Microembolic signals at 48 hours after stroke onset contribute to new ischaemia within a week.
OBJECTIVE
We investigated whether new ischaemic lesions (NIL) on follow-up diffusion weighted magnetic resonance imaging (DWI) are associated with microembolic signals (MES) within 24 h or at 48 h after stroke onset.


METHODS
Patients had acute ischaemic stroke and were studied within 24 h of onset. Transcranial Doppler ultrasonography (TCD) was prospectively examined twice, within 24 h and at 48 h after onset. DWI was conducted twice, on admission and on day 7. NIL were defined as the presence of hyperintense lesions undetected on initial DWI.


RESULTS
125 patients were consecutively enrolled from November 2004 to March 2006. TCD detected MES in 49% within 24 h and in 29% at 48 h after onset. In 27 patients with small vessel disease, MES were found in 8 (30%) patients within 24 h and in 5 (19%) patients at 48 h after stroke onset. In contrast, in 20 patients with large vessel disease, 11 (55%) patients within 24 h and 7 (35%) at 48 h had MES. Follow-up DWI detected NIL in 28 of 125 patients (22%) and NIL were significantly more frequent in MES positive patients (42%) than in MES negative patients at 48 h (15%; p = 0.002). MES at 48 h (OR 3.9; 95% CI 1.5 to 10; p = 0.005), atrial fibrillation (OR 3.6; 95% CI 1.3 to 11; p = 0.013) and arterial lesions (OR 4.3; 95% CI 1.5 to 12; p = 0.007) represented independent factors for NIL.


CONCLUSIONS
The presence of MES at 48 h, atrial fibrillation and arterial lesions were associated with recurrence of cerebral ischaemia on DWI.
Iguchi
Y
Y
Department of Stroke Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama, 701-0192, Japan. yigu@med.kawasaki-m.ac.jp
Kimura
K
K
Kobayashi
K
K
Ueno
Y
Y
Shibazaki
K
K
Inoue
T
T
D000368:Aged; D015984:Causality; D015897:Comorbidity; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000453:epidemiology; D002546:Ischemic Attack, Transient / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D015999:Multivariate Analysis; D011446:Prospective Studies; D012307:Risk Factors; D055502:Secondary Prevention; D020521:Stroke / Q000175:diagnosis* / Q000453:epidemiology; D013997:Time Factors; D017585:Ultrasonography, Doppler, Transcranial