To be thorough or tailored: influence of the arachnoid dissection range on the surgical outcomes of microvascular decompression for hemifacial spasm.

BACKGROUND: As one of the most fundamental elements in exposure and decompression, the dissection of arachnoid has been rarely correlated with the surgical results in studies on Microvascular decompression (MVD) procedures for Hemifacial spasm (HFS). MATERIALS AND METHODS: Patients' records of the HFS cases treated with MVD from January 2016 to December 2021 in our center was retrospectively reviewed. The video of the procedures was inspected thoroughly to evaluate the range of dissection of arachnoid. Four areas were defined in order to facilitate the evaluation of the dissection range. The correlation between the arachnoid dissection and the surgical outcomes were analyzed. RESULTS: The arachnoid structures between the nineth cranial nerve and the seventh, eighth cranial nerves were dissected in all cases, other areas were entered based on different consideration. The rate of neurological complications of the extended dissection pattern group was higher than that of the standard pattern group (P < 0.05). The procedures in which the arachnoid structure above the vestibulocochlear nerve was dissected, led to more neurological complications (P < 0.05). CONCLUSION: Thorough dissection as an initial aim for all cases was not recommended in MVD for HFS, arachnoid dissection should be tailored to achieving safety and effectiveness during the procedure.

GPR65 sensing tumor-derived lactate induces HMGB1 release from TAM via the cAMP/PKA/CREB pathway to promote glioma progression.

BACKGROUND: Lactate has emerged as a critical regulator within the tumor microenvironment, including glioma. However, the precise mechanisms underlying how lactate influences the communication between tumor cells and tumor-associated macrophages (TAMs), the most abundant immune cells in glioma, remain poorly understood. This study aims to elucidate the impact of tumor-derived lactate on TAMs and investigate the regulatory pathways governing TAM-mediated tumor-promotion in glioma. METHODS: Bioinformatic analysis was conducted using datasets from TCGA and CGGA. Single-cell RNA-seq datasets were analyzed by using UCSC Cell Browser and Single Cell Portal. Cell proliferation and mobility were evaluated through CCK8, colony formation, wound healing, and transwell assays. Western blot and immunofluorescence staining were applied to assess protein expression and cell distribution. RT-PCR and ELISA were employed to identify the potential secretory factors. Mechanistic pathways were explored by western blotting, ELISA, shRNA knockdown, and specific inhibitors and activators. The effects of pathway blockades were further assessed using subcutaneous and intracranial xenograft tumor models in vivo. RESULTS: Elevated expressions of LDHA and MCT1 were observed in glioma and exhibited a positive correlation with M2-type TAM infiltration. Lactate derived from glioma cells induced TAMs towards M2-subtype polarization, subsequently promoting glioma cells proliferation, migration, invasion, and mesenchymal transition. GPR65, highly expressed on TAMs, sensed lactate-stimulation in the TME, fueling glioma cells malignant progression through the secretion of HMGB1. GPR65 on TAMs triggered HMGB1 release in response to lactate stimulation via the cAMP/PKA/CREB signaling pathway. Disrupting this feedback loop by GPR65-knockdown or HMGB1 inhibition mitigated glioma progression in vivo. CONCLUSION: These findings unveil the intricate interplay between TAMs and tumor cells mediated by lactate and HMGB1, driving tumor progression in glioma. GPR65, selectively highly expressed on TAMs in glioma, sensed lactate stimulation and fostered HMGB1 secretion via the cAMP/PKA/CREB signaling pathway. Blocking this feedback loop presents a promising therapeutic strategy for GBM.

Beyond the observation of all or nothing: The clinical significance of the pre-decompression instability of abnormal muscle response in Microvascular decompression for Hemifacial spasm.

BACKGROUND: In microvascular decompression (MVD) surgery, abnormal muscle response (AMR) monitoring was utilized to confirm sufficient decompression. However, the AMR seems to contain more information that could improve surgical results. METHOD: Patients' records of HFS treated with MVD under AMR monitoring, from January 2018 to December 2019 in our centre, were retrospectively reviewed. MVD procedures were performed via a suboccipital retrosigmoid approach, and AMR monitoring was performed. Pre-Decompression Instability (PDI) of AMR before the final decompression, including amplitude inconsistency and waveform chaos, was inspected and notified to the surgeon. RESULT: 165 cases were found with full follow-up data. In these cases, PDI was recognized in 144 cases. And in the remaining 21 cases, the AMR disappeared abruptly or continued to exist to the end of the MVD surgery. When PDI appeared, the rate of electrophysiological relief was significantly higher (91.7 % vs 66.7 %, P = 0.001). In cases with PDI appearance during MVD procedure, the rate of neurological dysfunction was lower (13.2 % vs 38.1 %, P = 0.004). The relief rate the PDI group tended to be higher without statistical significance. CONCLUSION: The appearance and observation of pre-decompression instability of AMR monitoring made a positive impact on the surgical outcomes of MVD surgeries. The advent of PDI indicates that the key step of the procedure has arrived. The timely notification of the PDI advent improved the surgical outcomes of MVD surgery by increasing the electrophysiological relief rate, reducing the incidence of neurological dysfunction, and possible elevation of the relief rate. Therefore, continuous intra-operative communication between the surgeon and electrophysiological monitoring staff should be encouraged.

Neuronavigation-Guided Transcortical-Transventricular Endoport-Assisted Endoscopic Resection for Thalamic Lesions: Preliminary Experience.

BACKGROUND: Surgery for thalamic lesions is generally challenging because they are deep-seated lesions surrounded by vital neurovascular structures. Whether neuronavigation-guided transcortical-transventricular endoport-assisted endoscopic resection for thalamic lesions is feasible remains to be further evaluated. METHODS: A retrospective review of 8 who patients received neuronavigation-guided transcortical-transventricular endoport-assisted endoscopic resection for thalamic lesions was performed. Preoperative and tumor-related variables and postoperative outcomes were analyzed. RESULTS: All lesions were located in the medial part of the thalamus, and most of them expanded forward, downward, or backward. Median size of lesions was 31 mm (range, 16-52 mm). Final pathology results confirmed that 1 case was a cavernous malformation, 3 were pilocytic astrocytomas, and 4 were glioblastomas. None of the patients had postoperative seizures. Gross total resection and long-term postoperative survival were achieved in all patients with benign lesions, while near-total resection (>90%) was achieved in 3 of 4 patients (75%) with glioblastoma, and subtotal resection (<90%) was achieved in 1 patient (25%). Among patients with glioblastoma, 1 patient remained free of recurrence at 16 months of follow-up; the other 3 patients had worse Karnofsky performance scale scores after surgery and died within 6 months. CONCLUSIONS: Combining the advantages of neuronavigation, endoscopy, and endoport techniques via the middle frontal gyrus approach can safely and effectively remove benign lesions in the medial part of the thalamus. This procedure can also be performed in well-selected cases of glioblastoma and likely confers a survival advantage for this rapidly and universally fatal disease.

Is MVD the effective treatment for poorly controlled hypertension?

BACKGROUND: Studies have shown that microvascular decompression (MVD) surgery could improve the clinical symptoms of hemifacial spasm (HFS) and decrease the blood pressure (BP) in patients with refractory hypertension. More positive long-term results are required to establish MVD as a treatment option for high blood pressure (HBP) and to refine the patient selection criteria. METHODS: From October 2015 to September 2018, based on patient selection for cases with both HFS and poorly controlled HBP of nervous origin, MVD surgeries were performed on 12 patients aiming for better BP control. The patients were followed-up for at least 2 years. The surgical outcomes and associated factors were analyzed. RESULTS: With respect to neurovascular compression (NVC) of facial nerve, the intra-operative findings concurred with pre-operative radiological findings except that in one case. Intra-operatively ipsilateral cranial nerve (CN) IX-X root exit zone (REZ) and rostral ventrolateral medulla (RVLM) NVCs were confirmed and concordant with pre-operative radiological findings in all 12 cases. 9 Of the 12 cases were completely free of facial spasm after surgery. 2 patients achieved partial relief. 1 patient still suffered from frequent facial spasm. 10 out of 12 patients achieved BP lowering after surgery. The BP of those 10 patients stayed at a relatively stable scale over the follow-up period. Although statistical significance was not obtained, for patients who are operated on the left side and those who have only 1 offensive artery, the surgery might lead to better BP control. CONCLUSIONS: MVD is a safe and effective treatment for hypertension due to central nervous system (CNS) NVC in patients with both HBP and HFS. Further studies are required to examine long-term outcomes and establish criteria for patient selection.

Serum phosphate: Does it more closely reflect the true state of acromegaly?

An increased serum phosphate (P) level is common in acromegaly patients, however, the relationships among P, growth hormone (GH), insulin-like growth factor 1 (IGF-1) and disease status remain unknown. To reveal these relationships, we examined the association of P with comprehensive clinical data. We measured the serum P, calcium, GH, oral glucose tolerance test-GH (OGTT-GH), IGF-1, and insulin-like growth factor binding protein-3 (IGBP-3) levels in 103 acromegaly patients. SAGIT® was used to assess the disease status comprehensively. Spearman's rank correlation coefficient was obtained to evaluate the associations among the above parameters. Stepwise multiple linear regression analysis was performed to investigate factors independently associated factors with the SAGIT scores. The area under the receiver operating characteristic curve (AUCROC) was used to evaluate the efficacy of the percentage change in the serum phosphate level in predicting remission in patients with postoperatively discordant GH and IGF-1 levels. Hyperphosphatemia was found in 68.9% of patients at baseline. The serum P level was higher in the non-remission group, but no correlation was found between hyperphosphatemia and remission. We revealed a significant correlation between the P level and SAGIT® score in patients both preoperatively (r = 0.659, p = 0.000) and 1-year postoperatively without remission patients (r = 0.534, p = 0.027). All biochemical levels decreased significantly postoperatively, and the GH and OGTT-GH levels achieved early stability (1 month); however, the P, IGF-1 and IGBP-3 levels showed a gradual decline. A percentage change in P of -8.12% is recommended as a cut-off value for predicting remission in patients with postoperatively discordant GH and IGF-1 levels. As a metabolic product which affected by the GH/IGF-1 axis, serum P appears to more closely reflect the comprehensive disease status in acromegaly. When the GH and IGF-1 levels are discordant during follow-up, perioperative change in the P level may be a potential predictor of remission.

AMR monitoring in microvascular decompression for hemifacial spasm: 115 cases report.

In MVD operations assisted by AMR monitoring, the reliability and validity of decompression can be evaluated by observing whether AMR disappears. Although intraoperative AMR monitoring has been used widely, debate exists over its reliability and positive contribution. In this series, 115 cases of HFS treated with MVD operations with AMR monitoring were enrolled. All MVD procedures were performed via a suboccipital retrosigmoid approach. Microscope and endoscope were used alternately as was needed. Medtronic Nim-eclipse system was used for intra-operative AMR monitoring. The zygomatic branch of the facial nerve was stimulated and AMRs were recorded form the mentalis muscle. In 112 of the 115 cases, AMR was recorded during operation. In the 112 cases with typical AMR, AMR disappeared in 105 cases. Among the 105 cases, 79 achieved immediate cure after operation, 21 were spasm-free within 6-month follow-up, and the symptom of 5 cases persisted at 6-month follow-up. Among the 7 cases whose AMR did not disappear at the end of operation, 2 cases achieved immediate cure and 2 cases achieved delayed relief. For those cases with electrophysiological relief, the overall relief rate was 95.2% (100/105); for those with persistent AMR, the overall relief rate was 57.1% (4/7, P < 0.05). In conclusion, AMR monitoring provide valuable information to MVD operation for HFS. The use and investigation of AMR will undoubtedly contribute to the understanding and curing of HFS.

The Purely Endoscopic Supracerebellar Infratentorial Approach for Resecting Pineal Region Tumors with Preservation of Cerebellomesencephalic Vein: Technical Note and Preliminary Clinical Outcomes.

BACKGROUND: The cerebellomesencephalic vein (CMV) was frequently sacrificed in surgery approached via the supracerebellar infratentorial (SCIT) route for resecting pineal region tumors, which resulted in potential risk of neurologic deficit. Preserving the CMV in the SCIT approach could enhance the safety and effectiveness of this natural corridor surgery. The aim of this article was to identify the probability and safety of preserving the CMV through the application of neuroendoscopy in the SCIT approach. METHODS: Clinical data of patients who underwent pineal region tumor resection through a purely endoscopic SCIT approach were retrospectively analyzed, focusing on surgical techniques and clinical outcomes. RESULTS: The study included 8 patients with pineal region tumors. The CMV was preserved intact in all patients. Total tumor removal was achieved in 7 of 8 patients. In 1 patient with 2 tumors in the pineal region and roof of the third ventricle, the tumor in the pineal region was resected completely, followed by subsequent chemotherapy combined with radiotherapy, after which the other tumor disappeared totally. All patients recovered normally with uneventful postoperative outcomes. CONCLUSIONS: The advantage of close observation and panoramic view provided by neuroendoscopy combined with meticulous manipulation improved the ability to preserve the CMV in resecting pineal region tumors via the SCIT approach. The neuroendoscopic technique enhances the safety and efficacy of the SCIT approach.

Dynamic changes in the distribution of facial and abdominal adipose tissue correlated with surgical treatment in acromegaly.

PURPOSE: Acromegaly is a systemic metabolic disease. Growth hormone (GH) have a significant impact on adipose tissue (AT). A huge reduction of serum GH after surgical treatment may cause substantial AT redistribution. The objective of this study was to illustrate the dynamic changes in distribution of facial and abdominal AT correlated with surgical treatment in patients with acromegaly. METHODS: Abdominal AT in 17 acromegaly patients (group 1) was studied longitudinally preoperatively and 1 month to 1 year postoperatively. The facial and abdominal subcutaneous AT (fSAT and aSAT) of another 17 acromegaly patients (group 2) were compared with 7 nonfunctional pituitary adenoma (NFPA) controls. The areas of fSAT, aSAT, and visceral adipose tissue (VAT) were obtained by MRI and quantified by image analysis software, and intrahepatic lipid (IHL) was assessed by 1H magnetic resonance spectroscopy (MRS). RESULTS: Abdominal adipose tissue (aSAT, VAT, and IHL) increased overall after surgical treatment. However, IHL first decreased and then continuously increased during the follow-up. Compared with the increased amount of aSAT, the fSAT amount decreased after surgical treatment. The inconsistency of this phenomenon did not appear in the NFPA control subjects. CONCLUSION: The perioperative dynamic distribution of the facial and abdominal fat in acromegaly revealed regional differences in the intricate effect of GH on adipose tissue. Reduction of serum GH after surgical treatment of acromegaly was associated with dynamic increases of IHL, abdominal visceral, and subcutaneous fat, but a reduction of facial subcutaneous fat.

A low cost and stepwise training model for skull base repair using a suturing and knotting technique during endoscopic endonasal surgery.

PURPOSE: Cerebrospinal fluid leakage is always the primary complication during the endoscopic endonasal skull base surgery. Dural suturing technique may supply a rescue method. However, suturing and knotting in such a deep and narrow space are difficult. Training in the model can improve skills and setting a stepwise curriculum can increase trainers' interest and confidence. METHODS: We constructed an easy model using silicone and acrylic as sphenoid sinus and using the egg-shell membrane as skull base dura. The training is divided into three steps: Step 1: extracorporeal knot-tying suture on the silicone of sphenoid sinus, Step 2: intra-nasal knot-tying suture on the same silicone, and Step 3: intra-nasal egg-shell membrane knot-tying suture. Fifteen experienced microneurosurgical neurosurgeons (Group A) and ten inexperienced PGY residents (Group B) were recruited to perform the tasks. Performance measures were time, suturing and knotting errors, and needle and thread manipulations. The third step was assessed through the injection of full water into the other side of the egg to verify the watertight suture. The results were compared between two groups. RESULTS: Group A finishes the first and second tasks in significantly less time (total time, 125.1 ± 10.8 vs 195.8 ± 15.9 min) and fewer error points (2.4 ± 1.3 vs 5.3 ± 1.0) than group B. There are five trainers in group A who passed the third step, this number in group B was only one. CONCLUSIONS: This low cost and stepwise training model improved the suture and knot skills for skull base repair during endoscopic endonasal surgery. Experienced microneurosurgical neurosurgeons perform this technique more competent.

Endoscopic Supracerebellar Transtentorial Approach to Atrium of Lateral Ventricle: Preliminary Surgical and Optical Considerations.

OBJECTIVE: We sought to report the operative techniques of the endoscopic supracerebellar transtentorial approach (ESTA) to the atrium of the lateral ventricle, especially focusing on the role of the endoscope and analyzing optically related issues. METHODS: A retrospective data review was performed on 5 patients with lesions in the atrium of the lateral ventricle undergoing the ESTA. The patients were positioned in the three quarters prone position, and a paramidline linear incision was used. After performing a suboccipital craniotomy extending immediately above the transverse sinus and tentorium incision with precisely neuronavigation, corticotomy in the posterior mediobasal temporal region created a corridor to the tumor. All of the procedures were performed with an endoscope in a pneumatic arm holder. The preoperative and postoperative perimetry test and diffusion tensor imaging fiber tracking of the optic radiations were compared and analyzed. RESULTS: Three patients had meningiomas, and 2 patients had high-grade gliomas in the atrium. The meningiomas were totally removed, and the gliomas were subtotally resected. One patient with glioblastoma died 2 months later after surgery because of the tumor progression; the remaining 4 patients had a visual field deficit without any other neurologic complications. The endoscope improved the surgical viewing angle, which was restricted by the microscope and slope of the tentorium. CONCLUSIONS: ESTA is an alternative route to the atrium of the lateral ventricle. However, the collateral sulcus, which is highly relied on in neuronavigation, is illegible in the limited area. And the visual field deficit remains the primary challenge with this approach.

Learning curve for the endoscopic endonasal approach for suprasellar craniopharyngiomas.

The endoscopic endonasal approach is considered an alternative minimally invasive approach for suprasellar craniopharyngiomas. However, the complicated surgical manipulations required by this approach have limited its application. We evaluate whether the approach features a learning curve. Thirty-three patients were retrospectively reviewed and grouped as early (17 patients) and late (16 patient) groups. The operation time, extent of removal, ophthalmology, endocrinology, reconstruction and modifications of standard technique were evaluated. Between the two groups, the operation time decreased from 201.1±105.3min in the early group to 107.6±90.0min in the late group (p<0.05). Regarding clinical outcomes, non-significantly increasing trends toward the rate of gross total resection, visual improvement and (from 76.5% to 87.5%, 73.3% to 93.3%), significantly decreasing trends toward the rate of tumor recurrence (from 23.5% to 0% p<0.05) and non-significantly decreasing trends toward the rate of hypopituitarism recovery (26.7% to 0%) were observed between the two groups. With respect to complications, non-statistically significant decreasing trends toward transient cranial nerve paralysis (from 5.9% to 0%) and non-statistically significant increasing trends toward rate of CSF leakage, meningitis and new hypothyroidism (from 11.8% to 25%, 11.8% to 31.3%, 0 to 3%) were observed. We identified a learning curve for the endoscopic endonasal approach for suprasellar craniopharyngiomas. The exact number of patients necessary to establish a significant improvement in the clinical outcomes and decrease in the complications warrants further investigation. The outcomes of tumor recurrence may be associated with duration of follow-up. The CSF leakage represented the most common complication.

Endoscopic Transnasal Odontoidectomy.

Transoral microscopic odontoidectomy followed by posterior fixation has been accepted as a standard procedure to treat nonreducible basilar invagination during the half past century. In recent years, the development of endoscopic techniques has raised challenges regarding the traditional treatment algorithm. The endoscopic transnasal odontoidectomy is a feasible and effective method in the treatment of irreducible ventral cervicomedullary junction compression, which has several advantages over the transoral approach. The endoscopic odontoidectomy includes transnasal, transoral, and transcervical approaches. The 3 different approaches for endoscopic odontoidectomy present complementary advantages and limitations. The necessity of posterior fixation after odontoidectomy should be considered in every single case on the basis of the peculiar anatomic and clinical conditions.

Suprachiasmatic translamina terminalis corridor used in endoscopic endonasal approach for resecting third ventricular craniopharyngioma.

OBJECT: The translamina terminalis corridor was used in the transcranial anterior route to treat third ventricular craniopharyngioma (TVC), which presents a challenge to neurosurgeons. The endoscopic endonasal approach (EEA) has recently been used to treat craniopharyngiomas. However, there are few reports of the EEA being used to treat TVC. The authors' novel surgical approach of treating selected TVC by the endoscopic endonasal route via the suprachiasmatic translamina terminalis (STLT) corridor is described. METHODS: In this single-center study, the EEA via the STLT corridor was used to resect TVC with great upper and anterior extension causing bulged lamina terminalis, and TVC with a residual upper compartment, after routine infrachiasmatic transmetastalk corridor resection. RESULTS: The STLT corridor was used in 3 patients. Gross-total resection was achieved in all cases. One patient achieved visual improvement, and the other 2 patients showed partial visual improvement. Leakage of CSF occurred in 1 patient. Postoperative hormone replacement therapy was required in all patients. CONCLUSIONS: The STLT corridor is a complementary minimally invasive corridor used in the EEA for treating selected TVC. The STLT alone or combined with infrachiasmatic transmetastalk corridors should be selected depending on the size of suprachiasmatic and infrachiasmatic space.

The contralateral transfalcine transprecuneus approach to the atrium of the lateral ventricle: operative technique and surgical results.

BACKGROUND: Surgical approaches to the atrium of the lateral ventricle remain a challenging neurosurgical issue because of the eloquent nature of the surrounding anatomy. OBJECTIVE: To report our operative techniques and preliminary surgical results with the contralateral transfalcine transprecuneus approach. METHODS: A retrospective data review was performed of patients undergoing a contralateral transfalcine transprecuneus approach for the resection of lesions in the atrium of the lateral ventricle. Patients were positioned in the prone position with a 30° elevation, and a 15° rotation was used. After a contralateral parasagittal parieto-occipital craniotomy and falx incision, the corticotomy in the contralateral precuneus gyrus created a corridor to the tumor. An endoscope was used to assist with the surgery. RESULTS: Headache was the primary preoperative symptom, which improved in all patients after surgery. After treatment, symptoms were improved in all 3 patients with hemiparesis and in 3 of 6 patients with preexisting visual deficits; symptoms were unchanged in the other 3 patients with visual deficits during the 13- to 38-month follow-up. Nine lesions were totally removed, and 1 metastatic breast cancer lesion was subtotally removed; all patients had good neurological outcomes and no operative mortality. CONCLUSION: The contralateral transfalcine transprecuneus approach is appropriate for most lesions in the atrium of the lateral ventricle. It provides a wider surgical angle (especially for the lateral extension) and reduces the risk of disturbance of the optic radiation compared with the conventional approaches. The use of magnetic resonance venography-magnetic resonance imaging neuronavigation makes the procedure much easier and more accurate, and the neuroendoscope adds to the visualization of the microscope and can reduce surgical complications.

Combined use of a gasket seal closure and a vascularized pedicle nasoseptal flap multilayered reconstruction technique for high-flow cerebrospinal fluid leaks after endonasal endoscopic skull base surgery.

OBJECTIVE: To assess the efficacy of the combined use of a gasket seal closure and a vascularized pedicle nasoseptal flap (VP-NSF) multilayered reconstruction technique for high-flow cerebrospinal fluid (CSF) leaks resulting from endonasal endoscopic skull base surgery. METHODS: From October 2009-June 2011, a VP-NSF multilayered reconstruction technique was used (single technique group) for patients with intraoperative high-flow CSF leaks; from July 2011-February 2013, a combination of a gasket seal closure and a VP-NSF multilayered reconstruction technique was used (combined technique group). A lumbar drain was placed after the operation. The rates of postoperative CSF leaks and repair-related complications in the 2 groups were analyzed. RESULTS: The single technique group comprised 18 patients with a mean follow-up of 31.7 months; there were 5 postoperative CSF leaks (27.7%). The combined technique group comprised 15 patients with a mean follow-up of 13.6 months; no CSF leaks occurred (P < 0.05). The rate of intracranial infection in the single technique group was significantly higher than in the combined technique group. CONCLUSIONS: The combined use of a gasket seal closure and a VP-NSF multilayered reconstruction technique for high-flow CSF leaks after endonasal endoscopic skull base surgery may significantly reduce the rates of postoperative CSF leaks and intracranial infections. Lumbar drainage after the operation is a necessary auxiliary method.

Information filtering via biased random walk on coupled social network.

The recommender systems have advanced a great deal in the past two decades. However, most researchers focus their attentions on mining the similarities among users or objects in recommender systems and overlook the social influence which plays an important role in users' purchase process. In this paper, we design a biased random walk algorithm on coupled social networks which gives recommendation results based on both social interests and users' preference. Numerical analyses on two real data sets, Epinions and Friendfeed, demonstrate the improvement of recommendation performance by taking social interests into account, and experimental results show that our algorithm can alleviate the user cold-start problem more effectively compared with the mass diffusion and user-based collaborative filtering methods.

Personalized privacy-preserving frequent itemset mining using randomized response.

Frequent itemset mining is the important first step of association rule mining, which discovers interesting patterns from the massive data. There are increasing concerns about the privacy problem in the frequent itemset mining. Some works have been proposed to handle this kind of problem. In this paper, we introduce a personalized privacy problem, in which different attributes may need different privacy levels protection. To solve this problem, we give a personalized privacy-preserving method by using the randomized response technique. By providing different privacy levels for different attributes, this method can get a higher accuracy on frequent itemset mining than the traditional method providing the same privacy level. Finally, our experimental results show that our method can have better results on the frequent itemset mining while preserving personalized privacy.

To repeat or to recreate: a contralateral posterior interhemispheric transfalcine transprecuneus approach for recurrent meningiomas at the trigone of the lateral ventricle.

Surgery in the trigone of the lateral ventricle remains a challenge for neurosurgeons. In recurrent trigonal meningiomas (RTM), the disturbance of normal anatomic structures and adhesion due to previous surgeries, significant oedema, and their malignant properties heighten the difficulties associated with their surgical removal. This report presents two patients with recurrent meningiomas with anaplastic transformation at the trigone of the lateral ventricle who were successfully treated with contralateral posterior interhemispheric transfalcine transprecuneus (CITT) surgeries. The primary tumours were both completely removed through a transparietal approach in previous surgeries, but both patients experienced hemianopsia postoperatively. The second surgeries resulted in the complete resection of the recurrent tumours without any new-onset neurological dysfunction. The CITT approach suits most trigonal lesions with advantages of optic radiation preservation, reduction of retraction, improved exposure, and navigation accuracy, and because it addresses the origin of the trigonal lesion. Although the characteristics of RTM heighten the difficulty associated with their surgical removal, these challenges highlight the advantages of the CITT approach. In conclusion, the CITT approach is a safe and effective procedure for the removal of RTM.

Endoscopic transnasal odontoidectomy combined with posterior reduction to treat basilar invagination: technical note.

OBJECT: Transoral microscopic odontoidectomy has been accepted as a standard procedure to treat basilar invagination over the past several decades. In recent years the emergence of new technologies, including endoscopic odontoidectomy and posterior reduction, has presented a challenge to the traditional treatment algorithm. In this article, the authors describe 1 patient with basilar invagination who was successfully treated with endoscopic transnasal odontoidectomy combined with posterior reduction. The purpose of this report is to validate the effectiveness of this treatment algorithm in selected cases and describe several operative nuances and pearls based on the authors' experience. METHODS: One patient with basilar invagination caused by a congenital osseous malformation underwent endoscopic transnasal odontoidectomy combined with posterior reduction in a single operative setting. The purely endoscopic transnasal odontoidectomy was first conducted with the patient supine. The favorable anatomical reduction was then achieved through a posterior approach after the patient was moved prone. RESULTS: The patient was extubated after recovery from anesthesia and allowed oral food intake the next day. No complications were noted, and the patient was discharged 4 days after the operation. Postoperative imaging demonstrated excellent decompression of the anterior cervicomedullary junction pathology. The patient was followed up for 12 months and remarkable neurological recovery was observed. CONCLUSIONS: The endoscopic transnasal odontoidectomy is a better minimally invasive approach for anterior decompression and can make the posterior reduction easier because the anterior resistant force is eliminated. The subsequent posterior reduction can make decompression of the ventral side of the cervicomedullary junction more effective because the C-2 vertebral body is pushed forward. A combination of these 2 approaches has the advantages of minimally invasive access and a faster patient recovery, and thus is a valid alternative in selected cases.