Daniel Woo

Ischemic lesions, blood pressure dysregulation, and poor outcomes in intracerebral hemorrhage

Objective: To evaluate the associations among diffusion-weighted imaging (DWI) lesions, blood pressure (BP) dysregulation, MRI markers of small vessel disease, and poor outcome in a large, prospective study of primary intracerebral hemorrhage (ICH). Methods: The Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH) study is a multicenter, observational study of ICH among white, black, and Hispanic patients. Results: Of 600 patients, mean (±SD) age was 60.8 ± 13.6 years, median (interquartile range) ICH volume was 9.1 mL (3.5–20.8), and 79.6% had hypertension. Overall, 26.5% of cases had DWI lesions, and this frequency differed by race/ethnicity (black 33.8%, Hispanic 24.9%, white 20.2%, overall p = 0.006). A logistic regression model of variables associated with DWI lesions included lower age (odds ratio [OR] 0.721, p = 0.002), higher first recorded systolic BP (10-unit OR 1.12, p = 0.002), greater change in mean arterial pressure (MAP) prior to the MRI (10-unit OR 1.10, p = 0.037), microbleeds (OR 1.99, p = 0.008), and higher white matter hyperintensity (WMH) score (1-unit OR 1.16, p = 0.002) after controlling for race/ethnicity, leukocyte count, and acute in-hospital antihypertensive treatment. A second model of variables associated with poor 90-day functional outcome (modified Rankin Scale scores 4–6) included DWI lesion count (OR 1.085, p = 0.034) as well as age, ICH volume, intraventricular hemorrhage, Glasgow Coma Scale score, WMH score, race/ethnicity, acute in-hospital antihypertensive treatment, and ICH location. Conclusions: These results support the hypotheses that acute BP dysregulation is associated with the development of DWI lesions in primary ICH and that DWI lesions are, in turn, associated with poor outcomes.

Significance of Cerebral Small-Vessel Disease in Acute Intracerebral Hemorrhage

Background and Purpose— The significance of structural changes associated with cerebral small-vessel disease (SVD), including white matter lesions (WML), lacunes, and brain atrophy, to outcome from acute intracerebral hemorrhage is uncertain. We determined associations of computed tomographic radiological manifestations of cerebral SVD and outcomes, and in terms of any differential effect of early intensive blood pressure–lowering treatment, in the large-scale Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial (INTERACT2). Methods— We graded WML (van Swieten scale), the presence of lacunes, and brain atrophy (2 linear measurements and visual rating) for 2069 of 2839 patients with available baseline brain computed tomography (<6 hours of intracerebral hemorrhage onset) by 3 independent neurologists blind to clinical data. Results— WML grade and 2 linear measurements of brain atrophy were associated with death or major disability at 90 days: multivariable-adjusted odds ratios for WML (grade 3 and 4 versus 0), frontal ratio, and third ventricle Sylvian fissure distance (most versus least severe atrophy quartile) were 1.42 (95% confidence interval, 1.02–1.98), 1.47 (1.08–1.99), and 1.64 (1.21–2.22), respectively (all P for trend <0.05). There was no association between lacunes and outcomes. There were no significant differences in the effects of intensive blood pressure–lowering across subgroups of cerebral SVD. Conclusions— Preexisting cerebral SVD manifestations of WML and brain atrophy predict poor outcome in acute intracerebral hemorrhage. There is no apparent hazard of early intensive lowering of blood pressure according to the INTERACT2 protocol, in patients with underlying cerebral SVD. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00716079.

Sex-specific stroke incidence over time in the Greater Cincinnati/Northern Kentucky Stroke Study.

Objective: Recent data suggest stroke incidence is decreasing over time, but it is unknown whether incidence is decreasing in women and men to the same extent. Methods: Within our population of 1.3 million, all incident strokes among residents ≥20 years old were ascertained at all hospitals during July 1993–June 1994 and calendar years 1999, 2005, and 2010. A sampling scheme was used to ascertain out-of-hospital cases. Sex-specific incidence rates per 100,000 among black and white participants, age- and race-adjusted, were standardized to the 2000 US Census population. Trends over time by sex were compared; a Bonferroni correction was applied for multiple comparisons. Results: Over the 4 study periods, there were 7,710 incident strokes; 57.2% (n = 4,412) were women. Women were older than men (mean ± SE 72.4 ± 0.34 vs 68.2 ± 0.32, p < 0.001). Incidence of all strokes decreased over time in men (263 [confidence interval 246–281] to 192 [179–205], p < 0.001) but not in women (217 [205–230] to 198 [187–210], p = 0.15). Similar sex differences were seen for ischemic stroke (men, 238 [223–257] to 165 [153–177], p < 0.01; women, 193 [181–205] to 173 [162–184], p = 0.09). Incidence of all strokes and of ischemic strokes was similar between women and men in 2010. Incidence of intracerebral hemorrhage and subarachnoid hemorrhage were stable over time in both sexes. Conclusions: Decreases in stroke incidence over time are driven by a decrease in ischemic stroke in men. Contrary to previous study periods, stroke incidence rates were similar by sex in 2010. Future research is needed to understand why the decrease in ischemic stroke incidence is more pronounced in men.

Intracerebral Hemorrhage: The epidemiology of intracerebral hemorrhage

Introduction Advances in brain imaging have dramatically changed our understanding of intracerebral hemorrhage (ICH). In the pre-CT era, many small ICHs were misclassified as ischemic strokes and patients with massive ICH or subarachnoid hemorrhage (SAH) were often difficult to correctly classify. This chapter reviews the epidemiology of non-traumatic ICH in light of modern neuroimaging and includes discussions of the incidence, etiology, clinical presentation, and natural history of this condition.

Rare Coding Variation and Risk of Intracerebral Hemorrhage

Background and Purpose— Intracerebral hemorrhage has a substantial genetic component. We performed a preliminary search for rare coding variants associated with intracerebral hemorrhage. Methods— A total of 757 cases and 795 controls were genotyped using the Illumina HumanExome Beadchip (Illumina, Inc, San Diego, CA). Meta-analyses of single-variant and gene-based association were computed. Results— No rare coding variants were associated with intracerebral hemorrhage. Three common variants on chromosome 19q13 at an established susceptibility locus, encompassing TOMM40, APOE, and APOC1, met genome-wide significance (P<5e−08). After adjusting for the APOE epsilon alleles, this locus was no longer convincingly associated with intracerebral hemorrhage. No gene reached genome-wide significance level in gene-based association testing. Conclusions— Although no coding variants of large effect were detected, this study further underscores a major challenge for the study of genetic susceptibility loci; large sample sizes are required for sufficient power except for loci with large effects.

The adverse effect of spasticity on 3-month poststroke outcome using a population-based model.

Several devices and medications have been used to address poststroke spasticity. Yet, spasticitys impact on outcomes remains controversial. Using data from a cohort of 460 ischemic stroke patients, we previously published a validated multivariable regression model for predicting 3-month modified Rankin Score (mRS) as an indicator of functional outcome. Here, we tested whether including spasticity improved model fit and estimated the effect spasticity had on the outcome. Spasticity was defined by a positive response to the question “Did you have spasticity following your stroke?” on direct interview at 3 months from stroke onset. Patients who had expired by 90 days (n = 30) or did not have spasticity data available (n = 102) were excluded. Spasticity affected the 3-month functional status (β = 0.420, 95 CI = 0.194 to 0.645) after accounting for age, diabetes, leukoaraiosis, and retrospective NIHSS. Using spasticity as a covariable, the models R 2 changed from 0.599 to 0.622. In our model, the presence of spasticity in the cohort was associated with a worsened 3-month mRS by an average of 0.4 after adjusting for known covariables. This significant adverse effect on functional outcomes adds predictive value beyond previously established factors.

Stroke Incidence Is Decreasing in Whites But Not in Blacks: A Population-Based Estimate of Temporal Trends in Stroke Incidence From the Greater Cincinnati/Northern Kentucky Stroke Study * Supplemental Material

Background and Purpose— Although other studies (in largely white populations) have found that stroke incidence declined during the 1990s, we previously reported that stroke incidence in our population (18% of which was black) did not change during that decade and that incidence rates in blacks were significantly higher than in whites. We sought to update temporal trends in stroke incidence by adding new data obtained from our large, biracial population in 2005. The objective of this study was to examine temporal trends in stroke incidence and case-fatality within a large biracial population over time by comparing stroke incidence rates from 1993 to 1994, 1999, and 2005. Methods— Within the Greater Cincinnati/Northern Kentucky population of 1.3 million, all strokes among area residents were ascertained at all local hospitals during July 1993 to June 19/94 and calendar years 1999 and 2005. A sampling scheme was used to ascertain cases in the out-of-hospital setting. Only first-ever strokes were included in this analysis. Race-specific incidence rates, standardized to the 2000 US Census population, and case-fatality rates were calculated. Results— The number of physician-confirmed first-ever strokes in patients ≥20 years of age was 1942 in 1993 to 1994, 2041 in 1999, and 1921 in 2005. In all study periods, blacks had higher stroke incidence than whites, and case-fatality rates were similar between races. In contrast to previous study periods, we found a significant decrease in overall stroke incidence in 2005. When stratified by race and stroke subtype, this change was driven by a decrease in ischemic stroke incidence among whites, whereas ischemic stroke incidence in blacks was unchanged. Hemorrhagic stroke incidence was unchanged in both races. Conclusions— For the first time, we report a significant decrease in stroke incidence within our population, which is consistent with other reports in the literature. This decrease was found only among whites, which suggests a worsening of the racial disparity in stroke incidence.