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StrokeMarch 2013 infarction on MR-DWI. The incidence of SIC was 3.5% per patient (14/396). Among the patients who underwent MR-DWI, the incidence of SIC was 4.1% (14/342). All SIC developed within 12 hours posttreatment and were associated with the relevant brain. The ischemic symptoms were most severe at the beginning, but improved with time in all patients. The 1-month modified Rankin Scale scores of the 14 patients were 0 in 6, 1 in 5, 2 in 2, and 3 in 1 patient, respectively. The incidence of DWI(+) was 54.5%. The number of DWI(+) lesions was significantly larger than in the SIC group and in the asymptomatic one (12.1±10.4 versus 5.0±8.7, P<0.01). The cutoff value of DWI(+) for predicting SIC was ≥6 (sensitivity 85.7%, specificity 70.7%).The patients with DWI(+) ≥6 was 28.6% (98/343). Of the patients with SIC, the patients with DWI(+) ≥6 was 78.6% (11/14). Patients aged ≥65 had a trend for SIC, and it was the only independent risk factor for the number of DWI(+) ≥6 (Tables 1 and 2).
DiscussionAlthough a few small case series reported the incidence of DWI(+) after coiling, 2,3 there has been no report about the clinical implications of such lesions. In this study, the number of DWI(+) was significantly larger in the SIC group than in the asymptomatic one. Furthermore, we found the cutoff value (≥6) of DWI(+) for predicting SIC, and these data support the higher rate of microembolism detected, as DWI(+) may be a surrogate marker for SIC.According to ATENA study, dome size ≥7 mm was significantly associated with the rate of thromboembolic complications and patients aged >60 showed significantly higher morbidity and mortality rate on univariate analysis. 4 In our study, dome size ≥7 mm and neck size ≥4 mm were significantly associated with both SIC and DWI(+) ≥6 on univariate analysis, but neither was associated with SIC or DWI(+) ≥6 in the logistic regression analysis. It may be because of low statistical power from low incidence of SIC (Tables 1 and 2). In contrast, patients aged ≥65 were significantly associated with both SIC and DWI(+) ≥6 on univariate analysis and also had a trend for SIC, and it remained the only independent risk factor for DWI(+) ≥6 in the logistic regression analysis. These data suggest that theoretically more baseline atherosclerosis and vascular tortuosity in the older patients may increase microembolisms, and in turn may increase the probability of SIC.3 Additionally, it is notable that DWI(+) lesions ≥6 was significantly higher in stent group on univariate analysis, and its P-value was close from significance in logistic regression. Contrary to expectation, antiplatelet premedication significantly increased DWI(+) lesions ≥6 on univariate analysis. Until late 2010, antiplatelet premedication had been given only to patients who had undergone stent-assisted coiling. However, stent itself may increase DWI(+) lesions ≥6, which seemed to be a compounding factor.In conclusion, the number of DWI(+) lesions was significantly larger in the SIC than in the asymptomatic group af...
