SUMMARY:Foreign material emboli following cerebral, cardiac, and peripheral catheterizations have been reported since the mid-1990s. Catheter coatings have been frequently implicated. The most recent surge of interest in this phenomenon within the neurointerventional community is associated with procedures using flow-diversion devices for the treatment of cerebral aneurysms. Following coil-supported Pipeline embolization in 4 cases and stent-supported coiling in 1, 5 patients developed multiple subcentimeter enhancing lesions, usually with surrounding edema and variable magnetic susceptibility in the vascular territories of the treated aneurysms. Conventional angiography findings were unrevealing. Laboratory work-up showed mild CSF protein elevation with no leukocytosis. Brain biopsy in 2 cases revealed granulomatous angiitis encasing foreign material, identical in stain appearance to a polyvinylpyrrolidone catheter coating. Corticosteroid administration typically produced clinical improvement. A heterogeneous radiographic and clinical course was noted, with rise and fall in the number of enhancing lesions in 2 patients and persistence in others. The etiology may be related to widespread adoption of increasingly sophisticated catheterization techniques.

Using diffusion-weighted magnetic resonance (MR) imaging with white matter tractography, it is possible to delineate white matter tracts, 1 including those involved by tumors. 2 We present a case in which the corticospinal tract (CST) was infiltrated by an oligodendroglioma that spared the motor strip and the posterior limb of the internal capsule. This information was essential in the planning and performance of the operation.A 45-year-old woman presented with right-sided hemiparesis and dysphasia. Admission MR imaging revealed a large left frontal mass. We obtained a blood oxygen level-dependent (BOLD) functional (f)MR image to localize the motor strip, 3 and a diffusion-weighted scan to identify the CST. 2 These data indicated that the CST was infiltrated by the tumor (Fig. 1).Intraoperative mapping with electrical stimulation confirmed that the left motor strip was displaced posteriorly by the tumor. A radical subtotal resection was performed, guided by intraoperative MR imaging. During removal of the tumor in an area directly adjacent to the CST, as demonstrated by the diffusion white matter tractography, the patient lost spontaneous movement of her right hand. Although electrical stimulation of the white matter failed to elicit movement, cortical stimulation provoked finger twitching and the resection was halted. Over the next week her motor functions returned to baseline. References1. Conturo TE, Lori NF, Cull TS, et al: Tracking neuronal fiber pathways in the living human brain. Proc Natl Acad Sci USA 96:10422-10427, 1999 2. Holodny AI, Ollenschleger MD, Liu WC, et al: Identification of the corticospinal tracts using blood-oxygen-level-dependent and diffusion functional MR imaging in patients with brain tumors. AJNR 22:83-88, 2001 3. Schulder M, Maldjian JA, Liu WC, et al: Functional imageguided surgery of intracranial tumors located in or near the sensorimotor cortex. KEY WORDS • magnetic resonance imaging • diffusion-weighted imaging • corticospinal tract • oligodendroglioma J. Neurosurg. / Volume 95 /

Background A number of emerging studies have evaluated clot composition in acute ischemic stroke. Studies of clot composition of embolic strokes of undetermined strokes are lacking. Objectives We sought to analyze the RBC to platelet ratios in clots and correlated our findings with stroke etiology. Methods This was a prospective study analyzing clots retrieved by mechanical thrombectomy in acute ischemic stroke patients at our institution. All clots were stained and scanned at 200x magnification by using a Scanscope XT digital scanner (Apergio, Vista, California). Image-J software (National Institutes of Health, Bethesda, Maryland) was used for semi quantitative analysis of percentage RBC’s and platelets. Unpaired t-test was used to compare means of RBC to Platelet ratios. Correlation of RBC to Platelet ratios with stroke etiology was performed. Results A total of 33 clots from 33 patients were analyzed. Stroke etiology was undetermined in 6 patients, cardioembolic in 14, large vessel atherosclerosis (LVA) in 9, and carotid dissection in 4. The mean RBC to platelet ratio was 0.78:1 (+/− 0.65) in cardioembolic clots, 1.73:1 (+/− 2.38) in LVA and 1.4:1(+/− 0.70) in carotid dissections. Although patients with undetermined etiology had a similar clot composition to cardioembolic stroke (0.36:1+/− 0.33), (p = 0.19), it differed significantly from LVA and dissections respectively (p = 0.037, p = 0.01). Conclusion In our study, a low RBC to Platelet ratio was found among patients with embolic strokes of undetermined source, however shared similar characteristics with cardioembolic thrombi. Ongoing collection and analysis is needed to confirm these findings and its significance in evaluating stroke etiology.

All CTA measurements showed moderate correlation with both ultrasound grading and PSV. Selection of the level of the normal distal ICA influences the NASCET calculations and can produce discrepant stenosis grades. Multidimensional CTA analysis seems to have no additional value for stenosis grading, but provides other useful anatomic information.

No abstract

BACKGROUND: Middle meningeal artery (MMA) embolization is becoming increasingly studied as a safe, effective treatment for chronic subdural hematoma (cSDH) in adults. Among pediatric patients, however, MMA embolization for cSDH has been rarely described, and the potential benefit of this approach for pediatric patients remains unknown. OBJECTIVE: To systematically review the literature and identify cases of pediatric MMA embolization for cSDH. We also report our experience with pediatric MMA embolization. METHODS: A systematic review of the literature was performed to identify cases of pediatric MMA embolization for cSDH. Inclusion criteria included English language availability and pediatric age defined as less than 18 years. A pediatric patient treated with MMA embolization was also identified at our institution. RESULTS: Five cases of pediatric MMA embolization for cSDH were identified in the literature. Two were associated with arachnoid cysts, 2 with antiplatelet/anticoagulation therapy, and 1 with abusive head trauma. There were no adverse events, and all patients demonstrated clinical and radiological improvement on follow-up. At our institution, a previously healthy 8-year-old male was found to have a right-sided acute-on-chronic SDH during a headache evaluation. A diagnostic angiogram was performed to rule out a dural arteriovenous fistula, and right-sided MMA embolization was performed concurrently. Rapid clinical and radiological improvement was observed, with complete resolution by 6 months. CONCLUSION: MMA embolization may represent a treatment option for pediatric patients with cSDH.

No abstract

N/A.