A Dark Side of Subcortical Diffusion-Weighted Lesions?

Abstract

Background and Purpose— Diffusion-weighted imaging (DWI) is highly accurate in identifying and locating ischemic stroke injury. Few studies using DWI have investigated large subcortical infarctions (LSIs). We aimed to study clinical characteristics, cause, and outcome in patients with ischemic stroke with LSI diagnosed on DWI and compare these with those who had lacunar DWI lesions or DWI lesions located elsewhere. Methods— Patients with stroke admitted between February 2006 and July 2013 were prospectively registered in a stroke database and examined with DWI. Patients with DWI lesions classified as LSI (subcortical, ≥15 mm) were compared with those with lacunar lesions (subcortical, <15 mm, lacunar infarction [LI]), cortical lesions (cortical infarction [CI]), or no LSI, which included LI, CI, mixed cortical–subcortical, cerebellar, brain stem, and combined lesion locations. Results— A total of 1886 patients with ischemic stroke were included, of which 128 patients (6.8%) had LSI, 317 (16.8%) LI, and 544 (28.8%) CI. The no LSI group included 1758 patients. Occlusive pathology in the proximal middle cerebral artery was more frequent in patients with acute stroke with LSI. Lacunar syndrome was associated with LSI when compared with CI and no LSI. Unknown cause was frequent in the LSI group (60.4%) and independently associated with LSI in the LSI versus LI ( P <0.001), LSI versus CI ( P =0.002), and LSI versus no LSI population ( P <0.001). LSI was independently associated with unfavorable outcome, whether compared with LI ( P =0.002), CI ( P <0.001), or no LSI ( P =0.002). Conclusions— LSI is associated with distinct clinical characteristics, unknown cause, and unfavorable outcome, which separates this stroke entity from patients with lacunar subcortical DWI lesions or DWI lesions located elsewhere.

A stress-related explanation to the increased blood pressure and its course following ischemic stroke

“…The groups of patients depended on the following:

Group I, location of DWI lesions: DWI lesions were categorized into the following pre-defined subgroups: cortical lesions, confined to the supratentorial cortex; large subcortical lesions, located in the hemispheric white matter, basal ganglia, internal capsule, thalamus or corona radiata with a diameter ≥15 mm; lacunar lesions, located in the same territory as large subcortical lesions with a diameter <15 mm; mixed cortical–subcortical lesions, located in both supratentorial cortex and subcortex; cerebellar lesions, confined to the cerebellum; brainstem lesions, confined to the brain stem and multiple lesions, lesions located in more than one of the above defined areas. This predefined protocol of DWI location has been utilized in prior studies 16,17

Group II, time window: patients were categorized into two different subgroups depending on whether they were admitted within or after 6 h of stroke onset.

Group III, persisting major occlusion or no occlusion: patients were categorized into two different subgroups according to the presence of total proximal middle cerebral artery (MCA) occlusion or no occlusion of any cerebral vessel on MRA at 24 h. Total occlusion of intracranial arteries was defined as 100% occlusion on MRA.

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Lesion Patterns on Early Diffusion-weighted Magnetic Resonance Imaging and Ischemic Stroke Subtypes

“…It is not understood if the distribution and morphology of lesions are related to the stroke etiology and may be a clue for the rapid determination of the stroke subtype. Previously, several studies reported that some of the DWI-MRI lesion patterns are more frequently seen in some stroke subtypes (5,6). In this study, we investigated the association of early DWI-MRI lesion characteristics with the ischemic stroke subtypes.…”