Jamsheed A Desai

Not All “Successful” Angiographic Reperfusion Patients Are an Equal Validation of a Modified TICI Scoring System

Rapid reperfusion of the entire territory distal to vascular occlusions is the aim of stroke interventions. Recent studies defined successful reperfusion as establishing some perfusion with distal branch filling of <50% of territory visualized (Thrombolysis In Cerebral Infarction “TICI” 2a) or more. We investigate the importance of the quality of final reperfusion and whether a revision of the successful reperfusion definition is warranted. We retrospectively evaluated a prospective database of anterior circulation strokes treated using stentrievers to assess the quality of final reperfusion using two scores: the traditional TICI score and a modified TICI score. The modified TICI score includes an additional category (TICI 2c): near complete perfusion except for slow flow or distal emboli in a few distal cortical vessels. We compared different cut-off definitions of reperfusion (TICI 2a–3 vs. TICI-2b–3 vs. TICI 2c–3) using the area under the curve to identify their correlation with a favorable 90-day outcome (mRS≤2). In our cohort of 110 patients, 90% achieved TICI 2a-3 reperfusion with 80% achieving TICI 2b-3 and 55.5% achieving TICI 2c-3. The proportion of patients with a favorable 90-day outcome was higher in the TICI 2c (62.5%) compared to TICI 2b (44.4%) or TICI 2a (45.5%) but similar to the TICI 3 group (75.9%). A TICI 2c-3 reperfusion had a better predictive value than TICI 2b-3 for 90-day mRS 0–1. Defining successful reperfusion as TICI 2c/3 has merits. In this cohort, there was evidence toward faster recovery and better outcomes in patients with the TICI 2c vs. the traditional TICI 2b grade.

Overcoming the evening/weekend effects on time delays and outcomes of endovascular stroke therapy: the Calgary Stroke Program experience

Background Stentrievers have resulted in faster recanalization times in patients with acute ischemic stroke. Nonetheless, when strokes occur during evenings and weekends, delays are introduced in achieving this goal. We assessed the feasibility of achieving fast and successful endovascular reperfusion in patients with stroke treated during evenings and weekends and whether this has an impact on the outcome. Methods A retrospective review was performed of a longitudinal database of patients with acute anterior ischemic stroke treated with endovascular therapy in a comprehensive stroke center between January 2011 and December 2012. The imaging to reperfusion time was defined as the time from completion of the unenhanced CT scan to the time of angiographic successful reperfusion (TICI 2b–3). This time interval was compared between patients treated during working hours (Monday to Friday 07:00–18:00 h) and those treated in the evening outside these hours and at weekends. The 24-h NIH Stroke Scale score and 90-day favorable outcome score (modified Rankin scale ≤2) were compared between the two groups. Results In a cohort of 110 patients, 56 (50.9%) were treated on evenings and weekends. The median imaging to reperfusion time in these patients was 111 min compared with 90 min during working hours (p=0.019). The proportion of patients with successful reperfusion (TICI 2b or 3) during the evenings and weekends was 82.1% compared with 76.7% during working hours (p=0.4). The proportion of patients with a 90-day favorable outcome was not significantly different in the two groups (64.3% in those treated during evenings and weekends vs 52.1% in working hours, p=0.2). Conclusions Some delays were encountered during evenings and weekend hours. Despite that, it was feasible to achieve a relatively short imaging to reperfusion times during these hours, in comparison to existing literature. A target universal time metric is needed to assess the timeliness of endovascular therapy in stroke centers.

Lesion Sites Associated with Allocentric and Egocentric Visuospatial Neglect in Acute Stroke

Visuospatial neglect is a disorder that can often result from stroke and is characterized by an inability to attend to contralesional stimuli. Two common subtypes include allocentric (object-centered) neglect and egocentric (viewer-centered) neglect. In allocentric neglect, spatial inattention is localized to the contralesional side of an object regardless of its relative position to the observer. In egocentric neglect, spatial inattention is localized to the contralesional side of the individuals midline. The neuroanatomical correlates of each subtype are unknown. However, recent work has suggested that damage to temporal, inferior parietal, and occipital areas may result in allocentric neglect and that damage to frontoparietal areas may result in egocentric neglect. We used voxel-based lesion-symptom mapping (VLSM) to compare lesion location to behavioral performance on the conventional six subtests of the Behavioral Inattention Test (BIT) in 62 subjects with acute right hemisphere ischemic stroke. Results identified an anatomical dissociation in lesion location between subjects with neglect based on poor performance on allocentric tests (line bisection, copying, and drawing tasks) and on egocentric tests (star, letter, and line cancellation). VLSM analyses revealed that poor performance on the allocentric tests was associated with lesions to the superior and inferior parietal cortices, and the superior and middle temporal gyri. In contrast, poor performance on the egocentric tests was associated with lesions in the precentral gyrus, middle frontal gyrus, insula, and putamen. Interestingly, the letter cancellation test and average performance on egocentric tests were associated with frontal and parietal lesions. Some of these parietal lesion locations overlapped with lesion locations associated with allocentric neglect. These findings are consistent with suggestions that damage to temporal and parietal areas is more associated with allocentric neglect and damage to frontal lobe areas is more associated with egocentric neglect.

Central perception of position sense involves a distributed neural network - Evidence from lesion-behavior analyses.

It is well established that proprioceptive inputs from the periphery are important for the constant update of arm position for perception and guiding motor action. The degree to which we are consciously aware of the position of our limb depends on the task. Our understanding of the central processing of position sense is rather limited, largely based on findings in animals and individual human case studies. The present study used statistical lesion-behavior analysis and an arm position matching task to investigate position sense in a large sample of subjects after acute stroke. We excluded subjects who performed abnormally on clinical testing or a robotic visually guided reaching task with their matching arm in order to minimize the potential confound of ipsilesional impairment. Our findings revealed that a number of regions are important for processing position sense and include the posterior parietal cortex, the transverse temporal gyrus, and the arcuate fasciculus. Further, our results revealed that position sense has dissociable components - spatial variability, perceived workspace area, and perceived workspace location. Each component is associated with unique neuroanatomical correlates. These findings extend the current understanding of the neural processing of position sense and identify some brain areas that are not classically associated with proprioception.

Ultrasound guided V3 segment vertebral artery direct percutaneous puncture for basilar artery mechanical thrombectomy in acute stroke: a technical report

A middle aged patient presented with acute ischemic stroke due to basilar artery occlusion. The patient clinically deteriorated despite intravenous thrombolysis and was referred for mechanical thrombectomy. The right vertebral artery was occluded and could not be accessed despite attempting various shaped catheters, even when a radial artery access was used. The left vertebral artery ended in the posterior inferior cerebellar artery. Eventually, ultrasound guided V3 segment vertebral artery direct puncture was successfully done and the procedure was completed. No access related complications were encountered. Direct cervical arterial puncture can be safely used by experienced operators as a last resort in acute stroke cases with difficult access.

Diagnostic Yield of Echocardiography in Transient Ischemic Attack

BACKGROUND Echocardiography is often performed to identify a cardiac source of embolism (CSE) causing transient ischemic attack (TIA). However, the diagnostic yield of echocardiography in TIA remains uncertain, and its role in routine evaluation of TIA is controversial. METHODS Patients with acute TIA were prospectively enrolled at 4 stroke centers. A CSE was defined using the Causative Classification of Stroke system; patent foramen ovale was considered a relevant CSE only if the patient underwent closure or was placed on anticoagulation. Patients with a known CSE at time of admission were excluded from analysis of the yield of echocardiography. RESULTS A total of 869 patients were enrolled at stroke centers, and 129 had a known CSE at presentation. Of the 740 remaining patients, 603 (81%) underwent echocardiography. A potential CSE was identified in 60 (10%) of these patients. The most common CSEs noted on echocardiography were complex aortic arch atherosclerosis and patent foramen ovale. History of coronary artery disease (P < .001), lack of prior stroke or TIA (P = .007), and presence of acute infarction on magnetic resonance imaging (MRI) (P < .001) were predictors of CSE on echocardiography. The yield of echocardiography was 29% in patients with both history of coronary artery disease and acute infarction on MRI, 14% with one of these features, and 5% with neither of these features (P < .0001). A CSE identified by echocardiography prompted initiation of anticoagulation in 15 of the 603 (2.5%) subjects. CONCLUSIONS Echocardiography demonstrates a relevant CSE in a significant portion of patients with TIA. However, changes in antithrombotic therapy resulting from echocardiography are infrequent.