Middle cerebral artery occlusion methods in rat versus mouse model of transient focal cerebral ischemic stroke

Experimental stroke research commonly employs focal cerebral ischemic rat models （Bederson et al., 1986a; Longa et al., 1989）. In human patients, ischemic stroke typically results from thrombotic or embolic occlusion of a major cerebral artery, usually the mid- dle cerebral artery （MCA）. Experimental focal cerebral ischemia models have been employed to mimic human stroke （Durukan and Tatlisumak, 2007）. Rodent models of focal cerebral ischemia that do not require craniotomy have been developed using intraluminal suture occlusion of the MCA （MCA occlusion, MCAO） （Rosamond et al., 2008）. Furthermore, mouse MCAO models have been wide- ly used and extended to genetic studies of cell death or recovery mechanisms （Liu and McCullough, 2011）. Genetically engineered mouse stroke models are particularly useful for evaluation of isch- emic pathophysiology and the design of new prophylactic, neuro- protective, and therapeutic agents and interventions （Armstead et al., 2010）. During the past two decades, MCAO surgical techniques have been developed that do not reveal surgical techniques for mouse MCAO model engineering. Therefore, we compared MCAO surgical methods in rats and mice.

Is transesophageal echocardiography needed for evaluating tissue-based transient ischemic attack？

Transient ischemic attack（TIA） is a warning signal for stroke.A comprehensive evaluation of TIA may reduce the risk for subsequent stroke.Data on the findings of cardiac evaluation with transesophageal echocardiography（TEE） in patients with TIA are sparse.Our aims were to determine the frequency of TEE performance and to investigate the findings of TEE in patients with TIA based on the new definition of TIA（i.e.,transient neurological symptoms without evidence of infarction）.During a 4-year period（2011–2014）,1071 patients（mean age,70 ± 13 years;female,49.7%） with TIA were included in a prospective study and evaluated.Of 1071 consecutive patients suffering from TIA,288 patients（27%） underwent TEE.The median time between admission and TEE was 6 days.Patients with TIA who were evaluated by TEE were younger（67 vs.71 years,P 〈 0.001） than those who were not evaluated by TEE.They had a higher rate of sensibility disturbance as a TIA symptom（39% vs.31%,P = 0.012） but a lower rate of previous stroke（15% vs.25%,P = 0.001） and atrial fibrillation（2% vs.21%,P 〈 0.001） than those who did not.Foramen ovale was detected in 71 patients（25.7%）,atrial septal aneurysm in 13 patients（4.6%）,and severe atherosclerotic plaques（grade 4 and 5） in the aortic arch in 25 patients（8.7%）.One patient（0.3%） had a fibroma detected by TEE.In 17 of the 288 patients（6%） who underwent TEE,the indication for anticoagulation therapy was based on the TEE results,and 1 patient with fibroma underwent heart surgery.During hospitalization,7 patients experienced a subsequent stroke,and 27 patients had a recurrent TIA.At 3 months following discharge,the rates of readmission,stroke,recurrent TIA,and death were 19%,2.7%,4.2%,and 1.6%,respectively.The rates of mortality（0.9% vs.1.8%,P = 0.7）,stroke risk（1.9% vs.3.0%,P = 0.8）,and recurrent TIA（5.0% vs.3.9%,P = 0.8） were similar in patients who underwent TEE and in those who did not.Performing TEE in patients with tissue-based TIA is helpful in detecting cardiac sources for embolism and may indicate for anticoagulation.