Zhang, Yi

Background and Objective Hyperdense MCA (HDMCA) sign is an early sign seen on CT head after acute ischemic stroke indicating acute arterial thrombosis. It has been reported as a predictor of stroke morbidity and mortality. The relationship of size of hyperdense middle cerebral artery (MCA) sign with stroke volume and functional outcome has not been sufficiently studied. Methods We did a retrospective analysis of prospectively collected data from 206 cases of acute ischemic stroke eligible for IV rt-PA by time criteria, admitted to Mayo Clinic from March, 2002 through June, 2011. Admission CT Head was studied to identify HDMCA sign which was further subcategorized according to size. CT head at 24 hours after intravenous tissue plasminogen activator was used to calculate Alberta Stroke Program Early CT Score (ASPECTS) to measure ischemic damage area. Functional outcome was assessed using the modified Rankin score at 3 months and dichotomized into less than equal to 2 (good outcome) and more than 2 (bad outcome). Univariate analysis including t-test, Chi-square, and Fisher Exact test was used when appropriate. Results Mean admission NIHSS score was 11±7. HDMCA sign was seen in 99 (48%) patients: 100% MCA occlusion (7) 76-100% M1 (17), 50-75% M1 (17), less than 50% M1 (6), MCA dot sign (23), sylvian dot sign (21) and sylvian MCA sign, defined as any sylvian MCA occlusion bigger than a dot (8). Univariate analysis showed statistically significant associations between our HDMCA classification and ASPECTS at 24 hours (p<0.001) and modified Rankin score at 3 months (p<0.001). Smaller infarctions (ASPECTS >8) were observed more often with lower MCA clot burden; MCA dot (48%), less than 50% MCA (80%), sylvian dot (57%) and sylvian MCA (38%), 50-75% M1 (6%), 75-100% M1 (0%) and 100% MCA (0%). Good outcome (mRS≤2 at 3 months) was seen more often with lower MCA clot burden; MCA dot (52%), less than 50% MCA (67%), sylvian dot (67%) and sylvian MCA (63%). Conversely, larger HDMCA size was associated with poor outcome (mRS>2); 50-75% M1 (100%), 75-100% (88%) and 100% MCA (100%). Conclusion The size of the HDMCA sign size is an important predictor of ischemic stroke mortality and morbidity. HDMCA should be measured upon admission as it may help refine prognostication and identify patients who could benefit from endovascular rescue therapy after intravenous thrombolysis.

Background and Objective The Alberta Stroke Program Early CT Score (ASPECTS) is a validated grading system to assess ischemic changes on CT in acute ischemic stroke. Magnetic resonance imaging with diffusion weighted imaging (DWI) sequence is commonly used to identify the final ischemic changes. We examined the difference between the relationship of NIHSS at admission and ASPECT score calculated using CT scan versus MRI DWI sequence. Methods We conducted a retrospective analysis of prospectively collected data from 99 cases of acute ischemic stroke treated with IV rt-PA by time criteria, admitted to Mayo Clinic from March, 2002 through June, 2011. CT head at 24 hours and MRI DWI sequence were used to assign ASPECT score. We dichotomized ASPECTS (categorized as 0 to 7 versus 8 to 10) and favorable patient outcome at 3 month (modified Rankin score less than equal to 2 and more than 2). Univariate analysis including t-test, Chi-square, and Fisher Exact test was used when appropriate. Results Mean age was 70±14 years. Mean admission NIHSS score was 8±4. DWI ASPECTS (p<0.001) and CT ASPECTS (p=0.127) were inversely associated with admission NIHSS. Higher (8-10) CT ASPECTS (p=0.001) or DWI ASPECTS (p=0.002) were associated with good outcome (mRS ≤2) at 3 months. Sensitivity, specificity, positive predictive value and negative predictive value for good outcome identified by CT ASPECTS versus DWI ASPECTS were 81% vs 52%, 54% vs 54%, 83% vs 59% and 50% vs 47% respectively. Conclusion CT and MRI DWI are comparably useful to calculate the ASPECTS for estimation of functional outcome, but CT scan at 24 hours may be more sensitive for the prediction of good recovery.

Background: The influence of high body mass index (BMI) in acute stroke patients treated with intravenous thrombolysis has not been extensively studied. Previous studies have observed an “obesity paradox” among stroke patients, where better outcomes were observed among overweight and obese patients. The purpose of this study is to determine the influence of obesity and risk components of metabolic syndrome to stroke recovery in patients undergoing intravenous recombinant tissue plasminogen activator (rtPA) treatment. Methods: Patients with acute ischemic stroke who received intravenous rtPA within three-hour from symptom onset at St. Marys Hospital, Mayo Clinic, Rochester, between April 2006 and January 2011, were included in this study. Information on vascular risk factors, stroke severity, and baseline hemodynamic and laboratory indices, were collected. Study outcomes, consisting symptomatic intracerebral hemorrhage (sICH) and poor functional recovery (modified Rankin scale >2), were compared between obese (body mass index, BMI >30 kg/m 2 ), overweight (BMI 25-30 kg/m 2 ) and normal weight (BMI <25 kg/m 2 ) patients. The association between BMI, risk components of the metabolic syndrome and dose of rtPA per kg body weight to stroke outcomes were assessed in a multivariable model. Results: A total of 158 patients (mean age, 75 years; baseline NIHSS, 11), frequency-matched by age and baseline stroke severity, were included in this study. No differences in the frequency of SICH and poor functional recovery were observed among obese, overweight and normal weight patients, before and after adjusting for their baseline characteristics. A linear trend towards worse stroke recovery was observed in patients with a greater number of metabolic risk components (p-trend=0.043). By contrast, there were no significant associations between the number of risk components of metabolic syndrome with respect to sICH. Using stepwise regression analyses, age, baseline stroke severity and the number of risk components of the metabolic syndrome accounted for 52% variation in functional recovery following rtPA treatment. Conclusions: Acute stroke outcomes do not differ between obese and overweight patients. The presence of metabolic risk factors contributes significantly to functional outcomes following rtPA treatment. These results suggest that decreasing the prevalence of metabolic syndrome in the community could reduce the societal burden of stroke-related disability.

Object Timing of clinical grading has not been fully studied in patients with aneurysmal subarachnoid hemorrhage (SAH). The primary objective of this study was to identify at which time point clinical assessment using the World Federation of Neurosurgical Societies (WFNS) grading scale and the Glasgow Coma Scale (GCS) is most predictive of poor functional outcome. Methods This study is a retrospective cohort study on the association between poor outcome and clinical grading determined at presentation, nadir, and postresuscitation. Poor functional outcome was defined as a Glasgow Outcome Scale score of 1–3 at 6 months after SAH. Results The authors identified 186 consecutive patients admitted to a teaching hospital between January 2002 and June 2008. The patients' mean age (± SD) was 56.9 ± 13.7 years, and 63% were women. Twenty-four percent had poor functional outcome (the mortality rate was 17%). On univariable logistic regression analyses, GCS score determined at presentation (OR 0.80, p < 0.0001), nadir (OR 0.73, p < 0.0001), and postresuscitation (OR 0.53, p < 0.0001); modified Fisher scale (OR 2.21, p = 0.0013); WFNS grade assessed at presentation (OR 1.92, p < 0.0001), nadir (OR 3.51, < 0.0001), and postresuscitation (OR 3.91, p < 0.0001); intracerebral hematoma on initial CT (OR 4.55, p < 0.0002); acute hydrocephalus (OR 2.29, p = 0.0375); and cerebral infarction (OR 4.84, p < 0.0001) were associated with poor outcome. On multivariable logistic regression analysis, only cerebral infarction (OR 5.80, p = 0.0013) and WFNS grade postresuscitation (OR 3.43, p < 0.0001) were associated with poor outcome. Receiver operating characteristic/area under the curve (AUC) analysis demonstrated that WFNS grade determined postresuscitation had a stronger association with poor outcome (AUC 0.90) than WFNS grade assessed upon admission or at nadir. Conclusions Timing of WFNS grade assessment affects its prognostic value. Outcome after aneurysmal SAH is best predicted by assessing WFNS grade after neurological resuscitation.

Background and Purpose— There is uncertainty whether warfarin-treated patients (despite international normalized ratio <1.7) have increased risks of symptomatic intracerebral hemorrhage after intravenous thrombolysis. Methods— Vascular risk factors, stroke subtype, and outcome measures were compared between warfarin- and nonwarfarin-treated patients undergoing acute thrombolysis within 3 hours of symptom onset. Results— From 212 patients (mean age, 74±14 years; 50% men) studied, 14 (6.5%) had prior warfarin use. After adjusting for age, baseline National Institutes of Health Stroke Scale, and stroke subtype, warfarin-treated patients had significantly increased risks of developing symptomatic intracerebral hemorrhage (adjusted OR, 14.7; 95% CI, 1.3 to 54.3). A trend for poorer stroke recovery and increased mortality was observed in warfarin-treated patients on univariate, but not on multivariable, analyses. Conclusions— Warfarin-treated patients with stroke have increased risks of symptomatic intracerebral hemorrhage after thrombolytic treatment. These data raise safety concerns of thrombolytic treatment in warfarin-treated patients with subtherapeutic international normalized ratio.