Secondary Prevention of Atherothrombotic or Cryptogenic Stroke
A 65-year-old woman presents to the Emergency Department at 10:00 a.m. with abrupt onset of slurred speech and right arm weakness the previous night and no improvement today. She has a history of diabetes mellitus and hypertension. Magnetic resonance imaging (MRI) reveals a small acute ischemic lesion in the left basal ganglia.
The diagnostic evaluation (Figure) after an acute ischemic stroke should be initiated urgently, because the highest risk period for recurrent stroke is the first few days after the initial event. Identification of the most likely cause as well as risk factors for recurrent ischemic events is the objective of this evaluation. An MRI1 of the brain is the most sensitive imaging study to detect an acute ischemic stroke. An MR angiogram (MRA) of the cervical and intracranial vessels can be included to help identify relevant cerebrovascular lesions. If MRI is not available, a computed tomography (CT) combined with CT angiogram (or cervical ultrasound) can be used for initial diagnostic assessment. Based on the results of the initial neuroimaging studies, the stroke can be classified into preliminary diagnostic categories: large vessel occlusion, small vessel occlusion, potential cardioembolic, or unknown/other.2 If there is no relevant large vessel lesion (such as an ipsilateral carotid stenosis) and the ischemic stroke does not appear to be lacunar (small maximal diameter and subcortical location), then additional evaluation to look for a cardioembolic source should be performed; diagnostic options include a 12-lead ECG, a transthoracic or transesophageal echo,3 and longer term cardiac monitoring for paroxysmal atrial fibrillation. We will focus on prevention of recurrent stroke of atherothrombotic (noncardioembolic) origin.
Management of Risk Factors
Risk factor modification is a key component of secondary stroke prevention; …