[Clinical-diffusion mismatch and short-term clinical outcomes among patients with acute ischemic stroke]

To explore the law of clinical-diffusion mismatch (CDM) among patients with acute ischemic stroke (AIS) and analyze the relationships between CDM and short-term clinical outcomes.

A prospective study was conducted for 56 patients with AIS admitted into our hospital within 72 hours from March 2011 to March 2012. And brain magnetic resonance imaging (MRI) examinations were completed within one week. All cases were diagnosed with infarction in the area of middle cerebral artery (MCA). The diffusion-weighted imaging (DWI) volume was calculated by semi-automatic method. Also the scores of National Institutes of Health stroke Scale (NIHSS) and modified Rankin Scale (mRS) were scored at baseline, days 7, 15, 30 post-admission respectively. The non-parametric variables were analyzed by Spearman's rank correlation. And the differences for non-parametric variables between CDM and non-CDM groups were analyzed by Mann-Whitney rank-sum test.

A total of 16/56(28.6%) patients showed CDM. The CDM ratios of the patients undergoing MRI within 72 hours after onset and those beyond 72 hours after onset were 36.3% and 17.4% respectively. Also 50.0% of those with CDM had favorite neurological outcomes. While for the other group without CDM, only 6.7% did so. The differences were significant (P = 0.001). The correlations for all AIS patients between NIHSS scores and DWI volume were strong (rs = 0.721, P = 0.009). Specifically, the correlations for without CDM group (rs = 0.847, P = 0.000) were stronger than those of with CDM group (rs = 0.610, P = 0.012). No significant inter-group differences existed in favorite clinical outcome, mortality case or neurological deterioration.

CDM still occurs within 1 week after onset among patients with AIS. Although no significant differences exist in favorite clinical outcome between patients with CDM and without CDM, the CDM group may improve more in NIHSS scores and have better neurological outcomes.