Ana Calleja

Early Reperfusion Rates with IV tPA Are Determined by CTA Clot Characteristics

These authors evaluated CTA studies of 228 patients paying special attention to the clot features, and correlated these features with early reperfusion rates. Clot features that predicted successful early reperfusion included: shorter clot, residual flow within the clot, and distal location. Reperfusion was achieved in only 8% of patients with longer and proximal clots and in those without residual flow. BACKGROUND AND PURPOSE: An ability to predict early reperfusion with IV tPA in patients with acute ischemic stroke and intracranial clots can help clinicians decide if additional intra-arterial therapy is needed or not. We explored the association between novel clot characteristics on baseline CTA and early reperfusion with IV tPA in patients with acute ischemic stroke by using classification and regression tree analysis. MATERIALS AND METHODS: Data are from patients with acute ischemic stroke and proximal anterior circulation occlusions from the Calgary CTA data base (2003–2012) and the Keimyung Stroke Registry (2005–2009). Patients receiving IV tPA followed by intra-arterial therapy were included. Clot location, length, residual flow within the clot, ratio of contrast Hounsfield units pre- and postclot, and the M1 segment origin to the proximal clot interface distance were assessed on baseline CTA. Early reperfusion (TICI 2a and above) with IV tPA was assessed on the first angiogram. RESULTS: Two hundred twenty-eight patients (50.4% men; median age, 69 years; median baseline NIHSS score, 17) fulfilled the inclusion criteria. Median symptom onset to IV tPA time was 120 minutes (interquartile range = 70 minutes); median IV tPA to first angiography time was 70.5 minutes (interquartile range = 62 minutes). Patients with residual flow within the clot were 5 times more likely to reperfuse than those without it. Patients with residual flow and a shorter clot length (≤15 mm) were most likely to reperfuse (70.6%). Patients with clots in the M1 MCA without residual flow reperfused more if clots were distal and had a clot interface ratio in Hounsfield units of <2 (36.8%). Patients with proximal M1 clots without residual flow reperfused 8% of the time. Carotid-T/-L occlusions rarely reperfused (1.7%). Interrater reliability for these clot characteristics was good. CONCLUSIONS: Our study shows that clot characteristics on CTA help physicians estimate a range of early reperfusion rates with IV tPA.

Relative Cerebral Blood Volume as a Marker of Durable Tissue-at-Risk Viability in Hyperacute Ischemic Stroke

Background and Purpose— Selection of best responders to reperfusion therapies could be aided by predicting the duration of tissue-at-risk viability, which may be dependant on collateral circulation status. We aimed to identify the best predictor of good collateral circulation among perfusion computed tomography (PCT) parameters in middle cerebral artery (MCA) ischemic stroke and to analyze how early MCA response to intravenous thrombolysis and PCT-derived markers of good collaterals interact to determine stroke outcome. Methods— We prospectively studied patients with acute MCA ischemic stroke treated with intravenous thrombolysis who underwent PCT before treatment showing a target mismatch profile. Collateral status was assessed using a PCT source image–based score. PCT maps were quantitatively analyzed. Cerebral blood volume (CBV), cerebral blood flow, and Tmax were calculated within the hypoperfused volume and in the equivalent region of unaffected hemisphere. Occluded MCAs were monitored by transcranial Duplex to assess early recanalization. Main outcome variables were brain hypodensity volume and modified Rankin scale score at day 90. Results— One hundred patients with MCA ischemic stroke imaged by PCT received intravenous thrombolysis, and 68 met all inclusion criteria. A relative CBV (rCBV) >0.93 emerged as the only predictor of good collaterals (odds ratio, 12.6; 95% confidence interval, 2.9–55.9; P=0.001). Early MCA recanalization was associated with better long-term outcome and lower infarct volume in patients with rCBV<0.93, but not in patients with high rCBV. None of the patients with rCBV<0.93 achieved good outcome in absence of early recanalization. Conclusions— High rCBV was the strongest marker of good collaterals and may characterize durable tissue-at-risk viability in hyperacute MCA ischemic stroke.

Blood biomarkers of insulin resistance in acute stroke patients treated with intravenous thrombolysis: Temporal profile and prognostic value

Abstract Background: Metabolic syndrome and insulin resistance may hamper the beneficial effect of intravenous thrombolysis in acute ischemic stroke. We investigated the temporal profile and prognostic value of 11

Association of Clinical, Imaging, and Thrombus Characteristics With Recanalization of Visible Intracranial Occlusion in Patients With Acute Ischemic Stroke

Importance Recanalization of intracranial thrombus is associated with improved clinical outcome in patients with acute ischemic stroke. The association of intravenous alteplase treatment and thrombus characteristics with recanalization over time is important for stroke triage and future trial design. Objective To examine recanalization over time across a range of intracranial thrombus occlusion sites and clinical and imaging characteristics in patients with ischemic stroke treated with intravenous alteplase or not treated with alteplase. Design, Setting, and Participants Multicenter prospective cohort study of 575 patients from 12 centers (in Canada, Spain, South Korea, the Czech Republic, and Turkey) with acute ischemic stroke and intracranial arterial occlusion demonstrated on computed tomographic angiography (CTA). Exposures Demographics, clinical characteristics, time from alteplase to recanalization, and intracranial thrombus characteristics (location and permeability) defined on CTA. Main Outcomes and Measures Recanalization on repeat CTA or on first angiographic acquisition of affected intracranial circulation obtained within 6 hours of baseline CTA, defined using the revised arterial occlusion scale (rAOL) (scores from 0 [primary occlusive lesion remains the same] to 3 [complete revascularization of primary occlusion]). Results Among 575 patients (median age, 72 years [IQR, 63-80]; 51.5% men; median time from patient last known well to baseline CTA of 114 minutes [IQR, 74-180]), 275 patients (47.8%) received intravenous alteplase only, 195 (33.9%) received intravenous alteplase plus endovascular thrombectomy, 48 (8.3%) received endovascular thrombectomy alone, and 57 (9.9%) received conservative treatment. Median time from baseline CTA to recanalization assessment was 158 minutes (IQR, 79-268); median time from intravenous alteplase start to recanalization assessment was 132.5 minutes (IQR, 62-238). Successful recanalization occurred at an unadjusted rate of 27.3% (157/575) overall, including in 30.4% (143/470) of patients who received intravenous alteplase and 13.3% (14/105) who did not (difference, 17.1% [95% CI, 10.2%-25.8%]). Among patients receiving alteplase, the following factors were associated with recanalization: time from treatment start to recanalization assessment (OR, 1.28 for every 30-minute increase in time [95% CI, 1.18-1.38]), more distal thrombus location, eg, distal M1 middle cerebral artery (39/84 [46.4%]) vs internal carotid artery (10/92 [10.9%]) (OR, 5.61 [95% CI, 2.38-13.26]), and higher residual flow (thrombus permeability) grade, eg, hairline streak (30/45 [66.7%]) vs none (91/377 [24.1%]) (OR, 7.03 [95% CI, 3.32-14.87]). Conclusions and Relevance In patients with acute ischemic stroke, more distal thrombus location, greater thrombus permeability, and longer time to recanalization assessment were associated with recanalization of arterial occlusion after administration of intravenous alteplase; among patients who did not receive alteplase, rates of arterial recanalization were low. These findings may help inform treatment and triage decisions in patients with acute ischemic stroke.

Headache with transient neurological deficit: a case report with hemispheric hypoperfusion and without lymphocytosis.

Transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL) is an uncommon disorder described in 1981 by Bartleson et al. Current diagnostic criteria (ICHD-III beta version 7.3.5) consider episodes of moderate or severe headache, lasting hours and associating cerebrospinal fluid (CSF) pleocytosis with lymphocytic predominance [1]. Neuroimaging studies and CSF culture are required to be normal. Neurological deficits [2] more commonly reported are sensory symptoms (78 % of cases), aphasia (66 %), and motor weakness (41 %). In addition to these symptoms, other features as elevation of CSF proteins [2] have also been described. To draw attention to this potentially misdiagnosed disorder, our aim is to report a case of headache and transient neurological deficits with a severe cerebral perfusion disturbance and the absence of CSF lymphocytosis. A 15-year-old male with a prior history of migraine was admitted to emergency department due to a non-fluent aphasia and sensory and motor deficit in right limbs of 40 min of evolution. He described a severe stabbing headache starting in right fronto-parietal scalp associating phonophobia and photophobia. A cerebral unenhanced and perfusion computed tomography (CT) was performed, while headache and a mild sensory disturbance in his right limbs were still present. Unenhanced CT was normal, but perfusion CT revealed an increased mean transit time (MTT) and a diminished cerebral blood flow (CBF) throughout the entire left cerebral hemisphere not confined to a particular vascular territory (Fig. 1). Cerebral blood volume (CBV) was normal. Findings were consistent with hypoperfusion throughout all left cerebral hemisphere. Neurological deficits lasted less than 1 h. A diffusionweighted brain magnetic resonance imaging (DWI-MRI) was performed within 24 h from clinical onset with no restricted diffusion lesions and with normal signal intensity of the brain parenchyma. An ultra-early carotid ultrasound imaging and transcranial Duplex showed a generalized increase in distal vascular resistance and segmental accelerations in both middle cerebral arteries with the absence of arterial occlusion. The angiography TC showed no alterations. The existence of a complete hemispheric perfusion/ diffusion mismatch, together with the clinical course including the presence of headache, led to a presumed diagnosis of a syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL), so a lumbar puncture was performed 3 days after admission without pleocytosis or hyperproteinorrachia. A new CT perfusion 5 days after clinical onset showed normal cerebral flow with normal CBV, MTT, and CBF in left cerebral hemisphere. Carotid ultrasound imaging and transcranial Duplex study was repeated with normalization of distal resistance and flow accelerations. Cerebral SPECT 10 days after clinical onset showed areas of decreased radionuclide uptake suggesting decreased blood flow in left temporal–parietal region (Fig. 2). CSF microbiological studies and extensive immunological determinations were negative. The patient suffered no new episodes and neurological exam was normal at hospital discharge. Control cerebral SPECT was repeated 2 months later with blood flow normalization (Fig. 2b). The presentation of sudden-onset neurological deficits at emergency department always leads neurologist to be & Elena Martı́nez Velasco emartinezvelasco@gmail.com