Jauss M et al. (2006) Embolic lesion pattern in stroke patients with patent foramen ovale compared with patients lacking an embolic source. Stroke 37: 2159–2161

A pattern of multiple acute ischemic lesions on diffusion-weighted MRI (DWI-MRI) is thought to indicate an embolic source of stroke. In some stroke patients with this lesion pattern, however, no embolic source can be detected, and the stroke is described as cryptogenic; in other patients, patent foramen ovale (PFO) is the only pathological finding that might operate as an embolic source. Jauss et al. compared the prevalence of the multiple acute ischemic lesion pattern in patients with cryptogenic stroke with that in patients with PFO.

The authors screened 650 patients with stroke who underwent DWI-MRI. Patients with carotid stenosis, a cardiac embolic source other than PFO, or an obvious stroke cause such as dissection or vasculitis, were excluded. Of the remaining 106 patients, 73 had lesions on DWI-MRI and were included in the analyses.

There was no significant difference in the occurrence of a multiple ischemic lesion pattern between patients with PFO and those with cryptogenic stroke for the entire group, or for the subgroup of younger stroke patients aged ≤50 years. Multiple lesions occurring in the posterior circulation were more common in patients with PFO than in patients with cryptogenic stroke (7 vs 0 patients; P <0.05), but no significant differences were seen between groups in the distribution of lesions in the anterior circulation.

The authors conclude that a multiple ischemic lesion pattern limited to the posterior circulation territory is associated with PFO presence, whereas multiple ischemic lesions in general are not a specific feature of stroke patients with PFO.