Association of ischemic lesion patterns on early diffusion-weighted imaging with TOAST stroke subtypes.
BACKGROUND
Different topographic patterns in patients who experience an acute ischemic stroke may be related to specific stroke causes.


OBJECTIVE
To determine if lesion patterns on early diffusion-weighted imaging (DWI) are associated with stroke subtypes determined by the TOAST (Trial of ORG 10172 in Acute Stroke Treatment) classification.


METHODS
Cross-sectional study.


METHODS
General community hospital. Patients We studied 172 consecutive ischemic stroke patients with a symptomatic lesion on DWI performed within 24 hours of stroke onset.


METHODS
Lesion patterns on DWI were classified into single lesions (corticosubcortical, cortical, subcortical > or =15 mm, or subcortical <15 mm), scattered lesions in one vascular territory (small scattered lesions or confluent with additional lesions), and multiple lesions in multiple vascular territories (in the unilateral anterior circulation, in the posterior circulation, in bilateral anterior circulations, or in anterior and posterior circulations).


RESULTS
We found an overall significant relationship between DWI lesion patterns and TOAST stroke subtypes (P<.001). Corticosubcortical single lesions (P =.01), multiple lesions in anterior and posterior circulations (P =.03), and multiple lesions in multiple cerebral circulations (P =.008) were associated with cardioembolism. Multiple lesions in the unilateral anterior circulation (P =.04) and small scattered lesions in one vascular territory (P =.06) were related to large-artery atherosclerosis. Nearly half (11/23) of the patients with a single subcortical lesion that was 15 mm or larger were classified as having cryptogenic strokes (P =.001), although 9 of these patients had a classic lacunar syndrome without cortical hypoperfusion.


CONCLUSIONS
Early DWI lesion patterns are associated with specific stroke causes. Conventional 15-mm criteria for lacunes, however, may underestimate the diagnosis of small-vessel occlusion with DWI.
Kang
Dong-Wha
DW
Section on Stroke Diagnostics and Therapeutics, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1063, USA.
Chalela
Julio A
JA
Ezzeddine
Mustapha A
MA
Warach
Steven
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001161:Arteriosclerosis / Q000150:complications; D002545:Brain Ischemia / Q000145:classification* / Q000150:complications / Q000175:diagnosis*; D003327:Coronary Disease / Q000150:complications; D003430:Cross-Sectional Studies; D038524:Diffusion Magnetic Resonance Imaging; D004617:Embolism / Q000150:complications; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000209:etiology*