Chong, Brian W.

Abstract BackgroundThe presence of white matter hyperintensities (WMH) in migraine is well-documented, but the location of brain WMH in patients with migraine are insufficiently researched. Although recent semi-automatic software packages have been developed for calculating WMH, visual inspection remains the gold standard for measuring WMH. The goal of this study was to assess WMH in patients with migraine using a modified version of the Scheltens visual rating scale, a semiquantitative scale for categorizing WMH in the following brain regions: periventricular, lobar (frontal, temporal, parietal, occipital), basal ganglia, and infratentorial regions.Methods263 patients with migraine (31 male/232 female; mean age: 48.0) who were enrolled in the American Registry for Migraine Research from Mayo Clinic with a diagnosis of episodic (n = 46; 17.5%) or chronic migraine (n = 217; 82.5%) and who had brain magnetic resonance imaging were included in this study. Those with imaging evidence for gross anatomical abnormalities other than WMH were excluded. WMH were identified on axial T2 and FLAIR sequences by a board certified neuroradiologist. WMH were characterized via manual inspection and categorized according to the scale’s criteria.Results95 patients (36.1 %: mean age: 41.8) had no WMH on axial T2 and FLAIR imaging and 168 patients (63.9%, mean age: 51.4) had WMH. Of those with WMH, 94.1% (n = 158) had lobar hyperintensities (frontal: 148/158, 93.7%; parietal: 57/158, 36.1%; temporal: 35/158, 22.1%; occipital: 9/158, 5.7%), 13/168, 7.7% had basal ganglia WMH, 49/168, 29.1% had periventricular WMH, and 17/168, 10.1% had infratentorial WMH. 101/168 patients (60.1%) had bilateral WMH and 67/168 (39.9%) had unilateral WMH (34 right hemisphere /33 left hemisphere). 30.0% of patients with WMH did not have WMH reported in their clinical radiology reports.DiscussionNearly 2/3 of patients with migraine had WMH. They were most common in the lobar regions, specifically in the frontal lobe. The categorization of WMH in migraine using the modified Scheltens visual rating scale could help in future studies to clarify the relationship between WMH and headache features and might be a useful method for developing classifiers that differentiate between migraine-specific WMH and other causes of WMH.

INTRODUCTION: Despite more than a decade of endovascular coil treatment, the effects of coils on cerebral aneurysm (CA) hemodynamics are still poorly understood. Coils present several challenges to in vivo and in vitro flow measurement techniques and previous in silico methods have suffered from large assumptions on coil geometry. Here we present the first fluid dynamic simulations of coiled CAs that consider the structure and deployment mechanics of embolic coils. We also investigate the influence of coil packing density, design, and configuration on CA fluid dynamics. Methods: Coil deployment was modeled using a novel finite element approach that realistically simulates coil dynamics during deployment. Two coil designs were investigated: helical and 3D. Coil design and material properties were matched to manufacturer specifications. Five deployment sequences of each coil design, at different microcatheter placements, were simulated in two idealized CA models with variable neck sizes. Blood flow was simulated using computational fluid dynamics. Simulated deployments and fluid dynamics were then compared to deployments of actual coils in identical physical CA models and in vitro particle image velocimetry flow measurements. Results: Simulated results closely matched in vitro data. Reductions in aneurysmal velocity magnitudes were largest for 3D coils and in a narrow-neck model. In that model, 3D coil deployments reduced average aneurysmal velocity magnitudes by a 51% - 69% range at packing densities less than 20% and by a 74% - 84% range at packing densities greater than 30%. Linear regression results showed reductions were strongly dependent on the spacing between coil loops within the aneurysm and packing density, with correlations of 0.6 and 0.7 respectively. Conclusion: Coil design and packing density may play equally important roles in determining CA hemodynamics. Results in an anatomical model will also be presented. The proposed virtual coiling approach represents a novel and effective method for realistically simulating coiled CAs, and is an important step towards clinical preoperative planning of coil treatment.

Abstract Minimally invasive transcatheter embolization is a common nonsurgical procedure in interventional radiology used for the deliberate occlusion of blood vessels for the treatment of diseased or injured vasculature. A wide variety of embolic agents including metallic coils, calibrated microspheres, and liquids are available for clinical practice. Additionally, advances in biomaterials, such as shape‐memory foams, biodegradable polymers, and in situ gelling solutions have led to the development of novel preclinical embolic agents. The aim here is to provide a comprehensive overview of current and emerging technologies in endovascular embolization with respect to devices, materials, mechanisms, and design guidelines. Limitations and challenges in embolic materials are also discussed to promote advancement in the field.

Abstract Cognard type V dural fistulas represent a rare and unique entity, and present clinically with myelopathy. They are frequently located around the foramen magnum and are most commonly fed by dural branches of the vertebral and external carotid artery. Detection requires meticulous angiography to define the angioarchitecture of the fistula, which in turn defines the treatment modality. We present the case of a 63 yr old woman, after informed consent was obtained, with prolonged, severe and progressive lower extremity myelopathy for 6 yr, with T2-weighted signal changes in the thoracic spinal cord on magnetic resonance imaging (MRI). Cervical MRI was unremarkable. Following computed tomography (CT), angiography of the spinal canal that revealed tortuous and dilated veins on the thoracic spinal cord surface, catheter angiography was performed. This demonstrated a fistula in relation to a dural branch of left vertebral artery with a characteristic single draining vein coursing caudally to the thoracic level, with delayed outflow suggestive of venous hypertension. Given the fact that the dural feeder was tortuous and relatively small, thus, precluding distal microcatheter access, and with presence of a single accessible draining vein, microsurgical treatment was preferred. Following a midline suboccipital craniotomy in prone position, a limited vertical dural opening was performed. Careful microsurgical arachnoid dissection revealed the arterialized draining vein with the aid of Indocyanine Green angiography. The draining vein was clipped, coagulated, and disconnected. Postoperative recovery was uneventful and the patient is undergoing rehabilitation therapy. Follow-up angiography showed complete elimination of the fistula. Salient teaching points are narrated at conclusion.

Ehlers-Danlos syndrome (EDS) refers to a group of genetic disorders involving the connective tissues. Type IV EDS impairs type III collagen that is responsible for vessel integrity. Patients with type IV EDS are susceptible to vascular and visceral complications, including aortic aneurysms, pseudoaneurysms, dissections, and spontaneous rupture of internal organs. Treating aneurysms with open surgery versus endovascular techniques each carry a unique risk-to-benefit ratio that must be applied to each individual carefully. We present a patient with type IV EDS who presented with a rapidly growing inferior mesenteric artery aneurysm. The patient was treated with a percutaneous endovascular technique using coils and n-butyl-cyanoacrylate glue.