Surgical outcomes of basilar invagination type B without atlantoaxial dislocation through simple posterior fossa decompression: a retrospective study of 18 cases.

BACKGROUND: Basilar invagination (BI) is a common disease in the craniocervical junction (CVJ) area. Posterior fossa decompression with/without fixation is a controversial surgical strategy for BI type B. This study aimed to evaluate the efficacy of simple posterior fossa decompression in treating BI type B. METHODS: This study retrospectively enrolled BI type B patients who underwent simple posterior fossa decompression at Huashan Hospital, Fudan University between 2014.12 and 2021.12. Patient data and images were recorded pre- and postoperatively (at the last follow-up) to evaluate the surgical outcomes and craniocervical stability. RESULTS: A total of 18 BI type B patients (13 females), with a mean age of 44.2±7.9 years (range 37-62 years), were enrolled. The mean follow-up period was 47.7±20.6 months (range 10-81 months). All patients received simple posterior fossa decompression without any fixation. At the last follow-up, compared with preoperation, the JOA scores were significantly higher (14.2±1.5 vs. 9.9±2.0, p = 0.001); the CCA was improved (128.7±9.6° vs. 121.5±8.1° p = 0.001), and the DOCL was reduced (7.9±1.5 mm vs. 9.9±2.5 mm, p = 0.001). However, the follow-up and preoperative ADI, BAI, PR, and D/L ratio were similar. No patients had an unstable condition between the C1-2 facet joints that was observed in the follow-up CT and dynamic X-ray. CONCLUSIONS: In BI type B patients, simple posterior fossa decompression could improve neurological function and will not induce CVJ instability in BI type B patients. Simple posterior fossa decompression could be a satisfactory surgical strategy for BI type B patients, but preoperative CVJ stability assessment is crucial.

Resection of cervical extra-intraspinal neuromas through the enlarged intervertebral foramen: Results in 34 case series patients.

Objective: The purpose of this study was to analyze the techniques used to resection cervical extra-intraspinal neuromas (also known as cervical dumbbell neuromas) through the enlarged intervertebral foramen. Methods: A total of 34 consecutive patients (19 male, 15 female) with cervical dumbbell neuromas reviewed retrospectively between April 2008 and May 2020. Sixteen tumors were found in the intervertebral foramen of C1-C3, four in C3-C4, and 14 in C4-T1. The approach in all cases was to expose the tumors by intermuscular dissection and to remove them through the enlarged intervertebral foramen without excision of any bony structures. However, to expose tumors at different locations, the incisions shall be made accordingly. In this case series, the incisions were made along the posterior border of the sternocleidomastoid muscle for the C1-C3 tumors and along the anterior border of the muscle for the C3-C4 tumors. Transverse incisions were required for the C4-T1 tumors. Results: Following the mentioned incising approach, all 34 tumors were completely exposed. 31 were completely removed in one stage, and 3 tumors underwent subtotal resection because of brachial plexus nerve adhesion. The vertebral artery and spinal cord were undamaged for all cases. The patients who had total tumor resection showed no sign of recurrence on enhanced magnetic resonance imaging during follow-ups. The status of patients who underwent subtotal resection was stable after radiation therapy. None of the patients developed spinal instability. Conclusions: Cervical dumbbell neuromas can be exposed and removed through the enlarged intervertebral foramen without causing spinal instability or injury to the spinal cord or vertebral artery. This operative approach can retain the integrity of the structures of spine and should be considered the ideal approach for cervical dumbbell neuromas.

Hypoxia-Induced Glioma-Derived Exosomal miRNA-199a-3p Promotes Ischemic Injury of Peritumoral Neurons by Inhibiting the mTOR Pathway.

The underlying molecular mechanisms that the hypoxic microenvironment could aggravate neuronal injury are still not clear. In this study, we hypothesized that the exosomes, exosomal miRNAs, and the mTOR signaling pathway might be involved in hypoxic peritumoral neuronal injury in glioma. Multimodal radiological images, HE, and HIF-1α staining of high-grade glioma (HGG) samples revealed that the peritumoral hypoxic area overlapped with the cytotoxic edema region and directly contacted with normal neurons. In either direct or indirect coculture system, hypoxia could promote normal mouse hippocampal neuronal cell (HT22) injury, and the growth of HT22 cells was suppressed by C6 glioma cells under hypoxic condition. For administrating hypoxia-induced glioma-derived exosomes (HIGDE) that could aggravate oxygen-glucose deprivation (OGD)/reperfusion neuronal injury, we identified that exosomes may be the communication medium between glioma cells and peritumoral neurons, and we furtherly found that exosomal miR-199a-3p mediated the OGD/reperfusion neuronal injury process by suppressing the mTOR signaling pathway. Moreover, the upregulation of miRNA-199a-3p in exosomes from glioma cells was induced by hypoxia-related HIF-1α activation. To sum up, hypoxia-induced glioma-derived exosomal miRNA-199a-3p can be upregulated by the activation of HIF-1α and is able to increase the ischemic injury of peritumoral neurons by inhibiting the mTOR pathway.

Establishment and maintenance of a standardized glioma tissue bank: Huashan experience.

Cerebral glioma is the most common brain tumor as well as one of the top ten malignant tumors in human beings. In spite of the great progress on chemotherapy and radiotherapy as well as the surgery strategies during the past decades, the mortality and morbidity are still high. One of the major challenges is to explore the pathogenesis and invasion of glioma at various "omics" levels (such as proteomics or genomics) and the clinical implications of biomarkers for diagnosis, prognosis or treatment of glioma patients. Establishment of a standardized tissue bank with high quality biospecimens annotated with clinical information is pivotal to the solution of these questions as well as the drug development process and translational research on glioma. Therefore, based on previous experience of tissue banks, standardized protocols for sample collection and storage were developed. We also developed two systems for glioma patient and sample management, a local database for medical records and a local image database for medical images. For future set-up of a regional biobank network in Shanghai, we also founded a centralized database for medical records. Hence we established a standardized glioma tissue bank with sufficient clinical data and medical images in Huashan Hospital. By September, 2013, tissues samples from 1,326 cases were collected. Histological diagnosis revealed that 73 % were astrocytic tumors, 17 % were oligodendroglial tumors, 2 % were oligoastrocytic tumors, 4 % were ependymal tumors and 4 % were other central nervous system neoplasms.

Diffusion tensor magnetic resonance imaging for predicting the consistency of intracranial meningiomas.

BACKGROUND: The ability of preoperative MRI-sequences to predict the consistency of intracranial meningiomas has not yet been clearly defined. We aim to demonstrate that diffusion tensor imaging (DTI) improves the prediction of intracranial meningiomas consistency. METHODS: We prospectively studied 110 meningioma patients operated on in a single center from March 1st to the 25th of May 2012. Demographic data, location and size of the tumor, peritumoral edema, T1WI, T2WI, proton density weighted (PDWI), fluid-attenuated inversion recover (FLAIR) sequences, and arterial spin labeling (ASL) perfusion were studied and compared with the gray matter signal to predict meningioma consistency. Diffusion tensor imaging (DTI) with fractional anisotropy (FA) and mean diffusivity (MD) maps were included in the preoperative MRI. Meningioma consistency was evaluated by the operating surgeon who was unaware of the neuroradiological findings. RESULTS: In univariate analysis, meningioma size (diameter > 2 cm) and supratentorial or sphenoidal wing location were more frequently associated with hard-consistency meningiomas (p < 0.05). In addition, isointense signal on MD maps (p = 0.009), hyperintense signal on FA maps, and FA value > 0.3 (p = 0.00001) were associated with hard-consistency tumors. Age and sex, T1WI, T2WI, PDWI, FLAIR, or ASL perfusion sequences and peritumoral edema were not significantly associated with meningioma consistency. In logistic regression analysis, the most accurate model (AUC: 0.9459) for predicting a hard-consistency meningioma shows that an isointense signal in MD-maps, a hyperintense signal in FA-maps, and an FA value of more than 0.3 have a significant predictive value. CONCLUSIONS: FA value and MD and FA maps are useful for prediction of meningioma consistency and, therefore, may be considered in the preoperative routine MRI examination of all patients with intracranial meningiomas.

Papillary meningioma: clinical and histopathological observations.

Papillary meningioma is a rare subtype of malignant meningiomas, which is classified by the World Health Organization as Grade III. Because of lack of large sample size case studies, many of the specific characteristics of papillary meningioma are unclear. This study investigated by retrospective analysis the clinical, radiological and histopathological findings of 17 papillary meningioma patients who underwent surgical resection or biopsy, to assess the characteristics of papillary meningioma. Eight female and nine male patients were included, with a mean age of 40 (range: 6 to 55) years. Tumors were mostly located in the cerebral convexity and showed irregular margins, absence of a peritumoral rim, heterogeneous enhancement and severe peritumoral brain edema on preoperative images. Brain invasion was often confirmed during the operations, with abundant to exceedingly abundant blood supply. Intratumoral necrosis and mitosis was frequently observed on routinely stained sections. The average MIB-1 labeling index was 6.9%. Seven cases experienced tumor recurrence or progression, while seven patients died 6 to 29 months after operation. Radiation therapy was given in 52.9% of all cases. Univariate analysis showed that only the existence of intratumoral necrosis and incomplete resection correlated with tumor recurrence. The 3-year progression free survival was 66.7% after gross total resection and 63.6% for other cases. The 3-year mortality rate was 50% after gross total resection and 63.6% for other cases. Papillary meningioma has specific clinical and histopathological characteristics. Tumor recurrence (or progression) and mortality are common. Gross total tumor resection resulted in less recurrence and mortality.

Histopathological classification and location of consecutively operated meningiomas at a single institution in China from 2001 to 2010.

BACKGROUND: Meningioma is one of the most common primary tumors of the central nervous system, but there are not many detailed studies on the sex, age, subtypes and locations of large series. This study was a retrospective analysis of the characteristics of meningioma cases consecutively operated on at a single institution in China from 2001 to 2010. METHODS: This study investigated the demographic background of 7084 meningioma cases, and the subtypes and locations of the tumors. Sex and age distributions were analyzed, and the pathological subtypes were classified according to the World Health Organization (WHO) classification. The location of the meningiomas was also categorized. RESULTS: The female:male ratio of the 7084 cases was 2.34:1. The mean age was 51.4 years (range, 11 months-86 years). The mean age of cases of WHO grade I meningioma was significantly older than that of grade II or III meningiomas (P < 0.001, Fisher's Least Significant Digit test). There was a significantly higher female:male ratio in WHO grade I meningiomas than in grade II or grade III meningiomas (2.57, 1.03 and 0.76, respectively; P < 0.001, χ(2) test). Meningothelial (n = 2061) and fibrous meningiomas (n = 3556) were the most common subtypes, comprising 79.3% of all meningiomas. All meningioma cases were classified into 23 locations in this study, with the cerebral convexity the most common site (38.33%, n = 2722). Cases with uncommon locations such as extra-cranial and sylvian fissure meningiomas were also present in this series. CONCLUSIONS: Female predominance was found for benign meningiomas, while malignant subtypes showed male predominance. The mean age of patients with WHO grade I meningiomas was older than that of patients with higher-grade tumors. Meningothelial and fibrous meningiomas were the most common subtypes. The cerebral convexity was the most common meningioma location.

Anatomical studies on the temporal bridging veins with Dextroscope and its application in tumor surgery across the middle and posterior fossa.

OBJECTIVE: To evaluate the application of virtual reality technology in neurosurgical anatomy we compared the virtual three-dimensional (3D) microanatomy of the temporal bridging veins as part of the resection of tumors across the petrosal crest in 25 patients against the actual microanatomy of the temporal bridging veins on 20 cadaveric head sets. PATIENTS AND METHODS: The experiment was carried out by two groups of data: a virtual group made of 25 clinical cases and a physical body group made of 20 cadaveric head sets. In the physical body group, the temporal bridging veins on the cadaveric heads were examined under the microscope from the number of their tributaries to termination and measure the distance between emptying point on sinus of labbé vein and sigmoid transverse sinus. In the virtual group, the dissection of the temporal bridging veins was simulated on Dextroscope. We compared the anatomical features of temporal bridging veins in two groups. Virtual reality technology was used in the planning of 25 cases for which the anatomy of temporal bridging veins needed to be studied carefully by the neurosurgical team. RESULTS: Four basic configurations of veins were found: venous lakes running in the tentorium before emptying the sinuses 17.5% (7 hemispheres), candelabra of veins uniting to form one large drainage 40% (16 hemispheres), single independent draining veins 20% (8 hemispheres) and multiple independent draining veins 22.5% (9 hemispheres) in physical body group, venous lake16% (8 hemispheres), candelabra of veins uniting to form one large drainage 42% (21 hemispheres), single independent draining veins 18% (9 hemispheres) and multiple independent draining veins 24% (12 hemispheres) in virtual group. 213 tributaries (85 drainage to labbé veins) and 87 terminations of temporal bridging veins were found in cadaveric heads, whereas 167 tributaries (80 to labbé veins) and 81 terminations of temporal bridging veins were found in the virtual group. The distribution of anatomical terminations of temporal bridging veins were divided into three groups: transverse area 52.87% (46) tentorium area 24.13% (21) and petrosal area 23.10% (20) in physical body group, whereas 54.35% (50) 23.91% (22) and 21.74% (20) in virtual group, respectively. The proportion of fore-placed type veins of labbé is 7.69% in physical body group and 8.33% in virtual group (P>0.05). The distance from the emptying point of the labbé veins to the sigmoid transverse point in the virtual group was 18.75 ± 1.95 mm, in the physical body group was 20.12 ± 2.51 mm (P>0.05). The anatomical features of labbé veins found during the operation of the 25 patients with tumors extended from middle fossa to posterior fossa and were identical to what was seen in presurgical planning. CONCLUSIONS: Virtual reality technology can accurately simulate the anatomical feature of the temporal bridging veins which facilitates the planning of individual operations in neurosurgery.

Temporal base intradural transpetrosal approach to the petoclival region: an appraisal of anatomy, operative technique and clinical experience.

BACKGROUND: Tumours in the petroclival region have been a challenge to neurosurgeons. We present a cohort of 24 patients with petroclival meningioma (PCM) and trigeminal schwannoma (TS) in the petroclival region with extension to the middle fossa which were removed with the temporal base intradural transpetrosal (TBIT) approach. METHODS: To avoid damage to the important surrounding structures in the petrosal bone, a morphometric analysis in the TBIT approach was performed in 15 cadaveric heads, and the 'safe area of intradural petrosectomy' was identified in the TBIT approach. Subsequently, 14 patients with PCM and 10 patients with TS in the petroclival region were operated on with the TBIT approach. RESULTS: There were no operative deaths in this cohort related to the surgery. Common complications included light hemiparesis in two patients (8.0%), new cranial nerve paresis in nine (37.5%), post-operative pneumonia in one (4.0%) and transient cerebrospinal fluid leak in one (4.0%). Total tumour resection was achieved in 20 patients (83.3%) and subtotal resection in 4 (16.7%). There was no tumour recurrence in all patients at follow-up with a mean duration of 37 months. CONCLUSIONS: Surgical strategy for PCM and TS in the petroclival region should be tailored to individual patients. The TBIT approach may improve the exposure of tumours in the petroclival region. A clear description of the 'safe area of intradural petrosectomy' appears to decrease the risk associated with petrosectomy procedure in the TBIT approach.

Trigeminal neurinomas: clinical features and surgical experience in 84 patients.

Trigeminal neurinomas are the second most common intracranial neurinomas next to the vestibular neurinomas. Eighty-four patients with trigeminal neurinomas were treated between 2003 and 2007. There were 40 women and 44 men (mean age 43 years). The most frequent symptoms were headache or numbness of the ipsilateral hemiface. There were 24 type A, nine type B, 45 type C, and six type D tumors. Dextroscope virtual reality technology was used for preoperative planning in recent eight cases. Gross total resection was achieved in 63 patients. We found that the major impediments to complete removal were adherent to the brainstem and skull base vascular structure, the frontotemporal approach with zygomatic or orbitozygomatic osteotomy or subtemporal approach could offer excellent exposure of the middle fossa and access to the posterior fossa, and Dextroscope virtual reality technology was a very useful tool to identify surgical and anatomic nuances and enhance preoperative planning in trigeminal neurinomas resection.

Anatomy of the petrosphenoidal and petrolingual ligaments at the petrous apex.

The petrous apex is a complex area surrounded by the cavernous sinus, Dorello's canal and Meckel's cave. The petrosphenoidal ligament (PSL) and the petrolingual ligament (PLL) are important structures located in the region. These two ligaments were examined under a surgical microscope in 10 specimens of five adult cadaveric heads fixed in formalin. They were found to span from the petrous apex to the posterior clinoid process, and the lingula of the sphenoid bone, respectively. The dural sleeve of the abducens nerve, the dorsal meningeal artery or its medial branch, and the venous blood space were located below the PSL in all specimens, and the petrous or sphenoidal insertion of the PSL varied in five specimens. The PLL invariably surrounded part of the dorsal and lateral walls of the lacerum segment of the internal carotid artery (ICA), just under the anteroinferior portion of the anteromedial wall of Meckel's cave in all specimens. The PSL and PLL are valuable anatomical landmarks for identifying the ICA and the nerves in this region. A thorough understanding of the relationship of the two ligaments with neurovascular structures is a prerequisite for surgery in and around the petrous apex.

[The diagnosis and surgical management for intramedullary spinal cord cavernous angioma].

OBJECTIVE: The clinical diagnosis and surgical management of intramedullary spinal cord cavernous angioma were discussed. METHOD: Total 19 patients with intramedullary cavernous angioma were analyzed retrospectively on the clinical manifestation, radiographic feature, diagnosis and differentiation, surgical technique and caution. Of all the 19 patients, averaging 38.7 years old, 14 were male and 5 were female. Nine patients were followed. RESULT: All the 19 patients pathologically diagnosed with spinal cord cavernous angioma got good surgical results, besides one patient showed loss of proprioception. Nine patients were followed up and all demonstrated improvement on neurological function. CONCLUSION: The clinical symptom of most of the patients with spinal cord cavernous angioma presented mildly at onset, but deteriorated gradually because of repeated prehemorrhage. Since the lesion showed some characteristic in MRI, MRI examination was regarded as an important diagnostic tool. Dissection should be done between the tumor and the gliosis during the surgical procedure, special attention should be paid to avoiding tumor residual. It was not necessary to aggressively evacuate the hematoma derived from tumor hemorrhage, which extended along the central canal up and down, except obvious occupied syndrome exited.

[Diagnosis and treatment of spinal cord hemangioblastoma].

OBJECTIVE: To study the diagnosis and treatment of spinal cord hemangioblastoma. METHOD: The clinical data of 42 patients with spinal cord hemangioblastoma who were operated on between 1997 and 2005 were analyzed. RESULT: Spinal cord hemangioblastoma mostly showed space occupying lesions with clear boundary and Dd-DTPA homogenous enhancement by MRI. All the 42 patients underwent complete excision. 27 patients showed improvement of their symptoms, the 6 patients failed to show any change, and neurological deficits were aggravated in the 5 patients. CONCLUSION: MRI and DSA are helpful in qualitative and localized diagnoses of the spinal cord hemangioblastoma. Surgical outcomes are favorable.

[Choice of the surgical approach to petroclival tumor].

OBJECTIVE: To discuss the reasonable choice of the surgical approach to petroclvial tumors. METHODS: The clinical data of consecutive 53 patients with the petroclival tumors, treated from June 2002 to June 2004, were reviewed to compare the different surgical approaches to pertroclival region. RESULT: Subtemporal transtentorial approach were used in 11 patients, suboccipital retrosigmoid approach in 12 patients, (transzygomatic or orbitozygomatic) frontotemporal (pterional) approach in 12 patients, presigmoid sinus approach in 2 patients, subtemporal and retrosigmoid sinus combined approach in 7 patients, subtemporal anterior petrosal extradural approach in 7 patients and extended transfrontal base extradural approach in 2 patients. Of all patients in this group, total tumor removal was achieved in 32 patients, subtotal in 9, largely partial in 12. The new cranial nerve deficit took place in 16 patients postoperatively, two patients died from coma and serious pneumonia. CONCLUSIONS: Using perfect microsurgical technique, conventional surgical approaches on petroclival region such as suboccipital retrosigmoid approach, subtemporal transtentorial approach can be suitable for most petroclival tumor with the help of neuro-navigation and neuro-endoscopy. To the epidural tumor on petroclival region, the epidural approach should be used with less invasion to the brain tissue. And to the giant petroclival tumor, the combined-tentorial approach can provide an excellent access and exposure to the tumor.

Transforming growth factor-beta 1 increases bad phosphorylation and protects neurons against damage.

Despite the characterization of neuroprotection by transforming growth factor-beta1 (TGF-beta1), the signaling pathway mediating its protective effect is unclear. Bad is a proapoptotic member of the Bcl-2 family and is inactivated on phosphorylation via mitogen-activated protein kinase (MAPK). This study attempted to address whether MAPK signaling and Bad phosphorylation were influenced by TGF-beta1 and, furthermore, whether these two events were involved in the antiapoptotic effect of TGF-beta1. We found a gradual activation of extracellular signal-regulated kinase 1/2 (Erk1/2) and MAPK-activated protein kinase-1 (also called Rsk1) and a concomitant increase in Bad phosphorylation at Ser(112) in mouse brains after adenovirus-mediated TGF-beta1 transduction under nonischemic and ischemic conditions induced by transient middle cerebral artery occlusion. Consistent with these effects, the ischemia-induced increase in Bad protein level and caspase-3 activation were suppressed in TGF-beta1-transduced brain. Consequently, DNA fragmentation, ischemic lesions, and neurological deficiency were significantly reduced. In cultured rat hippocampal cells, TGF-beta1 inhibited the increase in Bad expression caused by staurosporine. TGF-beta1 concentration- and time-dependently activated Erk1/2 and Rsk1 accompanied by an increase in Bad phosphorylation. These effects were blocked by U0126, a mitogen-activated protein kinase/Erk kinase 1/2 inhibitor, suggesting an association between Bad phosphorylation and MAPK activation. Notably, U0126 and a Rsk1 inhibitor (Ro318220) abolished the neuroprotective activity of TGF-beta1 in staurosporine-induced apoptosis, indicating that activation of MAPK is necessary for the antiapoptotic effect of TGF-beta1 in cultured hippocampal cells. Together, we demonstrate that TGF-beta1 suppresses Bad expression under lesion conditions, increases Bad phosphorylation, and activates the MAPK/Erk pathway, which may contribute to its neuroprotective activity.