Radiological and intraoperative findings of a rare case of vestibular paroxysmia.

Vestibular paroxysmia (VP) is a rare condition. The pathogenesis is linked to a neurovascular conflict (NVC) between an abnormal arterial loop and the VII/VIII cranial nerve complex in the cerebello-pontine angle. Due to its rarity, intraoperative findings are only anecdotally reported. Here we reported on a case of VP, showing the radiological images and the intraoperative surgical video of microvascular decompression (MVD). Further we discussed our findings considering the pertinent literature. We think that in case of VP the concordance between the side of tinnitus/hypoacusia and the side of NVC on magnetic resonance imaging should be always looked for before considering MVD as a therapeutic option.

Hyperemia in head injury: can transcranial doppler help to personalize therapies for intracranial hypertension?

Introduction: An increase in cerebral blood flow is frequent after traumatic brain injury (TBI) and can lead to brain swelling and refractory intracranial hypertension. We hypothesized that Transcranial EcoDoppler (TCD) monitoring could be useful to detect the cause of intracranial hypertension in these patients. Our main objective was to investigate if the increase of velocity in the middle cerebral artery (MCA) on TCD could be associated with intracranial hypertension. Methods: We retrospectively studied TBI patients consecutively monitored with TCD. Hyperemia was defined as MCA mean velocity higher than 80 cm/s. Intracranial hypertension was considered when hyperosmolar therapy, hyperventilation, or deep sedation was used. Results: We found hyperemia in 40 patients out of 118 (33.9%). On average, it started at day 2.1 ± 0.9 from admission and significantly increased (MCA velocity at day 1: 74 ± 25 cm/s vs. 109 ± 36 cm/s at day 4; p < 0.001). Intracranial hypertension was significantly associated with hyperemia, occurring in 92.5% of hyperemic and 51.3% of non-hyperemic patients (p < 0.001). Moreover, we found that hyperemia preceded severe intracranial hypertension (p < 0.0001). In a logistic regression model, hyperemia was the only variable significantly correlated with intracranial hypertension (OR 10.64; p < 0.001). Discussion: Hyperemia was frequent in our population of TBI patients and preceded intracranial hypertension. TCD monitoring, if performed on a daily regular basis, can be a useful method to detect this phenomenon and to guide the therapy. It could be a tool for a cause-oriented therapy of intracranial hypertension.

Brain tissue oxygenation monitoring in subarachnoid hemorrhage for the detection of delayed ischemia: a systematic review and meta-analysis.

INTRODUCTION: Subarachnoid hemorrhage (SAH) is a severe subtype of stroke which can be caused by the rupture of an intracranial aneurysm. Following SAH, about 30% of patients develop a late neurologic deterioration due to a delayed cerebral ischemia (DCI). This is a metanalysis and systematic review on the association between values of brain tissue oxygenation (PbtO2) and DCI in patients with SAH. EVIDENCE ACQUISITION: The protocol was written according to the PRISMA-P (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and approved by the International Prospective Register of Systematic Reviews (PROSPERO registration number CRD42021229338). Relevant literature published up to August 1, 2022 was systematically searched throughout the databases MEDLINE, WEB OF SCIENCE, SCOPUS. A systematic review and metanalysis was carried out. The studies considered eligible were those published in English; that enrolled adult patients (≥18years) admitted to neurointensive care units with aneurysmal SAH (aSAH); that reported presence of multimodality monitoring including PbtO2 and detection of DCI during the period of monitoring. EVIDENCE SYNTHESIS: We founded 286 studies, of which six considered eligible. The cumulative mean of PbtO2 was 19.5 mmHg in the ischemic group and 24.1mmHg in the non ischemic group. The overall mean difference of the values of PbtO2 between the patients with or without DCI resulted significantly different (-4.32 mmHg [IC 95%: -5.70, -2.94], without heterogeneity, I2 = 0%, and a test for overall effect with P<0.00001). CONCLUSIONS: PbtO2 values were significantly lower in patients with DCI. Waiting for definitive results, monitoring of PbtO2 should be considered as a complementary parameter for multimodal monitoring of the risk of DCI in patients with SAH.

Bedside Ultrasound for Ventricular Size Monitoring in Patients with PEEK Cranioplasty: A Preliminary Experience of Technical Feasibility in Neurotrauma Setting.

BACKGROUND: Posttraumatic hydrocephalus is a known complication after traumatic brain injury, particularly affecting patients undergoing decompressive craniectomy. Posttraumatic hydrocephalus monitoring in these patients represents a common issue in neurosurgical practice. Patients require periodical assessments by means of computed tomography (CT) scans. This study presents a preliminary institutional series in which ultrasound was used as a bedside imaging technique to monitor ventricular size in patients harboring a polyetheretherketone (PEEK) cranioplasty. Exploiting the PEEK cranioplasty permeability to echoes, we evaluated the feasibility of this bedside imaging method in monitoring hydrocephalus evolution, determining effects of ventriculo-peritoneal shunt, and excluding complications. METHODS: Eight patients with traumatic brain injury harboring PEEK cranioplasty following decompressive craniectomy were prospectively evaluated. Ultrasound measurements were compared with CT scan data taken the same day, and ventricular morphometry parameters were compared. RESULTS: Ultrasound images through the PEEK cranioplasty were of high quality and intracranial anatomy was distinctly evaluated. A strong correlation was observed between ultrasound and CT measurements. Concerning distance between lateral ventricles frontal horns (IFH) and the diameter of the third ventricle (TV), we found a strong correlation between transcranial sonography and CT measurements in preventriculoperitoneal shunt (rho = 0.92 and p = 0.01 for IFH; rho = 0.99 and p = 0.008 for TV) and in postventriculoperitoneal shunt examinations (rho = 0.95 and p = 0.03 for IFH; rho = 0.97 and p = 0.03 for TV). The mean error rate between transcranial sonography and CT scan was 1.77 ± 0.91 mm for preoperative IFH, 0.65 ± 0.27 mm for preoperative TV, 2.18 ± 0.82 mm for postoperative IFH, and 0.48 ± 0.21 mm for postoperative TV. CONCLUSIONS: Transcranial ultrasound could represent a simplification of the follow-up and management of ventricular size of patients undergoing PEEK cranioplasty. Even if this is a small series, our preliminary results could widen the potential benefits of PEEK, not only as effective material for cranial reconstruction but also, in selected clinical conditions, as a reliable window to explore intracranial content and to monitor ventricular sizes and shunt functioning.

A systematic review and meta-analysis of factors involved in bone flap resorption after decompressive craniectomy.

Decompressive craniectomy (DC) is effective in controlling increasing intracranial pressure determined by a wide range of conditions, mainly traumatic brain injury (TBI) and stroke, and the subsequent cranioplasty (CP) displays potential therapeutic benefit in terms of overall neurological function. While autologous bone flap (ABF) harvested at the time of DC is the ideal material for skull defect reconstruction, it carries several risks. Aseptic bone flap resorption (BFR) is one of the most common complications, often leading to surgical failure. The aim of our study was to systematically review the literature and carry out a meta-analysis of possible factors involved in BFR in patients undergoing ABF cranioplasty after DC. A systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. Different medical databases (PubMed, Embase, and Scopus) were screened for eligible scientific reports until April 30th 2021. The following data were collected for meta-analysis to assess their role in BFR: sex, age, the interval time between DC and CP, the presence of systemic factors, the etiology determining the DC, CP surgical time, CP features, VP shunt placement, CP infection. Studies including pediatric patients or with less than 50 patients were excluded. Fifteen studies were included. There was a statistically significant increased incidence of BFR in patients with CPF > 2 compared to patients with CPF ≤ 2 (54.50% and 22.76% respectively, p = 0.010). TBI was a significantly more frequent etiology in the BFR group compared to patients without BFR (61.95% and 47.58% respectively, p < 0.001). Finally, patients with BFR were significantly younger than patients without BFR (39.12 ± 15.36 years and 47.31 ± 14.78 years, respectively, p < 0.001). The funnel plots were largely symmetrical for all the studied factors. Bone flap fragmentation, TBI etiology, and young age significantly increase the risk of bone resorption. Further studies are needed to strengthen our results and to clarify if, in those cases, a synthetic implant for primary CP should be recommended.

Factors associated with cerebrospinal fluid leak after a retrosigmoid approach for cerebellopontine angle surgery.

BACKGROUND: The retrosigmoid approach represents a crucial surgical route to address different lesions in the cerebellopontine angle but cerebrospinal fluid (CSF) leak still remains the most frequent complication after this approach. Here, we analyzed the impact of different factors in CSF leak development after a retrosigmoid approach. Identifying risk factors related to a specific approach may help the surgeon to tailor the perioperative management and to appropriately counsel patients regarding their risk profile. METHODS: We retrospectively reviewed the clinical, surgical, and outcome data of 103 consecutive patients (M/F, 47/56; mean follow-up 35.6 ± 23.9 months) who underwent a retrosigmoid approach for different cerebellopontine angle pathologies and studied the impact of different factors on the occurrence of a CSF leak to univariate and multivariate analysis. RESULTS: Seventy-nine patients (76.7%) were operated for tumors growing in the cerebellopontine angle. Twenty-four patients (23.2%) underwent microvascular decompression to treat a drug-resistant trigeminal neuralgia. Sixteen patients (15.5%) developed CSF leak in the postoperative course of which six underwent surgical revision. Performing a craniectomy as surgical procedure (P = 0.0450) and performing a reopening procedure (second surgery; P = 0.0079) were significantly associated to a higher risk of developing CSF leak. Moreover, performing a reopening procedure emerged as an independent factor for CSF developing on multivariate analysis (P = 0.0156). CONCLUSION: Patients submitted to craniectomy and patients who underwent a second surgery showed an higher CSF leak rate. Ongoing improvement of biomaterial technology may help neurosurgeons to prevent this potentially life-threatening complication.

Is There a Place for Spinal Cord Stimulation in the Management of Patients with Multiple Sclerosis? A Systematic Review of the Literature.

OBJECTIVE: Spinal cord stimulation (SCS) is a minimally invasive technique mainly used to treat neuropathic pain associated with failed back surgery syndrome. However, this therapy has been utilized to treat other chronic painful conditions, such as pain associated with multiple sclerosis (MS). Nonetheless, the efficacy of SCS in MS patients has not been fully established. In fact, in most of SCS series, MS patients represent only a subset of a bigger cohort which comprises different causes of pain, motor disorder, and other functional limitations. The aim of our study was to systematically review the literature to evaluate the effectiveness of SCS in MS patients. METHODS: A literature search was performed through different databases (PubMed, Scopus, and Embase) using the following terms: "multiple sclerosis," "spinal cord stimulation," and "dorsal column stimulation," according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. RESULTS: A total of 452 articles were reviewed, and 7 studies were included in the present analysis. 373 MS patients were submitted to a stimulation trial, and 82 MS patients underwent a de novo implantation. 285/373 (76.4%) of cases submitted to the SCS trial were enrolled for permanent stimulation. We found a long-lasting improvement in 193/346 (55.8%) MS patients with motor disorders, in 90/134 (67.13%) MS patients with urinary dysfunction, and in 28/34 (82.35%) MS patients with neuropathic pain. The efficacy of SCS was higher for urinary dysfunction (p = 0.0144) and neuropathic pain (p = 0.0030) compared with motor disorders. CONCLUSIONS: Our systematic review evidences that SCS is effective in MS patients. Urinary dysfunction and pain symptoms seem to be most responsive to SCS. Further studies are needed to improve the patient selection and clarify the best timing to perform SCS in these patients.

What Are the Results and the Prognostic Factors of Motor Cortex Stimulation in Patients with Facial Pain? A Systematic Review of the Literature.

INTRODUCTION: Facial pain (FP) is a type of neuropathic pain which recognizes both central and peripheral causes. It can be difficult to treat because it can often become resistant to pharmacological treatments. Motor Cortex Stimulation (MCS) has been used in selected cases, but the correct indications of MCS in FP have not been fully established. Here we systematically reviewed the literature regarding MCS in FP analysing the results of this technique and studying the possible role of different factors in the prognosis of these patients. METHODS: A literature search was performed through different databases (PubMed, Scopus, and Embase) according to PRISMA guidelines using the following terms in any possible combination: "facial pain" or "trigeminal" or "anaesthesia dolorosa" and "motor cortex stimulation." RESULTS: 111 articles were reviewed, and 12 studies were included in the present analysis for a total of 108 patients. Overall, at latest follow-up (FU), 70.83% of patients responded to MCS. The preoperative VAS significantly decreased at the latest FU (8.83 ± 1.17 and 4.31 ± 2.05, respectively; p < 0.0001). Younger age (p = 0.0478) and a peripheral FP syndrome (p = 0.0006) positively affected the definitive implantation rate on univariate analysis. Younger age emerged as a factor strongly associated to a higher probability to go to a definitive MCS implant on multivariate analysis (p = 0.0415). CONCLUSION: Our results evidenced the effectiveness of MCS in treating FP. Moreover, the younger age emerged as a positive prognostic factor for definitive implantation. Further studies with longer FU are needed to better evaluate the long-term results of MCS.

A systematic review and meta-analysis of factors affecting the outcome of the epidural blood patching in spontaneous intracranial hypotension.

Spontaneous intracranial hypotension (SIH) is an often misdiagnosed condition resulting from non-iatrogenic cerebrospinal fluid (CSF) hypovolemia, typically secondary to spinal CSF leakage. Patients commonly present with posture-related headache, nausea, and vomiting. Following failure of conservative measures, epidural blood patching (EBP) is the most commonly performed intervention for spinal CSF leaks. The authors performed a systematic review and meta-analysis of existing literature to evaluate the role of different factors possibly affecting the efficacy of the EBP procedure. In accordance with the PRISMA guidelines, PubMed/Medline and SCOPUS databases were searched. Six eligible articles were retrieved. Five hundred patients were treated for SIH with EBP, of which 300 reported good response defined as complete remission of symptoms within 48 h after the first EBP requiring no further invasive treatment. Among the factors available for meta-analysis, none was found to be statistically significant in affecting the efficacy of the EBP procedure. A largely symmetrical funnel plot is reported for all the variables evaluated, indicating that publication bias did not play a significant role in the observed effects. The current knowledge about SIH and the EBP is scarce. The existing literature is contradictory and insufficient to aid in clinical practice. More studies are needed to draw significant conclusions that may help in the identification of patients at higher risk of EBP failure, who may benefit from different approaches.

The Impact of Neuronavigation on the Surgical Outcome of Microvascular Decompression for Trigeminal Neuralgia.

OBJECTIVE: Microvascular decompression (MVD) is considered the only etiological treatment for drug-resistant trigeminal neuralgia (TN). Nonetheless, despite the recent technological advances, the risks associated with MVD remain non-negligible. The aim of this study was to evaluate the impact of using neuronavigation on the surgical outcomes of patients with TN submitted for MVD. METHODS: We analyzed 30 consecutive patients (11 men, 19 women) who underwent MVD for TN between January 2019 and December 2019. Patients were divided in 2 groups according to the use of neuronavigation (group A: MVD with neuronavigation; group B: MVD without neuronavigation). The impact of neuronavigation was assessed on the following parameters: craniotomy size, surgical duration, mastoid air cell opening, postoperative cerebrospinal fluid (CSF) leakage and other complications occurrence, and length of hospitalization. The acute pain relief and the Barrow Neurological Institute score at follow-up were used to evaluate the functional outcome. RESULTS: The craniotomy size, the surgical duration, and the CSF leak incidence were significantly reduced in group A compared with group B (P = 0.0009, P = 0.0369, and P = 0.0406, respectively). The incidence of mastoid air cell opening, and the length of hospitalization were reduced in group A compared with group B, although these differences were not statistically significant. We obtained an acute pain relief in all cases, and the Barrow Neurological Institute score at follow-up was significantly reduced (P < 0.0001). CONCLUSIONS: Neuronavigation is a useful tool that significantly reduced craniotomy size, surgical duration, and CSF leak incidence in patients with TN submitted for MVD. We advise to routinely implement neuronavigation in this type of surgery.

Continuous EEG monitoring by a new simplified wireless headset in intensive care unit.

BACKGROUND: In critically ill patients continuous EEG (cEEG) is recommended in several conditions. Recently, a new wireless EEG headset (CerebAir®,Nihon-Kohden) is available. It has 8 electrodes, and its positioning seems to be easier than conventional systems. Aim of this study was to evaluate the feasibility of this device for cEEG monitoring, if positioned by ICU physician. METHODS: Neurological patients were divided in two groups according with the admission to Neuro-ICU (Study-group:20 patients) or General-ICU (Control-group:20 patients). In Study group, cEEG was recorded by CerebAir® assembled by an ICU physician, while in Control group a simplified 8-electrodes-EEG recording positioned by an EEG technician was performed. RESULTS: Time for electrodes applying was shorter in Study-group than in Control-group: 6.2 ± 1.1' vs 10.4 ± 2.3'; p < 0.0001. Thirty five interventions were necessary to correct artifacts in Study-group and 11 in Control-group. EEG abnormalities with or without epileptic meaning were respectively 7(35%) and 7(35%) in Study-group, and 5(25%) and 9(45%) in Control-group;p > 0.05. In Study-group, cEEG was interrupted for risk of skin lesions in 4 cases after 52 ± 4 h. cEEG was obtained without EEG technician in all cases in Study-group; quality of EEG was similar. CONCLUSIONS: Although several limitations should be considered, this simplified EEG system could be feasible even if EEG technician was not present. It was faster to position if compared with standard techniques, and can be used for continuous EEG monitoring. It could be very useful as part of diagnostic process in an emergency setting.

Hemopatch® with fibrin glue as a dural sealant in cranial and spinal surgery. A technical note with a review of the literature.

A major complication in cranial and spinal surgery is the post-operative occurrence of a cerebrospinal fluid (CSF) leak. Here we reported a technical note firstly describing the use of Hemopatch® with fibrin glue as a dural sealant in cranial and spinal neurosurgical procedures. Moreover we carried out a review of the literature. Further to the best of our knowledge this was the first series including patients submitted to different spinal surgeries in whom Hemopatch® was used as dural sealant. We prospectively collected the data of 22 patients. In all procedures, fibrin glue was applied after Hemopatch®. The mean age was 59.68 ± 10.79 years and the mean follow-up (FU) was 3.63 ± 1.46 months, respectively. Overall, Hemopatch® with fibrin glue was used in 8 cranial procedures (36.36%; all were retrosigmoid craniotomies) and 14 spinal procedures (63.64%). 9/14 spinal cases (64.28%) were incidental durotomies during a spinal decompression procedure. No CSF leak, no postoperative infection, no adverse reaction were observed during the FU in all cases. The literature search revealed only two retrospective series, reporting only patients submitted to cranial surgery for a total of 56 patients and a CSF leak occurring in 3 patients (5.35%). In conclusion, we firstly reported the feasibility and the safety of using Hemopatch® with fibrin glue as dural sealant in cranial surgery and different spinal procedures. Further larger comparative studies are needed to confirm our initial encouraging results.

Factors involved in the development of subdural hygroma after decompressive craniectomy for traumatic brain injury. A systematic review and meta-analysis.

Subdural hygroma (SDG) represents a common complication following decompressive craniectomy (DC). To our knowledge we present the first meta-analysis investigating the role of clinical and technical factors in the development of SDG after DC for traumatic brain injury. We further investigated the impact of SDG on the final prognosis of patients. The systematic review of the literature was done according to the PRISMA guidelines. Two different online medical databases (PubMed/Medline and Scopus) were screened. Four articles were included in this meta-analysis. Data regarding age, sex, trauma dynamic, Glasgow Coma Scale (GCS), pupil reactivity and CT scan findings on admission were collected for meta-analysis in order to evaluate the possible role in the SDG formation. Moreover we studied the possible impact of SDG on the outcome by evaluating the rate of patients dead at final follow-up and the Glasgow Outcome Scale (GOS) at final follow-up. Among the factors available for meta-analysis only the basal cistern involvement on CT scan was associated with the development of a SDG after DC (p < 0.001). Moreover, patients without SDG had a statistically significant better outcome compared with patients who developed SDG after DC in terms of GOS (p < 0.001). The rate of patients dead at follow-up was lower in the group of patients without SDH (8.25%) compared with patients who developed SDG (11.51%). SDG after DC is a serious complication affecting the prognosis of patients. Further studies are needed to define the role of some adjustable technical aspect of DC in preventing such a complication.

Factors affecting serum lactate in patients with intracranial tumors - A report of our series and review of the literature.

BACKGROUND: A hyperlactemia may occur in the presence of tissue hypoperfusion, in diseases affecting metabolism and in cases of malignant neoplasm. However, the factors affecting the serum lactate levels in patients submitted to craniotomy for the resection of an intracranial tumor have been investigated only marginally. Here, we assessed the factors possibly affecting the levels of serum lactate in intracranial tumors and carried out a thorough literature review on this topic. METHODS: All patients submitted to elective craniotomy from January 2017 to August 2018 for the resection of a glioblastoma (GBM; 101 cases) and a benign meningioma (WHO I; 105 cases) were included in this study. The sex, age, histological diagnosis, body mass index (BMI), and diabetes were assessed as possible factors affecting the level of the preoperative and postoperative serum lactate in these patients. RESULTS: We found that preoperative hyperlactemia (> 2 mmol/l) was more frequent in patients with GBM than in patients with meningioma (P = 0.0003). Moreover, a strong correlation between a preoperative lactemia and postoperative lactemia (P < 0.0001) was observed. On univariate analysis, we found increased preoperative serum lactate levels in GBM patients (P = 0.0022) and in patients with a BMI ≥30 (P = 0.0068). Postoperative serum lactate levels were significantly higher in GBM patients (P = 0.0003). On multivariate logistic regression analysis, a diagnosis of GBM was an independent factor for higher level of preoperative (P = 0.0005) and postoperative (P < 0.0001) serum lactate. CONCLUSION: The malignant phenotype of GBM is the strongest factor associated with a pre- and postoperative hyperlactemia in patients submitted to craniotomy for the resection of an intracranial tumor.

Microvascular decompression in patients with trigeminal neuralgia and multiple sclerosis: results and analysis of possible prognostic factors.

We evaluated the results of microvascular decompression (MVD) in patients with trigeminal neuralgia (TN) and multiple sclerosis (MS) and we studied the role of several clinical and surgical factors as possible prognosticators of good outcome. To do this we performed, to our knowledge, the first literature review with a pooled analysis of data. A PubMed search of literature was conducted using the following terms: "microvascular decompression", "trigeminal neuralgia" and "multiple sclerosis". We screened 64 articles. Of them, 7 studies were eligible for this review. As outcome indicators we used the acute pain relief (APR) and the recurrence of pain. An APR was obtained in 71.42% and a recurrence of pain was reported in 26.00% of cases, respectively. At univariate analysis, younger age at surgery (p = 0.0419) and performing MVD as the first treatment (p = 0.0384) were associated to a higher probability of APR. The evidence of an MRI brainstem lesion related to the TN (p = 0.0482) was associated to a lower probability to obtain an APR after MVD. None of the evaluated factors affect the probability of recurrence of pain. At multivariate analysis the evidence of a brainstem MRI lesion related to the TN emerged as a negative prognosticator of APR (p = 0.0169). Our literature pooled analysis showed that MVD is effective in treating patients with MS-related TN. The evidence on MRI of a demyelinating plaque related to the TN is associated with a worse response to MVD. These data could suggest that MVD would be indicated mainly in patients without brainstem MRI lesions.

Possible Prognostic Role of Magnetic Resonance Imaging Findings in Patients with Trigeminal Neuralgia and Multiple Sclerosis Who Underwent Percutaneous Balloon Compression: Report of Our Series and Literature Review.

OBJECTIVE: We studied the correlation of magnetic resonance imaging (MRI) findings with the prognosis of patients with multiple sclerosis (MS)-related trigeminal neuralgia (TN) who had undergone percutaneous balloon compression (PBC). To the best of our knowledge, no studies have previously reported on this topic. We also performed a review of pertinent studies. METHODS: From a surgical series of 82 patients with TN who had undergone PBC from January 2013 to June 2017, we identified 16 patients with MS (mean age, 54.81 ± 8.51 years; mean follow-up, 38.12 ± 19.86 months). Using brain MRI, we evaluated the presence of a lesion in the trigeminal nerve root entry zone and trigeminal nuclei. With other clinical and procedure-related factors, we studied its effect on acute pain relief (pain free at hospital discharge) and pain-free survival (PFS). RESULTS: Of the 16 patients, 15 (93.75%) reported acute pain relief; 8 patients (50.00%) experienced a recurrence of pain. At the latest follow-up visit, an excellent outcome (Barrow Neurological Institute grade 1-2) was obtained for 75% of patients and a good outcome (Barrow Neurological Institute grade 3) for 25%. No patient experienced uncontrolled pain. The presence of a pear-like balloon shape during surgery (P = 0.0053) and a MRI detectable lesion in the trigeminal pathway (P = 0.049) were associated with greater PFS. CONCLUSIONS: PBC can be efficient in treating MS-related TN. Some factors, such as a pear-like balloon shape during surgery and evidence of a MRI-detectable lesion in the trigeminal pathway were associated with longer PFS.