Surgery For Trigeminal Neuralgia Research Articles

Different scale, different pain? Discordant pain measurements after surgery for trigeminal neuralgia

Trigeminal neuralgia (TN) has been described as one of the worst pains known to humankind. However, pain severity in TN has been measured using several different scales, resulting in difficulty comparing illness burden and response to TN surgery across studies. We examined the degree of concordance between standardized scales evaluating pain severity in a cohort of patients undergoing surgery for TN. In this cross-sectional study, we evaluated 39 surgical TN patients with three pain measurement instruments: a Visual Analog Pain Scale (VAS), the Brief Pain Inventory-Facial Pain (BPI-F), and the Barrow Neurological Institute Pain Intensity Score (BNI). Scores were transformed into a 0-10 scale, and grouped into five severity categories (none, mild, moderate, severe, worst). Discordant patients were those classified in different severity categories by at least two pain measurement instruments. Level of agreement was assessed with the intraclass correlation coefficient (ICC). Almost 50% of patients (18/39) had at least one categorical discordance when comparing all three scores. We found 30% discordance between VAS and BPI-F, 33% discordance between BPI-F and BNI, and 35% discordance between VAS and BNI. The highest degree of discordance between BNI and either VAS or BPI-F occurred in patients with moderate pain (BNI IIIb). The degree of agreement across all three scores was moderate (ICC = 0.72). TN patients with residual mild-moderate pain after surgery are often discordantly classified by different pain measurement scales. These findings argue for a more standardized method of reporting port-operative pain outcomes in the TN literature.

Abnormal electromyographical trigeminal activation through stimulation of the offending artery (Z-L response): An intraoperative tool during microvascular decompression for trigeminal neuralgia.

There are currently no intraoperative neurophysiological tools to assess the effectiveness of trigeminal nerve decompression during microvascular decompression surgery for drug-resistant trigeminal neuralgia. In microvascular decompression surgery for hemifacial spasm, an abnormal electromyographic activation of facial muscles after stimulation of the offending vessel was identified and named 'Z-L response'. We adapted a neurophysiological protocol to elicit a Z-L response during microvascular decompression surgery for trigeminal neuralgia and applied it to a prospective series of 18 surgical patients. Patients had suffered from trigeminal neuralgia for a median 9-year timeframe, and median preoperative Barrow Neurological Institute pain score was 4.5. Through monopolar stimulation, using rising amplitudes starting from 0.1 mA, we confirmed intraoperatively the true culprit vessel before decompression. In 4/18 cases, multiple offending vessels were identified (22 conflicts overall). After decompression, a significant increase in activation threshold (p < 0.0001) confirmed the effectiveness of the maneuver; in 10 cases, Z-L response was abolished. Using this technique, we obtained excellent or good outcome (Barrow Neurological Institute 1-3) in all patients, with a significant reduction in postoperative Barrow Neurological Institute score as compared with preoperative one (median Barrow Neurological Institute 1; p = 0.0002). we provide the first evidence on the applicability and clinical usefulness of Z-L response during microvascular decompression surgery for trigeminal neuralgia.

Comparison of Remimazolam and Propofol for Intravenous Anesthesia on Trigeminocardiac Reflex in Percutaneous Balloon Compression for Trigeminal Neuralgia: A Randomized Controlled Trial.

Trigeminal neuralgia usually presents as incapacitating facial pain. Percutaneous balloon compression (PBC) is frequently utilized to manage this ailment. Trigeminocardiac reflex (TCR) commonly presents with sudden severe bradycardia or even asystole, alongside a sudden increase in blood pressure during this surgical procedure. Notably, remimazolam has been reported to maintain higher heart rate (HR) levels during anesthesia than propofol. Thus, this study aims to assess the impact of remimazolam anesthesia versus propofol on TCR occurrence during this procedure. This randomized controlled trial involved patients with trigeminal neuralgia scheduled for elective PBC. Patients were randomly assigned to receive either remimazolam or propofol for anesthesia. The primary outcome was the incidence of TCR, a potential complication during the procedure. Secondary outcomes included the occurrence of severe TCR, usage of atropine, HR at the time of foramen ovale puncture (T4), HR at the time of trigeminal ganglion compression (T5), and any adverse events. A total of 80 patients were included in the study, with 40 patients in each group. The incidence of TCR was significantly lower in the remimazolam group compared to the propofol group (30.0% vs 82.5%; risk difference -52.5%, 95% CI -67.3% to -18.6%; P < 0.001). The remimazolam group also showed a lower incidence of severe TCR (7.5% vs 45.0%) and significantly lower usage of atropine compared to the propofol group (P < 0.001). Furthermore, HR at T4 and T5 were higher in the remimazolam than in the propofol group (P < 0.001). There was no significant difference in the incidence of adverse events between the two groups. In PBC surgery for trigeminal neuralgia, remimazolam-based intravenous anesthesia showed a higher HR and a lower incidence of TCR than propofol without any increased adverse events.

Intra-operative hypertension as a predictor of surgical outcomes in microvascular decompression surgery for trigeminal neuralgia

PurposeThe trigeminocardiac reflex (TCR) has traditionally been characterized by a sudden decrease in heart rate, asystole, or hypotension during the manipulation of the trigeminal nerve (MTN) or its branches. While this classical TCR is well-documented, there is limited literature on alternative forms of TCR, such as the development of intraoperative hypertension (HTN) or tachycardia, and the underlying pathogenesis. Furthermore, a gap exists in understanding the correlation between intraoperative blood pressure readings and postoperative outcomes, particularly regarding pain relief in patients with trigeminal neuralgia (TN). Our study aims to examine intraoperative blood pressure trends during microvascular decompression (MVD) for TN and assess their impact on postoperative outcomes.MethodsWe selected 90 patients who underwent MVD for TN treatment. Blood pressure and heart rate were recorded both preoperatively and during the procedure, specifically during the MTN period, using an arterial line. The Barrow Neurological Institute (BNI) Pain Scale was calculated for all patients both pre- and post-operatively to evaluate pain relief after surgery.ResultsThe mean age of the patients was 61.0 ± 12.35 years, with 64.4% being females. Classical TCR (hypotension) was observed in only 2.2% of patients, whereas 80% of patients developed hypertension (≥ 140/90) during MTN. The mean preoperative systolic blood pressure was 128 ± 22.25, and the mean intraoperative systolic blood pressure during MTN was 153.1 ± 20.2. An analysis of covariance, utilizing either preoperative BNI or duration of symptoms as covariate variables, revealed a statistically significant association between intraoperative HTN and postoperative BNI. A linear regression model demonstrated that intraoperative HTN following MTN significantly predicted a lower postoperative BNI score (p = 0.006).ConclusionsIntraoperative HTN during MTN, an observed yet underexplored phenomenon, demonstrated a correlation with improved postoperative outcomes. Furthermore, it is recommended to conduct additional investigations into potential neurovascular conflicts in patients not manifesting intraoperative HTN following MTN. A comprehensive understanding of TCR, encompassing its various forms, is vital for optimizing surgical management. This study underscores the imperative for further research to unravel the mechanisms linking intraoperative HTN to surgical outcomes in TN patients.

Proteomic Analysis to Identify Prospective Biomarkers of Treatment Outcome After Microvascular Decompression for Trigeminal Neuralgia: A Preliminary Study

Trigeminal neuralgia (TN) is a severe neuropathic facial pain disorder, often caused by vascular or neuronal compression of the trigeminal nerve. In such cases, microvascular decompression (MVD) surgery can be used to treat TN, but pain relief is not guaranteed. The molecular mechanisms that affect treatment response to MVD are not well understood. In this exploratory study, we performed label-free quantitative proteomic profiling of plasma and cerebrospinal fluid samples from patients undergoing MVD for TN, then compared the proteomic profiles of patients graded as responders (n = 7) versus non-responders (n = 9). We quantified 1,090 proteins in plasma and 1,087 proteins in the cerebrospinal fluid, of which 12 were differentially regulated in the same direction in both sample types. Functional analyses of differentially regulated proteins in protein-protein interaction networks suggested pathways of the immune system, axon guidance, and cellular stress response to be associated with response to MVD. These findings suggest potential biomarkers of response to MVD, as well as possible mechanisms of variable treatment success in TN patients. PerspectiveThis exploratory study evaluates proteomic profiles in plasma and cerebrospinal fluid of patients undergoing microvascular decompression surgery for trigeminal neuralgia. Differential expression of proteins between surgery responders versus non-responders may serve as biomarkers to predict surgical success and provide insight into surgical mechanisms of pain relief in trigeminal neuralgia.

Standardized analysis for measuring long-term results in patients after trigeminal neuralgia surgery

ObjectiveTo emphasize the importance of patients’ actual subjective satisfaction with the outcome of surgery for trigeminal neuralgia (TGN) using a standardized analysis that combines pain relief and complications. MethodsNinety-four patients with TGN who underwent surgery and were followed up for 2–15 years (2006–2019) at Shiroyama Hospital, Osaka, Japan were enrolled. Patient subjective satisfaction was measured by evaluating the surgical results: the pain score (P) represented residual pain levels, ranging from P-0 (complete pain relief) to P-1, P-2, and P-3, wherein pain persisted in variable degrees. The complication score (C) ranged from C-0 (no complications after surgery) to C-1 and C-2 in which slight or problematic nerve dysfunction remained. The total surgical result for patient satisfaction (T) represented the summed P and C scores (T = P + C). ResultsAmong the 94 patients, 81 (86.2%) were categorized as having P-0. In 13 (13.8%) patients, the pain persisted with P-1, P-2, or P-3. In 14 (14.9%) patients, complications occurred at the C-1 or C-2 level. The analysis results revealed T-0 in 71 (75.5%), T-1 in 15 (15.9%), T-2 in 5 (5.3%), T-3 in 2 (2.1%), and T-4 in 1 (1. 1%) patient. ConclusionsA standardized analysis is crucial for evaluating the actual surgical results regarding patient satisfaction with microvascular decompression for refractory TGN. Based on our single-institute study with long-term follow-up, our method that combined separate outcomes for pain relief and complication occurrence into a single score effectively measured the actual subjective satisfaction of patients after surgery for TGN.

Sling technique in microvascular decompression surgery for trigeminal neuralgia: early experience and functional outcomes

BackgroundTrigeminal neuralgia (TGN) is a facial pain disorder often caused by arterial compression of the trigeminal nerve. Microvascular decompression (MVD) remains the most definitive treatment for this disorder, with a reported cure rate between 60 and 80%. MVD techniques often involve a retrosigmoid craniotomy with placement of an inert foreign material, such as Gore-Tex or Teflon, between the nerve and the compressing vessel.Recurrence of TGN after MVD has been associated with vessel migration and adhesion formation. In this study, we tested the use of Gore-Tex sling, fixed in place with fibrin glue to displace the compressing vessel away from the nerve.ResultsThis is a retrospective study including 20 patients who had an MVD for treatment of idiopathic TGN where a sling of Gore-Tex was used with the application of fibrin glue to prevent dislocation of the vessel. It showed that sling MVD technique is an effective method for treatment of classic trigeminal neuralgia. Eighteen patients improved within 2 weeks postoperatively. One patient had recurrence of symptoms and was reoperated 1 year later.ConclusionGore-Tex slinging technique is a safe simple technique for preventing re-dislocation of the offending vessel and thus recurrence of symptoms. However, larger series is needed to judge on the long-term efficacy and safety of this technique.

Multivariate models to predict pain recurrence and sensitive complications after percutaneous balloon compression in trigeminal neuralgia.

Percutaneous balloon compression (PBC) is a popular treatment option for trigeminal neuralgia. However, the efficacy of PBC is widely considered to be associated with the occurrence of sensitive complications, although neither this correlation nor the underlying mechanisms have been established. The objectives of the present study were to identify factors predicting time to pain recurrence after PBC and identify factors predicting a severe sensitive complication. The authors conducted a retrospective study on patients who underwent PBC for the first time between 1985 and 2019 in two French hospitals. Data were retrieved from patients' medical records. Potential clinical and radiological predictors for time to pain recurrence and severe sensitive complication were evaluated using a Cox model and a logistic regression, respectively. A total of 131 patients were included in the study, with a median follow-up of 3.0 years. Pain recurrence occurred in 77 patients, and the median time to pain recurrence was 2.0 years. In the multivariate analysis, six independent factors predicting pain recurrence were identified: 1) longer duration of presurgical symptoms; 2) localization of the pain along the mandibular branch of the trigeminal nerve (V3); 3) atypical pain; 4) diagnosis of multiple sclerosis; 5) use of a medical device not specifically adapted for trigeminal neuralgia surgery; and 6) duration of balloon compression > 60 seconds. Regarding the secondary objective, 26 patients presented a severe sensitive complication after PBC, which the authors defined as the development of a new sensitivity disorder of the cornea, deafferentation pain known as anesthesia dolorosa, and/or long-lasting hypoesthesia augmentation characterized by the new appearance or increase in size or intensity of an area of hypoesthesia in the face for at least 3 months. The only predictor associated with a severe sensitive complication in the multivariate analysis was compression duration > 60 seconds. These results show that the risk of postoperative complications can be assessed at the patient level, the most important modifiable parameter being the time of compression by the balloon. Although this study shows the relevance of a personalized medicine approach, its clinical application remains to be validated.

A single centre case series of microvascular decompression surgery for classical trigeminal neuralgia: functional outcomes and report of a unique conflict

BackgroundMicrovascular decompression surgery for trigeminal neuralgia is now considered the benchmark surgical procedure for intractable trigeminal neuralgia of any variety. The objective of this study is to share our experience in managing classical trigeminal neuralgia with microvascular decompression surgery looking into both immediate and late functional outcomes at 3 and 6 months post op. We also report a unique case of trigeminal neuralgia due to a tributary of the petrosal vein passing through the substance of the trigeminal nerve itself at its root entry zone.ResultsThis study included 20 patients; it showed that microvascular decompression surgery of the trigeminal nerve is an effective method for treatment of classic trigeminal neuralgia (p value < 0.001). The trigeminal root was compressed by the superior cerebellar artery in 75% of patients. A vein contributed to the compression in 45% of patients and was the only compressing vessel in 15%.ConclusionMicrovascular decompression surgery is the treatment of choice in patients with medically refractory trigeminal neuralgia, unless their general condition prohibits it. It’s also worth noting that the normal anatomy of the veins in this region is quite variable and the venous structures causing a neurovascular contact are more or less inconsistent. To the best of our knowledge and despite the wide range and progress in microvascular decompression surgery for trigeminal neuralgia, this is the first reported case in the literature for a neurovascular conflict caused by a vein passing through the trigeminal nerve itself.

Treatment Strategies for Different Types of Intraneural Offending Vessels in Microvascular Decompression Surgery for Trigeminal Neuralgia: An Analytic Report of 58 Cases.

Microvascular decompression (MVD) surgery is the treatment of choice for trigeminal neuralgia (TGN). However, decompression becomes difficult when the offending vessel penetrates the trigeminal nerve root. To estimate the rates and patterns of different types of intraneural offending vessels in patients with TGN for MVD and to discuss respective management strategies. All patients with TGN undergoing MVD in our center from January 1, 2015, to December 31, 2019, were analyzed retrospectively. The intraneural offending vessels included veins and arteries. The postoperative pain relief rate, complications, and recurrences were evaluated. Of the 302 TGN cases, the intraneural offending vessels were identified in 58 of the cases (19.2%). The 9 cases (15.5%) of intraneural offending arteries were decompressed using shredded Teflon wrapping interposition. Of the 49 cases (84.5%) of intraneural offending veins (INOVs), 29 were not considered true offending vessels, and the treatment only addressed the offending artery in these patients. Of the remaining 20 INOVs, 15 were electrocoagulated and divided, and 5 were decompressed with shredded Teflon. Complete pain relief was achieved in all 58 patients. However, the pain recurred in 5 patients (8.6%), and transient hemifacial numbness occurred in 4 patients (6.9%). Intraneural offending vessels requiring treatment are uncommon and are seen in less than 1 in 10 patients undergoing MVD for TGN. For intraneural offending artery, decompression by shredded Teflon wrapping interposition is recommended. Management of the INOV depends on the individual situations, and the management includes sacrifice, wrapping decompression, or leaving them untreated.

The thalamus in trigeminal neuralgia: structural and metabolic abnormalities, and influence on surgical response

BackgroundMedically-refractory trigeminal neuralgia (TN) can be treated successfully with operative intervention, but a significant proportion of patients are non-responders despite undergoing technically successful surgery. The thalamus is a key component of the trigeminal sensory pathway involved in transmitting facial pain, but the role of the thalamus in TN, and its influence on durability of pain relief after TN surgery, are relatively understudied. We aimed to test the hypothesis that variations in thalamic structure and metabolism are related to surgical non-response in TN.MethodsWe performed a longitudinal, peri-operative neuroimaging study of the thalamus in medically-refractory TN patients undergoing microvascular decompression or percutaneous balloon compression rhizotomy. Patients underwent structural MRI and MR spectroscopy scans pre-operatively and at 1-week following surgery, and were classified as responders or non-responders based on 1-year post-operative pain outcome. Thalamus volume, shape, and metabolite concentration (choline/creatine [Cho/Cr] and N-acetylaspartate/creatine [NAA/Cr]) were evaluated at baseline and 1-week, and compared between responders, non-responders, and healthy controls.ResultsTwenty healthy controls and 23 patients with medically-refractory TN treated surgically (17 responders, 6 non-responders) were included. Pre-operatively, TN patients as a group showed significantly larger thalamus volume contralateral to the side of facial pain. However, vertex-wise shape analysis showed significant contralateral thalamus volume reduction in non-responders compared to responders in an axially-oriented band spanning the outer thalamic circumference (peak p = 0.019). Further, while pre-operative thalamic metabolite concentrations did not differ between responders and non-responders, as early as 1-week after surgery, long-term non-responders showed a distinct decrease in contralateral thalamic Cho/Cr and NAA/Cr, irrespective of surgery type, which was not observed in responders.ConclusionsAtrophy of the contralateral thalamus is a consistent feature across patients with medically-refractory TN. Regional alterations in preoperative thalamic structure, and very early post-operative metabolic changes in the thalamus, both appear to influence the durability of pain relief after TN surgery.

Redo surgery for trigeminal neuralgia: reasons for re-exploration and long-term outcomes

To investigate the causes of failure and recurrence after microvascular decompression (MVD) for trigeminal neuralgia (TGN) and to analyze the results of redo surgery. Sixty-three cases of redo surgery were retrospectively reviewed. Reasons for re-exploration were categorized into 4 groups based on the operative findings. Patient characteristics, outcomes of re-exploration, and operative complications were analyzed by Kaplan-Meier and logistic regression analyses. Reasons for redo surgery were divided into arterial compression in 13 patients (21%), venous compression in 11 patients (17%), prosthesis-related in 25 patients (40%), and adhesion or negative exploration in 14 patients (22%). Immediate pain relief was obtained in 59 patients (94%) postoperatively with newly developed facial numbness in 17 patients (27%). Of these, 48 patients (76%) maintained pain-free 1year postoperatively. Overall recurrence was noted in 17 patients (27%) during the median 49-month follow-up period. Most recurrences occurred within 1year after redo surgery, but the prosthesis-related patients showed a continuous recurrence up to 4years. Patients having vascular compression showed significantly better pain control than those without vascular contact in Kaplan-Meier analyses (p = 0.0421). No prognostic factor for pain-free 1year after redo surgery was found. Redo surgery is effective for patients with remaining vascular compression rather than those without vascular contact. Teflon contact onto the nerve root should be avoided because it is a potential risk for recurrence and causes poor prognosis after redo surgery.

Comparison of first-time microvascular decompression with percutaneous surgery for trigeminal neuralgia: long-term outcomes and prognostic factors

ObjectiveCommon surgical treatments for trigeminal neuralgia (TN) include microvascular decompression (MVD) and percutaneous procedures (glycerol rhizolysis; thermocoagulation; and balloon compression). Although the efficacy of each procedure has been documented, direct comparisons of their relative efficacies for TN are lacking. We aimed to directly compare long-term outcomes after first-time MVD with percutaneous surgery in primary (idiopathic and classical) TN and identify predictors of outcome.MethodsWe conducted a retrospective analysis of prospectively collected data on 185 patients undergoing MVD and 129 undergoing percutaneous surgery. Procedures were performed by one of two neurosurgeons in a single centre; an independent observer collected long-term follow-up data by interviews, using the same outcome measures for all procedures.ResultsMVD patients were younger than those undergoing percutaneous surgery (P <.001). MVD provided superior initial pain relief (P <.001): 87.0% had Barrow Neurological Institute class I or II pain scores after MVD compared with 67.2% after percutaneous surgery. The complication rate for percutaneous procedures was 35.7% and for MVDs was 24.9% (P =.04), including minor and transient complications. Kaplan-Meier analysis demonstrated that MVD provided longer pain relief than percutaneous procedures (P <.001); 25% of patients had recurrence at 96 months following MVD compared with 12 months after percutaneous surgery. Subgroup analysis showed that balloon compression provided more durable relief amongst percutaneous procedures. Multivariate analysis revealed that post-operative numbness and age were prognostic factors for percutaneous procedures (P =.03 and .01, respectively).ConclusionsMVD provides better initial pain relief and longer durability of relief than percutaneous surgery, although carrying a small risk of major complications. Amongst percutaneous procedures, balloon compression gave the most durable relief from pain. Older age and post-operative numbness were predictors of good outcome from percutaneous surgery. These results can help clinicians to counsel patients with primary TN on neurosurgical treatment selection for pain relief.

Evaluating YouTube as a Resource for Trigeminal Neuralgia Patient Education

The objective of this study was to examine the educational value of YouTube as a source of patient information regarding trigeminal neuralgia and its treatment. We also sought to determine the degree of bias that is present in the top videos regarding this condition. We selected 6 search terms related to trigeminal neuralgia to examine on YouTube for quality and bias using the DISCERN criteria. Filtering by relevance and total view count, we determined the top 20 results for each search term and evaluated all videos for overall educational quality and creator bias. We categorized the type of content creator and compared overall DISCERN scores and bias scores between creator type and search term. There were 80 unique and 40 duplicate videos. There were 10,745,574 total views across all videos, with an average view count of 89,546. The mean DISCERN score for all videos was 1.7, and the mean bias score was 2.2. Based on individual search terms, the highest mean DISCERN score was for trigeminal neuralgia surgery (2.1) and the highest mean bias score was for tic douloureux (2.8). Among creator types, medical professionals had significantly higher overall (2.2) and bias (2.6) scores. Overall, YouTube is a relatively poor source of unbiased information about trigeminal neuralgia. Among the existing content, medical professionals provide educational material that is the highest quality and the most unbiased.

Characteristics and management of the offending veins in microvascular decompression surgery for trigeminal neuralgia

The optimal technique of microvascular decompression (MVD) for trigeminal neuralgia (TN) caused by venous conflict remains unclear. The objectives of this study are to characterize the offending veins identified during MVD for TN and to evaluate intraoperative technique applied for their management. From 2007 till 2019, 308 MVD surgeries were performed in 288 consecutive patients with TN, and in 58 of them, pure venous conflict was identified. In 44 patients, the offending vein was interrupted, as was done for small veins arising from the cisternal trigeminal nerve (CN V) or its root entry zone (REZ) causing their stretching (19 cases), small veins on the surface of REZ (9 cases), transverse pontine vein (TPV) compressing REZ or distal CN V (12 cases), and superior petrosal vein (SPV) using flow conversion technique (4 cases). In 14 other cases, the offending vein was relocated, as was done for the SPV or the vein of cerebellopontine fissure (8 cases), TPV (3 cases), and the vein of middle cerebellar peduncle (3 cases). Complete pain relief after surgery was noted in 49 patients (84%). No one patient experienced major neurological deterioration. Postoperative facial numbness developed in 14 patients (24%), and in 8 of them, it was permanent. In 14 patients, MRI demonstrated venous infarction of the middle cerebellar peduncle, which was associated with the presence of any (P = 0.0180) and permanent (P = 0.0002) facial numbness. Ten patients experienced pain recurrence. Thus, 39 patients (67%) sustained complete pain relief at the last follow-up (median, 48 months), which was significantly associated with the presence of any (P = 0.0228) and permanent (P = 0.0427) postoperative facial numbness. In conclusion, in cases of TN, small offending veins arising from REZ and/or distal CN V and causing their stretching may be coagulated and cut. In many cases, TPV can be also interrupted safely or considered as collateral way for blood outflow. The main complication of such procedures is facial numbness, which is associated with the venous infarction of middle cerebellar peduncle and long-term complete pain relief.

Efficacy of microsurgical vascular decompression in trigeminal neuralgia

ObjectivesAnalysis of the long-term efficacy of microvascular decompression surgery in trigeminal neuralgia. Material and methodsA single-center retrospective study included patients undergoing microvascular decompression surgery for trigeminal neuralgia after failure of well-conducted medical or complementary therapy, with visualization of nerve compression syndrome on MRI. ResultsEighty-seven patients were included. Nerve compression was alleviated without interposition of polytetrafluoroethylene in 79.3% of cases. Postoperative efficacy on pain was immediate in 97.7% of cases. There were no postoperative deaths, and the rate of severe complications was low (2.3%). The efficacy of microvascular decompression surgery was total at 2 years in 90.8% of cases and at 10 years in 92.3%, without resumption of medical treatment. The failure rate was 10.3%; 26.3% of these patients had been previously treated by a lesional technique (P: 0.043) and 33.3% by interposition of polytetrafluoroethylene (P: 0.003). ConclusionsWith confirmed clinical and radiological diagnosis, microvascular decompression surgery for trigeminal nerve compression was safe, with total effectiveness in the immediate, short and long terms. It should be considered in first line in case of failure or intolerance of well-conducted medical treatment.

Natural Dural Defect of the Posterior Fossa Dura as a Risk Factor for Postoperative Cerebrospinal Fluid Leakage

During microvascular decompression surgery (MVD), small (2-3 mm diameter) natural dural defects have been noticed occasionally but never reported. These tiny dural defects cannot be detected by preoperative imaging studies or even in anatomical cadaver dissection, but may lead to complications including cerebrospinal fluid (CSF) leakage. Our objective was to analyze the features of these natural defects in the posterior fossa dura. Surgical reports and videos of 593 consecutive patients who underwent MVD surgery for trigeminal neuralgia (TN) or hemifacial spasm (HFS) were analyzed retrospectively. Video recording confirmed that these small holes were not related to the craniotomy procedure itself and were natural defects. Such natural defects of the posterior fossa dura were found in 6 of the 593 patients. All of the defects were about 2 mm in diameter and occurred on the left side in female patients with HFS. All were managed by patching with a fascial or muscle graft. Multivariate analysis showed that the defect was significantly associated with the left side and had a female predilection. Neither disease (HFS or TN) nor age was correlated with the presence of dural defects. After posterior fossa craniotomies, CSF leakage or pseudomeningocele may occur at the dural suture site because of the hydrostatic pressure. Because such natural dural defects may be a cause of CSF complications after posterior fossa surgery, their possible occurrence should be considered. This is the first report to document the occurrence of such natural defects of the posterior fossa dura.

Significance of degree of neurovascular compression in surgery for trigeminal neuralgia.

The aim of this study was to identify preoperative imaging predictors of surgical success in patients with classic trigeminal neuralgia (cTN) undergoing microvascular decompression (MVD) via retrospective multivariate regression analysis. All included patients met criteria for cTN and underwent preoperative MRI prior to MVD. MR images were blindly graded regarding the presence and severity (i.e., mild or severe) of neurovascular compression (NVC). All patients were contacted by telephone to determine their postoperative pain status. A total of 79 patients were included in this study. Sixty-two patients (78.5%) were pain-free without medication following MVD. The following findings were more commonly observed with the symptomatic nerve when compared to the contralateral asymptomatic nerve: NVC (any form), arterial compression alone, NVC along the proximal trigeminal nerve, and severe NVC (p values < 0.0001). The only imaging variable that was a statistically significant predictor of being pain-free without medication following MVD was severe NVC. Patients with severe NVC were 6.36 times more likely to be pain-free following MVD compared to those without severe NVC (p = 0.007). In patients with cTN undergoing MVD, severe NVC on preoperative MRI is a strong predictor of an excellent surgical outcome.

Herpes Simplex Reactivation After Surgical Treatment of Trigeminal Neuralgia: A Retrospective Cohort Study

Herpes simplex virus (HSV) reactivation after surgery for trigeminal neuralgia has long been recognized. Only a few studies to date have focused on this complication, and its actual incidence remains unknown. The aim of this study was to investigate the incidence of postoperative herpes labialis (HL) in a cohort of patients treated with either percutaneous balloon compression or microvascular decompression to identify potentially significant differences between different treatments. A total of 92 patients who were operated on for TN with microvascular decompression (group A) or percutaneous balloon compression (group B) in the period 2010-2017 were retrospectively evaluated. The 2 subgroups of patients were compared according to history of previous HL and incidence of postoperative HL. The final cohort comprised 56 male and 36 female patients. Average age was 58.50 years; 30 male patients belonged to group A and 26 male patients belonged to group B. Lifetime incidence of episodes of HL before surgery in 18/58 patients in group A (31.0%) and 12/34 patients in group B (35.3%), with no statistically significant difference among subgroups. Postoperatively, 1/56 patients in group A (1.7%) experienced HL compared 5/34 patients in group B (14.7%), with a strongly statistically significant difference between the 2 subgroups. In our clinical experience, herpes simplex virus reactivation after surgery for trigeminal neuralgia is not so rare and is still not completely understood. Postoperative herpes simplex virus reactivation could be due to a direct mechanical injury on gasserian ganglion neurons, which is more common after percutaneous balloon compression.

Successful Gamma Knife Surgery for Trigeminal Neuralgia associated with Epidermoid Tumor : A Case Report

Successful Gamma Knife Surgery for Trigeminal Neuralgia associated with Epidermoid Tumor : A Case Report