Biomedical subjects

Jose G Merino

Publications and source records attributed to Jose G Merino.

4 recordsLinked to original sources

PubMed2006

National Institute of Neurological Disorders and Stroke-Canadian Stroke Network vascular cognitive impairment harmonization standards.

BACKGROUND AND PURPOSE: One in 3 individuals will experience a stroke, dementia or both. Moreover, twice as many individuals will have cognitive impairment short of dementia as either stroke or dementia. The commonly used stroke scales do not measure cognition, while dementia criteria focus on the late stages of cognitive impairment, and are heavily biased toward the diagnosis of Alzheimer disease. No commonly agreed standards exist for identifying and describing individuals with cognitive impairment, particularly in the early stages, and especially with cognitive impairment related to vascular factors, or vascular cognitive impairment. METHODS: The National Institute for Neurological Disorders and Stroke (NINDS) and the Canadian Stroke Network (CSN) convened researchers in clinical diagnosis, epidemiology, neuropsychology, brain imaging, neuropathology, experimental models, biomarkers, genetics, and clinical trials to recommend minimum, common, clinical and research standards for the description and study of vascular cognitive impairment. RESULTS: The results of these discussions are reported herein. CONCLUSIONS: The development of common standards represents a first step in a process of use, validation and refinement. Using the same standards will help identify individuals in the early stages of cognitive impairment, will make studies comparable, and by integrating knowledge, will accelerate the pace of progress.

Brain↗

PubMed2006

ASPECT scoring to estimate >1/3 middle cerebral artery territory infarction.

PURPOSE: To compare the inter-observer reliability of Alberta Stroke Programme Early CT Scoring (ASPECTS) with the ICE (Idealize-Close-Estimate) method of estimating > 1/3 middle cerebral artery territory (MCAT) infarction amongst stroke neurologists and to determine how well ASPECT Scoring predicts > 1/3 MCAT infarctions in acute ischemic stroke (AIS). BACKGROUND: The European Cooperative Acute Stroke Study suggested that > 1/3 involvement of the MCAT on early CT scan was a risk factor for symptomatic intracerebral hemorrhage (SICH) following treatment with tissue plasminogen activator (tPA) for AIS but, in the absence of a systematic method of estimation had poor interobserver reliability (Kappa 0.49). The ICE method was developed to standardize the approach to estimating early MCAT infarct size and has very good interobserver reliability (Kappa 0.72). ASPECTS has comparable interobserver reliability and is reported to predict both neurological outcome and SICH. METHODS: Five stroke neurologists were tested with 40 AIS CT scans. Each performed blinded independent assessments of early ischemic changes with both ASPECTS and ICE. The reference standard was majority opinion of 1/3 MCAT determination of five neuroradiologists. A receiver operator curve (ROC) was constructed and likelihood ratios (LR) were calculated. Chance corrected agreement (kappa) and chance independent agreement (phi) were calculated for both methods, and analysis of variance was used to calculate reliability by intraclass correlation coefficient (ICC) for ASPECTS. RESULTS: The LR for a positive test (> 1/3 MCAT) were extremely large and conclusive (approaching infinity) for ASPECTS of 0-3; were large and conclusive (30, 20, and 10) for ASPECTS of 4, 5, and 6 respectively; was an unhelpful 1 for ASPECTS of 7, and were again extremely large and conclusive (approaching zero) for ASPECTS of 8-10. A ROC plot supported an ASPECTS cutoff of < 7 as best for 1/3 MCAT estimation (94% sensitivity and 98% specificity). Kappa and Phi statistics were moderately good for both ASPECTS and ICE (0.7). ICC for ASPECTS was 0.8. CONCLUSIONS: When experienced stroke neurologists utilize a formalized method of quantifying early ischemic changes on CT, either ASPECTS or ICE, the interobserver agreement and reliability are satisfactory. ASPECTS allows for a strong and conclusive estimation of the presence of 1/3 MCAT involvement and a cutoff point of < 7 results in best test performance.

Aged↗

PubMed2004

Update on stroke.

PURPOSE OF REVIEW: This review highlights some advances in the areas of epidemiology, therapy, and imaging of acute stroke. RECENT FINDINGS: Studies published in 2003 provided new insights into the epidemiology of stroke. The African American Antiplatelet Stroke Prevention Study found that traditional stroke risk factors are still undiagnosed and undertreated, particularly in minorities. Cohort studies have identified incident silent infarcts as risk factors for stroke and history of type I diabetes as a risk factor for death in patients with acute stroke. Cervical artery dissection, on the other hand, seems to have a benign course. Imaging has become an important tool for understanding the pathophysiology of stroke, as demonstrated in recent publications. New studies have shown the prognostic value of magnetic resonance imaging: it can predict the volume of ischemic tissue that will progress to infarction and detects cerebral microbleeds - a risk factor for intracranial hemorrhage. Computed tomographic scanning may have a role in selecting patients for thrombolysis, particularly when validated scales are used. Despite the barriers to the use of tissue plasminogen activator in the treatment of patients with stroke, data published this year show that it is a safe medication when used routinely in community and university hospitals. In addition to thrombolysis, other general medical measures, such as glucose control and adequate attention to nutritional status, can help improve the outcome of patients with stroke. SUMMARY: In acute stroke, recognition and modification of risk factors continue to be challenging tasks. Treatment of acute stroke should involve thrombolysis and attention to medical conditions that may influence outcome. New applications of magnetic resonance imaging and computed tomography may help guide stroke therapy.

Brain Ischemia↗

PubMed2003

Effects of thrombolysis for acute stroke in patients with pre-existing disability.

BACKGROUND: Thrombolysis for acute stroke is beneficial in selected patients. Because clinical trials generally exclude patients with pre-existing disability, this subgroup of patients has not been studied. We examined the outcomes after thrombolysis of patients with and without disability before their stroke. METHODS: We prospectively followed 112 consecutive patients with acute ischemic stroke who were given intravenous thrombolysis treatment according to published protocols. Three-month outcomes of the patients with pre-existing disability (defined as a prestroke score of 2 or more on the modified Rankin scale [MRS]) were compared with those of patients without pre-existing disability (defined as a prestroke MRS score of 0 or 1) and with those of 168 patients similarly treated in the National Institute of Neurological Disorders and Stroke trial. RESULTS: At 3 months after the stroke, patients with pre-existing disability (21% of the 112) had a higher mortality rate than those without (33% v. 14%) (odds ratio 3.2, 95% confidence interval 1.0-10.1) and worse function (median MRS score 3 v. 2, p = 0.03). However, there was little difference between the 2 groups in neurologic impairment among the survivors (median score on the National Institutes of Health stroke scale 4 v. 2, p = 0.41) or in the total proportion of those with an MRS score of 0 or 1 or, for those with a prestroke score greater than 1, a return to the prestroke score (42% v. 41%, p = 0.87). INTERPRETATION: Although the true effectiveness of thrombolysis for acute stroke in patients with pre-existing disability is not known, treated patients appear able to return to their prestroke level of function as often as patients without pre-existing disability, despite a significantly higher mortality rate.

Aged↗