Quantitative analysis of a posterior fossa teratomas with unusual CT and MR Characteristics--illustrative case.

Background: Intracranial teratomas or other cystic lesions with atypical imaging manifestations can still be frequently seen clinically. The specific reasons for unusual imaging manifestations need to be further explored. Observations: A case of adult teratoma in the posterior fossa with unusual imaging manifestations was reported. The chemical composition of its cystic fluid was quantitatively detected, and in vitro imaging simulation experiments were performed on some fluid substances with similar cystic fluid properties to explore the reasons for special imaging manifestations. The content of inorganic substances and protein in the cystic fluid were both low, with no melanin detected. In vitro experiments revealed that MR T1 signals could increase with protein content rising and changes in MR T2 signals presented no obvious correlation with it. CT values increased gradually with protein concentration rising. The substances with similar viscosity had similar CT values, whereas substance viscosity showed no significant correlation with changes in MR signals. Conclusion: The abnormality of imaging manifestations cannot be confirmed as the result of "high protein content", nor can it be simply attributed to bleeding. Further research is required for the impact of the combination of paramagnetic particles and biofluid on imaging.

[Applicability of multiple remotely sensed vegetation indices for extracting key phenological metrics of Tamarix chinensis shrubs based on CO2 flux observation and Sentinel-2 data]. / æŸ½æŸ³çŒä¸›å ³é”®ç‰©å€™å‚æ•°å¤šç§æ¤è¢«æŒ‡æ•°é¥æ„Ÿæå–çš„é€‚ç”¨æ€§­­åŸºäºŽCO2通量观测和Sentinel-2数据.

We analyzed the relationship between gross primary productivity (GPP) and environmental factors at Sidaoqiao Superstation of the Ejina Oasis in China's Gobi Desert, by combining eddy flux and meteorological data from 2018 to 2019 and Sentinel-2 remote sensing images from 2017 to 2020. We evaluated the applicability of 12 remote sensing vegetation indices to simulate the growth of Tamarix chinensis and extract key phenological metrics. A seven-parameter double-logistic function (DL-7) + global model function (GMF) was used to fit the growth curves of GPP and vegetation indices. Three key phenological metrics, i.e., the start of the growing season (SOS), the peak of the growing season (POS), and the end of the growing season (EOS), were extracted for each year. Growing season degree days (GDD) and soil water content were the main environmental factors affecting the phenological dynamics of T. chinensis. Compared with 2018, the lower temperatures in 2019 resulted in slower accumulation rate of accumulated temperature before the SOS. T. chinensis required longer heat accumulation to enter growing season, which might cause later SOS in 2019. The hydrothermal conditions between SOS and POS were similar for 2018 and 2019. Howe-ver, the POS in 2019 was 8 days later than that in 2018, because of the late SOS in 2019. Following the POS in 2019, high GDD and low soil water content caused the T. chinensis to suffer from water stress, resulting in a shortened late growing season. The linear regression between the standardized Sentinel-2 vegetation index and the average value of GPP between 10:00 and 14:00 indicated that the enhanced vegetation index of the broadband vegetation index and the chlorophyll red edge index, inverted red edge chlorophyll index, and red-edge normalized difference vegetation index (NDVI705) of the narrowband vegetation index were highly consistent with the GPP of T. chinensis. Remote sensing extraction of SOS and POS of T. chinensis suggested that the Sentinel-2 narrowband vegetation index was more accurate than the broadband vegetation index. The modified chlorophyll absorption in reflectance index provided the most accurate extraction of SOS, while the MERIS terrestrial chlorophyll index provided the most accurate extraction of EOS. Conversely, the Sentinel-2 broadband vegetation index was the most accurate for extracting POS, especially the 2-band enhanced vegetation index and the near-infrared reflectance of vegetation. Overall, NDVI705 was the best index to estimate phenological metrics.

Application of temperature vegetation dryness index for drought monitoring in Mongolian Plateau.

Taking the Mongolian Plateau as the study area, the MODIS normalized difference vegetation index (NDVI) and the land surface temperature (LST) in the growing season from 2000 to 2019 were used to construct the NDVI-LST feature space, and based on which the temperature vege-tation dryness index (TVDI) of the Mongolian Plateau was calculated. We used Theil-Sen Median trend analysis, Mann-Kendall test, and Hurst index method to analyze the spatial and temporal varia-tions and future trends of TVDI on the Mongolian Plateau. Furthermore, we examined the relationship between meteorological factors and TVDI on the Mongolian Plateau using partial correlation analysis. The results showed that the TVDI of the Mongolian Plateau during 2000-2019 showed an increasing trend with a rate of 0.0001·a-1, indicating that the Mongolian Plateau's drought condition became heavier slightly in the last 20 years. The drought condition in meadow steppe and typical steppe gradually decreased, and that in desert steppe and alpine grassland was increased. The average Hurst index of TVDI in the growing season was 0.45, and the area with TVDI less than 0.5 accounted for 71.5% of the total area, which indicated that the TVDI during 2000-2019 in most areas turned opposite to the past. In the future, the drought condition in the central desert steppe area and the eastern meadow steppe area might increase, and that in most of the typical steppe and the desert steppe in Inner Mongolia tended to decrease. The drought change in the alpine grassland area was uncertain. There was a significant positive correlation between the TVDI and temperature in 33.6% area of the Mongolian Plateau and a significant negative correlation between the TVDI and precipitation in 34.8% of the area. Moreover, the meteorological factors heavily affected the typical steppe.

Spatial heterogeneity of soil heavy metal content in Baiyinhua mining area, Inner Mongolia, China.

To evaluate the spatial distribution characteristics of soil heavy metal content in Xiwuzhumuqin Banner, Inner Mongolia, we analyzed the spatial heterogeneity of soil Cu, Cr, Pb, and Mn contents within 8 km distance of the mining area. Results showed that the contents of Cu, Cr, Pb and Mn in soil were 12.7, 32.6, 29.9 and 201.3 mg·kg-1, and their coefficients of variation were 26.8%, 33.9%, 27.1% and 45.7%, respectively. According to the model fitting by semi-variance function, the spatial distribution of Cu, Cr, Pb and Mn were consistent with the Gaussian model, Gaussian model, Gaussian model and linear model, respectively. Results of the spatial distribution pattern analysis showed that the spatial correlation levels of Mn, Cr and Cu were high, which were mainly affected by structural factors, but little affected by random factors. The spatial correlation level of Pb element was moderate, which was affected by both structural factors and random factors. Results of the fractal dimension analysis showed that the spatial distribution of four heavy metal contents was simple. Combined with 2D and 3D views, the four types of heavy metals all presented gradient distribution, which decreased with the increases of distance. The contents of Cu and Mn were mainly concentrated within 1.5 km from the mining area, while Cr and Pb were mainly concentrated within 2.0 km and 3.0 km from the mining area, respectively.

[Variation in the vegetation fade stage and its relationships with climate and vegetation productivity in Inner Mongolia, China].

Based on the MODIS NDVI data from 2001 to 2018, we extracted the fade stage of vegetation in Inner Mongolia and the characteristics of its temporal and spatial changes using the Logistic curve maximum curvature method of the cumulative normalized difference vegetation index (NDVI). We analyzed the responses of fade stage to climatic factors and NDVI at the ecological zone level. The results showed that the fade stage in Inner Mongolia occurred between the day of year (DOY) 260 and 280 during the study period. It was DOY 270-280 in the forest ecological zone, and was delayed from the south to north. The fade stage in the grassland ecological zone was the earliest and ranged between DOY 257 and 273, and was delayed from the northeast to southwest. The fade stage in the desert ecological zone ranged between DOY 270 and 283, which was delayed from the northeast to southwest. From 2001 to 2018, the fade stage in three ecological zones showed an insignificant delaying trend. Spatially, vegetation productivity decreased from the northeast to southwest, with a larger area of an increasing temporal trend than that of a decreasing trend. The fade stage in the entire Inner Mongolia and three ecological zones was greatly affected by precipitation during the two or three months before the fade stage and was positively correlated with the pre-season average temperature, maximum temperature, and minimum temperature, respectively. The increases/decreases in vegetation productivity in August and September delayed/advanced the fade stage in entire Inner Mongolia and three ecological zones. In contrast, the increases/decreases in vegetation productivity in June and July advanced/delayed the fade stage in the grassland and desert ecological zone.

Endoscopic Approach to Remove Intra-extracranial Tumors in Various Skull Base Regions: 10-year Experience of a Single Center.

BACKGROUND: Some problems have been found in the usually adopted combined approach for the removal of intra-extracranial tumors in skull base. Herein, we described a pure endoscopic transnasal or transoral approach (ETA) for the removal of intra-extracranial tumors in various skull base regions. METHODS: Retrospectively, clinical data, major surgical complications, pre- and postoperative images, and follow-up information of a series of 85 patients with intra-extracranial tumors in various skull base regions who were treated by surgery via ETA in our skull base center during the past 10 years were reviewed and analyzed. RESULTS: Gross total tumor removal was achieved in 80/85 cases (94.1%) in this study. All 37 cases with tumors in anterior skull base and all 14 cases with tumors in jugular foramen received total tumor removal. Thirteen and three cases with tumors in clivus received total and subtotal tumor removal, respectively. Total and subtotal tumor removal was performed for 16 cases and 2 cases in lateral skull base, respectively. The complications in this study included: cerebrospinal fluid leakage (n = 3), meningitis (n = 3), and new cranial nerve deficits (n = 3; recovered in 3 months after surgery). In the follow-up period of 40-151 months (median: 77 months), seven patients (8.8%) out of the 80 cases of total tumor removal experienced recurrence. CONCLUSIONS: Complete resection of intra-extracranial growing tumors in various skull base regions can be achieved via the pure ETA in one stage in selected cases. Surgical procedure for radical removal of tumors is feasible and safe.

Usefulness of intraoperative electromyographic monitoring of oculomotor and abducens nerves during skull base surgery.

BACKGROUND: Intraoperative neurophysiologic monitoring of the extraocular cranial nerve (EOCN) is not commonly performed because of technical difficulty and risk, reliability of the result and predictability of the postoperative function of the EOCN. METHODS: We performed oculomotor nerve (CN III) and abducens nerve (CN VI) intraoperative monitoring in patients with skull base surgery by recording the spontaneous muscle activity (SMA) and compound muscle action potential (CMAP). Two types of needle electrodes of different length were percutaneously inserted into the extraocular muscles with the free-hand technique. We studied the relationships between the SMA and CMAP and postoperative function of CN III and CN VI. RESULTS: A total of 23 patients were included. Nineteen oculomotor nerves and 22 abducens nerves were monitored during surgery, respectively. Neurotonic discharge had a positive predictive value of less than 50% and negative predictive value of more than 80% for postoperative CN III and CN VI dysfunction. The latency of patients with postoperative CN III dysfunction was 2.79 ± 0.13 ms, longer than that with intact CN III function (1.73 ± 0.11 ms). One patient had transient CN VI dysfunction, whose CMAP latency (2.54 ms) was longer than that of intact CN VI function (2.11 ± 0.38 ms). There was no statistically significant difference between patients with paresis and with intact function. CONCLUSIONS: The method of intraoperative monitoring of EOCNs described here is safe and useful to record responses of SMA and CMAP. Neurotonic discharge seems to have limited value in predicting the postoperative function of CN III and CN VI. The onset latency of CMAP longer than 2.5 ms after tumor removal is probably relevant to postoperative CN III and CN VI dysfunction. However, a definite quantitative relationship has not been found between the amplitude and stimulation intensity of CMAP and the postoperative outcome of CN III and CN VI.

Trigeminal neuralgia caused by a dilated superior cerebellar artery and a draining vein of cerebellar arteriovenous malformations: a case report and review of the literature.

Trigeminal neuralgia (TN) secondary to arterivenous malformations (AVMs) is relatively rare. We here report on a case of TN caused by cerebellar AVMs that was successfully treated by total AVMs resection in conjunction with microvasecular decompression (MVD) in one stage. In addition, we perform a review of the literature about the treatment of TN caused by cerebellar AVMs.

Neuronavigation Based on Track Density Image Extracted from Deterministic High-Definition Fiber Tractography.

BACKGROUND: Diffusion tensor imaging-based navigation is unable to resolve crossing fibers or to determine with accuracy the fanning, origin, and termination of fibers. It is important to improve the accuracy of localizing white matter fibers for improved surgical approaches. We propose a solution to this problem using navigation based on track density imaging extracted from high-definition fiber tractography (HDFT). CASE DESCRIPTION: A 28-year-old asymptomatic female patient with a left-lateral ventricle meningioma was enrolled in the present study. Language and visual tests, magnetic resonance imaging findings, both preoperative and postoperative HDFT, and the intraoperative navigation and surgery process are presented. Track density images were extracted from tracts derived using full q-space (514 directions) diffusion spectrum imaging (DSI) and integrated into a neuronavigation system. Navigation accuracy was verified via intraoperative records and postoperative DSI tractography, as well as a functional examination. DSI successfully represented the shape and range of the Meyer loop and arcuate fasciculus. Extracted track density images from the DSI were successfully integrated into the navigation system. The relationship between the operation channel and surrounding tracts was consistent with the postoperative findings, and the patient was functionally intact after the surgery. CONCLUSIONS: DSI-based TDI navigation allows for the visualization of anatomic features such as fanning and angling and helps to identify the range of a given tract. Moreover, our results show that our HDFT navigation method is a promising technique that preserves neural function.

Identification of cranial nerves around trigeminal schwannomas using diffusion tensor tractography: a technical note and report of 3 cases.

BACKGROUND: There are no large series studies identifying the locations of cranial nerves (CNs) around trigeminal schwannomas (TSs); however, surgically induced cranial neuropathies are commonly observed after surgeries to remove TSs. In this study, we preoperatively identified the location of CNs near TSs using diffusion tensor tractography (DTT). METHODS: An observational study of the DTT results and intraoperative findings was performed. We preoperatively completed tractography from images of patients with TSs who received surgical therapy. The result was later validated during tumorectomy. RESULTS: A total of three consecutive patients were involved in this study. The locations of CNs V-VIII in relation to the tumor was clearly revealed in all cases, except for CN VI in case 3.The predicted fiber tracts were in agreement with intraoperative observations. CONCLUSIONS: In this study, preoperative DTT accurately predicted the location of the majority of the nerves of interest. This technique can be applied by surgeons to preoperatively visualize nerve arrangements.

Optimization of Maximum Light Use Efficiency in Inner Mongolian Steppe.

For the case that the value of the maximum light use efficiency (MLUE) is not optimized for different steppes, we simulated the MLUE for meadow steppe, typical steppe and desert steppe in Inner Mongolia based on the field observed NPP and CASA ecosystem model, and analyzed the spatial and temporal pattern of the LUE and net primary productivity (NPP) in Inner Mongolia. The result indicate that the MLUE is optimized to be 0.654，0.553 and 0.511 gC·MJ-1 for meadow steppe, typical steppe and desert steppe in Inner Mongolia, respectively, with an average of 0.573 gC·MJ-1. Compared to the result that used same value of 0.541 gC·MJ-1 for MLUE, the correlation coefficient and relative mean square error was improved 0.024 and 2.62 gC·(m2·month-1)-1, respectively after optimization. Affected by the hydrothermal condition and distribution of grassland types, the LUE and NPP in Inner Mongolia decreased from northeast to southwest, and showed one crest shape. However, the maximum value of LUE and NPP was appeared in August and July. This difference could be attributed to the difference in the maximum value between absorbed photosynthetically active radiation and LUE. The LUE and NPP decreased by meadow steppe, typical steppe and desert steppe.

[Radiative Properties of Cirrus Clouds Based on Hexagonal and Spherical Ice Crystals Models].

Single scattering properties for spherical and hexagonal ice crystal models with different size parameters and wavelengths were employed to calculate satellite observed radiation and downward flux in ground surface using RSTAR radiative transfer model. Results indicated that simulated satellite observed radiation and ground surface downward radiant flux from different shapes of ice crystal models were different. The difference in the spectral radiation fluxes between 0. 4 and 1. 0 µm was largest, and particle shapes affected the downward radiant flux significantly. It was verified that the proper selection of the effective ice crystal model is not only important for retrieval of the microphysical and optical parameters of the cirrus cloud, but also important for obtaining the radiant flux on the earth's surface correctly. These results are important for retrieving cloud microphysical parameters and simulation of the ground surface downward radiant flux.

Identification of cranial nerves near large vestibular schwannomas using superselective diffusion tensor tractography: experience with 23 cases.

BACKGROUND: The preservation of the facial nerve (FN) and acoustic function in large vestibular schwannoma (VS) surgery is challenging because of nerve course uncertainties and morphological deviations. Preoperative diffusion tensor tractography (DTT) has been proposed to predict the FN location. This study was conducted to evaluate the effectiveness of this technique for identifying the FN, cochlear nerve (CN) and trigeminal nerve (TN) in large VSs. METHODS: The study included 23 consecutive patients with VS of Hannover classification T3b to T4b from November 2013 through May 2014. Diffusion tensor images and anatomical images were acquired. The DTT images of the cranial nerves were extracted before surgery for each patient to determine the relationships of these nerves with the tumor. The results were then validated during the tumorectomy. RESULTS: In 21 (91.30%) patients, the location of the FN on the DTT images agreed with the intraoperative findings, including in 2 patients in whom the FN passed through the interface between the parenchyma and the cystic changes and in 3 patients with a membranoid FN. The CN or fibers of unclear function were observed on DTT images in four patients with functional hearing. One penetrating fiber of unknown function was effectively constructed. The TN was accurately detected on the DTT images for all patients. CONCLUSIONS: DTT effectively revealed the location of the FN, including cases in which the FN was membranoid or passed through the interface between an area exhibiting cystic changes and the tumor nodule. Fibers aside from the FN and the TN were revealed by DTT in patients who retained functional hearing. Penetrating fibers were also found using DTT. This technique can be useful during VS resection.

Cerebral vasculopathy in a Chinese family with neurofibromatosis type I mutation.

Neurofibromatosis type I (NF1) is a hereditary, autosomal dominant, neurocutaneous syndrome that is attributed to NF1 gene mutation. NF1 has been associated with scoliosis, macrocephaly, pseudoarthrosis, short stature, mental retardation, and malignancies. NF1-associated vasculopathy is an uncommon and easily-overlooked presentation. Examination of a Chinese family affected by NF1 combined with cerebral vessel stenosis and/or abnormality suggested a possible relationship between NF1 and vessel stenosis. To determine which NF1 gene mutation is associated with vascular lesions, particularly cerebral vessel stenosis, we examined one rare family with combined cerebral vessel lesions or maldevelopment. Vascular lesions were detected using transcranial Doppler sonography and digital subtraction angiography in family members. Next, denaturing high-performance liquid chromatography and sequencing were used to screen for NF1 gene mutations. The results revealed a nonsense mutation, c.541C>T, in the NF1 gene. This mutation truncated the NF1 protein by 2659 amino-acid residues at the C-terminus and co-segregated with all of the patients, but was not present in unaffected individuals in the family. Exceptionally, three novel mutations were identified in unaffected family members, but these did not affect the product of the NF1 gene. Thus the nonsense mutation, c.541C>T, located in the NF1 gene could constitute one genetic factor for cerebral vessel lesions.

[An analysis of surgical outcome and influencing factors in patients of congenital basilar invagination with atlantal-axial dislocation: report of 120 cases].

OBJECTIVE: To investigate the surgical outcome and its influencing factors in patients of congenital basilar invagination (BI) with atlanto-axial dislocation (AAD). METHODS: From May 2004 to August 2010, 120 patients who had BI with AAD were surgically treated with direct posterior intraoperative distraction-reduction and fixation technique, 93 patients were successfully followed up by means of questionnaire survey, telephone and clinical evaluation. Pre- and postoperative dynamic cervical X-rays, computed tomographic scans, 3-dimentional reconstruction views and magnetic resonance imaging were performed. Pre- and postoperative Japanese Orthopaedic Association (JOA) score, distance between odontoid tip and Chamberlain's line and atlantodental interval were measured to evaluate the surgical result. Statistical analysis was performed by means of paired t test and Pearson Correlation analysis. RESULTS: There were 93 cases were followed up for 24-99 months with an average of 46.5 months. Until the final follow-up, clinical symptoms were improved in 79 patients (84.9%), and were stable in 7 patients (7.5%) and deteriorated in 4 patients (4.3%). Three patients died postoperatively (3.2%). Patients without intramedullary signal intensity change (ISIC) had better surgical outcome. Patients with compression from anterior odontoid tip and posterior bone margin of occipital foramen had the worst surgical outcome (F = 3.987, P < 0.01). Overall, good decompression and bone fusion were shown on postoperative image in 87 patients (93.5%). There were 3 deaths in this series because of basilar artery thrombosis, posterior fossa hematoma and unknown reasons each. CONCLUSIONS: The direct posterior intraoperative distraction-reduction and fixation technique is an effective simple and safe method for the treatment of BI with AAD. Anterior compression from odontoid tip and posterior compression from bone margin of occipital foramen-atlantal posterior arch play important roles in its developing mechanism. ISIC on MRI is a predictive factor for the worse surgical outcome.

[Hyperspectral remote sensing retrieval of inherent optical properties in the Bohai Sea].

Inherent optical properties are important marine optical parameters which are the basic input parameters of the radiative transfer model. Based on hyperspectral remote sensing reflectance and total absorption coefficient data measured in 2005 in the Bohai Sea, the nonlinear minimization model was firstly used to retrieve the inherent optical properties. The model was validated by in situ data. The averaged percent errors were 33.8%, 20.4%, 27.7%, 37.5%, 9.5% and 10.8% for the total absorption coefficients at 412, 440, 510, 555, 650 and 676 nm bands respectively. The main error sources of model were the uncertainty of the model parameters and measurement errors. According to the discussion, the spectral slope S has a slight influence on the retrieval of total absorption coefficients. However, the impact of the spectral power Y on the retrieval cannot be negligible. The model is suitable for hyperspectral data and can fulfill the gaps of inherent optical properties retrieval research in the Bohai Sea, so it can be used for hyperspectral remote sensing data to retrieve inherent optical properties.

[Early experience of resection of meningiomas in anterior skull base with intra-extracranial extension via a pure endoscopic endonasal approach].

OBJECTIVE: The early experience of treating anterior skull base meningiomas with intra-extracranial extension via pure endoscopic endonasal approach (EEA) was presented, the safety, feasibility and preliminary treatment outcomes were investigated. METHODS: Eight patients with intra-extradural meningiomas who were admitted from October 2006 to October 2010 were operated on via EEA in one stage in Xuanwu hospital. In this study, the operative technique was described, the degree of resection, complications and the early clinical outcomes were discussed. RESULTS: The complete resection of meningiomas with intra-extracranial extension was achieved in all patients using EEA in one stage. Preoperative visual symptoms were improved or resolved in all cases who presented with preoperative visual complaints. No patient in our series experienced a new neurological deficit after surgery or recurrence and death related meningiomas in the follow-up period (33-75 months). One patient experienced postoperative cerebrospinal fluid leak, delayed meningitis and secondary hydrocephalus which responded to therapy. After treatment, the patient was cure. CONCLUSION: Our limited experience indicates that EEA is feasible and safe for the complete resection of anterior skull base meningiomas with intra- and extracranial extension in one stage in selected cases.

[Surgery for jugular foramen schwannomas via a pure endoscopic transoral approach].

OBJECTIVE: To report a new approach, endoscopic transoral approach for the resection of jugular foramen schwannoma. METHODS: Nine patients with jugular foramen schwannoma (three males and six females, ranging in age from 15 to 61 years old) were treated by direct surgery via a pure endoscopic transoral approach to the jugular foramen. Eight patients complained of hypoglossal nerve palsy with hemiatrophy of the tongue; six cases complained of vagus nerve palsy. Three cases complained of glossopharyngeal nerve palsy, one case complained of facial nerve palsy and hearing loss. RESULTS: The nerves in this area were preserved and radical intracapsular removal of the tumor was performed via endoscopic transoral approach in the nine cases. Tumor removal, as assessed by intraoperative endoscopic inspection, postoperative magnetic resonance imaging and clinical evaluation, revealed all tumors were completely removed. One patient suffered from temporary swallowing difficulties and temporary right vagus palsy 1 day after surgery. There were no others intraoperative and postoperative complications. All patients were followed up for 4 - 29 months, no recurrences were occurred in all these patients and the muscle bulk, motor and the pre-postoperative swallowing function, the vagus palsy, the facial nerve palsy and hearing loss had improved in these patients. CONCLUSION: The endoscopic transoral approach and intracapsular removal of the tumor provided for successful minimally invasive surgery in the jugular foramen schwannomas.

Management and prognosis of symptomatic patients with intramedullary spinal cord cavernoma: clinical article.

OBJECT: The authors conducted a study to assess the clinical pattern, radiological features, therapeutic strategies, and long-term outcomes in patients with intramedullary spinal cord cavernomas (ISCCs) based on a large case series. METHODS: This retrospective study identified 96 patients (60 males, 36 females) surgically (81 cases) or conservatively (15 cases) treated for ISCCs between May 1993 and November 2007. Each diagnosis was based on MR imaging and spinal angiography evidence. For all surgically treated patients, the diagnosis was verified pathologically. The neurological outcomes pre- and postoperatively, as well as long-term follow-up, were assessed using the Aminoff-Logue Disability Scale. RESULTS: The mean age at the onset of symptoms was 34.5 years (range 9-80 years). Of the lesions, 68 (71%) were located in the thoracic spine, 25 (26%) in the cervical spine, and only 3 (3%) in the lumbar spine. The median symptom duration was 19.7 months. The clinical behavior of the lesion was a slow progression in 73 cases and an acute decline in 23 cases. Long-term follow-up data (mean 45.8 months, range 10-183 months) were available for 75 patients (64 surgical cases and 11 conservative cases). In the surgical group, a complete resection was achieved in 60 patients, and incomplete resection was detected in 4 patients after operation. At the end of the follow-up period in the operative group, 23 patients (36%) improved, 35 (55%) remained unchanged, and 6 (9%) worsened. In the nonoperative group, 5 patients improved, 6 patients remained unchanged, and none worsened. CONCLUSIONS: For differential diagnosis, spinal angiography was necessary in some cases. For most symptomatic lesions, complete microsurgical resection of the symptomatic ISCC is safe and prevents rebleeding and further neurological deterioration. However, in patients whose lesions were small and located ventrally in the spinal cord, one can also opt for a rigorous follow-up, considering the high surgical risk.