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The development of the human cerebral cortex is an orchestrated process involving the generation of neural progenitors in the periventricular germinal zones, cell proliferation characterized by symmetric and asymmetric mitoses, followed by migration of post-mitotic neurons to their final destinations in six highly ordered, functionally specialized layers (1,2). An understanding of the molecular mechanisms guiding these intricate processes is in its infancy, substantially driven by the discovery of rare mutations that cause malformations of cortical development (3-6). Mapping of disease loci in putative Mendelian forms of malformations of cortical development has been hindered by marked locus heterogeneity, small kindred sizes and diagnostic classifications that may not reflect molecular pathogenesis. Here we demonstrate the use of whole-exome sequencing to overcome these obstacles by identifying recessive mutations in WD repeat domain 62 (WDR62)as the cause of a wide spectrum of severe cerebral cortical malformations including microcephaly, pachygyria with cortical thickening as well as hypoplasia of the corpus callosum. Some patients with mutations in WDR62 had evidence of additional abnormalities including lissencephaly, schizencephaly, polymicrogyria and, in one instance, cerebellar hypoplasia, all traits traditionally regarded as distinct entities. In mice and humans, WDR62 transcripts and protein are enriched in neural progenitors within the ventricular and subventricular zones. Expression of WDR62 in the neocortex is transient, spanning the period of embryonic neurogenesis. Unlike other known microcephaly genes, WDR62 does not apparently associate with centrosomes and is predominantly nuclear in localization. These findings unify previously disparate aspects of cerebral cortical development and highlight the use of whole-exome sequencing to identify disease loci in settings in which traditional methods have proved challenging., Malformations of cortical development are a diverse group of often devastating structural brain disorders reflecting deranged neuronal proliferation, migration or organization. Application of traditional mapping approaches has proved to be [...]

Dural arteriovenous fistulas (DAVFs) are acquired pathological arteriovenous connections involving vessels that usually supply the meninges. A DAVF in the region of the hypoglossal canal is a rare form of fistula that involves the anterior condylar confluence or anterior condylar vein. We report a case of hypoglossal canal DAVF that was successfully embolized transvenously through a superior ophthalmic vein (SOV) approach. After failed attempts through jugular access, our patient was treated by a unique percutaneous direct puncture approach through the SOV, achieving complete obliteration of the fistula. A step-by-step description of the endovascular technique was described. The clinical course was uneventful without any new neurologic deficit. The eye symptoms and third nerve palsy had completely resolved at the 3-month follow-up visit. Hypoglossal canal DAVFs are rare and may exhibit complex venous drainage patterns. Knowledge of the complex venous anatomy is essential for planning an alternative transvenous route if the standard approach is not feasible. Xper CT (Philips Healthcare, Best, The Netherlands) is an excellent tool for identifying the exact site of the fistula as well as for confirming a safe position of the catheter tip for successful occlusion of this complex dural AV fistula. [ABSTRACT FROM AUTHOR]

Background: Design of flow-diverter stents for flexibility, tractability, and low profile limits their radiopacity on conventional digital subtraction angiography. Cone-beam computed tomography (CBCT) offers higher spatial resolution for the evaluation of flow-diverter stents. However, CBCT requires optimal dilution and timing of contrast medium for simultaneous visualization of the stent, arterial lumen, and vessel wall. There are only limited data on the effects of different contrast dilutions on CBCT image quality in neurointerventional applications. Materials and methods: In our institution, intra-arterial CBCTs were acquired during stent deployment and at follow-ups with 10% diluted contrast. We had recently started acquiring intra-arterial CBCTs with non-diluted contrast. Retrospective analysis of our flow-diverter data identified eight cases with different aneurysm locations who had intra-arterial CBCT with 10% diluted contrast immediately after flow-diverter stent deployment and with non-diluted contrast technique during follow-ups. For each case, the image quality between diluted and non-diluted contrast techniques was compared qualitatively by assessing stent visualization and quantitatively by plotting gray-scale intensity values along the vessel lumen. Results: In two sets of CBCT images per each case, there was no substantial difference between diluted and non-diluted CBTC techniques for the evaluation of stent architecture and lumen opacification. Gray-scale intensity values perpendicular to the lumen revealed similar intensity values along the neighboring parenchyma, vessel wall, and lumen for the two different contrast techniques. Conclusion: Intra-arterial CBCT angiography can be performed without contrast dilution and still achieve adequate image quality in certain cerebral aneurysms treated with flow diverter. The non-diluted contrast technique avoids the time loss during preparation of diluted contrast and installation of diluted contrast to the injector in angiography suites with a single power injector. [ABSTRACT FROM AUTHOR]

This article was first published in JNIS. Cite this article as: Pierot L, Jayaraman MV, Szikora I, et al. Standards of practice in acute ischemic stroke intervention: international recommendations. Journal of NeuroInterventional Surgery. Published Online First: 28 August 2018. doi: 10.1136/neurintsurg-2018-014287. [ABSTRACT FROM AUTHOR]

Aim: To investigate the added value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) sequences in predicting somatostatin analog (SSA) responses in patients with acromegaly., Material and Methods: This study included 55 active acromegaly patients with macroadenoma. Mean and maximum signal intensities were measured using region of interests in T2-weighted (T2W) and DCE-MRI sequences. Semi-quantitative values indicating relative signal intensity ratios and contrast-enhanced kinetics were obtained. Bivariate and multivariate analyses were used to determine whether the pathological granulation pattern of adenomas (dense versus others) was associated with patients' demographic variables and semi-quantitative MRI parameters., Results: Three parameters formed the logistic model, x2(3)=23.278, p < 0.0001: age (odds ratio [OR]=1.08), hypointensity of adenomas in T2W images (OR=15.45), and high maximum enhancement ratio in the second interval (ER2max) values (OR=2195.74). The overall accuracy of this model was 85.45% with an area under the curve of 0.880. Sensitivity, specificity, positive predictive, and negative predictive values of the model were 68.75%, 92.31%, 78.58%, and 87.8%, respectively., Conclusion: In patients with newly diagnosed acromegaly, the model created based on the relative T2W signal intensity, patient's age, and ER2 < submax parameter from DCE-MRI sequences might be used to more accurately predict SSA responses.

Aim: Superior cerebellar artery (SCA) aneurysms are uncommon vascular lesions, thus data about their presentation and clinical management are limited. Our aim was to determine clinical presentation, angiographic findings and mid and long-term clinical and imaging results of endovascular treatment of 49 patients with SCA aneurysm., Material and Methods: Forty-nine patients with SCA aneurysms underwent endovascular treatment (25 female, 24 male; mean age 46.7 years; range, 21-79 years) in our institution. Both aneurysms arising at the origin of SCA and peripheral SCA aneurysms were included to our retrospective study. 73.5% of the patients were presented with subarachnoid hemorrhage. Forty-two of 49 (85.7%) aneurysms were located in the origin of SCA. Mean aneurysm size was 6.5 mm (range 2-16 mm)., Results: Forty-seven (95.9%) of the aneurysms were coiled with detachable coils. In two peripheral aneurysms, liquid embolic agent was used. Overall control angiographic occlusion rates were as follows: 87.5% (34/40) total occlusion and 12.5% (6/40) dog-ear remnant. All peripheral SCA aneurysms were occluded with the parent artery. Procedure related mortality was seen in one patient (2%) due to the rupture of another aneurysm. There was no procedure related permanent morbidity., Conclusion: Endovascular treatment is an effective and safe option in both peripheral and proximal SCA aneurysms.

Aim: The present stent-assisted coil technique has many limitations especially in treating fusiform aneurysms. We aimed to introduce stenting following coiling technique to treat fusiform aneurysms., Material and Methods: From January 2009 to December 2010, we treated 6 patients with fusiform aneurysms in basilar artery (BA) by stenting following coiling technique. The 6 patients included four men and two women (age from 20 to 78 years, mean age 51 years). Two patients had subarachnoid hemorrhage, whereas 4 had unruptured aneurysms with progressive brainstem symptoms. In the procedure of endovascular treatment, the stent was delivered after coiling to compress the coils against the aneurysm wall and form a lumen in basilar artery., Results: Five patients had an excellent recovery with a satisfactory clinical result with an average 15.4 months follow-up. Four patients received follow-up angiographic imaging with an average 13 months, whereas 3 patients demonstrated complete aneurysm occlusion with reconstructive BA patency. Re-growth occurred in one patient, although clinically stable. None had angiographic evidence of in-stent stenosis., Conclusion: Stenting following coiling technique may be a feasible and effective method to reshape parent arteries and to embolize fusiform aneurysms safely. However, this technique may be considered in selected patients.

Percutaneous angioplasty and stenting for the treatment of extracranial vertebral artery (VA) stenosis seems a safe, effective and useful technique for resolving symptoms and improving blood flow to the posterior circulation, with a low complication rate and good long-term results. In patients with severe tortuosity of the vessel, stent placement is a real challenge. The new coronary balloon-expandable stents may be preferred. A large variability of restenosis rates has been reported. Drug-eluting stents may be the solution. After a comprehensive review of the literature, it can be concluded that percutaneous angioplasty and stenting of extracranial VA stenosis is technically feasible, but there is insufficient evidence from randomized trials to demonstrate that endovascular management is superior to best medical management.

We present a case of wide-necked giant aneurysm located at the P1-P2 segment of the posterior cerebral artery. The initial goal for treatment of the aneurysm was hemodynamic flow redirection with subsequent thrombosis so the procedure and involved stent placement to the neck of the aneurysm without any filling material. During follow up, significant in-stent stenosis due to intimal hyperplasia was found at the 6th month on digital subtraction angiography. Regression of in-stent neointimal stenosis at the 18th month and a total disappearance at the 76th month were observed on follow-up angiograms. Illustrating the reversibility of neointimal hyperplasia during a long follow up period was the main goal of this case report.

A 36-year-old man presented with trouble speaking and bilateral progressive hearing loss. MR imaging and histopathologic results revealed a posterior fossa melanotic ependymoma. Pial surfaces appeared hyperintense on T1-weighted images and hypointense on T2-weighted images. Histopathologic examination revealed that tumor cells and interstitial spaces had abundant melanin accumulation. There was no evidence of hemosiderin in tumor cells and in interstitial spaces. Pial melanin accumulation secondary to a posterior fossa melanotic ependymoma explained our MR findings.

We report the case of a 43-year-old man who underwent endovascular treatment for posterior inferior cerebellar aneurysm. Significant hemodynamic changes were observed as electric stimulation was applied during coil detachment for a PICA aneurysm. We postulate that changes in heart rate and blood pressure during coil detachment were due to the electric stimulation of the tonic vasomotor center located in the rostral ventrolateral medulla, which was very close to the PICA aneurysm.

Background and Purpose: Thromboembolic events may occur during or after the treatment of intracranial aneurysms with Guglielmi detachable coils (GDCs). The purpose of this study was to determine the frequency of thromboembolic events associated with balloon-assisted coil placement and to investigate possible risk factors for these events during balloon-assisted coil placement and embolization., Methods: Twenty patients with cerebral aneurysms treated with balloon-assisted coil placement and embolization at our institution were included. All patients underwent diffusion-weighted (DW) imaging within 6 hours after the procedure. Two neuroradiologists reviewed all DW images to detect ischemic lesions., Results: Hyperintense lesions compatible with thromboembolic events were detected on DW images of four (20%) patients. Three lesions were in the territory of posterior circulation, and one was in the territory of anterior circulation. The occurrence of new lesions was strongly associated with the number of times the microcatheter or coil was repositioned and removed and with the size of the aneurysmal neck (P < .01). DW imaging findings did not suggest a strong correlation between the occurrence of new ischemic lesions and potential risk factors (maximum balloon inflation time, number of times the balloon was inflated, etc.) associated with balloon-assisted coil placement and embolization (P > .05)., Conclusion: The risk of thromboembolic events during the treatment of intracranial aneurysms with balloon-assisted techniques is not more significant than when conventional GDC techniques are used. The only variables found to influence this risk during or after balloon-assisted coil placement were microcatheter repositioning, coil removal and repositioning, and size of the aneurysmal neck.

Principles: Despite many reports investigating the relationship of subarachnoid haemorrhage and seasonal variation in different parts of the world, there is no clear correlation. As far as we know this subject has not been reported from Istanbul yet. The purpose of this study is to determine if there is any correlation between season and spontaneous subarachnoid haemorrhage (SAH) caused by intracranial aneurysms and/or arteriovenous malformations (AVM) in Istanbul., Methods: Data were collected retrospectively from the medical reports of patients having intracranial haemorrhage due to aneurysm and/or arteriovenous malformation. The data were analysed with univariate and chi-square tests for all haemorrhages, for haemorrhages of aneurysms and arteriovenous malformations separately per month and per season respectively for all the patients together and according to gender separately. The ANOVA test was used for testing the monthly distribution of SAH cases with regard to age., Results: There were 761 cases (417 female, 344 male) of intracranial haemorrhage cases (683 intracranial aneurysms, 78 arteriovenous malformations) from 1994-2000. In this study, a seasonal peak in winter and a nadir in autumn for all subarachnoid haemorrhages were observed but the findings were not significant statistically. The peak season was winter for bleeding due to both aneurysms and AVM's. While the nadir season for aneurysmal bleeding was autumn and was summer for the AVM's., Conclusions: We did not find any significant statistical relation between seasonal variation and intracranial haemorrhage in the Istanbul province. But the peak of bleeding in winter and the nadir in autumn were noticeable for all intracranial haemorrhages. In Istanbul, beside the individual risk factors such as hypertension, alcohol consumption, lifestyle, and environmental factors like weather, season and other possible factors of which we are not yet aware, the relative increase of population in winter season due to social reasons may have a small contribution to these findings.

A 9-year-old girl with osteogenesis imperfecta (OI) type 4 was admitted to the hospital because of choreatic movement. Cerebral angiography demonstrated bilateral symmetrical stenosis of the proximal cavernous segment of internal carotid artery, prethrombotic occlusion of the M1 segment of left middle cerebral artery, and moyamoya-like collateral vascular structure arising from the right lenticulostriate arteries. After a literature review, these findings were interpreted as vasculopathic changes secondary to vascular fragility caused by the collagen abnormality in OI.

We present our initial experience with a newly developed endovascular stent graft technique in the treatment of two patients with giant aneurysms. In both of these patients, surgery and conventional endovascular techniques were likely to fail. The technique resulted in the successful management of the aneurysms in both cases. Our technique is described, and related experiences in the literature are discussed.

Involvement of the brain and meninges is rare in cases of Wegener granulomatosis, occurring in 2% to 8% of cases. Meningeal involvement in association with Wegener granulomatosis has scarcely been reported as being confined to the dura mater of brain on images and is thought to represent granulomatous infiltration. There are a few reported cases of Wegener granulomatosis that document involvement of dura at the level of the spinal cord. We present the case of a 52-year-old man with Wegener granulomatosis involving the cervical spinal dura and include detailed MR imaging findings.

Background and Purpose: Arterial fenestrations are associated with saccular aneurysms that are often difficult to treat with open surgical techniques. We evaluated our experience with endovascular treatment of such aneurysms., Methods: Ten consecutive patients with 11 basilar artery aneurysms associated with fenestrations were treated with coils by means of the endovascular route between November 1994 and February 2000. All patients underwent endovascular embolization by the femoral approach, under general anesthesia. Twelve embolization procedures were perfomed in the 10 patients., Results: Nine proximal and two distal basilar artery fenestration aneurysms were treated successfully. The embolization was complete in 10 of the 11 aneurysms. It was incomplete in one case, and complete occlusion could not be achieved at the second attempt. There was one regrowth at 1-year follow-up, which was successfully treated again. Four of the aneurysms were treated initially with balloon remodeling, whereas one aneurysm with regrowth and one with incomplete occlusion were treated with balloon remodeling at the second embolization procedure. In one case, one limb of the fenestration was sacrificed., Conclusion: Endovascular treatment of basilar artery aneurysms associated with fenestrations appears to offer advantages over traditional open surgical techniques.

The risk of fatal injury of the internal carotid artery (ICA) and surrounding anatomy during transsphenoidal surgery for pituitary adenoma is the most severe potential complication associated with this particular approach. We present a case in which iatrogenic injury to a patient's ICA and resultant carotid cavernous fistula and massive hemorrhage was successfully managed with the emergency placement of an endovascular stent-graft. Both findings in the relevant literature and practical considerations concerning both stent-grafts and other more commonly used options for the treatment of iatrogenic ICA injury are discussed.