Comparison of microvascular decompression, percutaneous radiofrequency rhizotomy, and stereotactic radiosurgery in the treatment of trigeminal neuralgia: A long term quasi-experimental study.

BACKGROUND: Microvascular decompression (MVD), radiofrequency rhizotomy (RFR), and stereotactic radiosurgery (SRS) are surgical techniques frequently used in the treatment of idiopathic trigeminal neuralgia (TN), although the results reported for each of these are diverse. OBJECTIVE: This study aimed to compare long-term pain control obtained by MVD, SRS, and RFR in patients with idiopathic TN. METHODS: To compare the results obtained by MVD, SRS, and RFR we chose a quasi-experimental, ambispective design with control groups but no pretest. A total of 52 participants (MVD n = 33, RFR n = 10, SRS n = 9) were included. Using standardized outcome measures, pain intensity, pain relief, quality of life, and satisfaction with treatment were assessed by an independent investigator. The TREND statement for reporting non-randomized evaluations was applied. Clinical outcomes were evaluated at the initial postoperative period and at 6 months, 1, 2, 3, 4, and 5 years postoperatively. RESULTS: MVD has shown better results in pain scales compared to ablative procedures. Significant differences between groups were found regarding pain intensity and pain relief at the initial postoperative period (p < 0.001) and 6 months (p = 0.022), 1 year (p < 0.001), 2 years (p = 0.002), and 3 years (p = 0.004) after the intervention. Those differences exceeded the thresholds of the minimal clinically important difference. A higher percentage of patients free of pain was observed in the group of patients treated by MVD, with significant differences at the initial postoperative period (p < 0.001) and 6 months (p = 0.02), 1 year (p = 0.001), and 2 years (p = 0.04) after the procedure. Also, a higher risk of pain recurrence was observed in the RFR and SRS groups (HR 3.15, 95% CI 1.33-7.46; p = 0.009; and HR 4.26, 95% CI 1.77-10.2; p = 0.001, respectively) compared to the MVD group. No significant differences were found in terms of quality of life and satisfaction with treatment. A higher incidence of complications was observed in the MVD group. CONCLUSION: Concerning pain control and risk of pain recurrence, MVD is superior to RFR and SRS, but not in terms of quality of life, satisfaction with treatment, and safety profile.

Current advances in the surgical treatment of glossopharyngeal neuralgia.

Glossopharyngeal neuralgia (GPN) is a neurological condition characterized by paroxysmal, stabbing-like pain along the distribution of the glossopharyngeal nerve that lasts from a couple of seconds to minutes. Pharmacological treatment with anticonvulsants is the first line of treatment; however, about 25% of patients remain symptomatic and require surgical intervention, which is usually done via microvascular decompression (MVD) with or without rhizotomy. More recently, the use of stereotactic radiosurgery (SRS) has been utilized as an alternative treatment method to relieve patient symptoms by causing nerve ablation. We conducted a systematic review to analyze whether MVD without rhizotomy is an equally effective treatment for GPN as MVD with the use of concurrent rhizotomy. Moreover, we sought to explore if SRS, a minimally invasive alternative surgical option, achieves comparable outcomes. We included retrospective studies and case reports in our search. We consulted PubMed and Medline, including articles from the year 2000 onwards. A total of 36 articles were included for review. Of all included patients with glossopharyngeal neuralgia, the most common offending artery compressing the glossopharyngeal nerve was the posterior inferior cerebellar artery (PICA). MVD alone was successful achieving pain relief immediately postoperatively in about 85% of patients, and also long term in 65-90% of patients. The most common complication found on MVD surgery was found to be transient hoarseness and transient dysphagia. Rhizotomy alone shows an instant pain relief in 85-100% of the patients, but rate of long-term pain relief was lower compared to MVD. The most common adverse effects observed after a rhizotomy were dysphagia and dysesthesia along the distribution of the glossopharyngeal nerve. SRS had promising results in pain reduction when using 75 Gy radiation or higher; however, long-term rates of pain relief were lower. MVD, rhizotomy, and SRS are effective methods to treat GPN as they help achieve instant pain relief and the decrease use of medication. Patients with MVD alone presented with less adverse effects than the group that underwent MVD plus rhizotomy. Although SRS may be a viable alternative treatment for GPN, further studies must be done to evaluate long-term treatment efficacy.

Intraoperative findings of abnormal muscle response for hemifacial spasm following botulinum neurotoxin treatment.

OBJECTIVE: This study aimed to investigate the effect of preoperative botulinum toxin (BTX) injection on intraoperative abnormal muscle response (AMR) in patients with hemifacial spasm (HFS). METHODS: A total of 104 patients (32 men, 72 women) who underwent microvascular decompression (MVD) for HFS were included in this study. A total of 62 patients without and 42 patients with preoperative BTX treatments were assigned to group A and group B, respectively. AMR recordings were obtained from the orbicularis oculi and mentalis muscles by stimulation of the marginal mandibular branch and zygomatic branch of the facial nerve, respectively. The intraoperative AMR monitoring findings and therapeutic effects were compared between groups A and B. RESULTS: The rates of the patients with unavailable AMRs recorded from the orbicularis oculi muscles in group B (38.1%) were significantly higher than those in group A (14.5%, p = 0.006). Moreover, in cases with over 4 times BTX injection, the recordings of AMR from the orbicularis oculi muscles were poorer than the cases with less BTX injection (p = 0.001). There were no significant differences in the rates of the patients with unavailable AMRs recorded from the mentalis muscles between the two groups. There were no significant differences in the surgical results obtained between the two groups. CONCLUSIONS: Preoperative BTX injections should be less than 4 times to ensure effective AMR monitoring. MVD using AMR monitoring is useful for patients with HFS who were previously treated by BTX as well as those who were not treated.

Wide distribution of central myelin segment along the facial nerve might explain hemifacial spasm with distal nerve compression.

INTRODUCTION: Many researchers have assumed that neurovascular compression of the facial nerve at the site covered by central myelin sheath causes hemifacial spasm. However, some cases do not correspond to this hypothesis. The aim of this study was to clarify the myelin histology in the facial nerve. MATERIALS AND METHODS: Histological analyses were conducted on 134 facial nerves from 67 cadavers. Three dimensions were measured in these sections: the length from the upper border of the medullopontine sulcus to the boundary between the central and peripheral myelin sheath along the anterior side; the length from the detachment point of the brain stem to the boundary along the posterior side; and the length of the transitional zone (TZ), known as the Obersteiner-Redlich zone. RESULTS: Of the 134 facial nerves, 41 were available for study. The length of the central myelin segment ranged from 4.62 to 12.6 mm (mean 8.06 mm; median 7.98 mm) along the anterior side and from 0.00 to 4.58 mm (mean 1.68 mm; median 1.42 mm) along the posterior side of the facial nerve, and the length of the TZ ranged from 0.00 to 2.76 mm (mean 1.51 mm; median 1.42 mm). CONCLUSIONS: In this study, the length of the central myelin segment in the facial nerve was found to be longer than that previously reported.

[Trigeminal neuralgia : Modern diagnostic workup and treatment]. / Trigeminusneuralgie : Moderne Diagnostik und Therapie.

The present article gives an update of relevant aspects in the diagnosis and therapy of trigeminal neuralgia from the neurological, neuroradiological and neurosurgical point of view. The diagnosis of trigeminal neuralgia is clinical, but high-quality imaging is mandatory to identify secondary causes and a neurovascular contact. New methods such as DTI (diffusion tensor imaging) allow a more differentiated assessment of the consequences of a vascular contact on the trigeminal nerve. Carbamazepine and oxcarbazepine continue to be first choice for the medical treatment, but have been supplemented by additional options such as pregabaline, lamotrigine, and onabotulinumtoxin A. In patients insufficiently responding to medical treatment, there are neurosurgical treatment options giving very good results. The best long-term results have been described for microvascular decompression, but percutaneous and radiosurgical treatments also are good options, especially in patients with an increased surgical risk profile, in secondary trigeminal neuralgia, and in case of recurrence after microvascular decompression.

Varying length of central myelin along the trigeminal nerve might contribute to trigeminal neuralgia.

Several studies have suggested that vascular compression of more distal portions of the trigeminal nerve (Vth cranial nerve: VN) may cause trigeminal neuralgia (TN). However, neurosurgeons performing microvascular decompression intraoperatively cannot identify which type of myelin is being compressed by blood vessels. The aim of this study was to clarify the histological anatomy of central and peripheral myelin in the human VN. Histological analyses were conducted using photomicrographs from 134 cisternal segments of the VN from the brains of 67 cadavers. The three dimensions of the VN were measured in these sections: distance from the point at which the lateral-most pontine VN merges with the boundary between central and peripheral myelin (line-a), distance along the medial aspect (line-b), and the length of the transitional zone (TZ), known as the Obersteiner-Redlich zone. Twenty-nine of 134 VNs were available for study. The length of central myelin ranged from 0.69 to 8.66 mm (mean, 3.56 mm; median, 3.10 mm) along the lateral aspect and from 0.36 to 5 mm (mean, 1.81 mm; median, 1.40 mm) along the medial aspect of the VN. The length of the TZ ranged from 0.31 to 3.37 mm (mean, 1.75 mm; median, 1.63 mm). We report here, for the first time, that some individuals had much longer spans of central myelin than those reported previously. Some cases of TN may thus be caused by vascular compression of VN peripheral myelin, especially in cases where central myelin is extended to an unprecedented degree. Clin. Anat. 32:541-545, 2019. © 2019 Wiley Periodicals, Inc.

Minimally invasive asterional approach for microvascular decompression in trigeminal neuralgia.

OBJECTIVE: Trigeminal neuralgia (TN) is a neuropathic disorder that can be treated surgically. This study aimed to present the surgical findings and the clinical outcomes of 26 patients with TN treated by minimally invasive asterional surgery. METHODS: Longitudinal descriptive study. Twenty-six patients with TN underwent minimally invasive asterional surgery. The medical history, surgical findings, therapeutic response, and complications were registered. They were followed for 36 months. RESULTS: Nineteen cases were associated with vascular compression; five were associated with arachnoiditis. The two remaining cases were associated with multiple sclerosis and post-herpetic neuralgia. The pain was substantially reduced in all patients in the immediate postoperative period. At 36 months, in 25 patients, total or acceptable pain control was achieved. In the long term, 22 patients evolved with no permanent complications. CONCLUSION: The microvascular decompression surgery by an asterional approach is an alternative with similar results to the classic retrosigmoid approach to treat TN, but that adds the benefits of the principles of minimally invasive surgery. Constant efforts need to be made to optimize minimally invasive surgical techniques for TN.

[Abordaje asterional mínimamente invasivo para descompresión microvascular en neuralgia del trigémino].

OBJECTIVE: Trigeminal neuralgia (TN) is a neuropathic disorder that can be treated surgically. This study aimed to present the surgical findings and the clinical outcomes of 26 patients with TN treated by minimally invasive asterional surgery. METHODS: Longitudinal descriptive study. Twenty-six patients with TN underwent minimally invasive asterional surgery. The medical history, surgical findings, therapeutic response, and complications were registered. They were followed for 36 months. RESULTS: Nineteen cases were associated with vascular compression; five were associated with arachnoiditis. The two remaining cases were associated with multiple sclerosis and post-herpetic neuralgia. The pain was substantially reduced in all patients in the immediate postoperative period. At 36 months, in 25 patients, total or acceptable pain control was achieved. In the long term, 22 patients evolved with no permanent complications. CONCLUSION: The microvascular decompression surgery by an asterional approach is an alternative with similar results to the classic retrosigmoid approach to treat TN, but that adds the benefits of the principles of minimally invasive surgery. Constant efforts need to be made to optimize minimally invasive surgical techniques for TN.

OBJETIVO: La neuralgia del trigémino (NT) es un trastorno neuropático susceptible de tratamiento quirúrgico. El objetivo es presentar los hallazgos quirúrgicos y resultados obtenidos en 26 pacientes con NT, tratados mediante un abordaje asterional mínimamente invasivo para descompresión vascular trigeminal. MÉTODOS: Estudio longitudinal descriptivo. Se intervino mediante abordaje asterional a 26 pacientes. Se registró el historial médico, hallazgos quirúrgicos, respuesta al tratamiento y complicaciones. Se les dio seguimiento durante 36 meses. RESULTADOS: Diecinueve casos se asociaron a compresión vascular, cinco casos a aracnoiditis y los dos restantes se relacionaron con esclerosis múltiple y neuralgia postherpética. El dolor se controló significativamente en todos los pacientes durante el postoperatorio inmediato. A 36 meses de seguimiento, en 25 pacientes se alcanzó un control total o aceptable del dolor. A largo plazo 22 pacientes evolucionaron sin complicaciones permanentes. CONCLUSIONES: La cirugía de descompresión microvascular a través de un abordaje asterional mínimamente invasivo para el tratamiento de la NT es una alternativa con resultados similares al abordaje retrosigmoideo clásico, pero que suma las bondades de una técnica quirúrgica que se rige con los principios de la mínima invasión. Se requieren esfuerzos constantes para optimizar las técnicas quirúrgicas en el tratamiento de la NT.

Bridging veins and veins of the brainstem in microvascular decompression surgery for trigeminal neuralgia and hemifacial spasm.

OBJECTIVE In microvascular decompression surgery for trigeminal neuralgia and hemifacial spasm, the bridging veins are dissected to provide the surgical corridors, and the veins of the brainstem may be mobilized in cases of venous compression. Strategy and technique in dissecting these veins may affect the surgical outcome. The authors investigated solutions for minimizing venous complications and reviewed the outcome for venous decompression. METHODS The authors retrospectively reviewed their surgical series of microvascular decompression for trigeminal neuralgia and hemifacial spasm in patients treated between 2005 and 2017. Surgical strategies included preservation of the superior petrosal vein and its tributaries, thorough dissection of the arachnoid sleeve that enveloped these veins, cutting of the inferior petrosal vein over the lower cranial nerves, and mobilization or cutting of the veins of the brainstem that compressed the nerve roots. The authors summarized the patient characteristics, operative findings, and postoperative outcomes according to the vascular compression types as follows: artery alone, artery and vein, and vein alone. They analyzed the data using chi-square and 1-way ANOVA tests. RESULTS The cohort was composed of 121 patients with trigeminal neuralgia and 205 patients with hemifacial spasm. The superior petrosal vein and its tributaries were preserved with no serious complications in all patients with trigeminal neuralgia. Venous compression alone and arterial and venous compressions were observed in 4% and 22%, respectively, of the patients with trigeminal neuralgia, and in 1% and 2%, respectively, of those with hemifacial spasm (p < 0.0001). In patients with trigeminal neuralgia, 35% of those with artery and venous compressions and 80% of those with venous compression alone had atypical neuralgia (p = 0.015). The surgical cure and recurrence rates of trigeminal neuralgias with venous compression were 60% and 20%, respectively, and with arterial and venous compressions the rates were 92% and 12%, respectively (p < 0.0001, p = 0.04). In patients with hemifacial spasm who had arterial and venous compressions, their recurrence rate was 60%, and that was significantly higher compared to other compression types (p = 0.0008). CONCLUSIONS Dissection of the arachnoid sleeve that envelops the superior petrosal vein may help to reduce venous complications in surgery for trigeminal neuralgia. Venous compression may correlate with worse prognosis even with thorough decompression, in both trigeminal neuralgia and hemifacial spasm.

Role of the petrous ridge and angulation of the trigeminal nerve in the pathogenesis of trigeminal neuralgia, with implications for microvascular decompression.

INTRODUCTION: Vascular compression is the main pathogenetic factor in apparently primary trigeminal neuralgia; however some patients may present with clinically classical neuralgia but no vascular conflict on MRI or even at surgery. Several factors have been cited as alternative or supplementary factors that may cause neuralgia. This work focuses on the shape of the petrous ridge at the point of exit from the cavum trigeminus as well as the angulation of the nerve at this point. METHODS: Patients with trigeminal neuralgia that had performed a complete imagery workup according to our protocol and had microvascular decompression were included as well as ten controls. In all subjects, the angle of the petrous ridge as well as the angle of the nerve on passing over the ridge were measured. These were compared from between the neuralgic and the non-neuralgic side and with the measures performed in controls. RESULTS: In 42 patients, the bony angle of the petrous ridge was measured to be 86° on the neuralgic side, significantly more acute than that of controls (98°, p = 0.004) and with a trend to be more acute than the non-neuralgic side (90°, p = 0.06). The angle of the nerve on the side of the neuralgia was measured to be on average 141°, not significantly different either from the other side (144°, p = 0.2) or from controls (142°, p = 0.4). However, when taking into account the grade of the conflict, the angle was significantly more acute in patients with grade II/III conflict than on the contralateral side, especially when the superior cerebellar artery was the conflicting vessel. CONCLUSION: This pilot study analyzes factors other than NVC that may contribute to the pathogenesis of the neuralgia. It appears that aggressive bony edges may contribute-at least indirectly-to the neuralgia. This should be considered for surgical indication and conduct of surgery when patients undergo MVD.

[Anatomy and management of superior petrosal vein in microvascular decompression for trigeminal neuralgia].

Objective: To investigate the characteristics of superior petrosal vein (SPV) and its influence on the surgical field in microvascular decompression (MVD) for trigeminal neuralgia (TN), and to analyze the effect of the surgical treatment of SPV on the surgical approach, indication and prognosis. Methods: The clinical data of 280 patients with trigeminal neuralgia between Jan. 2013 and Jun. 2016 were collected, including the trunks and the branches of SPV, intraoperative electrocoagulation status, the surgery outcome and complications. Results: The petrosal vein during the operation was fully preserved in 152 cases (54.29%). The SPV were completely sectioned in 25 cases (8.92%), while some branches of SPV were sectioned in 103 cases (36.79%). We found that SPV have 1 to 3 trunks, accounted for 67 cases (23.90%), 168 cases (60%), and 45 cases (16.10%), while the SPV with 1 to 4 branches accounted for 17 cases (6.07%), 112 cases (40%), 136 cases (48.57%), and 15 cases (5.36%). The SPV was identified as offending vessel in 17 cases (6.07%). One patient with cutoff SPV trunk encountered cerebellar infarction and recovered completely at 2 weeks after MVD by using intravenous medication. Conclusions: MVD is the recommended treatment method for PTN, mostly SPV is unnecessary to be sectioned completely and small branches of SPV could be sacrificed. Very few patients may develop cerebellar infarction or hematoma.

[The study of hearing loss after microvascular decompression for hemifacial spasm].

Objective: To compare the difference of hearing loss after microvascular decompression for hemifacial spasm between control and experimental groups, and to explore the possible causes. Methods: A retrospective analysis including 443 patients was performed, including 203 cases of group A (before the operation was improved) and 240 cases of group B (after the operation was improved). Chi-square test was used to compare the rate of hearing loss. Results: There were 18(8.9%) cases with postoperative hearing loss in group A, including 9 cases of conductive hearing loss and 9 cases of sensorineural hearing loss.While 2 cases of conductive hearing loss and 3 cases of sensorineural hearing loss occurred in group B. Conductive hearing loss and sensorineural hearing loss of two groups had the significant deference (P=0.015 and P=0.04). Conclusion: The type of hearing loss after microvascular decompression for hemifacial spasm included conductive and sensorineural hearing loss.It could be reduced by early closing of the mastoid air chamber, avoiding continuous traction of the cerebellum, avoiding excessive irrigation and exhaust, and intraoperative auditory brainstem evoked potential monitoring.

Sumatriptan improves postoperative quality of recovery and reduces postcraniotomy headache after cranial nerve decompression.

BACKGROUND: Microvascular decompression (MVD) is a surgical treatment for cranial nerve disorders via a small craniotomy. The postoperative pain of this procedure can be classified as surgical site somatic pain and postcraniotomy headache similar in nature to a migraine, including its association with photophobia, nausea, and vomiting. This headache can be difficult to treat and can impact on postoperative recovery. Sumatriptan is used to treat migraine-like headaches in various settings. This single-centre randomized controlled trial investigated whether postoperative administration of sumatriptan after MVD surgery impacts the quality of postoperative recovery. METHODS: Fifty patients who complained of postoperative headache after MVD were randomized to receive an s.c. injection of sumatriptan (6 mg) or saline. The primary outcome was quality of recovery as measured by the Quality of Recovery-40 (QoR-40) score at 24 h. RESULTS: The QoR-40 scores were significantly higher in the sumatriptan group (median 184; interquartile range 169-196) than in the placebo group (133; 119-155; P<0.01), suggesting higher quality of recovery. The sumatriptan group also had significantly lower headache scores at 4, 12, and 24 h. There were no significant differences in other secondary outcomes. CONCLUSIONS: Use of sumatriptan improved the quality of recovery as measured by the QoR-40 and reduction of headache at 24 h after surgery. Sumatriptan is a useful alternative treatment for postcraniotomy headache. The mechanism remains unknown but could be related to reduction in headache, mood modulation, or both, mediated by a serotonin effect. CLINICAL TRIAL REGISTRATION: NCT01632657.

Factors associated with outcomes following microvascular decompression for the treatment of primary trigeminal neuralgia in adults: a systematic review and meta-analysis.

This study aimed to evaluate pain assessment strategies and factors associated with outcomes after microvascular decompression for the treatment of primary trigeminal neuralgia in adults. We conducted a systematic review and meta-analysis of English, Spanish, and French literature. We searched three databases, PubMed, Ovid, and EBSCO, from 2010 to 2022 and selected studies including patients with primary trigeminal neuralgia, clear pain assessment, and pain outcomes. Population means and standard deviations were calculated. Studies that included factors associated with postoperative outcomes were included in the meta-analysis. A total of 995 studies involving 5673 patients with primary trigeminal neuralgia following microvascular decompression were included. Patients with arteries compressing the trigeminal nerve demonstrated optimal outcomes following microvascular decompression (odds ratio [OR]= 0.39; 95% confidence interval [CI] = 0.19-0.80; X2 = 46.31; Dof = 15; I2 = 68%; P = < 0.0001). Conversely, when comparing arterial vs venous compression of the trigeminal nerve (OR = 2.72; 95% CI = 1.16-6.38; X2 = 23.23; Dof = 10; I2 = 57%; P = 0.01), venous compression demonstrated poor outcomes after microvascular decompression. Additionally, when comparing single-vessel vs multiple-vessel compression (OR = 2.72; 95% CI = 1.18-6.25; X2 = 21.17; Dof = 9; I2 = 57%; P = 0.01), patients demonstrated unfavorable outcomes after microvascular decompression. This systematic review and meta-analysis evaluated factors associated with outcomes following microvascular decompression (MVD) for primary trigeminal neuralgia (PTN). Although MVD is an optimal treatment strategy for PTN, a gap exists in interpreting the results when considering the lack of evidence for most pain assessment strategies.

Preliminary Report of Fully Endoscopic Microvascular Decompression.

Objective: Microscopic microvascular decompression (MVD) has been considered to be a useful treatment modality for medically refractory hemifacial spasm (HFS) and trigeminal neuralgia (TN). But, the advent of the endoscopic era has presented new possibilities to MVD surgery. While the microscope remains a valuable tool, the endoscope offers several advantages with comparable clinical outcomes. Thus, fully endoscopic MVD (E-MVD) could be a reasonable alternative to microscopic MVD. This paper explores the safety and efficacy of the fully E-MVD technique. Methods: A single-center retrospective study was conducted in 25 patients diagnosed with HFS between September 2019 and July 2023. All surgeries were performed by a single neurosurgeon using the fully E-MVD technique without any assistance of a microscope. The study reviewed intraoperative brainstem auditory evoked potentials and disappearance of the lateral spread response. Outcomes were assessed based on the patients' clinical status immediately after surgery and at their last follow-up. Complications, including facial palsy, hearing loss, ataxia, dysphagia, palsy of other cranial nerves, and cerebrospinal fluid (CSF) leakage, were also examined. Results: The most common offending artery was the anterior inferior cerebellar artery (AICA) in 15 cases (60.0%), followed by the posterior inferior cerebellar artery (PICA) in 8 cases (32.0%), vertebral artery (VA) in 1 case (4.0%), tandem lesions involving the AICA and VA in 1 case (4.0%). Ten patients (40.0%) had pre-operative facial palsy on the ipsilateral side, and 8 patients (32.0%) experienced delayed facial palsy on the ipsilateral side, from which they fully recovered by the last follow-up. The median operation time was 105 minutes. All patients were symptom free immediately after surgery and at the last follow-up. One patient experienced a permanent complication, such as high-frequency hearing loss, from which he partially recovered over time. Conclusion: Fully E-MVD demonstrated similar clinical outcomes to microscopic MVD. It offered a similar complication rate, shorter operation time, and a panoramic view with a smaller craniectomy size. Although there is a learning curve associated with fully E-MVD, it presents a viable alternative in the endoscopic era.

Results from 228 Patients with Hemifacial Spasm Undergoing Microvascular Decompression without Intraoperative Neuroelectrophysiology Monitoring.

BACKGROUND: Intraoperative neuroelectrophysiology monitoring (IONM) has been used to decrease complications and to increase the successful rate of microvascular decompression (MVD) MVD for hemifacial spasm (HFS). Still, it is not available at limited resource centers. We report the outcome of patients undergoing MVD for HFS without using IONM. METHODS: The variables concerning the patients' demographics (age and gender), clinical characteristics, offending vessels (vertebral artery type and non-vertebral artery type), postoperative grade of HFS, and postoperative complications of HFS patients undergoing MVD were retrospectively reviewed and collected. The scoring system provided by the Japan Society for MVD was used to evaluate the postoperative outcome of HFS. Postoperative hearing ability was evaluated according to a subjective assessment of the patients. RESULTS: A total of 228 patients were recruited. Their median age was 51.0 (44.0-57.0) years old. The total cure effect was observed in 207 (90.8%) patients within the first week after the surgery and in 200 (96.1%) patients in a 2-year follow-up. Permanent hearing disturbance happened in 2 patients (0.9%). No patient had permanent unilateral deafness (0%). No postoperative permanent facial paralysis was reported. CONCLUSIONS: MVD without IONM may be performed safely and effectively to treat patients with HFS.

Prediction of hemifacial spasm re-appearing phenomenon after microvascular decompression surgery in patients with hemifacial spasm using dynamic susceptibility contrast perfusion MRI.

Objective: Hemifacial spasm (HFS) is treated by a surgical procedure called microvascular decompression (MVD). However, HFS re-appearing phenomenon after surgery, presenting as early recurrence, is experienced by some patients after MVD. Dynamic susceptibility contrast (DSC) perfusion MRI and two analytical methods: receiver operating characteristic (ROC) curve and machine learning, were used to predict early recurrence in this study. Methods: This study enrolled sixty patients who underwent MVD for HFS. They were divided into two groups: Group A consisted of 32 patients who had early recurrence, and Group B consisted of 28 patients who had no early recurrence of HFS. DSC perfusion MRI was undergone by all patients before the surgery to obtain the several parameters. ROC curve and machine learning methods were used to predict early recurrence using these parameters. Results: Group A had significantly lower relative cerebral blood flow (rCBF) than Group B in most of the selected brain regions, as shown by the region-of-interest (ROI)-based analysis. By combining three extraction fraction (EF) values at middle temporal gyrus, posterior cingulate, and brainstem, with age, using naive Bayes machine learning method, the best prediction model for early recurrence was obtained. This model had an area under the curve (AUC) value of 0.845. Conclusion: By combining EF values with age or sex using machine learning methods, DSC perfusion MRI can be used to predict early recurrence before MVD surgery. This may help neurosurgeons to identify patients who are at risk of HFS recurrence and provide appropriate postoperative care.

Task force of the Brazilian Society of Otology - evaluation and management of peripheral facial palsy.

OBJECTIVE: To review key evidence-based recommendations for the diagnosis and treatment of peripheral facial palsy in children and adults. METHODS: Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on peripheral facial palsy were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions. RESULTS: The topics were divided into 2 main parts: (1) Evaluation and diagnosis of facial palsy: electrophysiologic tests, idiopathic facial palsy, Ramsay Hunt syndrome, traumatic peripheral facial palsy, recurrent peripheral facial palsy, facial nerve tumors, and peripheral facial palsy in children; and (2) Rehabilitation procedures: surgical decompression of the facial nerve, facial nerve grafting, surgical treatment of long-term peripheral facial palsy, and non-surgical rehabilitation of the facial nerve. CONCLUSIONS: Peripheral facial palsy is a condition of diverse etiology. Treatment should be individualized according to the cause of facial nerve dysfunction, but the literature presents better evidence-based recommendations for systemic corticosteroid therapy.

A Case With Twists and Turns: A Report of Vertebrobasilar Dolichoectasia.

Vertebrobasilar dolichoectasia (VBD) is a rare anatomical abnormality of the vertebral artery system, defined as irregular expansion, elongation, and tortuosity of vertebral arteries. Anomalies of the vertebrobasilar artery can have a wide variety of clinical presentations, ranging from simple headaches to debilitating strokes. We present the case of an atypical presentation of VBD which mimicked trigeminal neuralgia by compressing the trigeminal nerve. There are currently no guidelines concerning the management of VBD, nor is there evidence of a definitive cure. This case invoked discussions among the medical team as to whether management should be medically or surgically focused, as well as long-term outcomes for patients with VBD. The superiority of medical versus surgical treatment of this issue is still a debated topic. This patient trialed medical management with dexamethasone and carbamazepine with no improvement in symptoms. He then underwent surgical gamma knife treatment but even this invasive measure was unsuccessful at relieving his symptoms. We hope that by presenting this case, we can display how the therapies available for VBD are limited and often unsuccessful in relieving the disease burden in patients with VBD.

5-Hydroxytryptamine and postoperative nausea and vomiting after microvascular decompression surgery.

BACKGROUND: The incidence of postoperative nausea and vomiting (PONV) after microvascular decompression (MVD) surgery is high; however, its underlying mechanisms remain unknown. Serum 5-hydroxytryptamine (5-HT) levels are elevated in patients with PONV. However, the relationship between 5-HT and patients experiencing PONV after MVD surgery is still unknown. Therefore, we hypothesized that 5-HT levels are associated with PONV after MVD surgery. METHODS: This prospective study included 85 patients with hemifacial spasm who received MVD surgery. Blood samples were collected preoperatively, postoperatively, and on postoperative day 1, and cerebrospinal fluid samples were collected intraoperatively. 5-HT levels were detected by enzyme-linked immunosorbent assay (ELISA). The incidence and severity of PONV were evaluated at 2, 6, and 24 h after MVD surgery. RESULTS: In the multivariate regression analysis, PONV within 24 h after MVD surgery was associated with elevated cerebrospinal fluid 5-HT levels [odds ratio (OR) = 1.21, 95% confidence interval (CI): 1.01-1.45, p = 0.044], and reduction of intraocular pressure [OR = 11.54, 95% CI: 1.43-92.84, p = 0.022]. Receiver operating characteristic curve analysis revealed an area under the curve of 0.873 (95% CI: 0.77-0.98, p < 0.001). CONCLUSION: Our study found that the cerebrospinal fluid 5-HT levels is an independent risk factor for PONV within 24 h after MVD surgery.