Characteristic fingerprint spectrum of α-synuclein mutants on terahertz time-domain spectroscopy.

α-Synuclein, a presynaptic neuronal protein encoded by the SNCA gene, is involved in the pathogenesis of Parkinson's disease. Point mutations and multiplications of α-synuclein (A30P and A53T) are correlated with early-onset Parkinson's disease characterized by rapid progression and poor prognosis. Currently, the clinical identification of SNCA variants, especially disease-related A30P and A53T mutants, remains challenging and also time consuming. This study aimed to develop a novel label-free detection method for distinguishing the SNCA mutants using transmission terahertz (THz) time-domain spectroscopy. The protein was spin-coated onto the quartz to form a thin film, which was measured using THz time-domain spectroscopy. The spectral characteristics of THz broadband pulse waves of α-synuclein protein variants (SNCA wild type, A30P, and A53T) at different frequencies were analyzed via Fourier transform. The amplitude A intensity (AWT, AA30P, and AA53T) and peak occurrence time in THz time-domain spectroscopy sensitively distinguished the three protein variants. The phase φ difference in THz frequency domain followed the trend of φWT > φA30P > φA53T. There was a significant difference in THz frequency amplitude A' corresponding to the frequency ranging from 0.4 to 0.66 THz (A'A53T > A'A30P > A'WT). At a frequency of 0.4-0.6 THz, the transmission T of THz waves distinguished three variants (TA53T > TA30P > TWT), whereas there was no difference in the transmission T at 0.66 THz. The SNCA wild-type protein and two mutant variants (A30P and A53T) had distinct characteristic fingerprint spectra on THz time-domain spectroscopy. This novel label-free detection method has great potential for the differential diagnosis of Parkinson's disease subtypes.

Risk stratification and predictive modeling of postoperative delirium in chronic subdural hematoma.

Background- Postoperative delirium is a common complication associated with the elderly, causing increased morbidity and prolonged hospital stay. However, its risk factors in chronic subdural hematoma patients have not been well studied. Methods- A total of 202 consecutive patients with chronic subdural hematoma at Peking University Third Hospital between January 2018 and January 2023 were enrolled. Various clinical indicators were analyzed to identify independent risk factors for postoperative delirium using univariate and multivariate regression analyses. Delirium risk prediction models were developed as a nomogram and a Markov chain. Results- Out of the 202 patients (age, 71 (IQR, 18); female-to-male ratio, 1:2.7) studied, 63 (31.2%) experienced postoperative delirium. Univariate analysis identified age (p < 0.001), gender (p = 0.014), restraint belt use (p < 0.001), electrolyte imbalance (p < 0.001), visual analog scale score (p < 0.001), hematoma thickness (p < 0.001), midline shift (p < 0.001), hematoma side (p = 0.013), hematoma location (p = 0.018), and urinal catheterization (p = 0.028) as significant factors. Multivariate regression analysis confirmed the significance of restraint belt use (B = 7.657, p < 0.001), electrolyte imbalance (B = -3.993, p = 0.001), visual analog scale score (B = 2.331, p = 0.016), and midline shift (B = 0.335, p = 0.007). Hematoma thickness and age had no significant impact. Conclusion- Increased midline shift and visual analog scale scores, alongside restraint belt use and electrolyte imbalance elevate delirium risk in chronic subdural hematoma surgery. Our prediction models may offer reference value in this context.

Granuloma formation as a late complication of burr-hole surgery for chronic subdural hematoma.

BACKGROUND: Surgical treatment remains the mainstream therapeutic regimen for chronic subdural hematoma (CSDH), and burr-hole craniostomy with subdural drainage is the preferable approach. Herein, we reported a case of intracranial granuloma formation as a late complication of burr-hole surgery for CSDH. CASE PRESENTATION: A 31-year-old man presented with a 1-month history of headache. Head computed tomography (CT) showed a subdural hematoma in the left frontal-temporal-parietal region with significant midline shifting. A burr-hole evacuation of the hematoma with closed-system drainage was performed. CT obtained immediately after the surgery demonstrated that the hematoma was mostly evacuated. Nine months later, he presented to us again due to intermittent headache in the left temporoparietal region. Brain magnetic resonance imaging revealed a space-occupying mass at the site of the original hematoma. A bone-flap craniotomy was performed for resecting the mass. Histopathological examination revealed a granuloma. The microbial cultivation of the resected specimen was negative. The postoperative course was uneventful, and the headache was relieved. CONCLUSION: Granuloma formation is an extremely rare late complication of burr-hole surgery for CSDH. Physicians involved in the perioperative management of CSDH should be aware of this condition, and bone-flap craniotomy may be warranted.

Design, methodology, and preliminary results of the non-human primates eye study.

PURPOSE: To describe the normative profile of ophthalmic parameters in a healthy cynomolgus monkey colony, and to identify the characteristic of the spontaneous ocular disease non-human primates (NHP) models. METHODS: The NHP eye study was a cross-sectional on-site ocular examination with about 1,000 macaques held in Guangdong Province, southeastern China. The NHPs (Macaca fascicularis, cynomolgus) in this study included middle-aged individuals with a high prevalence of the ocular disease. The NHP eye study (NHPES) performed the information including systematic data and ocular data. Ocular examination included measurement of intraocular pressure (IOP), anterior segment- optical coherence tomography (OCT), slit-lamp examination, fundus photography, autorefraction, electroretinography, etc. Ocular diseases included measurement of refractive error, anisometropia, cataract, pterygium, etc. RESULTS: A total of 1148 subjects were included and completed the ocular examination. The average age was 16.4 ± 4.93 years. Compared to the male participants, the females in the NHPES had shorter axial length and the mean Average retinal nerve fiber layer (RNFL) thickness (except for the nasal quadrants). The mean IOP, anterior chamber depth, lens thickness, axial length, central corneal thickness, choroid thickness and other parameters were similar in each group. CONCLUSION: The NHPES is a unique and high-quality study, this is the first large macaque monkey cohort study focusing on ocular assessment along with comprehensive evaluation. Results from the NHPES will provide important information about the normal range of ophthalmic measurements in NHP.

Spinal cysticercosis: a rare cause of myelopathy.

BACKGROUND: Neurocysticercosis is a neuroinfectious disease caused by the larval stage of the tapeworm Taenia solium. Isolated spinal cysticercosis is rare, with limited cases having been reported in the literature. This entity poses great diagnostic and therapeutic challenges. METHODS: This retrospective study included seven patients pathologically diagnosed with spinal cysticercosis. The clinical manifestations, radiological features on magnetic resonance imaging (MRI), treatment, and outcomes were analyzed. RESULTS: This case series consisted of four male and three female patients, with an average age of 34.9 ± 10.9 years. Clinically, six patients manifested with localization-related myelopathy. There were four solid lesions, one cystic-solid lesion, and three cystic lesions. The solid and cystic-solid lesions showed characteristic MRI features: 1) within the lesion, there was a mural nodule with isointensity on T1WI and iso- to hyperintensity on T2WI; 2) the signals at the periphery of the mural nodule were variable, ranging from hypointense to hyperintense on T2WI; and 3) ring-like or cyst wall enhancement could be present, and dot-like enhancement could be noted in the mural nodule. Complete resection of the responsible lesion was achieved in all patients, and oral albendazole was administered in a patient with one more suspected homologous lesion. After a mean follow-up period of 56.7 ± 35.1 months, the patient's symptoms mostly regressed. CONCLUSION: Spinal cysticercosis is an extremely rare cause of myelopathy. Characteristic MRI features can facilitate preoperative diagnosis. Clinicians should be aware of this entity, and it should be included in the differential diagnosis of myelopathy.

Multisegmental versus monosegmental intramedullary spinal cord ependymomas: perioperative neurological functions and surgical outcomes.

Multiple factors, such as tumor size, lateralization, tumor location, accompanying syringomyelia, and regional spinal cord atrophy, may affect the resectability and clinical prognosis of intramedullary spinal cord ependymomas. However, whether long-segmental involvement of the spinal cord may impair functional outcomes remains unclear. This study was aimed to compare perioperative neurological functions and long-term surgical outcomes between multisegmental ependymomas and their monosegmental counterparts. A total of 62 patients with intramedullary spinal cord ependymoma (WHO grade II) were enrolled, and all of them underwent surgical resection. The patients were classified into the multisegmental group (n = 43) and the monosegmental group (n = 19). Perioperative and long-term (average follow-up period, 47.3 ± 21.4 months) neurological functions were evaluated using the modified McCormick (mMC) scale and the modified Japanese Orthopaedic Association (mJOA) scoring system. Preoperative neurological functions in the multisegmental group were significantly worse than those in the monosegmental group (P < 0.05). However, postoperative short-term neurological functions, as well as long-term functional outcomes, were similar between the two groups (P > 0.05). Logistic regression analysis showed that preoperative mMC and mJOA scores were significantly correlated with neurological improvement during the follow-up period (P < 0.05). Multisegmental involvement of the spinal cord is associated with worse neurological functions in patients with intramedullary spinal cord ependymoma, while the long-term prognosis is not affected. The preoperative neurological status of the patient is the only predictor of long-term functional improvement.

Multiple dimensions of radiographic reconstruction for the optimal operative strategy of sacral meningeal cysts.

BACKGROUND AND PURPOSE: The contents and subtypes of sacral cysts are sophisticated in many cases. We applied multiple dimensional magnetic resonance imaging (MRI) reconstruction to preoperatively clarify the specific subtype of sacral meningeal cysts. MATERIALS AND METHODS: We preoperatively used multimodal neural reconstruction MRI sequences to evaluate 76 patients with sacral cysts. The linear nerve roots were precisely traced based on sagittal or coronal images processed at various angles and levels which was conducive to the design of the operation strategy. RESULTS: Cysts with nerve passage were detected in 47 cases (62%, 47/76), whereas cysts without nerve roots were detected in 24 cases (32%, 24/76). Five patients had mixed cysts with or without nerve roots. Intraoperative exploration results proved the high accuracy of image reconstruction; only one cyst without a nerve root was misdiagnosed prior to surgery. CONCLUSION: MRI reconstruction based on the three-dimensional fast imaging employing steady-state acquisition T2 sequence precisely tracked the nerve roots of sacral cysts and guided the optimal strategy during surgery.

Clinical characteristics and surgical outcomes of ependymomas in the upper cervical spinal cord: a single-center experience of 155 consecutive patients.

Ependymomas occurring in the upper cervical spinal cord (above the level of the C4 segment) are rare entities with great therapeutic challenges. This study was aimed to investigate the clinicoradiological characteristics and the prognosis in a large cohort of upper cervical ependymomas from a single institution. This retrospective study enrolled 155 patients with primary ependymomas in the upper cervical spinal cord. The pre- and post-operative clinical and magnetic resonance imaging profiles were collected. The neurological outcomes and survival events were evaluated, and potential independent risk factors were analyzed. There were 82 females and 73 males, with an average age of 43.1 ± 11.3 years. Immediately post-operatively, 118 (76.1%) patients experienced neurological deterioration and 32 (20.7%) patients remained unchanged. Three months after surgery, 61 (39.4%) patients showed deteriorated neurological functions compared to the pre-operative baseline levels. After an average follow-up period of 56.0 ± 24.7 months, the neurological functions were worse than the baseline status in 37 (23.9%) patients and improved in 33 (21.3%) patients, respectively. Logistic regression analysis identified that lower age (≤ 42 years) and lower pre-operative MMS (I-II) were independent protective factors for predicting favorable neurological functions. Multivariate Cox regression analysis revealed that incomplete resection was the only independent risk factor associated with a shorter progression-free survival. Age and pre-operative functional status affect the long-term neurological outcomes, and incomplete resection was associated with a shorter survival. Our findings indicate that gross total resection should be the goal of surgical treatment of upper cervical ependymomas.

Clinical characteristics and surgical outcomes of spinal myxopapillary ependymomas.

Spinal myxopapillary ependymoma (SME) is a rare pathological variant of ependymoma, which most commonly occurs in the cauda equina and filum terminale of the spinal cord. Although SME is considered as a benign entity, histologically corresponding to WHO grade I, local recurrence and metastasis have been reported in many cases. The purpose of this large-scale, single-center study was to investigate the clinical characteristics and surgical outcomes of SME. A total of 34 consecutive patients diagnosed with SME were enrolled in this retrospective study. All patients underwent magnetic resonance imaging (MRI) and were treated with surgical resection. Individual clinical data were collected, and surgical outcomes were evaluated during the follow-up period. There were 21 males and 13 females, with an average age of 29.97 years. Clinical symptoms included back pain (82.4%), weakness (44.1%) and numbness (20.6%) in extremities, and sphincter dysfunction (26.5%). The tumor locations included lumbar segments (52.9%), thoracolumbar segments (23.5%), lumbosacral segments (17.6%), and thoraco-lumbo-sacral segments (5.9%). On MRI, all SMEs appeared hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging, with remarkable enhancement. Gross total resection was achieved in 18 patients, and subtotal resection (STR) was achieved in 16 patients. After an average follow-up period of 41.5 months, recurrence was noted in 5 patients (5 of 16) who underwent STR. SMEs have some characteristic features on MRI which can facilitate the preoperative diagnosis. Complete surgical resection is the best treatment of choice with a favorable outcome. In cases of incomplete resection, postoperative radiotherapy may be an effective alternative.

Chordoid glioma: an entity occurring not exclusively in the third ventricle.

Chordoid gliomas are extremely rare entities, which are generally considered occurring exclusively in the third ventricle. Despite the low-grade histological grade, aggressive behaviors have been reported in literatures. Due to the low morbidity, the origins, clinical, and radiological features, management and prognosis are still yet to be well elucidated. We retrospectively reviewed the clinical profiles from a series of 6 patients with chordoid gliomas. All patients underwent surgical treatment, and the diagnoses were based on histopathological examinations. Magnetic resonance imaging (MRI) was performed perioperatively. Follow-up outcomes were presented. This case series consisted of three male and three female patients (age range 27-67 years; mean age 43.3 years). MRI results showed tumors in the third ventricle (4/6), temporal-parietal-occipital lobe involving the lateral ventricle (1/6), and cerebellar hemisphere (1/6). Three tumors were solid, and the others were cystic-solid. Hydrocephalus was present in one patient. The T1-weighted imaging showed hypo- to isointensity, and T2-weighted imaging showed iso- to hyperintensity; enhancement was homogeneous (4/6) or heterogeneous (2/6). Diffusion-weighted imaging showed no evidence of restricted diffusion. Magnetic resonance spectrum showed an elevated choline value and reduced N-acetylaspartate value. Gross total resection was achieved in all patients, and during an average follow-up period of 35.8 months, no recurrence was noted. Chordoid gliomas can occur outside the third ventricle with a great diagnostic challenge. The MRI characteristics suggest a low-grade tumor, and the accurate diagnosis depends on pathological criteria. Complete surgical resection is associated with a favorable outcome.

Y-box binding protein-1 promotes tumorigenesis and progression via the epidermal growth factor receptor/AKT pathway in spinal chordoma.

Chordomas are rare bone tumors with a poor prognosis and no approved targeted therapy. Y-box binding protein-1 (YBX1) promotes tumor growth, invasion and drug resistance. However, the role of YBX1 in chordoma is unclear. In this study, we examined the expression of YBX1 using immunohistochemistry and found that YBX1 was significantly upregulated in 32 chordoma tissues compared to distant normal tissues. In addition, YBX1 upregulation was associated with surrounding tissue invasion, recurrence and poor prognosis. Biological function studies demonstrated that YBX1 promoted cell proliferation and invasion, accelerated G1/S phase transition, and inhibited apoptosis. Further investigation revealed that YBX1 enhanced epidermal growth factor receptor (EGFR) transcription by directly binding to its promoter in chordoma cells. YBX1 regulated protein expression of p-EGFR, p-AKT and its downstream target genes that influenced cell apoptosis, cell cycle transition and cell invasion. YBX1 activated the EGFR/AKT pathway in chordoma and YBX1-induced elevated expression of key molecules in the EGFR/AKT pathway were downregulated by EGFR and AKT pathway inhibitors. These in vitro results were further confirmed by in vivo data. These data showed that YBX1 promoted tumorigenesis and progression in spinal chordoma via the EGFR/AKT pathway. YBX1 might serve as a prognostic and predictive biomarker, as well as a rational therapeutic target, for chordoma.

Shunt dependency syndrome and acquired Chiari malformation secondary to cerebrospinal fluid diversion procedures: a 9-year longitudinal observation.

BACKGROUND: Shunt dependency syndrome is a rare long-term complication of cystoperitoneal (CP) shunting for intracranial arachnoid cysts, which is characterized by acute intracranial hypertension with normal-sized or small ventricles. Additionally, acquired Chiari type I malformations (ACIM) could be infrequently secondary to extrathecal shunt drainage of cerebrospinal fluid. CASE REPORT: We described a 12-year-old boy who developed shunt dependency syndrome following a CP shunting for treating a temporal arachnoid cyst. To manage this rare complication, we placed a lumboperitoneal (LP) shunt. During the follow-up period, shunt-induced ACIM and concomitant syringomyelia were noted. CONCLUSION: Shunt dependency syndrome is a rare complication secondary to CP shunting in the treatment of temporal arachnoid cysts, and LP shunting is an effective option to relieve the intracranial hypertension. However, the clinicians should be alert to the ACIM as a rare late complication of cerebrospinal fluid diversion procedures, and the potential protecting effect of the programmable valve should be emphasized.

Oleandrin sensitizes human osteosarcoma cells to cisplatin by preventing degradation of the copper transporter 1.

A major problem in osteosarcoma treatment is cisplatin resistance. We have reported the anti-osteosarcoma effect of oleandrin; however, whether oleandrin sensitizes osteosarcoma to cisplatin is unknown. We investigated the chemosensitization of oleandrin and potential mechanisms in osteosarcoma cells U-2OS, SaOS-2, and MG-63. The median-effect analysis demonstrated that cisplatin + oleandrin exerted synergistic (U-2OS and MG-63) or additive effects (SaOS-2), which were consistent with the changes of the intracellular accumulation of platinum (Pt) and Pt-DNA adducts. Immunohistochemistry staining showed that the expression level of the mature form CTR1, the major influx transporter of cisplatin, was low in osteosarcoma tissue. However, oleandrin with or without cisplatin significantly increased the expression and membrane localization of the mature CTR1. Furthermore, CTR1 knockdown reversed the synergistic effect and decreased cisplatin uptake. The mRNA microarray analysis suggested that oleandrin downregulated the expression of proteasome-related genes, which was verified by the proteasome activity assay. Besides, the proteasome inhibitor MG132 upregulated the expression of the mature CTR1 in U-2OS and MG-63 cells. Overall, we conclude that oleandrin sensitizes osteosarcoma cells to cisplatin in synergistic or additive manners. The synergy results from the enhanced cisplatin uptake via oleandrin-mediated inhibition of proteasome activity and subsequent blockage of the mature CTR1 degradation.

Ultrasonic Inspection of Localized Defects in Low-Porosity CFRP.

A preliminary backscattered signal model of carbon-fiber-reinforced plastic (CFRP) laminate was established. The backscattered signal model was composed of three sub models, which were concerned with structural signal, scattering signal, and non-acoustic noise. Resonance in structural signal and echoes excited by defects (porosity and rich-resin) were studied. The results showed that: resonance would occur when there was sufficient bandwidth; when the CFRP laminate contained voids, the center frequency of the backscattered signal decreased; and the localized defects, including rich-resin and localized porosity, tended to generate apparent echoes where they located. A simplified backscattered signal model was subsequently put forward, showing certain potential in revealing time-frequency properties of backscattered signals. The newly proposed variational mode decomposition was used for defect modes extraction, successfully avoiding the mode mixing and false modes which easily exist in empirical mode decomposition. Subsequently, the generalized Stockwell transform was adopted for the defects localization. The simulation and experiment denoted the coincidence between the backscattered signal model and the experimental signal, and showed the effectiveness of variational mode decomposition and generalized Stockwell transform in localized defects detection.

Ultrasonic Flaw Echo Enhancement Based on Empirical Mode Decomposition.

The detection of flaw echoes in backscattered signals in ultrasonic nondestructive testing can be challenging due to the existence of backscattering noise and electronic noise. In this article, an empirical mode decomposition (EMD) methodology is proposed for flaw echo enhancement. The backscattered signal was first decomposed into several intrinsic mode functions (IMFs) using EMD or ensemble EMD (EEMD). The sample entropies (SampEn) of all IMFs were used to select the relevant modes. Otsu's method was used for interval thresholding of the first relevant mode, and a window was used to separate the flaw echoes in the relevant modes. The flaw echo was reconstructed by adding the residue and the separated flaw echoes. The established methodology was successfully employed for simulated signal and experimental signal processing. For the simulated signals, an improvement of 9.42 dB in the signal-to-noise ratio (SNR) and an improvement of 0.0099 in the modified correlation coefficient (MCC) were achieved. For experimental signals obtained from two cracks at different depths, the flaw echoes were also significantly enhanced.

Mixed gangliocytoma-pituitary adenoma in the sellar region: a large-scale single-center experience.

BACKGROUND: Mixed gangliocytoma-pituitary adenoma is an extremely rare tumor occurring in the sellar region, histologically composed of both gangliocytic and pituitary adenomatous architectures. The histogenesis of these tumors remains unknown, and the diagnosis, treatment, and prognosis are yet to be fully understood. METHODS: We retrospectively reviewed the clinical, radiological, and histopathological profiles from a series of 20 patients with sellar mixed gangliocytoma-pituitary adenomas. All patients underwent surgical tumorectomy via an endoscopic or microscopic transsphenoidal approach. Perioperative magnetic resonance imaging (MRI) and computed tomography (CT) data were reviewed. Immunohistochemical stains and electron microscopy examination were performed. Follow-up outcomes were presented. RESULTS: This case series consisted of 13 females and seven males (age range, 20-59 years; mean age, 42.3 ± 11.2 years). Preoperative endocrine examination showed elevated growth hormone (GH) in nine patients and hyperprolactinemia in eight patients. The tumors were positive for GH in 15 cases, prolactin in 13 cases, adrenocorticotropic hormone in three cases, and thyroid-stimulating hormone in one case. Gross total resection was achieved in 15 patients, and subtotal resection in five patients. During an average follow-up period of 42.5 ± 29.0 months, no recurrence was noted. CONCLUSIONS: The clinical and neuroimaging features of sellar mixed gangliocytoma-pituitary adenomas are non-specific, and invasion into the cavernous sinus is common. Surgical resection via a transsphenoidal approach is the preferred treatment, and the surgical outcomes are favorable. Moreover, our histopathological findings are more likely to support the theory that mixed gangliocytoma-pituitary adenoma originates from the neuronal transdifferentiation of adenomatous cells.

Clinical features and long-term outcomes of pediatric spinal meningiomas.

Pediatric spinal meningiomas are very rare. Most studies on pediatric spinal meningiomas are case reports with literature reviews. This study presented a surgical series of 14 pediatric patients with histologically proven sporadic spinal meningiomas, including 5 WHO grade II tumors. In this series, there were 9 male and 5 female patients with a mean age of 11.1 years. Seven tumors were located in the cervical spine, 5 in the thoracic spine, and 2 in the lumbar spine. Gross total resection (GTR) of the tumor with a well-demarcated dissection plane was achieved in 11 cases, subtotal resection was achieved in 2 cases, and partial resection was performed in 1 case. The symptoms were improved in 10 cases at the last follow-up and the current status of 2 patients worsened and 1 patient had no change compared to the preoperative presentation. One patient died of progressive tumor regrowth after partial resection and adjuvant radiotherapy. The postoperative follow-up magnetic resonance imaging showed tumor recurrence in one of the 11 GTR cases during the mean follow-up period of 72.5 months. Recurrence/regrowth of the residual tumors was observed in both the 2 STR cases. Although pediatric spinal meningiomas have a higher incidence of WHO grade II meningiomas, they are amenable to surgery if it is possible to achieve GTR. A good clinical outcome after GTR can be expected, even for WHO grade II meningiomas. Effect of adjuvant radiochemotherapy for controlling the tumors is still unclear and requires further investigation.

Spinal meningeal melanocytomas: clinical manifestations, radiological and pathological characteristics, and surgical outcomes.

Meningeal melanocytoma is a rare benign tumor, most frequently located in the posterior fossa and spinal canal. The aim of this study was to investigate the clinical manifestations, radiological features, management, and follow-up data of spinal meningeal melanocytomas. We present the clinical data and long-term outcomes from a consecutive surgical series of 16 patients with pathologically diagnosed spinal meningeal melanocytomas. All of the patients underwent surgical resection. Pre and postoperative MRI was performed. Follow-up data and neurological functional assessment is presented and discussed. The mean age at diagnosis was 42.0 years, with a significant male predominance. The primary clinical symptoms were weakness or numbness of the extremities. The appearance of melanocytoma on MRI is typically isointense to hyperintense on T1-weighted images, hypointense on T2-weighted images, and contrast enhancement tends to be remarkable and homogeneous. In most cases, gross total resection is achievable; however, in rare cases with dumbbell-shaped tumors involving the extraspinal region, a staging operation and subtotal resection should be attempted. During a mean follow-up period of 58.1 months, the symptoms were completely relieved in all the patients, and no tumor progression or recurrence was noted. Melanocytic tumors of the central nervous system have a typical appearance on MRI scans, varying with the content and distribution of melanin. However, the differential diagnosis between malignant melanoma and melanocytoma still depends on pathological criteria. Spinal meningeal melanocytoma has a benign course, and it is amenable for gross total resection. The outcome is favorable following complete resection.

Treatment strategies and long-term outcomes for primary intramedullary spinal germinomas: an institutional experience.

Primary intramedullary germinomas are very rare tumors in the spinal cord. This study presented a series of 11 patients with histologically proven primary intramedullary spinal germinomas. Their clinical and radiological findings, treatment records and long-term outcomes were reviewed. There were four male and seven female patients with a mean age of 27.1 years. Because germ cell tumors were suspected by frozen-section biopsy, gross total resection was unattempted. Partial resection was performed in four cases, while biopsy was performed in seven cases. Postoperatively, carboplatin and etoposide chemotherapy combined with low dose radiotherapy (30.6 Gy) to local spine was performed in seven cases, followed by radiotherapy alone (40 Gy) in four cases. All 11 patients had a complete response to either combination treatment or single radiotherapy, and the mass effect on the spinal cord vanished. The mean follow-up period was 75.4 months. At the last follow-up, the symptoms were improved in 10 cases and the current status of one patient was unchanged. The postoperative follow-up magnetic resonance imaging showed no recurrence or dissemination in any of the patients. Primary intramedullary germinomas are amenable to adjuvant radiochemotherapy and low dose radiation with etoposide and carboplatin chemotherapy is recommended. When combination therapy cannot be performed, relatively high doses of radiotherapy are advised, and radiation to the craniospinal axis may be unnecessary. A good clinical outcome after combination therapy or radiotherapy alone can be expected, and the risk of long-term recurrence and dissemination is low.

Clinical characteristics and surgical outcomes of primary spinal paragangliomas.

Spinal paragangliomas are extremely rare tumors, most frequently involving the cauda equina and the filum terminale. We aimed to investigate the clinical manifestations, radiological features, management, and follow-up data of primary spinal paraganglioma. We present the clinical data and long-term outcomes from a consecutive surgical series of 19 patients with pathologically diagnosed spinal paragangliomas. All of the patients had undergone surgical resection. Pre- and postoperative magnetic resonance imaging was performed and follow-up data and neurological functional assessment are presented and discussed. The mean age at diagnosis was 47.7 years, with a significant male predominance. The primary clinical symptoms were low back pain and sciatica. Magnetic resonance images (MRI) showed characteristic signs that help differentiate paragangliomas from other spinal tumors, including a "salt & pepper" sign, serpiginous flow void, and a peripheral hypointense rim. Also, a well-encapsulated appearance can be found intraoperatively. During a mean follow-up period of 62.1 months, remnant tumor progression was noted on MRI in three patients with incomplete resection. Pain symptoms were relieved immediately after surgical intervention, while motor and sphincter dysfunction were much slower to improve. Differential diagnosis of paraganglioma based on MR images alone is challenging, but the presence of specific characteristic features provides suggestive clues; however, accurate diagnosis depends on pathological criteria. Despite the benign course, gross total resection is ideal, given an increased risk of recurrence in situ. Timely recognition and surgical treatment should be emphasized to avoid progressive neurological deficits.