C ryptogenic stroke accounts for 20% to 40% of all ischemic strokes.1,2 High risk of stroke recurrence has been reported in cryptogenic stroke patients. 3,4 However, the indicators related to stroke recurrence have not been fully elucidated. Moreover, recurrent stroke prevention strategies are lacking; therefore, cryptogenic stroke persists as a serious issue.Diffusion-weighted magnetic imaging (DWI) is a widely used and essential modality in clinical settings for the diagnosis of ischemic stroke. In addition, ischemic lesion patterns identified via DWI images are useful for classifying stroke subtype. Multiple ischemic lesions (observed by DWI) are associated with the occurrence of right-to-left shunting (RLS), aortic arch atheroma, and cancer-associated stroke among ischemic and cryptogenic stroke patients. [5][6][7] However, it is unclear whether ischemic lesion patterns predict stroke recurrence in cryptogenic stroke patients.In this study, we used DWI images to assess the association between ischemic lesion patterns and clinical characteristics among cryptogenic ischemic stroke patients according to the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) criteria. 8 Additionally, we investigated the prognosis of cryptogenic stroke patients and determined whether patient ischemic lesion patterns predict long-term stroke outcomes.
Methods
SubjectsThis was a retrospective, observational study. This study complied with the Declaration of Helsinki for investigations involving humans, and the study protocol was approved by the Ethics Committee of the Kawasaki Medical School Hospital. We enrolled consecutive, acute ischemic stroke patients who were admitted to the Kawasaki Medical School Hospital within 7 days of stroke onset between April 2008 and March 2012. A total of 1338 acute ischemic stroke patients were classified according to the TOAST criteria. Among these patients, we excluded patients with small vessel occlusion (n=221), large artery atherosclerosis (n=137), and cardioembolism (n=412). Of the remaining 568 patients, we diagnosed 122 patients with stroke caused by Background and Purpose-Brain infarct patterns that are observed via diffusion-weighted imaging are useful for classifying stroke subtypes. However, it is unclear whether infarct patterns can predict long-term outcomes in cryptogenic stroke patients. Herein, we investigated the association between acute brain infarct patterns and long-term stroke outcomes in cryptogenic stroke patients. Methods-Acute cryptogenic stroke patients were consecutively enrolled between April 2008 and March 2012. Diffusionweighted imaging ischemic lesion patterns were classified as single lesions, scattered lesions in one vascular territory, or multiple lesions in multiple vascular territories. Survivors (at discharge) were followed up for 3 years after stroke onset.
Clinical Information During HospitalizationPatient data were collected by attending physicians including age, sex, body mass index, known vascular risk factors (eg, hypertension, diabetes mellitus, and ...