Diffusion-weighted imaging findings differ between stroke attributable to spontaneous cervical artery dissection and patent foramen ovale.
OBJECTIVE
Spontaneous cervical arterial dissection and patent foramen ovale (PFO) are important causes of stroke in younger patients. We tested whether characteristics of cerebral ischaemia visible on diffusion-weighted imaging (DWI) aid in differentiating between these two aetiologies.


METHODS
Diffusion-weighted imaging was performed after a median of 2 days [interquartile range (IQR) 1-3 days] in 94 consecutive patients with an acute ischaemic stroke caused either by carotid or vertebral artery dissection (n = 33) or PFO (n = 61). We compared number, size, location and predefined patterns of DWI lesions between both aetiologies.


RESULTS
Ninety-three out of 94 patients had acute DWI lesions and were included in the analysis. Multiple DWI lesions occurred more frequently in patients with dissection (23/33, 70%) than in those with PFO (26/60, 43%, P = 0.02). Lesions were larger in the dissection group [median diameter of largest lesion, 50 mm (IQR 19-68 mm)] than in the PFO group [23 (9-48) mm; P = 0.02]. The distribution of lesion patterns differed between the two aetiologies (P < 0.001): single, non-territorial infarcts were more frequent in PFO (25/60, 42%) than in dissection (2/33, 6%); large territorial infarcts with or without additional smaller lesions in the same territory occurred in 20/33 (61%) patients with dissection and in 16/60 (27%) patients with PFO.


CONCLUSIONS
Diffusion-weighted imaging characteristics differ between PFO and dissection, suggesting differences in the pathogenesis of brain infarction between these aetiologies. A single non-territorial infarct seems to favour PFO as stroke aetiology. Whether this or other features are distinctive enough to diagnose PFO or dissection in individual patients requires further testing.
Bonati
L H
LH
Department of Neurology and Stroke Unit, University Hospital Basel, Basel, Switzerland. bonatil@uhbs.ch
Wetzel
S G
SG
Kessel-Schaefer
A
A
Buser
P
P
Lyrer
P A
PA
Engelter
S T
ST
D000328:Adult; D001921:Brain / Q000473:pathology*; D020520:Brain Infarction / Q000209:etiology / Q000473:pathology; D002561:Cerebrovascular Disorders / Q000150:complications* / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D054092:Foramen Ovale, Patent / Q000150:complications* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012042:Registries; D020521:Stroke / Q000209:etiology* / Q000473:pathology*; D013997:Time Factors; D020217:Vertebral Artery Dissection / Q000150:complications / Q000473:pathology