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
Nontraumatic Subarachnoid Hemorrhage with Vasoconstriction Should be Differentiated from Aneurysmal Subarachnoid Hemorrhage
Source: Muehlschlegel S, et al. Differentiating reversible cerebral vasoconstriction syndrome with subarachnoid hemorrhage from other causes of subarachnoid hemorrhage. JAMA Neurol 2013 Aug 12; doi: 10.1001/jamaneurol.2013.3484. [Epub ahead of print].
Reversible vasoconstriction syndrome (rvcs) is a poorly understood cause of spontaneous subarachnoid hemorrhage (SAH) that may present with sudden thunderclap headache, SAH, intracerebral hemorrhage, or ischemic stroke, and shows angiographic evidence of multifocal and bilateral arterial constrictions. An intensive search for ruptured aneurysm (aSAH) is often ensued, and the end result may be that many useless and potentially morbid tests are performed. Additionally, therapies for aSAH may be instituted that have adverse effects and are not indicated.
The authors reviewed all of their cases of non-aneurysmal SAH at their two hospitals (Massachusetts General and University of Massachusetts Medical Center) and identified important clinical and imaging differences between a group of patients with RVCS (n = 38), a group with aSAH (n = 515), and a group with cryptogenic subarachnoid hemorrhage (cSAH; n = 93).
Predictors differentiating RCVS from aSAH included younger age, chronic headache disorder, prior depression, prior chronic obstructive pulmonary disease, lower Hunt-Hess Grade, lower Fisher CT score, higher number of affected arteries, and bilateral arterial constriction. Predictors that differentiated RCVS from cSAH were younger age, female sex, prior hypertension, chronic headache disorder, lower Hunt-Hess grade, lower Fisher CT score, and the presence of bilateral narrowing. The underlying common denominator for the development of RVCS may be serotonin excess, since many of the patients were exposed to the SSRI-class of medications. In most cases, patients with RVCS can de differentiated from aSAH and cSAH using clinical and imaging features.
Ischemic Stroke in Young Adults Is Associated with a Different Frequency of Risk Factors than in the Older Patient Population
Source: Barlas NY, et. al. Etiology of first-ever ischaemic stroke in European young adults: The 15 cities young stroke study. Eur J Neurol 2013;20:1431-1439.
Fifteen european stroke centers combined their data regarding the first-ever ischemic stroke in 1331 patients aged 15-49, to investigate the etiology of their stroke, based on age and gender differences. Classification was done according to Trial of Org in Acute Stroke Treatment (TOAST) criteria: large-artery atherosclerosis (LAA), cardioembolism (CE), small-vessel occlusion (SVO), other determined etiology, or undetermined etiology. CE was categorized into low- and high-risk sources. "Other determined" group was divided into dissection and other non-dissection causes. Comparisons were done using logistic regression, adjusting for age, gender, and center heterogeneity.
Of note, etiology remained undetermined in 39.6%, which is higher than in other published series. Other determined etiology was found in 21.6%, CE in 17.3%, SVO in 12.2%, and LAA in 9.3%. Other determined etiology was more common in females and younger patients, with cervical artery dissection being the single most common etiology (12.8%). CE was more common in younger patients. Within CE, the most frequent high-risk sources were atrial fibrillation/flutter (15.1%) and cardiomyopathy (11.5%). LAA, high-risk sources of CE, and SVO were more common in males. LAA and SVO showed an increasing frequency with age.
Although it is impossible to determine this with certainty, it is presumed that many of the "undetermined" cases were caused by cardiogenic embolism, but this was never ascertained. We know that the longer one does remote cardiac rhythm monitoring, the more likely it is to pick up intermittent atrial fibrillation, and this may be part of the explanation. In any case, CE and arterial dissection are common causes of ischemic stroke in young adults and should be looked for intensively.