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Intramedullary astrocytomas (IMAs) are rare tumors, and few studies specific to the molecular alterations of IMAs have been performed. Recently, KIAA1549-BRAF fusions and the H3F3A p.K27M mutation have been described in low-grade (LG) and high-grade (HG) IMAs, respectively. In the present study, we collected clinico-radiological data and performed targeted next-generation sequencing for 61 IMAs (26 grade I pilocytic, 17 grade II diffuse, 3 LG, 3 grade III and 12 grade IV) to identify KIAA1549-BRAF fusions and mutations in 33 genes commonly implicated in gliomas and the 1p/19q regions. One hundred seventeen brain astrocytomas were analyzed for comparison. While we did not observe a difference in clinico-radiological features between LG and HG IMAs, we observed significantly different overall survival (OS) and event-free survival (EFS). Multivariate analysis showed that the tumor grade was associated with better OS while EFS was strongly impacted by tumor grade and surgery, with higher rates of disease progression in cases in which only biopsy could be performed. For LG IMAs, EFS was only impacted by surgery and not by grade. The most common mutations found in IMAs involved TP53, H3F3A p.K27M and ATRX . As in the brain, grade I pilocytic IMAs frequently harbored KIAA1549-BRAF fusions but with different fusion types. Non-canonical IDH mutations were observed in only 2 grade II diffuse IMAs. No EGFR or TERT promoter alterations were found in IDH wild-type grade II diffuse IMAs. These latter tumors seem to have a good prognosis, and only 2 cases underwent anaplastic evolution. All of the HG IMAs presented at least one molecular alteration, with the most frequent one being the H3F3A p.K27M mutation. The H3F3A p.K27M mutation showed significant associations with OS and EFS after multivariate analysis. This study emphasizes that IMAs have distinct clinico-radiological, natural evolution and molecular landscapes from brain astrocytomas.

Stent-assisted coiling is an accepted endovascular treatment (EVT) for complex intracranial aneurysms. The Enterprise self-expandable stent (Cordis, Miami Lakes, FL) is a new retractable stent that is delivered via a conventional coiling catheter to potentially circumvent the limitations of other stents. The aim of this study was to evaluate the use of this stent for EVT of complex aneurysms. Between January and May 2007, 14 patients with 15 unruptured wide-necked or fusiform aneurysms were treated. EVT consisted of stent placement and subsequent endosaccular coiling. Clinical outcome was assessed with the modified Glasgow Outcome Scale. EVT was successfully performed and led to an excellent outcome in all patients. The stent was easily navigated and precisely positioned in all cases. However, the stent's visibility was poor once it was delivered. Moreover, procedural complications occurred in three patients, including stent migration (n = 1) and coil protrusion between the stent and the vessel wall (n = 2). In these latter two cases, a remodeling balloon was required to assist in delivery of the coils. No clinical incidence of complications was observed when the parent artery had a diameter of more than 4 mm. Angiographic results consisted of eight complete occlusions, four neck remnants, and three incomplete occlusions. The Enterprise stent is very useful for EVT of complex intracranial aneurysms because it is easy to navigate and place precisely. However, the currently available stent has two relatively limiting characteristics: 1) it has poor visibility, and 2) it should only be used for aneurysms located on a parent artery with a maximal diameter of 4 mm.

This study aims at testing the hypothesis that neurodevelopmental abilities at age 2 years are related with local brain microstructure of preterm infants at term equivalent age. Forty-one preterm infants underwent brain MRI with diffusion tensor imaging sequences to measure mean diffusivity (MD), fractional anisotropy (FA), longitudinal and transverse diffusivity (λ// and λ[perpendicular]) at term equivalent age. Neurodevelopment was assessed at 2 years corrected age using the Bayley III scale. A voxel-based analysis approach, statistical parametric mapping (SPM8), was used to correlate changes of the Bayley III scores with the regional distribution of MD, FA, λ// and λ[perpendicular]. We found that language abilities are negatively correlated to MD, λ// and λ[perpendicular] in the left superior temporal gyrus in preterm infants. These findings suggest that higher MD, λ// and λ[perpendicular] values at term-equivalent age in the left superior temporal gyrus are associated with poorer language scores in later childhood. Consequently, it highlights the key role of the left superior temporal gyrus for the development of language abilities in children. Further studies are needed to assess on an individual basis and on the long term the prognostic value of brain DTI at term equivalent age for the development of language.

Introduction Stent-assisted coiling (SAC) is an alternative to surgical clipping for the treatment of wide-necked intracranial aneurysms (IA). However, little information is available concerning the long-term results of this treatment. The aim of this study was to report the long-term clinical and anatomical findings in 32 patients with 34 wide-necked IA treated by SAC. Methods A retrospective review of our prospectively maintained database identified all patients followed up for wide-necked IA treated by SAC. The clinical charts, procedural data, and angiographic results were reviewed. Results Thirty-two patients with 34 IA were identified including 25 asymptomatic patients, four with cranial nerve palsies, two with a subarachnoid hemorrhage, and one with transient ischemic attacks. Mean aneurysm size was 10.2 mm (range 3.5 to 26 mm). Embolization was successful in all patients and no procedure-related neurological morbidity or mortality was observed. Immediate anatomical results included nine complete occlusions (26.5%), two neck remnants (6%), and 23 incomplete occlusions (67.5%). Mean imaging follow-up of 20 months showed 18 further thrombosis (53%) and 16 stable results (47%). Finally, 27 aneurysms were completely occluded (79%), three had a neck remnant (9%), and four were incompletely occluded (12%). Asymptomatic and nonsignificant in-stent stenosis occurred in seven patients (22%). Conclusions SAC is safe and effective for the treatment of wide-necked IA. Despite unsatisfying immediate aneurysm occlusion, the adjunctive effect of the stent is stabilizing or significantly improving long-term anatomical results.

In this MRI study, we aimed to provide new in vivo structural markers of asymmetry in motor and language networks in a population of healthy preterm neonates scanned at term equivalent age. Using diffusion tensor imaging and probabilistic tractography, we showed that, besides volume and microstructural asymmetries in the parieto-temporal part of the superior longitudinal fasciculus (SLF) and a trend towards microstructural asymmetry in the corticospinal tract (CST), volume asymmetry in the motor part of the superior thalamic radiations (STR) and a trend towards volume asymmetry in the CST are already present in the neonatal period. No asymmetry was found in the sensory part of the STR, the anterior thalamic radiations (ATR), and posterior thalamic radiations (PTR) neither in the fronto-parietal part of the SLF. These results suggest that structural asymmetries in the motor and language networks are present in healthy preterm neonates at term equivalent age, well before the development of speech and hand preference.

Using diffusion tensor imaging (DTI), we explored microstructural brain maturation in a population of 65 preterm neonates who underwent magnetic resonance imaging between 35 and 43 weeks of corrected gestational age. A voxel-based analysis approach, statistical parametric mapping (SPM8), was used to evidence the nonlinear changes with the corrected gestational age in the regional distribution of mean diffusivity (MD), fractional anisotropy (FA), longitudinal and transverse diffusivities (λ//and λ⊥). We found that FA changes nonlinearly with age around the right superior temporal sulcus and in the right lateral occipitotemporal gyrus, with FA decrease between 34 and 39 weeks followed by FA increase from 40 weeks to 43 weeks. Considering the key role of these brain areas in verbal and non-verbal communicative behaviors, the effect of these microstructural changes in terms of early social network functional maturation needs to be assessed by joint functional and anatomical studies.

Introduction Within the neurosurgical literature on intracranial aneurysms, balloon-assisted coiling (BAC) remains controversial when compared to conventional coiling (CC). The aim of this study was to compare our results with BAC and CC over a 4-year period. Methods Daily interventional neuroradiology has been available since March 2004 in our institution. Between March 2004 and February 2008, 275 patients with 357 aneurysms were treated by an endovascular approach, including 174 patients/204 aneurysms treated by CC (group I) and 80 patients/92 aneurysms treated by BAC (group II). The remaining patients were treated with other endovascular techniques. Indications of BAC were as follow: aneurysms with an unfavourable neck/sac ratio and/or a branch arising from the neck (90.2%), unstable coiling catheter (6.5%), and anticipated aneurysm rupture (3.3%). The clinical charts, procedural data, and angiographic results of groups I and II were compared. Results BAC was used in 25.8% (92/357) of all embolized aneurysms and it was successful in 83/92 aneurysms (90%). There was no significant difference in the procedure-related morbidity and mortality rates between group I (2.3% and 1.15%, respectively) and group II (2.5% and 1.25%, respectively). Although retreatment was more frequent in group II (13%) than in group I (11%), the difference was not statistically significant ( P = 0.8125). Conclusion When BAC is used frequently, it is a safe and effective technique that is associated with complication rates comparable to those of CC. Although BAC is not associated with more stable anatomical results, it should be considered as an alternative therapeutic option for the treatment of broad-based intracranial aneurysms.

This review article includes infections of the vertebral body, intervertebral disc, ligaments and paravertebral soft tissues, epidural space, meninges and subarachnoid space, and the spinal cord. A wide range of infective organisms may be implicated and the incidence of some, notably tuberculosis, is rising due to increased immunocompromise and other factors. Imaging plays a key role in early diagnosis of these diseases, which may be severe and potentially life threatening. Infection may be acquired by the hematogenous route, by infection from contiguous structures or from direct inoculation. Of available imaging techniques, CT and MRI offer the clinically most valuable methods of evaluating all the structures potentially involved in infection. Although many signs are non-specific, indication is given of where appearances raise strong suspicion of infection. The extent of the inflammatory process is well evaluated by imaging, particularly in terms of severity and morbidity of clinical sequelae, which may be severe. Early investigation is mandatory and as MRI presently has the key role in investigation, it should be employed at an early stage of clinical suspicion.

Introduction Follow-up of intracranial aneurysms treated by embolisation with detachable coils is mandatory to detect a possible recanalisation. The aim of this study was to compare contrast-enhanced magnetic resonance angiography (CE-MRA) with digital substraction angiography (DSA) used to detect aneurysm recanalisation to determine if DSA is still needed during follow-up. Materials and methods From May 2006 to May 2007, 55 patients with 67 aneurysms were treated by endosaccular coiling with ( n  = 9) or without ( n  = 58) an adjunctive stent. Follow-up imaging protocol included MRA at 6 and 12 months and a DSA at 12 months or earlier if a major recanalisation was identified on the 6-month MRA. Two neuroradiologists independently reviewed MRA images (readers 1 and 2) and two other reviewed DSA images. Results Follow-up DSA showed stability of the aneurysm occlusion in 52 cases, recanalisation in 14 cases, and further thrombosis in one. On CE-MRA, both readers identified all recanalisations but one (sensitivity of 93%) as they missed a major recanalisation in a 2-mm ruptured aneurysm. There were two false-positive evaluations by reader 1 and three for reader 2. Mean specificity of CE-MRA to detect aneurysm recanalisation was 95.5%. Conclusion CE-MRA is accurate to detect aneurysm recanalisation after embolisation with detachable coils. CE-MRA may be proposed as first-intention imaging technique for their follow-up. However, its sensitivity and specificity remain inferior to that of DSA and major recurrences may be missed in very small aneurysms. Therefore, a single DSA remains mandatory during the imaging follow-up.