Stroke Alert: A Review of Current Clinical Stroke Literature
Stroke Alert: A Review of Current Clinical Stroke Literature
By Matthew E. Fink, MD, Professor and Chairman, Department of Neurology, Weill Cornell Medical College, and Neurologist-in-Chief, New York Presbyterian Hospital
Stroke Incidence May Be Increasing in Younger People
Source: Kissela BM, et al. Age at stroke: Temporal trends in stroke incidence in a large, biracial population. Neurology 2012;79:1781-1787.
Investigators in the greater Cincinnati/Northern Kentucky Stroke Study reported on their case ascertainment of all strokes in their 1.3 million population base, using a retrospective review of all hospital discharges and medical records. They compared years 1993-1994, and calendar years 1999 and 2005, and stratified patients by age groups. Age, race, and gender-specific incidence rates with 95% confidence intervals were calculated, assuming a Poisson distribution.
The mean age at stroke significantly decreased from 71.2 years in 1993-94 to 69.2 years in 2005 (P < 0.0001), and the differences were predominantly due to ischemic stroke rates, not hemorrhagic stroke. The proportion of all strokes under age 55 increased from 12.9% in 1993-94 to 18.6% in 2005. Stroke incident rates in those 20-54 years of age were increased in both black and white patients in 2005 compared to earlier years, and decreased in the elderly groups.
What accounts for these changes over time? The authors postulate increasing risk factors in younger people including obesity, diabetes, drug abuse, hypertension, smoking, and hyperlipidemia, which all increased in the younger population over time. However, one must also consider a false-positive change in age distribution, due to more sensitive neuroimaging techniques, which might increase the frequency of diagnosis without a true change in incidence or prevalence.
Cancer May Be a Risk Factor for Ischemic Stroke
Source: Schwarzbach CJ, et al. Stroke and cancer. The importance of cancer-associated hypercoagulation as a possible stroke etiology. Stroke 2012;43:3029-3034.
A history of cancer in a patient with ischemic stroke often raises additional concerns for the clinician, including assessment of cancer activity, as well as possible thrombophilias. The use of thrombolytic agents is also controversial in patients with active cancers. These investigators in Mannheim, Germany, attempted to assess the role of cancer-associated hypercoagulability as a risk factor for stroke by comparing a group of 140 patients with active cancer (solid tumors, excluding hematological malignancies and brain tumors) and ischemic stroke to a group of age- and sex-matched controls who had ischemic stroke without any cancer history. They collected data prospectively, including laboratory data, MRI, etiology and risk factors for stroke, types of cancer, deep vein thrombosis or pulmonary embolism, and D-dimer levels.
One hundred forty stroke/cancer patients were compared to 140 stroke controls. In the cancer patients with stroke, an unidentified cause for stroke (P < 0.001) and infarction in multiple vascular territories (P < 0.001) were more frequent, and D-dimer levels were significantly higher (P < 0.05) in patients with stroke and cancer. In the noncancer stroke patients, conventional risk factors, such as hypertension (P < 0.05) and hyperlipidemia (P < 0.01), were more common. Deep vein thrombosis and pulmonary embolism were more frequent (P < 0.01) and D-dimer levels were higher (P < 0.01) in cancer-associated stroke compared to controls. Lung and pancreatic cancer were significantly overrepresented and manifested higher D-dimer levels compared to patients with stroke and other types of cancer.
This study supports the concept that there is a hypercoagulable state associated with solid tumor cancers, especially in those who have an elevated D-dimer level, and that cancer may be a risk factor for ischemic stroke. The role of antithrombotic therapies in this group of patients is unknown and needs further investigation.
Physical Exercise Reduces White Matter Lesion Burden and Brain Atrophy in the Elderly
Source: Gow AJ, et al. Neuroprotective lifestyles and the aging brain. Activity, atrophy, and white matter integrity. Neurology 2012;79:1802-1808.
In a longitudinal study of aging in Scotland, the investigators examined the impact of physical activity on brain atrophy and white matter lesions (WML) over time. Six hundred ninety-one people born in 1936 were examined and studied by MRI at age 70 and again at age 73. Structural brain biomarkers, including white matter tractography, gray and white matter volume, and WML load, were measured.
At age 73, a higher level of physical activity was associated with higher fractional anisotropy in the white matter, larger gray, and white matter volumes, and a lower WML load, and these associations remained statistically significant after adjustments for covariables, such as age, social class, and health status. Leisure activity, as opposed to physical activity, was not significantly associated with brain biomarkers after adjustment for covariables. In this narrow sample, physical activity was associated with less brain atrophy and WML, but the mechanism is unclear. The investigators are uncertain if physical activity mediates its effects via neuroprotection or a cardiovascular mechanism.
Serious Cardiac Arrhythmias May Occur During First 72 Hours After Stroke
Source: Kallmunzer B, et al. Serious cardiac arrhythmias after stroke: Incidence, time course, and predictors — a systematic, prospective analysis. Stroke 2012;43:2892-2897.
Investigators of the Stroke Arrhythmia Monitoring Database in Erlangen, Germany, performed continuous telemetric cardiac rhythm monitoring on 501 acute stroke patients admitted to their stroke unit. Arrhythmias were systematically detected and categorized in a prospective fashion, and time of onset and predisposing factors were noted.
Significant cardiac arrhythmias occurred in 25.1% of all patients during the 72 hours of monitoring, with the highest risk period being the first 24 hours after admission. Serious tachyarrhythmias (ventricular or supraventricular arrhythmias > 130 beats per minute) were more frequent then bradyarrhythmias. All arrhythmias were independently associated with higher patient age and higher NIH Stroke Scale scores (more severe stroke). The risk of serious cardiac arrhythmias declines during the first 72 hours after stroke and is at highest risk during the first 24 hours. Patients with more severe strokes and advanced age are at highest risk, and continuous cardiac monitoring is strongly advised during the initial 3 days of hospitalization.
Stroke Incidence May Be Increasing in Younger People; Cancer May Be a Risk Factor for Ischemic Stroke; Physical Exercise Reduces White Matter Lesion Burden and Brain Atrophy in the Elderly; Serious Cardiac Arrhythmias May Occur During First 72 Hours After StrokeSubscribe Now for Access
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