K. Alwell

The increasing incidence of anticoagulant-associated intracerebral hemorrhage

Objective: To define temporal trends in the incidence of anticoagulant-associated intracerebral hemorrhage (AAICH) during the 1990s and relate them to rates of cardioembolic ischemic stroke. Methods: We identified all patients hospitalized with first-ever intracerebral hemorrhage (ICH) in greater Cincinnati during 1988, from July 1993 through June 1994, and during 1999. AAICH was defined as ICH in patients receiving warfarin or heparin. Patients from the same region hospitalized with first-ever ischemic stroke of cardioembolic mechanism were identified during 1993/1994 and 1999. Incidence rates were calculated and adjusted to the 2000 US population. Estimates of warfarin distribution in the United States were obtained for the years 1988 through 2004. Results: AAICH occurred in 9 of 184 ICH cases (5%) in 1988, 23 of 267 cases (9%) in 1993/1994, and 54 of 311 cases (17%) in 1999 (p < 0.001). The annual incidence of AAICH per 100,000 persons was 0.8 (95% CI 0.3 to 1.3) in 1988, 1.9 (1.1 to 2.7) in 1993/1994, and 4.4 (3.2 to 5.5) in 1999 (p < 0.001 for trend). Among persons aged ≥80, the AAICH rate increased from 2.5 (0 to 7.4) in 1988 to 45.9 (25.6 to 66.2) in 1999 (p < 0.001 for trend). Incidence rates of cardioembolic ischemic stroke were similar in 1993/1994 and 1999 (31.1 vs 30.4, p = 0.65). Warfarin distribution in the United States quadrupled on a per-capita basis between 1988 and 1999. Conclusions: The incidence of anticoagulant-associated intracerebral hemorrhage quintupled in our population during the 1990s. The majority of this change can be explained by increasing warfarin use. Anticoagulant-associated intracerebral hemorrhage now occurs at a frequency comparable to subarachnoid hemorrhage.

Population-based study of wake-up strokes

Objective: Previous studies have estimated that wake-up strokes comprise 8%to 28% of all ischemic strokes, but these studies were either small or not population-based. We sought to establish the proportion and event rate of wake-up strokes in a large population-based study and to compare patients who awoke with stroke symptoms with those who were awake at time of onset. Methods: First-time and recurrent ischemic strokes among residents of the Greater Cincinnati/Northern Kentucky region (population 1.3 million) in 2005 were identified using International Classification of Diseases–9 codes 430–436 and verified via study physician review. Ischemic strokes in patients aged 18 years and older presenting to an emergency department were included. Baseline characteristics were ascertained, along with discharge modified Rankin Scale scores and 90-day mortality. Results: We identified 1,854 ischemic strokes presenting to an emergency department, of which 273 (14.3%) were wake-up strokes. There were no differences between wake-up strokes and all other strokes with regard to clinical features or outcomes except for minor differences in age and baseline retrospective NIH Stroke Scale score. The adjusted wake-up stroke event rate was 26.0/100,000. Of the wake-up strokes, at least 98 (35.9%) would have been eligible for thrombolysis if arrival time were not a factor. Conclusions: Within our population, approximately 14% of ischemic strokes presenting to an emergency department were wake-up strokes. Wake-up strokes cannot be distinguished from other strokes by clinical features or outcome. We estimate that approximately 58,000 patients with wake-up strokes presented to an emergency department in the United States in 2005.

Temporal Trends in the Incidence and Case Fatality of Stroke in Children and Adolescents

A recent study reported that mortality from stroke in children and adolescents decreased by 58% from 1979 to 1998, although it wasnt clear if the case fatality or the incidence of stroke in this age group is decreasing. We report trends of stroke incidence and case fatality in children and adolescents within a large biracial population. The study involved collection of all strokes in the study population between January 1, 1988 and December 31, 1989, July 1, 1993 and June 30, 1994, and January 1, 1999 and December 31, 1999, at all of the regional hospitals serving the Greater Cincinnati/Northern Kentucky population (only the childrens hospital in 1988). Study nurses reviewed the medical records of all inpatients with stroke-related discharge diagnoses and abstracted relevant data. A study physician reviewed each abstract to determine whether a stroke or transient ischemic attack had occurred. A total of 54 strokes occurred in children or adolescents younger than 20 years during the three study periods (30% African American, 70% Caucasian, and 56% female). The overall incidence rate of all strokes in children younger than 15 years was 6.4/100,000 in 1999, a nonsignificant increase when compared to 1988. The 30-day case-fatality rates were 18% in 1988—1989, 9% in 1993—1994, and 9% in 1999. We found that the incidence of strokes in children has been stable over the past 10 years. The previously reported nationwide decrease in overall stroke mortality in children might be due to decreasing case fatality after stroke and not decreasing stroke incidence. Based on our data, we conservatively estimated that approximately 3000 children less than 20 years old would have a stroke in the United States in 2004. (J Child Neurol2006;21:415—418; DOI 10.2310/7010.2006.00091).

Emergency medical services use by stroke patients: a population-based study ☆

OBJECTIVESnEmergency medical services (EMS) use by stroke patients varies from 38% to 65%. In an epidemiological study, we determined the proportion of stroke patients who used EMS, hypothesizing that demographics, stroke severity, stroke type, and location at stroke onset would be associated with EMS use.nnnMETHODSnStroke and transient ischemic attack patients were identified in a population of 1.3 million in the Cincinnati area in 1999. Patient charts and EMS records were abstracted by research nurses and reviewed by study physicians. The proportion of EMS users was computed. Logistic regression was used to test for associations with EMS use.nnnRESULTSnOf 3949 strokes, we excluded strokes/transient ischemic attacks that occurred in the hospital (n = 283), out of town (n = 10), during EMS transport (n = 2), and at unknown locations (n = 73). Patients with unknown EMS use (n = 301); those with missing estimated stroke severity (n = 174), prestroke disability (n = 78), race (n = 3), and stroke type (n = 3); and those younger than 18 years (n = 14) were also excluded. The remaining 3008 patients had a mean age of 74 years, 17% were black, and 45% were men. Emergency medical services was used by 1532 (50.9%) patients. Age, prestroke disability, stroke severity, hemorrhagic stroke, and stroke at work were associated with EMS use. Race, sex, and prior stroke were not associated with EMS use.nnnCONCLUSIONnHalf of stroke patients used EMS in our population-based study. Older patients; those with greater prestroke disability, more severe stroke, and hemorrhagic stroke; and those having stroke at work were more likely to use EMS.

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.