Reverse Flow Thromboembolism From Distal Subclavian Artery Aneurysm Due to Arterial Thoracic Outlet Syndrome and Posterior Circulation Stroke- Role of Dynamic Doppler Imaging.

INTRODUCTION: Arterial thoracic outlet syndrome (aTOS) is the least common among the 3 subtypes of thoracic outlet syndrome and can be the cause of posterior circulation infarction due to thrombus from a secondary thrombosed subclavian-axillary artery aneurysm. CASE REPORT: Here, we report a case of a 51-year-old man who presented to our institute with sudden onset vertigo, dizziness, vomiting, gait imbalance, and visual field defects immediately after strenuous exercise. Computed tomography angiography revealed bilateral cervical ribs with aneurysmal dilatation of the left distal subclavian and proximal axillary arteries. The computed tomography also revealed subacute infarcts in the bilateral cerebellar hemispheres, as well as in the bilateral occipital lobes. Color Doppler evaluation of the subclavian artery after hyperabduction of the ipsilateral arm revealed a continuous reversal of flow in the subclavian artery, which reached the vertebral ostia. The left cervical rib was resected, aneurysm was repaired, and the patient remained asymptomatic on follow-up. CONCLUSION: Posterior circulation stroke caused by the ipsilateral thrombosed subclavian artery aneurysm in an adult patient with aTOS due to a complete cervical rib is rare. A high index of suspicion should be present for thoracic outlet syndrome in patients with stroke and upper-limb arterial claudication symptoms. Dynamic Doppler evaluation in such patients can be used to demonstrate the underlying pathomechanism, and definitive surgical treatment can prevent further ischemic episodes. Posterior circulation stroke caused by partially thrombosed distal subclavian and axillary artery aneurysms due to aTOS is rare.

Semi-automated mapping of occluded arterial segments in acute large vessel stroke from computed tomography angiography.

OBJECTIVES: Catheterisation of occluded artery is the most crucial step in the mechanical thrombectomy of large vessel occlusions. Being a blind procedure, potential major untoward events could be anticipated at this stage. In this study, we evaluated the feasibility of reconstruction of the occluded vascular segment from CT angiography, exploiting the attenuation difference between the clot and adjacent brain parenchyma. METHODS AND RESULTS: Twenty-five patients with large vessel occlusion who achieved TICI2B/3 recanalization were identified. The semi-automated reconstruction was done using an open-source 3D segmentation software by two observers. The generated arterial anatomy was categorized as congruent, if all the major arterial segments namely, internal carotid artery, M1 middle cerebral artery, bifurcation, and major divisions matched with post thrombectomy angiograms. The discrepancy of one or more than one arterial segment was classified as mild or total mismatch respectively. Congruent arterial mapping was possible in 88% and 92 % patients for observer 1 and observer 2 respectively, while mild mismatch was noted in two patients for both the observers. Mismatch mostly occurred in superior division for both observers(100% vs 66.6%). The interrater agreement was good (0.77) and the accuracy was not influenced by the length of the clot. The median time for reconstruction was 4 minutes for both the observers (p - 0.21). CONCLUSION: Delineation of the anatomy of the occluded major intracranial artery is possible and corresponds with the actual anatomy. It could be used as a guide during thrombectomy procedures.

Noncontrast Computed Tomography versus Computed Tomography Angiography Source Images for Predicting Final Infarct Size in Anterior Circulation Acute Ischemic Stroke: a Prospective Cohort Study.

BACKGROUND: There has been a recent debate regarding the superiority of computed tomography angiography source images (CTASIs) over noncontrast computed tomography (NCCT) to predict the final infarct size in acute ischemic stroke (AIS). We hypothesized that the parenchymal abnormality on CTASI in faster scanners would overestimate ischemic core. METHODS: This prospective study assessed the correlation of Alberta Stroke Program Early CT Score (ASPECTS) on NCCT, CTASI, and computed tomography perfusion (CTP) with final infarct size in patients within 8 hours of AIS. Follow-up with NCCT or diffusion-weighted magnetic resonance imaging (MRI) was performed at 24 hours. Correlations of NCCT and CTASI with final infarct size and with CTP parameters were assessed. Subgroup analysis was performed in patients who underwent intravenous thrombolysis or mechanical thrombectomy. Inter-rater reliability was tested using Spearman's rank correlation. A P value less than .05 was considered statistically significant. RESULTS: A total of 105 patients were included in the final analysis. NCCT had a stronger correlation with the final infarct size than did CTASI (Spearman's ρ = .85 versus .78, P = .13). We found an overestimation of the final infarct size by CTASI in 47.6% of the cases, whereas NCCT underestimated infarct size in 60% of the patients. NCCT correlated most strongly with CBV (ρ = .93), whereas CTASI correlated most strongly with CBF (ρ = .87). Subgroup analysis showed less correlation of CTASI with final infarct size in the group that received thrombolysis versus the group that did not (ρ = .70 versus .88, P = .01). CONCLUSION: In a 256-slice scanner, the CTASI parenchymal abnormality includes ischemic penumbra and thus overestimates final infarct size-this could result in inappropriate exclusion of patients from thrombolysis or thrombectomy.

Primary CNS vasculitis presenting as intraventricular bleeding.

Primary angiitis of the central nervous system (PACNS) is a rare disorder affecting both medium- and small-sized vessels. Intracranial haemorrhages though less reported are in the form of parenchymal haemorrhage and subarachnoid haemorrhage. We report a case of PACNS with intraventricular haemorrhage due to aneurysms secondary to progression of vasculitis.