Steven Warach

Acute Ischemic Cerebrovascular Syndrome: Diagnostic Criteria

Background— Existing diagnostic classification systems for cerebrovascular disease are based primarily on clinical impression of temporal features, clinical syndrome, inferred localization, or ischemic mechanism. Diagnostic certainty of the ischemic pathology based on supportive or refuting laboratory or radiological evidence has been of secondary importance. Summary of Comment— Acute ischemic cerebrovascular syndrome (AICS) describes a spectrum of clinical presentations that share a similar underlying pathophysiology: cerebral ischemia. Diagnostic criteria for AICS incorporate prior classification systems and currently available information provided by neuroimaging and laboratory data to define 4 categories ranging from “definite AICS” to “not AICS,” which define the degree of diagnostic certainty. Conclusions— Clinical trials testing new treatments for acute ischemic stroke or secondary stroke prevention should limit enrollment to patients with “definite” AICS whenever feasible.

Chapter 19 – Magnetic Resonance Imaging

Nuclear magnetic resonance techniques were first employed in the 1940s, and the first images were obtained in the 1970s. In the 1980s structural nuclear magnetic resonance imaging (MRI) emerged as a clinically useful diagnostic modality for stroke and other neurologic disorders. 1 2 3 4 5 In the detection of ischemic stroke lesions, structural MRI is more sensitive than computed tomography (CT), particularly for small infarcts and in sites such as the cerebellum, brainstem, and deep white matter. 6 7 8 In the investigation of ischemic stroke, conventional structural MRI techniques, such as T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), and fluid-attenuated inversion recovery (FLAIR) imaging, are valuable for the assessment of infarct extent and location after the first 12 to 24 hours from onset. These methods can be combined with MR angiography (MRA) to noninvasively assess the intracranial and extracranial vasculature.