Predicting long-term outcomes in patients with classical trigeminal neuralgia following microvascular decompression with an MRI-based radiomics nomogram: a multicentre study.

OBJECTIVES: This study aimed to develop a clinical-radiomics nomogram to predict the long-term outcomes of patients with classical trigeminal neuralgia (CTN) following microvascular decompression (MVD). MATERIALS AND METHODS: This retrospective study included 455 patients with CTN who underwent MVD from three independent institutions A total of 2030 radiomics features from the cistern segment of the trigeminal nerve were extracted computationally from the three-dimensional steady-state free precession and three-dimensional time-of-flight magnetic resonance angiography sequences. Using the least absolute shrinkage and selection operator regression, 16 features were chosen to develop radiomics signatures. A clinical-radiomics nomogram was subsequently developed in the development cohort of 279 patients via multivariate Cox regression. The predictive performance and clinical application of the nomogram were assessed in an external cohort consisting of 176 patients. RESULTS: Sixteen highly outcome-related radiomics features extracted from multisequence images were used to construct the radiomics model, with concordance indices (C-index) of 0.804 and 0.796 in the development and test cohorts, respectively. Additionally, a clinical-radiomics nomogram was developed by incorporating both radiomics features and clinical characteristics (i.e., pain type and degree of neurovascular compression) and yielded higher C-indices of 0.865 and 0.834 in the development and test cohorts, respectively. K‒M survival analysis indicated that the nomogram successfully stratified patients with CTN into high-risk and low-risk groups for poor outcomes (hazard ratio: 37.18, p < 0.001). CONCLUSION: Our study findings indicated that the clinical-radiomics nomogram exhibited promising performance in accurately predicting long-term pain outcomes following MVD. CLINICAL RELEVANCE STATEMENT: This model had the potential to aid clinicians in making well-informed decisions regarding the treatment of patients with CTN. KEY POINTS: Trigeminal neuralgia recurs in about one-third of patients after undergoing MVD. The clinical-radiomics nomogram stratified patients into high- and low-risk groups for poor surgical outcomes. Using this nomogram could better inform patients of recurrence risk and allow for discussion of alternative treatments.

Efficacy and Complications of Percutaneous Balloon Compression for Patients With Trigeminal Neuralgia With and Without Concomitant Continuous Pain.

BACKGROUND: Percutaneous balloon compression (PBC) has become one of the most common and effective minimally invasive treatments for trigeminal neuralgia (TN). However, the initial and long-term pain outcomes, as well as the complication rates of PBC for patients with TN with concomitant continuous pain (CCP) have yet to be specifically documented. OBJECTIVE: In this clinical study, we aimed to evaluate and compare the results of PBC in treating TN with and without CCP. STUDY DESIGN: Retrospective study. METHODS: This research retrospectively analyzed the pain outcomes and complications of 57 patients with TN with CCP and 118 patients with TN without CCP who had undergone PBC at our institution from January 2019 through June 2022. Procedures were performed by one senior neurosurgeon in a single center. The postdischarge follow-up and the collection of clinical data, including immediate and long-term pain relief, time to recurrence, and complications, were completed through phone contact by an independent neurosurgeon blind to the patients' information. Then, the results of the 2 groups were compared; demographic and clinical data were evaluated for possible predictive factors for poor pain outcomes. RESULTS: In this study, PBC immediately resulted in complete pain relief in 70.2% of patients with CCP and significant pain relief in 84.2% of patients with CCP. For patients without CCP, the rates were 73.7% for complete pain relief and 85.6% for significant pain relief. After a minimum 6-month follow-up period, the rates decreased to 52.6% for complete pain relief and 73.7% for significant pain relief in patients with CCP, compared to 54.2% and 75.4% in those without CCP. The initial and long-term pain control rates in patients without CCP were slightly higher than those with CCP, but the differences were not statistically significant (P = 0.878, P = 0.968, respectively). The incidences of postoperative complications were similar between patients with and without CCP (21.1% vs 22.0%, P = 0.883), whereas the remission rate of complications in patients with CCP was significantly lower than that in patients without CCP (25.0% vs 69.2%, P = 0.011). A longer symptoms duration and having a history of neurodestructive procedures were predictive factors for poor outcomes following PBC. LIMITATIONS: The study was performed in a single-center. The nature of this research is retrospective instead of prospective and randomized, with the inability to control completely for variables. Additionally, the follow-up duration was not long enough to observe recurrence in some patients. CONCLUSIONS: This is the first specifically reported experience treating TN with CCP with PBC. PBC can result in significant relief of both episodic and constant pain from TN with CCP. Patients with a longer duration of pain and prior neurodestructive procedures have a higher risk of poor outcomes. The presence of CCP is not associated with pain outcomes and should not be considered a contraindication to PBC.

Association of concomitant continuous pain in trigeminal neuralgia with a narrow foramen ovale.

Background: The pathogenesis of concomitant continuous pain remains unclear and is worthy of further study. In this clinical study, we aimed to explore the potential role of a narrow foramen ovale in the development of concomitant continuous pain. Methods: A total of 108 patients with classical trigeminal neuralgia affecting the third branch of the trigeminal nerve and 46 healthy individuals were enrolled in this study. Three-dimensional reconstructed computerized tomography images of all participants were collected, and the morphometric features of the foramen ovale were examined by two investigators who were blinded to the clinical data of the patients. Results: In this cohort, patients with concomitant continuous pain suffered from more sensory abnormalities (18.4% vs. 2.9%, p = 0.015) and responded more poorly to medication (74.3% vs. 91.9%, p = 0.018) than patients without concomitant continuous pain. While no significant differences regarding the mean length (5.02 mm vs. 5.36 mm, p > 0.05) and area (22.14 mm2 vs. 23.80 mm2, p > 0.05) were observed between patients with and without concomitant continuous pain, the mean width of the foramen ovale on the affected side in patients with concomitant continuous pain was significantly narrower than that in patients without concomitant continuous pain (2.01 mm vs. 2.48 mm, p = 0.003). Conclusion: This neuroimaging and clinical study demonstrated that the development of concomitant continuous pain was caused by the compression of the trigeminal nerve owing to a narrow foramen ovale rather than responsible vessels in classical trigeminal neuralgia.

Proximal trigeminal nerve atrophy is associated with favourable outcomes and persistent facial numbness following percutaneous balloon compression for primary trigeminal neuralgia.

OBJECTIVE: Whether nerve atrophy can affect the prognosis of primary trigeminal neuralgia (PTN) patients undergoing percutaneous balloon compression (PBC) remains unclear. This study aimed to determine the association between nerve characteristics observed on preoperative magnetic resonance imaging (MRI) and PBC outcomes. METHODS: Between January 2019 and December 2022, a cohort of 58 patients with unilateral PTN treated with PBC were analysed retrospectively and included in this study. The relationship between MRI findings, including the proximal and distal nerve cross-sectional areas (CSAs), and favourable pain outcomes (BNI Grades I-III) was analysed through Kaplan‒Meier analysis. RESULTS: After a mean follow-up period of 23.8 ± 13.0 months (range, 6-50 months), 48 (82.8%) patients with PTN were pain free with or without medication. A smaller proximal CSA ratio (proximal CSA of the affected nerve/proximal CSA of the unaffected nerve) was significantly associated with favourable outcomes. The Kaplan-Meier survival analysis showed that patients with proximal nerve atrophy (proximal CSA ratio ≤ 87% after receiver operating characteristic curve analysis) had a higher estimated 4-year probability of maintaining a favourable outcome than those without nerve atrophy (94.4% vs. 30.8%, p = 0.005). In addition, patients with proximal nerve atrophy were more likely to suffer from postoperative persistent facial numbness. CONCLUSIONS: Proximal nerve atrophy is correlated with both favourable outcomes and persistent facial numbness following PBC. Prospective studies are required to determine the optimal duration and pressure of balloon compression in relation to the proximal CSA ratio to achieve better pain outcomes and less facial numbness.

Multi-omics analysis revealed the role of CYP1A2 in the induction of mechanical allodynia in type 1 diabetes.

Background: Mechanical allodynia (MA) is one of the leading clinical symptoms of painful diabetic peripheral neuropathy (PDPN), which is a primary reason for non-traumatic amputations, foot ulceration, and gait abnormalities in patients with diabetes. However, the pathogenic mechanisms of MA have not yet been fully elucidated, and there is no effective treatment. This study aims to study the potential pathogenetic mechanisms of MA and to provide targets for the therapy of MA. Methods: A single intraperitoneal injection of streptozotocin induced type 1 diabetes in rat models. Subsequently, rats were divided into the control group, the diabetic group without MA, and the diabetic group with MA based on weekly behavioral assays. The differentially expressed lipids in the sciatic nerve of each group were detected using untargeted lipidomics, and the differentially expressed genes in the sciatic nerve of each group were detected by transcriptomics. The pathogenesis of MA was predicted using integrated analysis and validated by immunofluorescence staining and transmission electron microscopy. Results: Untargeted lipidomics revealed the accumulation of a more severe lipid in MA rats. Transcriptomics results suggested that differentially expressed genes in MA rats were primarily related to lipid droplets and myelin sheath. Integrated analysis results indicated that the downregulation of Cytochrome P450 1A2 (CYP1A2) expression was closely linked to lipid metabolism disorders. Immunofluorescence staining demonstrated that down-regulation of CYP1A2 expression occurred in MA rats. Transmission electron microscopy results showed that more severe lipid droplet accumulation and myelin sheath degeneration occurred in MA rats. Conclusion: Our findings imply that the downregulation of CYP1A2 expression leads to disorders of lipid metabolism and further leads to lipid droplet accumulation and myelin sheath degeneration, which might ultimately lead to the development of MA. Therefore, our study contributes to promoting the understanding of the molecular mechanisms of MA and providing potential targets for the clinical treatment of MA.

Impact of ferroptosis-related risk genes on macrophage M1/M2 polarization and prognosis in glioblastoma.

Objective: To explore the effect impact of ferroptosis on macrophage polarization and patient prognosis in glioblastoma. Methods: We screened ferroptosis-related risk from the public datasets of primary and recurrent glioblastoma, combined with reported ferroptosis genes, calculated the risk genes among the ferroptosis-related genes using the LASSO Cox regression model, and investigated the relationship between these ferroptosis-related risk genes in the tumor and the spectrum of infiltrating M1/M2 macrophages. Macrophages were analyzed using the CIBERSORTx deconvolution algorithm. Samples from The Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA) and a single-cell RNA sequencing dataset (GSE84465) were included. The expression levels of ferroptosis-related risk genes and molecular markers of M1 and M2 macrophages were detected by qPCR and western blot. Results: A total of fourteen ferroptosis-related risk genes were obtained and the patients' risk scores were calculated. Compared with patients in the low-risk group, patients in the high-risk group had worse prognosis. The M1/M2 macrophage ratio and risk score were negatively correlated, indicating that the tumor microenvironment of glioblastoma in the high-risk group contained more M2 than M1 macrophages. In the single-cell RNA sequencing dataset, the risk score of ferroptosis-related genes in tumor cells was positively correlated with the proportion of high M2 macrophages. The expression of eight ferroptosis-related risk genes was increased in glioblastoma cell, which promoted the polarization of M1 macrophages to M2. Conclusion: We investigated the fourteen ferroptosis-related risk genes in glioblastoma for the first time, and clarified the impact of ferroptosis-related risk genes on M1/M2 macrophage polarization and patient prognosis.

DUSP8/TAK1 signaling mediates neuropathic pain through regulating neuroinflammation and neuron death in a spinal nerve ligation (SNL) rat model.

Nerve injury-induced neuropathic pain is a type of chronic pain associated with neuroinflammatory response and neuronal death; however the underlying molecular mechanisms are still unclear. Dual-specificity phosphatase 8 (DUSP8) can mediate numerous cellular events, but whether it's involved in neuropathic pain is unknown. In the study, we found that spinal nerve ligation (SNL) operation on rats significantly decreased DUSP8 expression levels in ipsilateral spinal cord (ISC) tissues. Consistently, lipopolysaccharide (LPS) exposure also reduced DUSP8 in murine microglial cells. Adeno-associated virus (AAV)-mediated DUSP8 over-expression was found to considerably ameliorate SNL-induced neuropathic pain in rats. Additionally, neuronal death in the ISC tissues was also attenuated by AAV-DUSP8 following SNL surgery. Moreover, SNL-triggered neuroinflammation and microglial activation were also mitigated upon DUSP8 over-expression by suppressing nuclear factor κB (NF-κB) signaling, which were validated in LPS-exposed microglial cells. Importantly, our in vitro experiments indicated that inflammatory response in microglial cells contributed to neuron death, and such effect could also be ameliorated by DUSP8 over-expression. Notably, we found that DUSP8 directly interacted with transforming growth factor ß activated kinase-1 (TAK1) in microglial cells. Both SNL and LPS led to the activation of TAK1/p38/JNK1/2 signaling, whereas being strongly abolished by DUSP8. Intriguingly, TAK1 blockage significantly diminished LPS-induced inflammation and neuron death, whereas being accelerated by DUSP8 knockdown, further indicating that DUSP8-ameliorated neuropathic pain was largely TAK1-dependent. Together, all our findings revealed that DUSP8/TAK1 signaling may be a potential target for neuropathic pain alleviation.

Narrow ovale foramina may be involved in the development of primary trigeminal neuralgia.

Background: The etiology of primary trigeminal neuralgia remains unclear and is worthy of further study; In this study, the morphometric characteristics of ovale foramina between various groups were compared and analyzed to explore the novel cause of primary trigeminal neuralgia. Methods: High-resolution three-dimensional reconstruction images from head computed tomography of 109 patients with primary trigeminal neuralgia affecting the third branch of the trigeminal nerve and 46 healthy controls were retrospectively reviewed. Among the 109 primary trigeminal neuralgia patients, 79 patients with apparent neurovascular compression (not simply contact) demonstrated on MRI or during surgery were divided into the classical trigeminal neuralgia group and 30 patients with MRI showing no significant abnormalities were divided into idiopathic trigeminal neuralgia group. The morphometric parameters including the area, width and length of ovale foramina were examined through the use of radiologic methods. Results: In this study, the average minimum area, width and length of 79 ovale foramina on the affected and unaffected sides in the classical trigeminal neuralgia group were 21.83 ± 8.45, 21.94 ± 7.93 mm2, 2.32 ± 0.91, 2.58 ± 0.81, 5.32 ± 1.29, and 5.26 ± 1.21 mm, respectively. No significant difference in these parameters was observed (p > 0.05). However, in the idiopathic trigeminal neuralgia group, the average minimum area, width and length of 30 ovale foramina were 21.33 ± 8.21, 22.85 ± 8.36 mm2, 2.25 ± 0.90, 2.79 ± 0.96, 5.20 ± 1.27, and 5.28 ± 1.19 mm, respectively. The width on the symptomatic side was significantly smaller (p = 0.03) than that on the asymptomatic side. No significant difference in area (p = 0.48) or length (p = 0.79) was observed. In addition, when compared with the healthy control group, the area and width of ovale foramina on the symptomatic side in both groups were significantly smaller. No significant difference in length was observed. Conclusions: By comparing and analyzing the statistical data, it can be inferred that a narrow foramen ovale is associated with primary trigeminal neuralgia, as well as its recurrence after microvascular decompression.

The Development of Mechanical Allodynia in Diabetic Rats Revealed by Single-Cell RNA-Seq.

Mechanical allodynia (MA) is the main reason that patients with diabetic peripheral neuropathy (DPN) seek medical advice. It severely debilitates the quality of life. Investigating hyperglycemia-induced changes in neural transcription could provide fundamental insights into the complex pathogenesis of painful DPN (PDPN). Gene expression profiles of physiological dorsal root ganglia (DRG) have been studied. However, the transcriptomic changes in DRG neurons in PDPN remain largely unexplored. In this study, by single-cell RNA sequencing on dissociated rat DRG, we identified five physiological neuron types and a novel neuron type MAAC (Fxyd7 + /Atp1b1 +) in PDPN. The novel neuron type originated from peptidergic neuron cluster and was characterized by highly expressing genes related to neurofilament and cytoskeleton. Based on the inferred gene regulatory networks, we found that activated transcription factors Hobx7 and Larp1 in MAAC could enhance Atp1b1 expression. Moreover, we constructed the cellular communication network of MAAC and revealed its receptor-ligand pairs for transmitting signals with other cells. Our molecular investigation at single-cell resolution advances the understanding of the dynamic peripheral neuron changes and underlying molecular mechanisms during the development of PDPN.

Patterns of Nerve Fibre Impairments and Neuronal Activation in Male Diabetic Rats With and Without Mechanical Allodynia: A Comparative Study.

BACKGROUND: It is still clinically difficult to definitively distinguish between painful and nonpainful diabetic peripheral neuropathy (DPN). In this study, pain patterns were further categorized; diabetic rats were grouped according to the presence or absence of mechanical allodynia (MA), which is a hallmark of neuropathic pain, and comparisons were made between diabetic rats with and without MA. METHODS: Diabetes was established in rats by a single intraperitoneal streptozotocin injection, and vehicle injection was administered in the control group. Pain behaviour tests for MA and thermal hyperalgesia were performed every week. At week 4, the diabetic group with thermal hyperalgesia was further grouped by the presence of MA. Morphometric analysis of sciatic nerves and myelin basic protein quantification were conducted. The numbers of c-Fos-immunoreactive neurons in both the dorsal root ganglion (DRG) and the spinal dorsal horn (SDH) were determined. RESULTS: Diabetic rats with MA had more severe impairment of myelinated nerve fibres than those without MA (p<0.001). Higher percentages of NF-200-positive neurons in the DRG were c-Fos immunoreactive in the DPN-with-MA group than in the DNP-without-MA group (p=0.014). The numbers of c-Fos-immunoreactive neurons in both the superficial (I-II) and deeper (III-V) laminae of the SDH in the DPN-with-MA group were larger than those in the subgroups without MA (p<0.001). CONCLUSIONS: The impairment of primary myelinated fibres and the pattern of neuronal activation in both the DRG and the SDH are specific features that differentiate diabetic rats with MA from those without MA.

Triple-nerve decompression surgery for the treatment of painful diabetic peripheral neuropathy in lower extremities: A study protocol for a randomized controlled trial.

Objectives: Painful diabetic peripheral neuropathy (DPN) is often refractory to conventional medications. Triple-nerve decompression was proposed for painful DPN due to the frequent involvement of multiple nerve entrapments in diabetes. However, the role of decompressive surgery remains controversial. This trial aims to assess the efficacy of triple-nerve decompression for patients with painful DPN suggestive of nerve entrapment using a randomized controlled trial (RCT) design. Methods and analysis: This trial is a single-center RCT and will be conducted in Shanghai Ninth People's Hospital. Enrolled subjects (n = 74) with painful DPN due to nerve compression, which can be detected by nerve conduction studies, will be randomly allocated at a 1:1 ratio into surgical and non-surgical groups. The primary outcome will be measured by 50% responder rates, which is defined as the proportion of subjects with at least 50% reduction of the mean weekly visual analog score (VAS) of pain from baseline after 6 months of treatment. Mean weekly VAS will be additionally evaluated 1 week (W1), 1 month (M1), and 3 months (M3) after treatment to monitor the changes in pain intensity. The secondary outcomes include two-point discrimination (TPD), Toronto clinical scoring system (TCSS), electrophysiological indexes, hospital anxiety and depression scale (HADS), and the medical outcome study short-form 36-item questionnaire (SF-36). A quantitative analgesic questionnaire (QAQ) will be used as a secondary outcome to quantify the analgesic medication weekly. TPD and TCSS will be conducted at W1, M1, M3, and M6 after treatment. Electrophysiological tests, HADS, and SF-36 will be performed at M3 and M6. Ethics and dissemination: Ethics approval has been obtained from the Ethics Committee of Shanghai Ninth People's Hospital (SH9H-2-21-T323-2). It was registered on the Chinese Clinical Trial Registry website (http://www.chictr.org.cn) on 16 August 2021 with the number ChiCTR2100050049. Written informed consent will be obtained from all participants. The results of this trial will be disseminated via peer-reviewed journals, mass media, and presentations at national and international academic conferences.

Application of hyperspectral imaging technology in the rapid identification of microplastics in farmland soil.

Microplastics (MPs) are emerging environmental pollutants and their accumulation in the soil can adversely affect the soil biota. This study aims to employ hyperspectral imaging technology for the rapid screening and classification of MPs in farmland soil. In this study, a total of 600 hyperspectral data are collected from 180 sets of farmland soil samples with a hyperspectral imager in the wavelength range of 369- 988 nm. To begin, the hyperspectral data are preprocessed by the Savitzky-Golay (S-G) smoothing filter and mean normalization. Second, principal component analysis (PCA) is used to minimize the dimensions of the hyperspectral data and hence the amount of data, making the subsequent model easier to construct. The cumulative contribution rate of the first three principal components is reached 98.37%, including the main information of the original spectral data. Finally, three models including decision tree (DT), support vector machine (SVM), and convolutional neural network (CNN) are established, all of which can achieve well classification effects on three MP polymers including polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC) in farmland soil. By comparing the recognition accuracy of the three models, the classification accuracy of DT and SVM is 87.9% and 85.6%, respectively. The CNN model based on the S-G smoothing filter obtains the best prediction effect, the classification accuracy reaches 92.6%, exhibiting obvious advantages in classification effect. Altogether, these results show that the proposed hyperspectral imaging technique identifies the soil MPs rapidly and nondestructively, and provides an effective automated method for the detection of polymers, requiring only rapid and simple sample preparation.

Combined surgical and endovascular treatment for spinal arteriovenous fistula associated with Parkes Weber syndrome.

BACKGROUND: Parkes Weber syndrome (PWS) is a rare and congenital vascular malformation manifesting as hemihypertrophy of the extremities, cutaneous hemangiomas, varicose veins, and arteriovenous fistula of the affected limbs. The incidence rate of spinal arteriovenous fistula (AVF) associated with PWS is extremely rare. CASE PRESENTATION: We reported a case of an adolescent girl with PWS who presented with a rupture spinal perimedullary AVF at the level of T12-L1. She was successfully treated with emergent surgical decompression and subsequent endovascular embolization. The clinical features and treatment of spinal AVF associated with PWS were discussed and a brief literature review was presented. CONCLUSION: Based on this case report, we suggested that the management of spinal AVF in PWS should also be individualized and be tailored according to the condition and expectation of the patients as well as the angioarchitecture of the vascular malformation.

Controlled release of ciliary neurotrophic factor from bioactive nerve grafts promotes nerve regeneration in rats with facial nerve injuries.

It is critical to repair severed facial nerves, as lack of treatment may cause long-term motor and sensory impairments. Ciliary neurotrophic factor (CNTF) plays an important role in terms of enhancing nerve axon regrowth and maturation during peripheral nerve regeneration after injury. However, simple application of CNTF to the transected nerve site does not afford functional recovery, because it is rapidly flushed away by bodily fluids. The aim of the present study was the construction of a new, bioactive composite nerve graft facilitating persistent CNTF delivery to aid the reconstruction of facial nerve defects. The in vitro study showed that the bioactive nerve graft generated sustainable CNTF release for more than 25 days. The bioactive nerve graft was then transplanted into the injury sites of rat facial nerves. At 6 and 12 weeks post-transplantation, functional and histological analyses showed that the bioactive nerve graft featuring immobilized CNTF significantly enhanced nerve regeneration in terms of both axonal outgrowth and Schwann cell proliferation in the rat facial nerve gap model, compared to a collagen tube with adsorbed CNTF that initially released high levels of CNTF. The bioactive nerve graft may serve as novel, controlled bioactive release therapy for facial nerve regeneration.

The Relationship Between Basilar Invagination and Chiari Malformation Type I: A Narrative Review.

Basilar invagination (BI) and Chiari malformation type I CM-I) are the most common adult craniovertebral junction malformations, and they are frequently associated with each other and present synchronously. The relationship between BI and CM-I has remained incompletely understood, and the choice of surgical strategy has remained controversial. This brief review focuses on the different aspects of BI and CM-I, and further discusses the relationship between these two concomitant pathologies on the basis of the concepts proposed over the last three decades.

Transoral Versus Transnasal Approach for Craniovertebral Junction Pathologies: Which Route Is Better?

BACKGROUND: Several pathologies that affect the craniovertebral junction (CVJ) can be treated by means of a microsurgical transoral approach (TOA) or, alternatively, with an endoscopic endonasal approach (EEA), which is potentially able to overcome some complications associated with the former approach. In this paper, after discussing updates in the recent literature, to which we add our own surgical experience, we critically analyse these procedures with the aim of demonstrating that the TOA still deserves to be considered a viable alternative and that, in selected cases, it can even be considered superior to the EEA. METHODS: Our experience involves 25 anterior procedures in 24 paediatric and adult patients (18 TOA and seven EEA). The TOA group (13 male and five female patients) encompassed three tumours, three rheumatoid arthritis cases, one condylus tertius, three basilar invaginations, four impressio basilaris cases, one developmental anomaly of C0-C1, one os odontoideum, one posttraumatic C1-C2 compression and one C2 fracture. The EEA group (three male and four female patients, median age 39 years, operated on over a 7-year period) comprised four tumours, two impressio basilaris cases and one case of impressio basilaris with platybasia. RESULTS: In the TOA group, all but one patient were discharged after posterior procedures within 2 weeks and improved or remained unchanged after surgery and during the follow-up period. No major complications occurred in the TOA group. In the EEA group, two patients who developed a cerebrospinal fluid (CSF) infection died, one from disease progression and the other from myocardial infarction. CONCLUSION: Our data, in agreement with those from previous reports on other series, suggest that no clear superiority of the EEA over the endoscopic TOA can be postulated so far; in fact, the EEA can produce complications similar to those observed with the TOA in CVJ surgery.

The Endoscopic Endonasal Approach for Treatment of Craniovertebral Junction Pathologies: A Minimally Invasive but not Minimal-Risk Approach.

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Dynamic Quantitative Assessment of Motor Axon Sprouting after Direct Facial-Hypoglossal End-To-Side Neurorrhaphy in Rats.

BACKGROUND: End-to-side (ETS) neurorrhaphy is a promising procedure for peripheral nerve repair, yet controversies regarding the efficacy of this repair in facial nerve anastomosis for facial paralysis still exist. MATERIALS AND METHODS: Thirty rats were divided into three groups: intact control group, direct facial-hypoglossal ETS neurorrhaphy, and end-to-end (ETE) neurorrhaphy. Nerve regeneration was assessed with vibrissae motor performance, electrophysiological tests, retrograde labeling, and histomorphological analysis at 4 and 8 months postoperatively. RESULTS: Both ETS and ETE neurorrhaphies resulted in axonal regeneration and functional recovery of the recipient nerve but did not reach the level of intact controls. Significantly higher numbers of myelinated axons and labeled neurons giving regenerating fibers were found in group ETE compared with group ETS at both time points, consistent with the functional and electrophysiological recovery. Group ETS showed significantly smaller fiber diameter and thinner myelin thickness than group ETE at 4 months, but the difference became nonsignificant at 8 months. ETS neurorrhaphy had a very slight effect on the donor nerve, as determined electrophysiologically and histomorphologically. Sparsely distributed double-labeled neurons and relatively large amounts of single-labeled neurons contributing to reinnervation were found through double retrograde neuronal labeling in group ETS. Further quantitative analysis of the percentage of double-labeled neurons showed a pronounced tendency to decline from 19.8% at 4 months to 6.0% at 8 months postoperatively. CONCLUSION: Successful reinnervation after ETS neurorrhaphy could be achieved through both collateral sprouting and terminal sprouting, with the latter seeming to be the principal origin of motor nerve sprouting.