrospective studies reviewing outcomes and pain relief in patients who underwent treatment. The case reports and retrospective studies reviewed demonstrated that TN patients realized > 50% pain relief following permanent electrode implantation. In all the cases discussed, complications from SCS were rare and/or not reported. Additionally, most of the cases report that patients who had adequate pain relief from SCS were able to wean off, or significantly reduce, oral medications given the vast improvement in pain reduction. Cervical spinal cord stimulation (SCS) is a safe and effective procedure for patients with trigeminal neuralgia (TN) who have refractory pain despite the use of medications. In many cases, the procedure provides an adequate level of pain relief with very few complications or side effects. The vast majority of current research on the use of cervical SCS for TN currently consists of case reports and retrospective analysis. In order to further evaluate the efficacy of SCS for treatment, large-scale randomized controlled studies or observational studies need to be conducted to properly evaluate SCS as a treatment modality for trigeminal neuralgia.

Early postsurgical diffusivity metrics for prognostication of long-term pain relief after Gamma Knife radiosurgery for trigeminal neuralgia.

Gamma Knife radiosurgery (GKRS) is an important treatment modality for trigeminal neuralgia (TN). Current longitudinal assessment after GKRS relies primarily on clinical diagnostic measures, which are highly limited in the prediction of long-term clinical benefit. An objective, noninvasive, predictive tool would be of great utility to advance the clinical management of patients. Using diffusion tensor imaging (DTI), the authors' aim was to determine whether early (6 months post-GKRS) target diffusivity metrics can be used to prognosticate long-term pain relief in patients with TN. Thirty-seven patients with TN treated with GKRS underwent 3T MRI scans at 6 months posttreatment. Diffusivity metrics of fractional anisotropy, axial diffusivity, radial diffusivity, and mean diffusivity were extracted bilaterally from the radiosurgical target of the affected trigeminal nerve and its contralateral, unaffected nerve. Early (6 months post-GKRS) diffusivity metrics were compared with long-term clinical outcome. Patients were identified as long-term responders if they achieved at least 75% reduction in preoperative pain for 12 months or longer following GKRS. Trigeminal nerve diffusivity at 6 months post-GKRS was predictive of long-term clinical effectiveness, where long-term responders (n = 19) showed significantly lower fractional anisotropy at the radiosurgical target of their affected nerve compared to their contralateral, unaffected nerve and to nonresponders. Radial diffusivity and mean diffusivity, correlates of myelin alterations and inflammation, were also significantly higher in the affected nerve of long-term responders compared to their unaffected nerve. Nonresponders (n = 18) did not exhibit any characteristic diffusivity changes after GKRS. The authors demonstrate that early postsurgical target diffusivity metrics have a translational, clinical value and permit prediction of long-term pain relief in patients with TN treated with GKRS. Importantly, an association was found between the footprint of radiation and clinical effectiveness, where a sufficient level of microstructural change at the radiosurgical target is necessary for long-lasting pain relief. DTI can provide prognostic information that supplements clinical measures, and thus may better guide the postoperative assessment and clinical decision-making for patients with TN.

Comparing Microvascular Decompression with Gamma Knife Radiosurgery for Trigeminal Neuralgia. A Cost-Effectiveness Analysis

Both microvascular decompression (MVD) and Gamma Knife radiosurgery (GKRS) are time-tested treatment modalities for trigeminal neuralgia (TN). There is little evidence in the literature studying these modalities head to head in a cost-effectiveness comparison. To evaluate the cost-effectiveness of MVD compared with GKRS for treating patients with TN. We developed a Markov cost-effectiveness model for the U.S. health care system to account for all costs related to MVD and GKRS as treatment modalities for TN, from the health care system perspective, over a patient lifetime horizon. A base case was estimated using data from previous studies, from our own GKRS experience, and from a current data analysis of patients undergoing MVD. We derived model inputs, including health care costs, survival, and utility estimates, from the literature. We used age-specific, sex-specific, and race-specific mortality from national registries. Costs studied included those for MVD, for GKRS, for treating complications from either procedure, and for medications throughout patient lifetimes. We performed multiple 1-way, 2-way, and probabilistic sensitivity analyses to confirm the robustness of model assumptions and results. The incremental cost-effectiveness ratio (ICER), with a threshold of $50,000 per quality-adjusted life-year (QALY) gained, defined cost-effectiveness. The base case had an ICER of $12,154 per QALY for MVD compared with GKRS. Probabilistic sensitivity (Monte Carlo) analysis showed that MVD was cost-effective in 70% of model iterations. GKRS was favored when the willingness to pay threshold was <$12,000 per QALY gained. In patients medically eligible for either procedure, we found MVD to be the most cost-effective modality to treat TN, primarily because of its reported greater durability. MVD remained the most cost-effective strategy across a broad range of model input values in sensitivity analyses.

Microvascular decompression versus stereotactic radiosurgery as primary treatment modality for trigeminal neuralgia: A systematic review and meta-analysis of prospective comparative trials.

The current opinion among neurosurgeons regarding the selection between microvascular decompression (MVD) and gamma knife radiosurgery for trigeminal neuralgia is not based on clear evidence. In this meta-analysis, we have attempted to synthesize the findings of the prospective trials comparing the efficacy and complications of the two procedures as primary treatment modality for medically refractory trigeminal neuralgia. The authors performed a systematic review of PubMed for manuscripts comparing the efficacy or complications of MVD and stereotactic radiosurgery for medically refractory trigeminal neuralgia. The data of the identified studies was pooled and a meta-analysis was done. Five prospective studies fulfilling the eligibility criteria were identified. The mean age of the patients subjected to gamma knife therapy (GKT) was more than those who underwent MVD. The initial success rate in the pooled data with MVD was 96% (95% confidence interval [C.I.] 93.3%-98.6%) as compared to GKT which was 71.8% (95% C.I. 64.9%-78.7%) with the ratio of 1.309 (95% C.I. 1.217-1.409; P= <0.001). This superiority was sustained till the last follow up available in all the studies. Out of the complications common to both procedures, MVD had a lower rate of facial numbness, with a risk ratio of 0.481 (95% C.I. 0.297-0.778); and dysesthetic pain, with a risk ratio of 0.470 (95% C.I. 0.172-1.286). MVD seems to be more efficacious than GKT as a first line treatment for trigeminal neuralgia immediately as well as on a long term basis. However, the dilemma regarding the choice of treatment to be adopted still remains for special subgroups of patients, like the elderly patients and those in whom no vascular compression has been found during surgery. Further studies are needed for elucidating the unequivocal treatment plan under these circumstances.

SU‐F‐J‐160: Clinical Evaluation of Targeting Accuracy in Radiosurgery Using Tractography

Purpose:Focal radiosurgery is a common treatment modality for trigeminal neuralgia (TN), a neuropathic facial pain condition. Assessment of treatment effectiveness is primarily clinical, given the paucity of investigational tools to assess trigeminal nerve changes. The efficiency of radiosurgery is related to its highly precise targeting. We assessed clinically the targeting accuracy of radiosurgery with Gamma knife. We hypothesized that trigeminal tractography provides more information than 2D‐MR imaging, allowing detection of unique, focal changes in the target area after radiosurgery.Methods:Sixteen TN patients (2 females, 4 males, average age 65.3 years) treated with Gamma Knife radiosurgery, 40 Gy/50% isodose line underwent 1.5Tesla MR trigeminal nerve. Target accuracy was assessed from deviation of the coordinates of the target compared with the center of enhancement on post MRI. Radiation dose delivered at the borders of contrast enhancement was evaluated.Results:The median deviation of the coordinates between the intended target and the center of contrast enhancement was within 1mm. The radiation doses fitting within the borders of the contrast enhancement the target ranged from 37.5 to 40 Gy. Trigeminal tractography accurately detected the radiosurgical target. Radiosurgery resulted in 47% drop in FA values at the target with no significant change in FA outside the target, suggesting that radiosurgery primarily affects myelin. Tractography was more sensitive, since FA changes were detected regardless of trigeminal nerve enhancement.Conclusion:The median deviation found in clinical assessment of gamma knife treatment for TN Is low and compatible with its high rate of efficiency. DTI parameters accurately detect the effects of focal radiosurgery on the trigeminal nerve, serving as an in vivo imaging tool to study TN. This study is a proof of principle for further assessment of DTI parameters to understand the pathophysiology of TN and treatment effects.

Variegated treatment modalities for trigeminal neuralgia

Variegated treatment modalities for trigeminal neuralgia

SU‐E‐J‐34: Clinical Evaluation of Targeting Accuracy and Tractogrphy Delineation of Radiosurgery

Purpose:Focal radiosurgery is a common treatment modality for trigeminal neuralgia (TN), a neuropathic facial pain condition. Assessment of treatment effectiveness is primarily clinical, given the paucity of investigational tools to assess trigeminal nerve changes. The efficiency of radiosurgery is related to its highly precise targeting. We assessed clinically the targeting accuracy of radiosurgery with Gamma knife. We hypothesized that trigeminal tractography provides more information than 2D‐MR imaging, allowing detection of unique, focal changes in the target area after radiosurgery.Methods:Sixteen TN patients (2 females, 4 male, average age 65.3 years) treated with Gamma Knife radiosurgery, 40 Gy/50% isodose line underwent 1.5Tesla MR trigeminal nerve . Target accuracy was assessed from deviation of the coordinates of the target compared with the center of enhancement on post MRI. Radiation dose delivered at the borders of contrast enhancement was evaluatedResults:The median deviation of the coordinates between the intended target and the center of contrast enhancement was within 1mm. The radiation doses fitting within the borders of the contrast enhancement the target ranged from 37.5 to 40 Gy. Trigeminal tractography accurately detected the radiosurgical target. Radiosurgery resulted in 47% drop in FA values at the target with no significant change in FA outside the target, suggesting that radiosurgery primarily affects myelin. Tractography was more sensitive, since FA changes were detected regardless of trigeminal nerve enhancementConclusion:The median deviation found in clinical assessment of gamma knife treatment for TN Is low and compatible with its high rate of efficiency. DTI parameters accurately detect the effects of focal radiosurgery on the trigeminal nerve, serving as an in vivo imaging tool to study TN. This study is a proof of principle for further assessment of DTI parameters to understand the pathophysiology of TN and treatment effects

Tractography Delineates Microstructural Changes in the Trigeminal Nerve after Focal Radiosurgery for Trigeminal Neuralgia

PurposeFocal radiosurgery is a common treatment modality for trigeminal neuralgia (TN), a neuropathic facial pain condition. Assessment of treatment effectiveness is primarily clinical, given the paucity of investigational tools to assess trigeminal nerve changes. Since diffusion tensor imaging (DTI) provides information on white matter microstructure, we explored the feasibility of trigeminal nerve tractography and assessment of DTI parameters to study microstructural changes after treatment. We hypothesized that trigeminal tractography provides more information than 2D-MR imaging, allowing detection of unique, focal changes in the target area after radiosurgery. Changes in specific diffusivities may provide insight into the mechanism of action of radiosurgery on the trigeminal nerve.Methods and MaterialsFive TN patients (4 females, 1 male, average age 67 years) treated with Gamma Knife radiosurgery, 80 Gy/100% isodose line underwent 3Tesla MR trigeminal nerve tractography before and sequentially up to fourteen months after treatment. Fractional anisotropy (FA), radial (RD) and axial (AD) diffusivities were calculated for the radiosurgical target area defined as the region-of-interest. Areas outside target and the contralateral nerve served as controls.ResultsTrigeminal tractography accurately detected the radiosurgical target. Radiosurgery resulted in 47% drop in FA values at the target with no significant change in FA outside the target, demonstrating highly focal changes after treatment. RD but not AD changed markedly, suggesting that radiosurgery primarily affects myelin. Tractography was more sensitive than conventional gadolinium-enhanced post-treatment MR, since FA changes were detected regardless of trigeminal nerve enhancement. In subjects with long term follow-up, recovery of FA/RD correlated with pain recurrence.ConclusionsDTI parameters accurately detect the effects of focal radiosurgery on the trigeminal nerve, serving as an in vivo imaging tool to study TN. This study is a proof of principle for further assessment of DTI parameters to understand the pathophysiology of TN and treatment effects.

The role of peripheral glycerol injection in the management of trigeminal neuralgia

Study ObjectivesTo evaluate the efficacy of glycerol injection in controlling neuralgic pain distributed in peripheral branches of trigeminal nerve, the reversibility of the lost sensory function of the nerve and also to evaluate the morbidity associated with this procedure. MethodTen randomly selected diagnosed patients of trigeminal neuralgia of either sex were given glycerol injection in the peripheral branches of trigeminal nerve. Patients were followed up for next 1 year at monthly intervals and intensity of their pain was assessed. ResultThe time period of pain relief after glycerol injection in the trigeminal nerve was 20–56 weeks (mean duration of pain relief was 41 weeks). The mean period for return of sensory functions after glycerol injection was 3.7 weeks. There was no morbidity in any patient. ConclusionPeripheral glycerol injection can be used as one of the treatment modalities for trigeminal neuralgia. Although recurrence rate after peripheral glycerol injection may be like any other peripheral surgical procedures, but the ease in performing this procedure, early return of lost sensations and faster onset of pain relief with minimal complications makes it a worthwhile choice.

Biplane Fluoroscopy Guided Maxillary Nerve Block and Pulsed Radiofrequency Lesioning of the Mandibular Nerve -A report of two cases-

Biplane fluoroscopy is usually used in angiography. Biplane fluoroscopy gives a biplane image with high resolution during the performance of operations. Trigeminal nerve blocks are effective treatment modalities for trigeminal neuralgia, and maxillary nerve block is the most dangerous procedure among them. The anatomic structures can change after head and neck surgery, so the trigeminal nerve block procedures cannot be done so easily. We used biplane fluoroscopy in these difficult cases. Our first case was a 60-year-old man who had undergone maxillary nerve block. The second case was of a 64-year-old man who had pulsed radiofrequency lesioning of mandibular nerve performed after head and neck surgery. With biplane fluoroscopy, we got good results without any complications.