Acute Middle Cerebral Artery Territory Research Articles

Real-world evaluation of Brainomix e-Stroke software.

Brainomix e-Stroke is an artificial intelligence-based decision support tool that aids the interpretation of CT imaging in the context of acute stroke. While e-Stroke has the potential to improve the speed and accuracy of diagnosis, real-world validation is essential. The aim of this study was to prospectively evaluate the performance of Brainomix e-Stroke in an unselected cohort of patients with suspected acute ischaemic stroke. The study cohort included all patients admitted to the University College London Hospital Hyperacute Stroke Unit between October 2021 and April 2022. For e-ASPECTS and e-CTA, the ground truth was determined by a neuroradiologist with access to all clinical and imaging data. For e-CTP, the values of the core infarct and ischaemic penumbra were compared with those derived from syngo.via, an alternate software used at our institution. 1163 studies were performed in 551 patients admitted during the study period. Of these, 1130 (97.2%) were successfully processed by e-Stroke in an average of 4 min. For identifying acute middle cerebral artery territory ischaemia, e-ASPECTS had an accuracy of 77.0% and was more specific (83.5%) than sensitive (58.6%). The accuracy for identifying hyperdense thrombus was lower (69.1%), which was mainly due to many false positives (positive predictive value of 22.9%). Identification of acute haemorrhage was highly accurate (97.8%) with a sensitivity of 100% and a specificity of 97.6%; false positives were typically caused by areas of calcification. The accuracy of e-CTA for large vessel occlusions was 91.5%. The core infarct and ischaemic penumbra volumes provided by e-CTP strongly correlated with those provided by syngo.via (ρ=0.804-0.979). Brainomix e-Stroke software provides rapid and reliable analysis of CT imaging in the acute stroke setting although, in line with the manufacturer's guidance, it should be used as an adjunct to expert interpretation rather than a standalone decision-making tool.

Natural Language Processing of Radiology Reports to Detect Complications of Ischemic Stroke.

Abstraction of critical data from unstructured radiologic reports using natural language processing (NLP) is a powerful tool to automate the detection of important clinical features and enhance research efforts. We present a set of NLP approaches to identify critical findings in patients with acute ischemic stroke from radiology reports of computed tomography (CT) and magnetic resonance imaging (MRI). We trained machine learning classifiers to identify categorical outcomes of edema, midline shift (MLS), hemorrhagic transformation, and parenchymal hematoma, as well as rule-based systems (RBS) to identify intraventricular hemorrhage (IVH) and continuous MLS measurements within CT/MRI reports. Using a derivation cohort of 2289 reports from 550 individuals with acute middle cerebral artery territory ischemic strokes, we externally validated our models on reports from a separate institution as well as from patients with ischemic strokes in any vascular territory. In all data sets, a deep neural network with pretrained biomedical word embeddings (BioClinicalBERT) achieved the highest discrimination performance for binary prediction of edema (area under precision recall curve [AUPRC] > 0.94), MLS (AUPRC > 0.98), hemorrhagic conversion (AUPRC > 0.89), and parenchymal hematoma (AUPRC > 0.76). BioClinicalBERT outperformed lasso regression (p < 0.001) for all outcomes except parenchymal hematoma (p = 0.755). Tailored RBS for IVH and continuous MLS outperformed BioClinicalBERT (p < 0.001) and linear regression, respectively (p < 0.001). Our study demonstrates robust performance and external validity of a core NLP tool kit for identifying both categorical and continuous outcomes of ischemic stroke from unstructured radiographic text data. Medically tailored NLP methods have multiple important big data applications, including scalable electronic phenotyping, augmentation of clinical risk prediction models, and facilitation of automatic alert systems in the hospital setting.

Role of S100β Glial Protein as a Serological Marker for Analysis of Acute Ischemic Stroke

Background: Stroke is a major cause of neurological disability, which can be often predicted with serological markers. Glial-derived S100β protein is a potential biomarker for cerebral ischemia and may be helpful in predicting the severity, outcome, and recovery of stroke. Aim: This study aimed to study the role of S100β glial protein as a serological marker in predicting the severity of acute ischemic stroke (AIS), outcome, and functional recovery after 1 month. Methods: A hospital-based prospective case control study included 43 consecutive patients, &gt;18 years old, who were admitted with acute middle cerebral artery (MCA) territory infarcts within 72 h of onset of neurological deficits. Control group comprised of 43 age-matched asymptomatic volunteers. Independent t-test and chi square test were used to compare the means and evaluate the association between protein level and various parameters. P ≤ .05 was statistically significant. Results: S100β protein level in AIS patients was significantly higher compared to controls ( P &lt; .05). Elevated serum S100β protein level was found to be associated with larger infarct volumes, higher National Institute Health Stroke Scale scores, and higher modified Rankin Scale scores at admission ( P &lt; .05). Patients with higher S100β protein levels at admission had poor recovery at 1 month compared to patients having normal S100β protein levels. Conclusion: S100β protein levels at admission after an acute MCA territory infarct may be used as a reliable serological tool in predicting the severity, outcome, and functional recovery in stroke.

Prevalence of cognitive impairment in acute ischaemic stroke and use of Alberta Stroke Programme Early CT Score (ASPECTS) for early prediction of post-stroke cognitive impairment.

This study aims to assess the prevalence of post-stroke cognitive impairment, and to evaluate the correlation of ASPECTS with impaired cognition. 150 patients presenting with acute middle cerebral artery territory ischaemic stroke were included in this study. Risk factors of ischaemic stroke and the initial NIHSS were determined. An initial and a follow-up non-contrast CT brain were carried out after seven days which were assessed by ASPECTS. The prevalence of cognitive impairment was determined by MoCA during the follow up of patients after three months. Correlations of ASPECTS, NIHSS and MoCA were done by Spearman correlation. Multivariate logistic regression analysis was carried out for the independent variables of cognitive impairment. The prevalence of post-stroke cognitive impairment in this study, according to the threshold for cognitive impairment with a MoCA score of 25 or less, was 25.3% (38 patients). Significant positive correlations between ASPECTS and total MoCA test domains were found (r = 0.73 and P = 0.002). Logistic regression analysis demonstrated that the independent factors associated with cognitive impairment were older age, certain domains of the MoCA test like executive functions, memory, attention, language, NIHSS, HTN, and ASPECTS. There is a prevalence of cognitive impairment in about 25% of patients after three months of follow-up in cases with acute ischaemic stroke. ASPECTS is directly correlated with cognitive impairment, and may be considered as a biomarker of post-stroke cognitive impairment.

Predictive Value of the Alberta Stroke Program Early CT Score (ASPECTS) in the Outcome of the Acute Ischemic Stroke and Its Correlation with Stroke Subtypes, NIHSS, and Cognitive Impairment.

Objectives This study is aimed at correlating ASPECTS with mortality and morbidity in patients with acute middle cerebral artery territory infarction and at determining the cutoff value of ASPECTS that may predict the outcome. Methods 150 patients diagnosed with acute middle cerebral artery territory infarction were involved in this study. Risk factors, initial NIHSS, and GCS were determined. An initial or follow-up noncontrast CT brain was done and assessed by ASPECTS. Outcomes were determined by mRS during the follow-up of cases after 3 months. Correlations of ASPECTS and outcome variables were done by Spearman correlation. Logistic regression analysis and ROC curve were done to detect the cutoff value of ASPECTS that predicts unfavorable outcomes. Results The most common subtypes of ischemic strokes were lacunar stroke in 66 patients (44%), cardioembolic stroke in 39 patients (26%), and LAA stroke in 30 cases (20%). The cardioembolic stroke had a statistically significant lower ASPECT score than other types of ischemic strokes (P < 0.05). Spearman correlation showed that lower ASPECTS values (worse outcome) were more in older patients and associated with lower initial GCS. ASPECTS values were inversely correlated with initial NIHSS, inpatient stay, inpatient complications, mortality, and mRS. The ASPECTS cutoff value determined for the prediction of unfavorable outcomes was equal to ≤7. The binary logistic regression analysis detected that patients with ASPECTS ≤ 7 were significantly associated with about fourfold increased risk of poor outcomes (OR 3.95, 95% CI 2.09–11.38, and P < 0.01). Conclusions ASPECTS is a valuable and appropriate technique for the evaluation of the prognosis in acute ischemic stroke. Patients with high ASPECTS values are more likely to attain favorable outcomes, and the cutoff value of ASPECTS is a strong predictor for unfavorable outcomes. This trial is registered with ClinicalTrials.gov NCT04235920.

Clot composition in retrieved thrombi after mechanical thrombectomy in strokes due to carotid web

BackgroundThe association of carotid webs (CaW) and ischemic stroke is being increasingly recognized. Data on the histologic clot architecture in strokes caused by CaW has not been previously described. Understanding...

The comparative efficacy of theta burst stimulation or functional electrical stimulation when combined with physical therapy after stroke: a randomized controlled trial

Objective: To study the long-term effectiveness of Theta Burst Stimulation (TBS) or Functional Electrical Stimulation (FES) combined with Physical therapy (PT) as compared to PT alone for improving arm functions in patients with acute stroke. Design: Single blind randomized controlled trial. Setting: Outpatient clinics and inpatient wards at tertiary care neurology center. Subjects: Adult patients with acute middle cerebral artery territory ischemic stroke. Interventions: 60 patients were randomized into three groups of 20 each: TBS+PT; FES+PT; and PT alone. TBS group received intermittent TBS of ipsilesional hemisphere and continuous TBS of contralesional hemisphere while FES group received FES of paretic limb, both for four weeks. All groups received supervised physical therapy for four weeks followed by home physiotherapy for one year. Outcome measures: Fugl Meyer Assessment upper limb score (FMA-UL) was primary outcome measure. Patients were evaluated at baseline and subsequently at one, three and six months and one year. Results: Compared to PT group, mean FMA-UL scores were higher in TBS and FES groups at all follow-ups (P < 0.001). From baseline to one year, mean (SD) FMA-UL scores increased from 14.9(2.1) to 55.55(2.46) in TBS group, 15.5(1.99) to 55.85(2.46) in FES group, and 14.3(2.2) to 43.3(4.22) in PT group indicating an increase of 273%, 260%, and 203% respectively. There was no difference between FES and TBS groups. Conclusion: A four-week intervention with TBS or FES combined with PT produces better long-term arm functions as compared to PT alone in patients with acute stroke.

Differential MicroRibonucleic Acid Expression in Cardioembolic Stroke

BackgroundMicroRNAs (miRNA) are a class of small, endogenous (17-25 nucleotide) noncoding ribonucleic acids implicated in the transcriptional and post-transcriptional regulation of gene expression. This study examines stroke-specific miRNA expression in large vessel territory cardioembolic stroke. MethodsPeripheral blood was collected from controls and ischemic stroke patients 24 hours after stroke onset. Whole blood miRNA was isolated and analyzed for differential expression. A total of 16 patients with acute middle cerebral artery territory strokes of cardioembolic origin were included in this pilot study. MiRNA profiling was conducted by miRCURY LNA™ microRNA Array. ResultsIn patients with cardioembolic stroke, significant differential expression of 14 miRNAs was observed when compared to controls. Ten of these miRNA had not previously been associated with ischemic stroke (miR-664a-3p, -2116-5pp, -4531, -4765-5p, -647, -4709-3p, -4742-3p, -5584-3p, -4756-3p, and -5187-3p). Subanalysis of severe strokes (NIHSS > 10) identified an additional 5 differentially expressed miRNA. No significant effects of sex or tissue plasminogen activator treatment were seen on miRNA expression. ConclusionsIschemic stroke patients show a differential miRNA expression profile as compared to controls. These new associations between circulating miRNAs and ischemic stroke may help to refine stroke subtype diagnosis and identify novel therapeutic miRNA targets for the treatment of ischemic stroke.

Susceptibility-diffusion mismatch in middle cerebral artery territory acute ischemic stroke: clinical and imaging implications.

Background Recent studies have suggested a correlation between susceptibility-diffusion mismatch and perfusion-diffusion mismatch in acute ischemic stroke patients. Purpose To determine the clinical and imaging associations of susceptibility-diffusion mismatch in patients with acute ischemic stroke in the middle cerebral artery (MCA) territory. Material and Methods Consecutive patients with MCA territory acute ischemic stroke, who had magnetic resonance imaging (MRI) performed with susceptibility-weighted imaging (SWI) and diffusion-weighted imaging (DWI) within 24 h of symptom onset or time last-seen-well, were included. Two neuroradiologists reviewed SWI scans for SWI-DWI mismatch defined by regionally increased vessel number or diameter on SWI extending beyond the DWI hyperintensity territory in the affected hemisphere. The stroke severity at admission was evaluated using the National Institutes of Health Stroke Scale (NIHSS) score. Poor clinical outcome was defined by a 3-month modified Rankin Scale (mRS) score >2. Results The SWI-DWI mismatch was identified in 44 (29.3%) of 150 patients included in this study. Patients with SWI-DWI mismatch had smaller admission infarct volumes (31.2 ± 44.7 versus 55.9 ± 117.7 mL, P = 0.045) and were younger (60.4 ± 18.9 versus 67.1 ± 15.5, P = 0.026). After correction for age, admission NIHSS score, and infarct volume, the SWI-DWI mismatch was associated with a 22.6% lower rate of poor clinical outcome using propensity score matching ( P = 0.032). In our cohort, thrombolytic therapy showed no significant effect on outcome. Conclusion The presence of SWI-DWI mismatch in acute MCA territory ischemic infarct is associated with smaller infarct volume. Moreover, SWI-DWI mismatch was associated with better outcome after correction for infarct size, severity of admission symptoms, and age.

Perfusion-Weighted MRI Parameters for Prediction of Early Progressive Infarction in Middle Cerebral Artery Occlusion.

ObjectiveEarly progressive infarction (EPI) is frequently observed and related to poor functional outcome in patients with middle cerebral artery (MCA) infarction caused by MCA occlusion. We evaluated the perfusion parameters of magnetic resonance imaging (MRI) as a predictor of EPI.MethodsWe retrospectively analyzed patients with acute MCA territory infarction caused by MCA occlusion. EPI was defined as a National Institutes of Health Stroke Scale increment ≥2 points during 24 hours despite receiving standard treatment. Regional parameter ratios, such as cerebral blood flow and volume (rCBV) ratio (ipsilateral value/contralateral value) on perfusion MRI were analyzed to investigate the association with EPI.ResultsSixty-four patients were enrolled in total. EPI was present in 18 (28%) subjects and all EPI occurred within 3 days after hospitalization. Diabetes mellitus, rCBV ratio and regional time to peak (rTTP) ratio showed statically significant differences in both groups. Multi-variate analysis indicated that history of diabetes mellitus [odds ratio (OR), 6.13; 95% confidence interval (CI), 1.55–24.24] and a low rCBV ratio (rCBV, <0.85; OR, 6.57; 95% CI, 1.4–30.27) was significantly correlated with EPI.ConclusionThe incidence of EPI is considerable in patients with acute MCA territory infarction caused by MCA occlusion. We suggest that rCBV ratio is a useful neuro-imaging parameter to predict EPI.

Prominent Vessel Sign on Susceptibility-Weighted Imaging in Acute Stroke: Prediction of Infarct Growth and Clinical Outcome

Background and PurposePredicting the risk of further infarct growth in stroke patients is critical to therapeutic decision making. We aimed to predict early infarct growth and clinical outcome from prominent vessel sign (PVS) identified on the first susceptibility-weighted image (SWI) after acute stroke.Materials and MethodsTwenty-two patients with middle cerebral artery (MCA) infarction had diffusion-weighted imaging, SWI, MR angiography, and clinical evaluation using the National Institutes of Health Stroke Scale at 7–60 hours and 5–14 days after stroke onset. Late-stage clinical evaluation at 1 and 3 months used the modified Rankin Scale. The infarct area and growth were scored from 10 (none) to 0 (infarct or growth in all 10 zones) using the Alberta Stroke Program Early CT Score (ASPECTS) system.ResultsInfarct growth on the second MRI occurred in 13 of 15 patients with PVS on the first MRI and not in any patient without PVS (n=7; r=0.86, P<0.001). The extent of PVS was significantly correlated with infarct growth (r=0.82, P<0.001) and early-stage outcome (P=0.02). No between-group difference in late-stage clinical outcome was found.ConclusionPVS on the first SWI after acute MCA territory stroke is a useful predictor of early infarct growth. Extensive PVS within the large MCA territory is related to poor early-stage outcome and could be useful for clinical assessment of stroke.

Early infarct growth predicts long-term clinical outcome after thrombolysis

BackgroundIschemic lesion growth may be a surrogate marker of clinical outcome, but no such interrelationship after thrombolysis has yet been determined. We evaluated the association between early infarct growth on diffusion-weighted imaging (DWI) and long-term clinical outcome after thrombolysis. MethodsWe retrospectively reviewed outcomes in patients with acute middle cerebral artery territory stroke who had been treated with intravenous tissue plasminogen activator or intra-arterial urokinase. DWI lesion volumes were measured at baseline and within 7days, and the difference was calculated. Clinical outcome was evaluated using the modified Rankin Scale (mRS) at 3months. Good and poor clinical outcomes were defined as: a) mRS 0–1 vs. mRS 2–6, b) mRS 0–2 vs. mRS 3–6, and c) responder analysis which was influenced by the baseline National Institutes of Health Stroke Scale (NIHSS) scores: good and poor outcomes were defined as mRS 0 vs. mRS 1–6 if the baseline NIHSS score was <8, mRS 0–1 vs. mRS 2–6 if the NIHSS score was 8–14, and mRS 0–2 vs. mRS 3–6 if the NIHSS score was >14. The relationship between the ischemic lesion volume change and clinical outcome was explored. The cut-off value of infarct growth predicting long-term outcome was estimated using receiver operating characteristic analysis. ResultsOf the 81 patients included, 67 (82.7%) showed lesion growth, and absolute growth was significantly related to poor outcomes (P<0.001 all for mRS 2–6, mRS 3–6, and responder analysis). Multivariate analysis showed that absolute lesion growth was an independent predictor of poor outcome, defined as mRS 2–6 (P=0.002; odds ratio [OR], 1.06; 95% confidence interval [CI], 1.02–1.10), mRS 3–6 (P=0.001; OR, 1.06; 95% CI, 1.02–1.10), and poor outcome by responder analysis (P=0.001; OR, 1.06; 95% CI, 1.03–1.10). The cut-off values of lesion growth that discriminated between good and poor outcomes were 14.11cm3 for mRS 2–6; 15.87cm3 for mRS 3–6; and 14.11cm3 in responder analysis. ConclusionsEarly DWI lesion growth is an independent predictor of poor outcome after thrombolysis and may serve a potential surrogate marker of clinical outcome in acute stroke trials.

Acute insular infarct increases risk of electrocardiogram changes and sudden cardiac death

To investigate the influence of location and size of acute insular infarct on stroke-related electrocardiogram (ECG) changes and cardiovascular events. Ninety-nine cases admitted to hospital from October 2007 to June 2009, who were diagnosed as acute middle cerebral artery territory infarct within 48 h after onset and without the history of cardiac diseases, were included in the study. The patients were further divided into three groups: major insular infarct, minor insular infarct and control group, according to the infarct size on MRI diffusion-weighted image. The clinical data, ECG changes and cardiovascular events were compared between left and right insular infarct. Logistic regression was applied to determine the independent risk factors of ECG changes and cardiovascular events. Large artery atherosclerosis was the main cause of acute insular infarct (71.8 %), which was associated with higher NIHSS score compared to the control group (P < 0.01). Comparing the left and right insular infarct, the frequencies of sinus bradycardia and sudden cardiac death were significantly higher in left insular infarct (P < 0.01 and P < 0.05), while there was a trend that the frequency of atrial fibrillation was higher in right insular infarct (P = 0.079). With the larger size of insular infarct, the frequency of sinus bradycardia, new atrial fibrillation and sudden cardiac death (P<0.01, P<0.05 and P<0.05, respectively) became much higher. Logistic regression analysis showed that major insular infarct was related to the higher frequency of sinus bradycardia (OR = 4.660, 95% CI: 1.646 ~ 13.195; P = 0.004). Acute insular infarct is associated with the stroke-related ECG changes and sudden cardiac death. Left insular infarct is related to sinus bradycardia, possibly due to the enhanced parasympathetic tone. It deserves clinical attention that the incidence of cardiac autonomic disturbance becomes higher with the enlarged insular infarct size.

Aortic Valve Vegetation Without Endocarditis

We present a 30-year-old man with an acute middle cerebral artery territory infarction. A transesophageal echocardiogram showed a large, highly mobile mass attached to the patient's aortic valve. We discuss the differential diagnosis of a cardiac mass that includes infection, tumor, and thrombus. A complete workup showed no evidence of systemic infection but did reveal the presence of antiphospholipid antibodies. The patient also had a history of a right lower extremity deep venous thrombosis. Anticoagulation therapy was started, and follow-up showed complete resolution of the aortic valve lesion. This case highlights that when a valvular vegetation is encountered in a clinical setting that does not suggest infectious endocarditis, the diagnosis of antiphospholipid antibody syndrome should be considered. This case and our review of the literature suggest that vegetations in antiphospholipid antibody syndrome, no matter how large and ominous in appearance, can be treated successfully with anticoagulation and vigilant observation.

Prediction of clinical outcome with baseline and 24-hour perfusion CT in acute middle cerebral artery territory ischemic stroke treated with intravenous recanalization therapy

We sought to determine whether Alberta Stroke Program Early CT Scores (ASPECTS) derived from baseline noncontrast CT (NCCT) and perfusion CT (CTP) imaging maps can predict clinical outcome after recanalization therapy in acute ischemic stroke of the middle cerebral artery (MCA) territory and whether changes in the ASPECTS from baseline to 24 h after recanalization therapy can help predict clinical outcome. We retrospectively studied consecutive patients with acute ischemic stroke of the MCA territory treated with intravenous tissue plasminogen activator (t-PA) or abciximab within 6 h of symptom onset. We performed NCCT and CTP before and 24 h after intravenous t-PA or abciximab treatment and determined the ASPECTS and the changes in the ASPECTS from baseline to 24 h. A favorable outcome was defined as a modified Rankin scale score of 0 or 1 at 3 months. During the 18-month study period 44 patients were studied. In multivariate logistic regression analysis, the cerebral blood volume (CBV) ASPECTS (OR 1.80, 95% CI 1.10 to 2.93) at baseline and the increase in cerebral blood flow (CBF) ASPECTS (OR 1.68, 95% CI 1.13 to 2.50) from baseline to 24 h were associated with a favorable outcome. The cutoff values for a favorable outcome using receiver operating characteristic curves were 8 and 1, respectively. When the CBV ASPECTS at baseline was 8 or more, its positive predictive value was only 58.1%. When the CBV ASPECTS at baseline was 8 or more and the increase in CBF ASPECTS from baseline to 24 h was 1 or more, the positive predictive value was 100% and the negative predictive value was 74.2%. The CBV ASPECTS derived from baseline CTP maps was found to be predictive of a favorable outcome, but its positive predictive value was suboptimal. The change in the CBF ASPECTS from baseline to 24 h after treatment was helpful in predicting outcome.

Treatment of acute ischemic brain infarction with the assistance of local intraarterial thrombolysis with recombinant tissue-type plasminogen activator

Cerebral infarction is usually due to arterial occlusion. Prompt treatment with thrombolytic drugs can restore blood flow and improve recovery from an infarct. To evaluate the clinical efficacy and safety of local intraarterial thrombolysis with recombinant tissue-type plasminogen activator (rtPA) in patients with acute middle cerebral artery (MCA) infarctions within 6 hours of the onset of symptoms. Sixteen patients (10 females and six males) aged from 42 to 61 years, with acute MCA territory infarcts were selected for treatment with local i.a. rtPA up to 6 hours after the onset of symptoms. Patient selection was based on clinical examination, computed tomography (CT), and digital subtraction angiography (DSA). A clinical evaluation was performed before treatment, at the time of discharge, and 90 days post-procedure on the basis of modified Rankin and NIHSS scores. Controls (n = 16, nine females and seven males) aged from 51 to 70 years were treated only with intravenous anticoagulation using i.v. heparin infusion. The control group was evaluated with multidetector CT (MDCT) angiography performed on entry to the study and at 2-4 hours afterwards. Eight patients (50%) achieved a modified Rankin score of 2 or less as the primary outcome after 90 days follow-up. The secondary clinical outcome at 90-day follow-up was as follows: NIHSS score < or =1, three (19%) of the patients; NIHSS score > or =50% decrease, nine (56%) of the patients. A recanalization rate of 75% was achieved in 12 of the 16 treated patients, but only 12.5% in two of the 16 patients in the control group. Intracerebral hemorrhage occurred in two (12.5%) of the patients in the treatment group, but in only one patient (6%) in the control group. There were no deaths in the treated group after thrombolysis up to the time of discharge; however, during the 90-day follow-up, two patients died compared to three patients in the control group (19% vs. 12.5% mortality rate). Patients with cerebral infarction who were treated within 6 hours of onset using intraarterial rtPA thrombolysis had a significantly improved clinical outcome 90 days after the procedure compared to patients treated only with intravenous anticoagulation.

Insular Cortex Infarction in Acute Middle Cerebral Artery Territory Stroke

Insula infarction is an early computed tomographic sign of middle cerebral artery (MCA) territory stroke and may affect cardiovascular autonomic function. To determine insula involvement in MCA territory infarction and its relationship with infarcts in the remainder of the MCA territory, stroke severity, and clinically relevant cardiovascular conditions. Case series (August 1, 1997, to June 30, 2000). Academic stroke center. A total of 150 consecutive patients with nonlacunar MCA territory stroke who underwent magnetic resonance imaging within 48 hours of stroke onset. Association of insula infarction with the National Institutes of Health Stroke Scale (NIHSS) score, location of vascular occlusion, and cardiovascular events. Insular lesions were present in 72 patients (48%); 34 (23%) had major insular lesions and 38 (25%) had minor lesions. Insula infarction was associated with lenticulostriate territory infarction (46% vs 14%; P<.001), more than one third of MCA territory infarction (35% vs 3%; P<.001), higher NIHSS score (13.5 vs 6; P<.001), and proximal vascular occlusion detected on magnetic resonance angiography. These associations were strongest for patients with major insular lesions. Clinically significant new arrhythmia was present in 15 of 72 with insula infarction (13 atrial fibrillations) and 4 of 78 without (P = .06). Insula infarction was associated with lower diastolic blood pressure at admission but was not associated with pulse rate, QTc interval, myocardial infarction, or sudden death. The insular cortex is involved in almost half of patients with nonlacunar ischemic MCA territory strokes. Major insula involvement is associated with large MCA territory infarcts, proximal MCA occlusions, and greater stroke severity. Insula infarction was not a predictor of clinically significant acute cardiovascular events during hospital stay in our patients.

Relationship between cerebral blood flow and the development of swelling and life-threatening herniation in acute ischemic stroke

Object The purpose of this study was to determine whether cerebral blood flow (CBF) measurements in acute stroke could be correlated with the subsequent development of cerebral edema and life-threatening brain herniation. Methods Twenty patients with aggressively managed acute middle cerebral artery (MCA) territory strokes who underwent xenon-enhanced computerized tomography (Xe-CT) CBF scanning within 6 hours of onset of symptoms were retrospectively reviewed. The relationship among CBF and follow-up CT evidence of edema and clinical evidence of brain herniation during the 36 to 96 hours following stroke onset was analyzed. Initial CT scans displayed abnormal findings in 11 patients (55%), whereas the Xe-CT CBF scans showed abnormal findings in all patients (100%). The mean CBF in the symptomatic MCA territory was 10.4 ml/100 g/minute in patients who developed severe edema compared with 19 ml/100 g/minute in patients who developed mild edema (p &lt; 0.05). The mean CBF in the symptomatic MCA territory was 8.6 ml/100 g/minute in patients who developed clinical brain herniation compared with 18 ml/100 g/minute in those who did not (p &lt; 0.01). The mean CBF in the symptomatic MCA territory that was 15 ml/100 g/minute or lower was significantly associated with the development of severe edema and herniation (p &lt; 0.05). Conclusions Within 6 hours of acute MCA territory stroke, Xe-CT CBF measurements can be used to predict the subsequent development of severe edema and progression to clinical life-threatening brain herniation. Early knowledge of the anatomical and clinical sequelae of stroke in the acute phase may aid in the triage of such patients and alert physicians to the potential need for more aggressive medical or neurosurgical intervention.

2-07-17 The value of three-phase spiral CT in acute middle cerebral artery territory ischemic stroke

2-07-17 The value of three-phase spiral CT in acute middle cerebral artery territory ischemic stroke

Improved CT diagnosis of acute middle cerebral artery territory infarcts with density-difference analysis.

A new postprocessing method is described for CT detection of acute middle cerebral artery (MCA) territory infarcts by histograph analysis of density values. The density values in each CT slice were histographically recorded for each hemisphere. A density-difference diagram was calculated by digital subtraction of the histogram of the left hemisphere from that of the right. Pixels within the highest density-difference ranges were highlighted. To investigate the value of this method CT studies of 30 patients with acute MCA territory infarcts and of 15 normal CT studies were analysed by two radiologists and neurosurgeons. CT images with and without postprocessing were assessed for the presence, site and size of infarcts. Follow-up CTwas used as control. With density-difference analysis (DDA) the detection rate for infarcts increased significantly (96 % compared to 61 %). In no case was a correct diagnosis made on the unpostprocessed images falsely revised with DDA. All normal CT studies were detected correctly using DDA.