Recurrent Trigeminal Neuralgia Research Articles

Technical Nuances in Surgery for Recurrent Trigeminal Neuralgia

Technical Nuances in Surgery for Recurrent Trigeminal Neuralgia

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.

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.

Comparative safety and efficacy of percutaneous radiofrequency thermocoagulation and percutaneous balloon compression in CT-guided and local anesthesia for recurrent trigeminal neuralgia.

There are several ways to treat trigeminal neuralgia (TN); however, TN may recur after treatment. Although microvascular decompression (MVD) is considered an effective treatment for trigeminal neuralgia, patients with recurrence may not be willing to undergo craniotomy. This study compared the safety and efficacy of percutaneous radiofrequency thermocoagulation and percutaneous balloon compression for treating recurrent trigeminal neuralgia. This was a prospective non-randomized controlled study. A total of 52 with recurrent TN were scheduled to undergo surgery in our Hospital from January-June 2021. The patients were classified into percutaneous radiofrequency thermocoagulation (PRT) and percutaneous balloon compression (PBC) groups based on the treatment. All surgeries were performed under computed tomography guidance and local anesthesia. Post-operative complications were also observed. Pain was assessed using the visual analog scale (VAS) and Barrow Neurological Institute (BNI) scale. Efficacy indices were evaluated at 3, 6, 12, and 18 months after surgery. During follow-up, the efficacy rates of the two methods within 18 months were 76.0 and 88.9%, respectively. All patients had hypoesthesia on the affected side, and no severe complications. Notably, 5 patients (20%) in the PRT group with multiple-branch pain, including the first branch of the trigeminal nerve (V1) pain in the PRT group, received radiofrequency therapy for the supraorbital notch (foramen) after puncture of the foramen ovale. However, multiple pain episodes resolved with only one operation in the PBC group. CT-guided percutaneous radiofrequency thermocoagulation and percutaneous balloon compression under local anesthesia may be good options for treating recurrent trigeminal neuralgia. Percutaneous balloon compression may be recommended when multiple branches are involved, particularly in cases of V1 neuralgia.

Transposition versus interposition method in microvascular decompression for trigeminal neuralgia: midterm analysis of both techniques in a single-center study.

Operative interposition of material between the trigeminal nerve and offending artery for surgical treatment of drug-resistant trigeminal neuralgia (TGN), following the Jannetta method, has been proven to be the most successful invasive treatment. Reexplorations of patients with recurrence of TGN have revealed nerve root irritations and scarring due to interposed material. To prevent these complications, modifications of microvascular decompression (MVD) aim at transposing the vessel away from the trigeminal nerve, without attachment of additional material to the nerve root. Given that both techniques (interposition and transposition) have been performed in the authors' institution, they decided to analyze them for the short- and midterm outcomes. All patients who had undergone MVD for drug-resistant TGN in the authors' institution between 2008 and 2022 were analyzed retrospectively. Outcome at discharge and follow-up was evaluated using the Barrow Neurological Institute pain intensity score. Additionally, complications and pain recurrence were assessed. A total of 114 patients were operated on using transposition and 110 patients were treated using interposition. For transposition 102 patients were followed up for a median of 31.5 months, and for interposition 100 patients were followed up for a median of 95 months. At discharge 92.1% versus 94.5% of patients in the transposition and interposition groups, respectively, experienced a good outcome (Barrow Neurological Institute pain intensity scores I-III). At follow-up, 83.3% versus 85% of patients in the transposition and interposition groups, respectively, continued to demonstrate a good outcome. In 4.9% of patients in the transposition group and in 6% of patients in the interposition group, recurrence of pain occurred. Complications occurred in 24.6% of patients in the transposition and in 27.3% of those in the interposition group. The most frequent complications were facial hypesthesia (10.5% vs 11.8%, transposition vs interposition), followed by CSF leaks (2.6% vs 8.2%). Transposition for MVD is an elegant way of solving vessel-nerve conflicts at the cerebellopontine angle. Similar to interposition, transposition shows positive short- and midterm outcomes for patients experiencing drug-resistant TGN. However, the main objective of transposition, which is improved prevention of recurrence and reduction of complications at the trigeminal nerve, could not be confirmed in this study.

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.

Fully endoscopic microvascular decompression for the treatment of hemifacial spasm, trigeminal neuralgia, and glossopharyngeal neuralgia: a retrospective study

BackgroundMicrovascular decompression (MVD) is already the preferred surgical treatment for medically refractory neurovascular compression syndromes (NVC) such as hemifacial spasm (HFS), trigeminal neuralgia (TN), and glossopharyngeal neuralgia (GPN). Endoscopy has significantly advanced surgery and provides enhanced visualization of MVD. The aim of this study is to analyze the efficacy and safety of fully endoscopic microvascular decompression (E-MVD) for the treatment of HFS, TN, and GPN, as well as to present our initial experience.Materials and methodsThis retrospective case series investigated fully E-MVD performed in 248 patients (123 patients with HFS, 115 patients with TN, and 10 patients with GPN ) from December 2008 to October 2021 at a single institution. The operation duration, clinical outcomes, responsible vessels, intra- and postoperative complications, and recurrences were recorded. Preoperative and immediate postoperative magnetic resonance imaging (MRI) and computerized tomography (CT) were performed for imageological evaluation. The Shorr grading and Barrow Neurological Institute (BNI) pain score were used to evaluate clinical outcomes. The efficacy, safety, and risk factors related to the recurrence of the operation were retrospectively analysed, and the surgical techniques of fully E-MVD were summarised.ResultsA total of 248 patients (103 males) met the inclusion criteria and underwent fully E-MVD were retrospectively studied. The effective rate of 123 patients with HFS was 99.1%, of which 113 cases were completely relieved and 9 cases were significantly relieved. The effective rate of 115 patients with TN was 98.9%, of which 105 cases had completely pain relieved after surgery, 5 cases had significant pain relieved, 4 cases had partial pain relieved but still needed to be controlled by medication. The effective rate of 10 patients with GPN was 100%, 10 cases of GPN were completely relieved after surgery. As for complications, temporary facial numbness occurred in 4 cases, temporary hearing loss in 5 cases, dizziness with frequent nausea and vomiting in 8 cases, headache in 12 cases, and no cerebral hemorrhage, intracranial infection, and other complications occurred. Follow-up ranged from 3 to 42 months, with a mean of 18.6 ± 3.3 months. There were 4 cases of recurrence of HFS and 11 cases of recurrence of TN. The other effective patients had no recurrence or worsening of postoperative symptoms. The cerebellopontine angle (CPA) area ratio (healthy/affected side), the length of disease duration, and the type of responsible vessels are the risk factors related to the recurrence of HFS, TN, and GPN treated by fully E-MVD.ConclusionsIn this retrospective study, our results suggest that the fully E-MVD for the treatment of NVC such as HFS, TN, and GPN, is a safe and effective surgical method. Fully E-MVD for the treatment of NVC has advantages and techniques not available with microscopic MVD, which may reduce the incidence of surgical complications while improving the curative effect and reducing the recurrence rate.

Percutaneous balloon compression for trigeminal neuralgia due to the primitive trigeminal artery: A case report and review of the literature

Trigeminal neuralgia (TN) is often caused by vascular compression of the trigeminal nerve cisternal segment. TN due to the primitive trigeminal artery formed by developmental variants of cerebral vessels is rare. We report here a 59-year-old male with TN whose preoperative MRI showed a primitive trigeminal artery that compressed the trigeminal nerve, and microvascular decompression (MVD) was performed to separate the vessel from the trigeminal nerve cisternal segment. The pain was relieved after MVD, but it recurred two months later. MRI reexamination showed that although MVD relieved the vascular compression of the trigeminal nerve cisternal segment, the nerve in the Meckel’s cave was still compressed by PTA, which was thought to be the cause of TN recurrence. Due to the limitations of the surgical microscope view, completing the vascular decompression at the Meckel’s cave is challenging. So percutaneous balloon compression was performed. After the procedure, the TN subsided. The patient remained pain free at one year follow-up. To our knowledge, this is the first case of primitive trigeminal artery-associated TN treated by percutaneous balloon compression. This case suggests that percutaneous balloon compression may be considered for TN caused by compression of the primitive trigeminal artery when MVD is difficult to perform.

White epidermoid cyst transformation after stereotactic radiosurgery: illustrative case.

White epidermoid cysts (WECs) are a rare type of epidermoid cyst with atypical radiological features. The epidemiological aspects and mechanisms of their onset remain unknown. Herein, the authors report a unique case of WEC transformation from a typical epidermoid cyst after stereotactic radiosurgery (SRS), confirmed by radiological and pathological findings. The case involved a 78-year-old man with a history of 2 surgeries for a left cerebellopontine angle typical epidermoid cyst 23 years earlier and SRS using the CyberKnife for recurrent trigeminal neuralgia (TN) 14 years earlier. The tumor with high intensity on T1-weighted imaging, low intensity on T2-weighted imaging, without restriction on diffusion-weighted imaging had gradually enlarged after SRS. Therefore, a salvage surgery was performed via a left suboccipital craniotomy, and the intraoperative findings showed a cyst with a brown, viscous liquid component, consistent with those of WECs. Histopathologically, keratin calcification and hemorrhage were identified, leading to a diagnosis of WEC. The postoperative course was uneventful, and the TN resolved. No tumor recurrence was recorded at 2 years postoperatively. To the best of the authors' knowledge, this is the first world case of WEC transformation from a typical epidermoid cyst after SRS, confirmed by radiological and pathological findings. Radiation effects could have been involved in this transformation.

Radiosurgery in recurrent trigeminal neuralgia secondary to Multiple Sclerosis: A prospective clinical research study

Radiosurgery in recurrent trigeminal neuralgia secondary to Multiple Sclerosis: A prospective clinical research study

Radiofrequency Ablation for Trigeminal Neuralgia Patient: A Case Report

Introduction: Radiofrequency ablation is the most commonly used percutaneous procedure to treat trigeminal neuralgia. This therapy is less invasive, safe, and provides immediate results and minimal side effects. This study aims to demonstrate the potential of radiofrequency ablation in the management of trigeminal neuralgia pain.
 Case presentation: A 64-year-old man with recurrent trigeminal neuralgia was treated with radiofrequency ablation at Hasanuddin University Hospital. The patient had previously received radiofrequency ablation at the same site as now, and the patient was pain-free for up to three years. After the procedure, complaints of pain gradually subsided for two months until the patient felt pain-free.
 Conclusion: Radiofrequency ablation is a minimally invasive alternative treatment for chronic pain that is not controlled by pharmacotherapy, such as trigeminal neuralgia. Good knowledge of anatomy and imaging techniques is required for successful therapy. In this patient, the radiofrequency ablation procedure was quite successful, characterized by complaints of pain which gradually subsided in two months until the patient felt pain-free.

Long-term outcomes and predictors of percutaneous radiofrequency thermocoagulation of Gasserian ganglion for maxillary trigeminal neuralgia: a retrospective analysis of 1070 patients with minimum 2-year follow-up

Objective To estimate long-term efficacy and safety for maxillary trigeminal neuralgia (TN) using radiofrequency thermocoagulation (RFT) targeted on Gasserian ganglion, and to identify the factors which may influence outcomes after procedure. Methods From 2006 to 2019, 1070 patients underwent RFT for the treatment of medically refractory maxillary TN was included. All patients were followed up for at least 2 years. Outcomes and complications were recorded and analysed. Logistic regression analysis was employed to identify risk factors of long-term pain recurrence. Prognostic value was calculated from receiver-operating characteristic curve (ROC). Results Longitudinal analysis was taken place for 97 non-responders (9.1%) with ineffective pain relief, 253 responders (23.6%) with pain recurrence and 720 responders (67.3%) without pain recurrence. The median pain-free survival (PFS) was 112.0 months (95% CI: 107.5, 116.5). The pain-free rates were 89.9% (95% CI: 88.0–91.8%) at 1 year, 83.8% (95% CI: 81.5–86.1%) at 2 years, 75.4% (95% CI: 72.7–78.1%) at 5 years and 70.2% (95% CI: 67.4–73.0%) at 10 years. Atypical facial pain (HR = 5.373, 95% CI: 2.623–11.004, p < .001), previous facial numbness (HR = 5.224, 95% CI: 3.107–8.784, p < .001) and poor initial response to medication (HR = 3.185, 95% CI: 2.087–4.860, p < .001) were independently associated with long-term pain recurrence. Patients with prognostic index (PI) > 0.25 were identified as high-risk for recurrent TN (HR = 5.575, 95% CI: 3.991–7.788, p < .001). New and worsen facial hypoesthesia was recorded in 77.9% of patients corresponding with BNI score II–IV, and 18.7% reported improved sensation. Severe complication incidence including troublesome dysesthaesia, keratitis and masseter weakness was higher in 80 °C group. Conclusions Favourable outcomes were achieved in terms of long-term pain relief and complications rate after RFT for maxillary TN. Patients with typical facial pain, normal facial sensation, and good initial response to medications may have favourable long-term outcomes. Key messages This is a retrospective analysis of radiofrequency thermocoagulation (RFT) targeted on Gasserian ganglion for the treatment of maxillary trigeminal neuralgia (TN) during long-term follow-up. Recurrence-free survival among a large sample was assessed and risk factors associated with long-term pain recurrence was identified. It has been verified that inadvertent damage of ophthalmic and mandibular division causes ophthalmic and masticatory complications. Therefore, a more precise needle tip position and thermocoagulation using a relatively low temperature was recommended.

Predictors of response for percutaneous balloon compression for the treatment of recurrent trigeminal neuralgia following surgical procedures: a retrospective study.

Recurrent trigeminal neuralgia (TN) after surgical procedures can be rather difficult to treat, and standardized treatment measures are not available yet. It is unclear whether percutaneous balloon compression (PBC) can be used as the preferred surgical treatment for postoperative recurrent TN. To determine the efficacy of PBC and identify the predictors of response of PBC for the treatment of recurrent TN following TN-related surgeries, we retrospectively collected and analyzed the data of patients with recurrent TN following surgical treatments who underwent PBC under three-dimensional computed tomography (3D-CT) guidance at the Department of Pain Management of Beijing Tiantan Hospital, Capital Medical University from January 2018 to January 2022. We found, within 1month after PBC, that the total efficacy of PBC on recurrent TN following TN-related surgeries was 86.7%. Based on the effectiveness of PBC 1month postoperatively, patients were divided into the effective group (130, 86.7%) and the ineffective group (20, 13.3%). Fourteen (10.8%) patients in the effective group had undergone RFT before, which was significantly lower than that in the ineffective group (6, 30%, p = 0.02). Multivariate logistic regression analysis showed that previous RFT alone (OR = 0.20, 95%CI 0.06-0.66, P = 0.01) was an independent predictor of the negative response of PBC. Thus, PBC was found to be a moderately effective and safe treatment for recurrent TN after TN-related surgery. However, previous RFT procedures may predict a slightly worse outcome after PBC.

Extracranial Radiofrequency Treatment for Painful Tic Convulsif Syndrome Under Local Anesthesia.

IntroductionPainful tic convulsif syndrome is ipsilateral facial trigeminal neuralgia combined with hemifacial spasm, which is relatively rare in the clinic. Microvascular decompression is currently considered to be an effective treatment. We report extracranial radiofrequency treatment of painful tic convulsif syndrome under local anesthesia, a technique which provides a safer and more economical treatment for this kind of patient.Case PresentationWe report a case of painful tic convulsif syndrome which was treated with extracranial radiofrequency therapy of the trigeminal nerve and facial nerve. After operations, the symptoms of pain and spasm were relieved immediately, but the right facial numbness and facial paralysis (House–Brackmann grade III) were left. The facial paralysis was completely relieved after 3 months of follow-up, and there was no recurrence of trigeminal neuralgia or hemifacial spasm after 35 months.DiscussionPainful tic convulsif syndrome is a combination of ipsilateral facial trigeminal neuralgia and hemifacial spasm, which is relatively rare in the clinic. So far, only one treatment method of microvascular decompression has been reported for the disease. We report the first case of CT-guided extracranial radiofrequency therapy for painful tic convulsif syndrome.ConclusionExtracranial radiofrequency therapy can provide safe and economical treatment for patients with painful tic convulsif syndrome.

Factors that may affect recurrence of trigeminal neuralgia after percutaneous balloon compression

ObjectiveTo investigate the efficacy of percutaneous balloon compression of the Gasserian Ganglion (PCGG) in the treatment of trigeminal neuralgia(TN)and the influencing factors of recurrence after PCGG. MethodsThe clinical data of 221 patients with TN treated by PCGG were retrospectively analyzed and followed-up to explore the postoperative efficacy. ResultsThere were 158 cases of immediate disappearance of pain and 59 cases of delayed pain disappearance in patients after one PCGG operation, for an overall efficacy rate of 98.2%. Forty-nine patients experienced recurrence of pain, for a recurrence rate of 22.6%, and average recurrence time of 18 months. The effective rate of medication in patients with recurrent trigeminal neuralgia is 85.7%.Univariate and multivariate logistic regression analyses showed that hypertension disease and delayed pain disappearance were independent factors for recurrence. The incidence of inhibitory reaction of the trigeminal nerve during the operation was 97.3%. The most common postoperative complications were facial numbness, masticatory-muscle weakness, tinnitus, diplopia and keratitis, which occurred at rates of 76.9%, 28.1%, 14.5%, 11.8% and 10.4%, respectively. All of the complications resolved within 3 years after PCGG. ConclusionsPCGG is a safe and effective surgical method for the treatment of TN. The pain in most patients disappeared after surgery, leaving sequelae such as facial numbness, masticatory-muscle weakness and tinnitus. The mean time to recurrence of postoperative pain was 18 months, with hypertension disease and delayed pain disappearance as associated factors.

Treatment of redo-microvascular decompression or internal neurolysis plus microvascular decompression for recurrent trigeminal neuralgia: a review of long-term effectiveness and safety.

ObjectiveWe examined the clinical characteristics and outcomes of patients with recurrent trigeminal neuralgia (TN) and assessed the long-term efficacy and safety of microvascular decompression (MVD) to treat typical recurrent TN.MethodsWe identified 3024 patients who underwent MVD for treatment of TN at the China-Japan Friendship Hospital from March 2009 to December 2020. We retrospectively analyzed the data and outcomes of 137 patients who underwent redo-MVD and 74 patients who did not undergo redo-MVD as the control group. These outcomes were evaluated using the Barrow Neurological Institute scoring system.ResultsRecurrence in 68 of the 137 patients was due to incomplete or absent decompression or new responsible vessels. To ensure thorough pain relief, redo-MVD should include decompression of both the trigeminal root entry zone and the peripheral nerve segments, where blood vessels can cause symptoms. Factors associated with reduced effectiveness of redo-MVD were no period of initial pain relief after the first MVD and a longer duration of symptoms before the first MVD.ConclusionsRedo-MVD should not be excluded as a treatment option for patients with refractory TN who develop recurrent pain after a first MVD procedure.

190 Brain Structural MRI Predicts Outcome of Radiosurgical Treatment in Trigeminal Neuralgia

INTRODUCTION: Growing evidence supports the role of the central nervous system (CNS) in the modulation of pain in trigeminal neuralgia (TN) patients. METHODS: Thirty patients with idiopathic or classic TN, who underwent GKSRS and were followed for at least 24 months, were retrospectively included. Pre-treatment structural MRI and pre- and serial, post-operative clinical features were investigated. Fifteen age- and sex-matched healthy controls were also enrolled. Cortical thickness and gray matter (GM) volumes were assessed in TN patients relative to controls, as well as between patient subgroups according to treatment outcomes (initial responders/non-responders, patients with pain recurrence/long-lasting pain relief at the last follow-up). Clinical and MRI predictors of treatment outcomes were explored. RESULTS: Cortical thinning of temporal, prefrontal, cingulate, somatosensory and occipital areas bilaterally was found in TN patients relative to controls. No cortical thickness and GM volume differences were observed when TN initial responders and non-responders were compared. Patients who experienced TN recurrence after initial pain relief were characterized by thicker parahippocampal and temporal cortices bilaterally and greater volume of right amygdala and hippocampus compared to patients with long-lasting pain relief. In TN patients, disease duration and baseline cortical thinning of right parahippocampal, left fusiform and middle temporal cortices were associated with poor outcome after GKSRS at the last follow-up (R2 = 0.57, p &lt; 0.001). CONCLUSION: The study provides novel insights into structural brain alterations of TN patients, which might contribute to disease development and pain maintenance.

Can fifth nerve mapping guide rhizotomy for recurrent trigeminal neuralgia? Case report

IntroductionMicrovascular decompression (MVD) is usually considered the first-line treatment for trigeminal neuralgia (TN) when medical treatments fail. Recurrence is rare and best treatment option is controversial. MVD was proposed as a feasible and effective technique for recurrent TN by many authors. Nevertheless, in a substantial number of cases, not any impingement or deterioration are found intraoperatively and partial selective rhizotomy is then advised. The rhizotomy site is mostly guided by anatomical landmarks, but variations due to scarring and adhesions are common pitfalls in these second surgeries. Intraoperative monitoring is infrequently used during MVD for trigeminal neuralgia. We describe the use of nerve mapping in a case of recurrence, revealing an unexpected rootlet distribution and thus safely guiding partial rhizotomy. Clinical presentationA 53-year-old woman had suffered from bilateral trigeminal neuralgia for 10 years. Symptoms began on the right side. MVD resolved her symptoms but, after a few months, she developed left TN which persisted after left MVD, radiofrequency and radiosurgery. She was referred to our center for a second MVD on the left side. Intraoperative inspection detected no relevant findings, and nerve mapping followed by partial selective rhizotomy was performed. Complete pain relief was achieved. There were no complications. ConclusionRhizotomy is seldom employed for refractory trigeminal neuralgia. The effects of previous treatments can jeopardize anatomical landmarks. Nerve mapping seems a promising tool to improve results.

Letter to the Editor. Repeated Gamma Knife radiosurgery for recurrent trigeminal neuralgia: is it the next over-the-counter treatment?

"Letter to the Editor. Repeated Gamma Knife radiosurgery for recurrent trigeminal neuralgia: is it the next over-the-counter treatment?" published on 13 Aug 2021 by American Association of Neurological Surgeons.