Purpose This study evaluated the feasibility of using 4D flow MRI and a semi‐automated analysis tool to assess the hemodynamic impact of intracranial atherosclerotic disease (ICAD). The ICAD impact was investigated by evaluating pressure drop (PD) at the atherosclerotic stenosis and changes in cerebral blood flow distribution in patients compared to healthy controls. Methods Dual‐venc 4D flow MRI was acquired in 25 healthy volunteers and 16 ICAD patients (ICA, N = 3; MCA, N = 13) with mild (<50%), moderate (50–69%), or severe (>70%) intracranial stenosis. A semi‐automated analysis tool was developed to quantify velocity and flow from 4D flow MRI and to evaluate cerebral blood flow redistribution. PD at stenosis was estimated using the Bernoulli equation. The PD calculation was examined by an in vitro phantom study against flow simulations. Results Flow analysis in controls indicated symmetry in blood flow rate (FR) and peak velocity (PV) between the brain hemispheres. For patients, PV in the affected hemisphere was significantly (65%) higher than the normal side (P = 0.002). However, FR to both hemispheres of the brain was the same. The PD depicted significant correlation with PV asymmetry in patients (ρ = 0.67 and P = 0.02), and it was significantly higher for severe compared to moderate stenosis (3.73 vs. 2.30 mm Hg, P = 0.02). Conclusion 4D flow MRI quantification enables assessment of the hemodynamic impact of ICAD. The significant difference of the PD between patients with severe and moderate stenosis and its correlation with PV asymmetry suggest that PD may be a pertinent hemodynamic biomarker to evaluate ICAD.

BackgroundAdmission neutrophil-lymphocyte ratio (NLR) is significantly correlated to clinical outcomes in acute ischemic stroke (AIS). We investigated follow-up NLR and temporal changes in NLR after endovascular thrombectomy (EVT) with respect to successful revascularization, clinical outcomes, symptomatic intracranial hemorrhage (sICH) and mortality.MethodsRetrospective analysis of EVT for anterior circulation emergent LVO was performed with both admission (NLR1) and 3–7 day follow-up NLR (NLR2) laboratory data. Patient demographics, National Institutes of Health Stroke Scale (NIHSS) presentations, reperfusion efficacy (modified Thrombolysis in Cerebral Infarction (mTICI) score), sICH, and clinical outcomes (modified Rankin Scale (mRS)) at 90 days were studied. Univariate analyses correlated NLR1, NLR2, and temporal change in NLR (NLR2-NLR1) with successful reperfusion (mTICI ≥2b), favorable outcomes (mRS ≤2), sICH, and mortality. Multivariable logistic regression model evaluated the independent effects of NLR2 on favorable outcomes.Results142 AIS patients with median NIHSS 17 underwent EVT within 24 hours, and met NLR laboratory inclusion criteria. Lower follow-up NLR2 and less temporal change in NLR over 3–7 days, but not admission NLR1, inversely correlated with successful reperfusion (p<0.05) and favorable clinical outcomes (p<0.001). Higher follow-up NLR2 and greater temporal change in NLR was significantly associated with sICH and mortality (p≤0.05). In multivariable logistic regression, lower follow-up NLR2 remained a predictor of favorable outcomes (OR 0.785, p=0.001), independent of age or successful reperfusion.ConclusionsFollow-up NLR is a readily available and modifiable biomarker that correlates with the degree of reperfusion after mechanical stroke thrombectomy. Lower follow-up NLR2 at 3–7 days is associated with successful reperfusion and an independent predictor of favorable clinical outcomes, with reduced risk for sICH and mortality.

Background and Purpose 3D high resolution BBMRI or MR VWI allows evaluation of the intracranial arterial wall and extraluminal pathology. We investigated the diagnostic accuracy and reliability of BBMRI for the intraluminal detection of large vessel arterial occlusions. Materials and Methods We retrospectively identified patients with intracranial arterial occlusions, confirmed by CTA or DSA who also underwent 3D BBMRI with non-enhanced and contrast enhanced T1 SPACE sequences. BBMRI findings were evaluated by two independent and blinded neuroradiologists. Large vessel intracranial arterial segments were graded on a three-point scale (grade 0-2) for intraluminal baseline T1 hyperintensity and contrast enhancement. Vessel segments were considered positive for arterial occlusion if focal weak (grade 1) or strong (grade 2) T1 hyperintense signal and/or enhancement replaced the normal intraluminal black blood signal. Results Thirty-one patients with 38 intracranial arterial occlusions were studied. Median interval time between BBMRI scanning and CTA/DSA reference standard studies was 2 days (0-20). Interobserver agreement was good for T1 hyperintensity (κ=0.63) and excellent for contrast enhancement (κ= 0.89). High sensitivity (100%) and specificity (99.8%) for intracranial arterial occlusion diagnosis was observed with either intraluminal T1 hyperintensity or contrast enhancement imaging criteria on BBMRI. Strong grade 2 intraluminal enhancement was maintained in > 80% of occlusions irrespective of location or chronicity. Relatively increased strong grade 2 intraluminal T1 hyperintensity was noted in chronic/incidental versus acute/subacute occlusions (45.5% vs 12.5%, p=0.04). Conclusion BBMRI with or without contrast has high diagnostic accuracy and reliability in evaluating intracranial large vessel arterial occlusions with near equivalency to DSA and CTA.

The main purpose of this article is to assess the safety and efficacy of transforaminal lumbar puncture for the injection of nusinersen (Spinraza) in patients with extensive spinal fusion and/or scoliosis.A retrospective chart reviews of all spinal muscular atrophy patients (adults and children) were conducted. Demographic data, procedure details, follow-ups, and related complications were recorded.We performed 85 transforaminal injections in nine pediatric patients (5 male and 4 female) aged between 8 and 17 years (mean = 11 years) and seven adult patients (5 females and 2 males) aged between 24 and 41 years (mean= 30 years). Fluoroscopy guidance was used in 87% of our patients. No major complication was reported.Fluoroscopy-guided transforaminal nusinersen injection is a safe and successful alternative approach in adult and pediatric patients with severe spinal scoliosis, interlaminar osseous fusion, and spinal fusion hardware.

BACKGROUND AND PURPOSE: Acute stroke intervention refractory to mechanical thrombectomy may be due to underlying vessel wall pathology including intracranial atherosclerotic disease and intracranial arterial dissection or recalcitrant emboli. We studied the prevalence and etiology of refractory thrombectomy, the safety and efficacy of adjunctive interventions in a North American-based cohort. MATERIALS AND METHODS:We performed a multicenter, retrospective study of refractory thrombectomy, defined as unsuccessful recanalization, vessel reocclusion in ,72 hours, or required adjunctive antiplatelet glycoprotein IIb/IIIa inhibitors, intracranial angioplasty and/or stenting to achieve and maintain reperfusion. Clinical and imaging criteria differentiated etiologies for refractory thrombectomy. Baseline demographics, cerebrovascular risk factors, technical/clinical outcomes, and procedural safety/complications were compared between refractory and standard thrombectomy groups. Multivariable logistic regression analysis was performed to determine independent predictors of refractory thrombectomy. RESULTS:Refractory thrombectomy was identified in 25/302 cases (8.3%), correlated with diabetes (44% versus 22%, P ¼ .02) as an independent predictor with OR ¼ 2.72 (95% CI, 1.05-7.09; P ¼ .04) and inversely correlated with atrial fibrillation (16% versus 45.7%, P ¼ .005). Refractory etiologies were secondary to recalcitrant emboli (20%), intracranial atherosclerotic disease (60%), and/or intracranial arterial dissection (44%). Four (16%) patients were diagnosed with early vessel reocclusion, and 21 patients underwent adjunctive salvage interventions with glycoprotein IIb/IIIa inhibitor infusion alone (32%) or intracranial angioplasty and/or stenting (52%). There were no significant differences in TICI 2b/3 reperfusion efficacy (85.7% versus 90.9%, P ¼ .48), symptomatic intracranial hemorrhage rates (0% versus 9%, P ¼ .24), favorable clinical outcomes (39.1% versus 48.3%, P ¼ .51), or mortality (13% versus 28.3%, P ¼ .14) versus standard thrombectomy.CONCLUSIONS: Refractory stroke thrombectomy is encountered in ,10% of cases, independently associated with diabetes, and related to underlying vessel wall pathology (intracranial atherosclerotic disease and/or intracranial arterial dissection) or, less commonly, recalcitrant emboli. Emergent salvage interventions with glycoprotein IIb/IIIa inhibitors or intracranial angioplasty and/or stenting are safe and effective adjunctive treatments.

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Spinal cord ischemia (SCI) is a rare entity with high mortality and morbidity which can arise from causes such as atherosclerosis, aortic dissection or aneurysm, thromboembolic events or systemic hypotension, and is a potential complication of spinal surgery. Published literature contains very few reports of SCI as a complication of intracranial interventions, highlighting the uncommon nature of SCI in these circumstances. We report the occurrence of anterior SCI in a 69-year-old patient following successful embolization of a cerebellar arteriovenous malformation (AVM), marked by upper extremity weakness, lower extremity paraplegia, loss of bladder and bowel control, and hypercapnic respiratory failure requiring mechanical ventilation. Magnetic resonance imaging (MRI) demonstrated upper cervical diffusion restriction and T2/STIR hyperintensity. Unusually, SCI occurred in this case without intraprocedural catheter wedging or obvious flow limitation, prolonged procedure time, hypercoagulable state, or general hypotension. We review previous cases in the literature as well as spinal cord vascular anatomy, and discuss the possible etiologies of this complication. Spinal cord ischemia could be a very rare complication of neuroendovascular procedures even in the absence of warning signs and should be carefully evaluated in patients with suspected neurologic symptoms after such procedures.

Cerebrovascular dual-venc 4D Flow MRI has utility in evaluating intracranial hemodynamics - benefitting from full circle of Willis (CoW) volumetric coverage, time-resolved, three-directional velocity encoding, and velocity dynamic range. Analysis of hemodynamic measures was completed using a comprehensive, semi-automated vessel identification and segmentation workflow for 10 subjects who underwent two scans within 30 days. Test-retest analysis of cerebrovascular dual-venc 4D Flow MRI and measures of CoW 3D flow dynamics demonstrated excellent repeatability for flow and peak velocity measures and lower reproducibility for pulsatility and resistive indices. Future work may include a larger cohort or more advanced analysis of velocity-derived parameters.