Novel standardized indexes of brainstem auditory evoked potentials for predicting hearing preservation in vestibular schwannomas.

Hearing preservation (HP) during vestibular schwannomas (VSs) surgery poses a significant challenge. Although brainstem auditory evoked potentials (BAEPs) on the affected side are commonly employed to monitor cochlear nerve function, their low signal-to-noise ratio (SNR) renders them susceptible to interferences, compromising their reliability. We retrospectively analyzed the data of patients who underwent tumor resection, while binaural brainstem auditory evoked potentials (BAEPs) were simultaneously recorded during surgery. To standardize BAEPs on the affected side, we incorporated the synchronous healthy side as a reference (interval between affected and healthy side ≤ 3 min). A total of 127 patients were enrolled. Comparison of the raw BAEPs data pre- and post-tumor resection revealed that neither V-wave amplitude (Am-V) nor latency (La-V) could serve as reliable predictors of HP simultaneously. However, following standardization, V-wave latency (STIAS-La-V) and amplitude (STIAS-Am-V) emerged as stable predictors of HP. Furthermore, the intraoperative difference in V-wave amplitude (D-Am-V) predicted postoperative HP in patients with preoperative HP and remained predictive after standardization. The utilization of intraoperative synchronous healthy side BAEPs as a reference to eliminate interferences proves to be an effective approach in enhancing the reliability of BAEPs for predicting HP in VSs patients.

The role of the nucleus basalis of Meynert in neuromodulation therapy: a systematic review from the perspective of neural network oscillations.

As a crucial component of the cerebral cholinergic system and the Papez circuit in the basal forebrain, dysfunction of the nucleus basalis of Meynert (NBM) is associated with various neurodegenerative disorders. However, no drugs, including existing cholinesterase inhibitors, have been shown to reverse this dysfunction. Due to advancements in neuromodulation technology, researchers are exploring the use of deep brain stimulation (DBS) therapy targeting the NBM (NBM-DBS) to treat mental and neurological disorders as well as the related mechanisms. Herein, we provided an update on the research progress on cognition-related neural network oscillations and complex anatomical and projective relationships between the NBM and other cognitive structures and circuits. Furthermore, we reviewed previous animal studies of NBM lesions, NBM-DBS models, and clinical case studies to summarize the important functions of the NBM in neuromodulation. In addition to elucidating the mechanism of the NBM neural network, future research should focus on to other types of neurons in the NBM, despite the fact that cholinergic neurons are still the key target for cell type-specific activation by DBS.

A Systematic Review of Repeat Microvascular Decompression for Recurrent or Persistent Trigeminal Neuralgia.

OBJECTIVE: When conservative therapy fails, microvascular decompression (MVD) has been the preferred treatment of primary trigeminal neuralgia (TN). However, the management of recurrent or persistent TN after MVD can often be difficult. The purpose of the present systematic review was to objectively analyze and summarize the reported literature regarding the feasibility of repeat MVD. METHODS: We conducted a database search using the MEDLINE and PubMed databases until July 2020. The search terms used for title and abstract screening were as follows: "recurrent trigeminal neuralgia," "persistent trigeminal neuralgia," "repeat microvascular decompression," and "reexploration." The inclusion criteria for the systematic review were as follows: clinical studies (excluding case studies), repeat MVD treatment of TN, and studies that had recorded the pain relief outcomes, operative findings, and complications (if any). RESULTS: Of the 1771 initial results obtained, we performed a full text screening of 43 studies, and, ultimately, 19 were deemed eligible. A total of 2247 patients had undergone MVD for TN, of whom, 311 had experienced recurrence (13.84%). Of the 311 patients, 178 had undergone repeat MVD. The average pain-free interval was 27.75 months after the first MVD. The effective rate of repeat MVD was 91.66%, and 71.48% of the patients had had obvious compression found at repeat MVD. The postoperative complication rate after repeat MVD was 37.31% and was due to postoperative adhesions around the nerve and nerve injury caused by partial sensory rhizotomy. The most common complication after repeat MVD was facial numbness (21.89%), although the incidence of other complications was <5%. CONCLUSIONS: For patients with recurrent or persistent pain after MVD, the findings from our systematic review support that repeat MVD remains a feasible treatment for recurrent or persistent TN.

MRPS16 facilitates tumor progression via the PI3K/AKT/Snail signaling axis.

Background: Although aberrant expression of MRPS16 (mitochondrial ribosomal protein S16) contributes to biological dysfunction, especially mitochondrial translation defects, the status of MRPS16 and its correlation with prognosis in tumors, especially glioma, which is a common, morbid and frequently lethal malignancy, are still controversial. Methods: Herein, we used high-throughput sequencing to identify the target molecule MRPS16. Subsequently, we detected MRPS16 protein and mRNA expression levels in normal brain tissue (NBT) and different grades of glioma tissue. The molecular effects of MRPS16 in glioma cells were tested by Western blotting, quantitative polymerase chain reaction (qRT-PCR), EdU, CCK-8, colony formation, Transwell migration and invasion assays. Results: Intriguingly, we found that MRPS16 knockdown suppressed tumor cell growth, migration and invasion. Conversely, MRPS16 over-expression increased tumor cell growth, migration and invasion. In addition, subsequent mechanistic studies indicated that MRPS16 promoted glioma cell growth, migration and invasion by the activating PI3K/AKT/Snail axis. Furthermore, we observed that the decrease in tumor cell growth, migration, invasion and Snail expression mediated by MRPS16 knockdown could be rescued by Snail over-expression. Conclusion: In short, our data demonstrate that MRPS16 over-expression remarkably promotes tumor cell growth, migration and invasion via the PI3K/AKT/Snail axis, which may be a promising prognostic marker for glioma.

Solitary Fibrous Tumor/Hemangiopericytoma of Spinal Cord: A Retrospective Single-Center Study of 16 Cases.

OBJECTIVE: In this study, we retrospectively reviewed our experience in the surgical management of solitary fibrous tumor (SFT)/hemangiopericytomas (HPCs) of the spinal cord. METHODS: Sixteen patients with SFT/HPCs of the spinal cord were enrolled in this study. Data on clinical presentation, radiologic findings, histopathologic features, surgical treatment, adjuvant therapy, and prognosis were retrospectively reviewed. Kaplan-Meier curves and log-rank tests were used to identify the prognostic factors for recurrence and overall survival (OS). RESULTS: Our series included 6 men and 10 women, with a male/female ratio of 1:1.7. Magnetic resonance imaging (MRI) showed slightly hyperintense lesions on T2-weighted images for all 16 patients. All tumors showed positive immunohistochemical staining for signal transducer and activator of transcription 6. Statistical analysis of clinical data showed that age, gender, tumor location, tumor size, medullary compartment location, and Ki-67 index were not associated with recurrence and OS (P > 0.05). However, World Health Organization grade III was significantly associated with recurrence (P < 0.01). Gross total resection (GTR) and postoperative radiotherapy significantly reduced recurrence (P < 0.01 and P < 0.05), but only GTR showed remarkable benefits to improve OS (P < 0.05). CONCLUSIONS: SFT/HPCs of spinal cord are rare neoplasms with a propensity to recur. Hyperintensity on T2-weighted magnetic resonance imaging combined with positive immunohistochemical staining for signal transducer and activator of transcription 6 are important clues for classification and differentiation of these tumors. The extent of resection, World Health Organization grade, and postoperative radiotherapy might be predictive factors for recurrence. Complete tumor resection should be sought whenever possible, and adjuvant radiotherapy is recommended after surgical resection. Moreover, regular and long-term follow-up is mandatory to monitor recurrence.

Clinical, radiological, and histological features and treatment outcomes of supratentorial extraventricular ependymoma: 14 cases from a single center.

OBJECTIVE Reports on supratentorial extraventricular ependymoma (STE) are relatively rare. The object of this study was to analyze the clinical, radiological, and histological features and treatment outcomes of 14 patients with STE. METHODS Overall, 227 patients with ependymoma underwent surgical treatment in the authors' department between January 2010 and June 2015; 14 of these patients had STE. Data on clinical presentation, radiological studies, histopathological findings, surgical strategies, and treatment outcomes in these 14 cases were retrospectively analyzed. RESULTS The patients consisted of 6 women and 8 men (sex ratio 0.75). Mean age at diagnosis was 24.5 ± 13.5 years (range 3-48 years). Tumors were predominantly located in the frontal and temporal lobes (5 and 4 cases, respectively). Typical radiological features were mild to moderate heterogeneous tumor enhancements on contrast-enhanced MRI. Other radiological features included well-circumscribed, "popcorn" enhancement and no distinct adjoining brain edema. Gross-total resection was achieved in 12 patients, while subtotal removal was performed in 2. Radiotherapy was administered in 7 patients after surgery. Seven tumors were classified as WHO Grade II and the other 7 were verified as WHO Grade III. The mean follow-up period was 22.6 months (range 8-39 months). There were 3 patients with recurrence, and 2 of these patients died. CONCLUSIONS Supratentorial extraventricular ependymoma has atypical clinical presentations, various radiological features, and heterogeneous histological forms; therefore, definitive diagnosis can be difficult. Anaplastic STE shows malignant biological behavior, a higher recurrence rate, and a relatively poor prognosis. Gross-total resection with or without postoperative radiotherapy is currently the optimal treatment for STE.

Clinical analysis and surgical treatment of trigeminal neuralgia caused by vertebrobasilar dolichoectasia: A retrospective study.

BACKGROUND: Trigeminal neuralgia (TN) caused by vertebrobasilar dolichoectasia (VBD) is rare and needs further exploration. The purpose of this study is to investigate the clinical features and surgical treatment of TN caused by VBD. METHODS: 15 patients with TN caused by VBD were included in our study. The patient data regarding clinical characteristics, neuroimaging presentations, intraoperative findings and treatment outcomes were analyzed retrospectively. Moreover, the previous relevant literature was reviewed simultaneously. Simple MVD was performed in 13 cases and MVD plus trigeminal nerve selective partial posterior rhizotomy (SPPR) was conducted in 2 patients. RESULTS: Of all patients, 7 cases were female and 8 were male. The average age at operation was 60.8 years old (range, 35yrs-75yrs). 13 patients suffered from hypertension and 7 had a history of stoke. The extended and ectatic vetebrobasilar artery (VBA) was preliminarily identified in preoperative imaging presentations and finally confirmed during surgical procedure. The facial neuralgia disappeared immediately after surgery in all patients. All patients were relieved of pain (BNI score I) with an average of 29.8 months follow-up. CONCLUSIONS: Our results suggest that simple MVD is effective for TN caused by VBD. MVD plus SPPR can be cautiously performed if patient has advanced age and is susceptible to numbness.