The Significance of Microembolic Signals and New Cerebral Infarcts on the Progression of Neurological Deficit in Acute Stroke Patients with Large Artery Stenosis

Abstract

Background: Early neurological deterioration is common in the acute phase after stroke. We sought to investigate the correlation between the progression of microembolic signal (MES), ischemic infarcts and the neurological deficits in the acute phase of stroke patients with large artery occlusive disease. Methods: Transient ischemic attack or stroke patients with relevant significant large artery stenosis (≧50% diameter reduction) and admitted within 7 days of the symptom onset were recruited in this study. MES, infarcts on diffusion-weighted imaging and National Institutes of Health Stroke Scale (NIHSS) score were assessed on days 1 and 7 of recruitment. Results: Among 67 patients, 50.7% (34 of 67) had MES on day 1. Presence of MES correlated with both a higher number of infarcts (p = 0.006) and the incidence of multiple infarcts (χ² test, p = 0.002), but not with the NIHSS score. On day 7, MES was detected in 25.4% of the patients (17 of 67), 11.8% of them (2 of 17) displayed new or extended infarct on DWI (p = 0.14) and 29.4% (5 of 17) showed neurological improvement (p = 0.039). Among the patients with positive MES at baseline, NIHSS reduction was positively correlated with disappearance of MES on day 7 (MES disappearance vs. persistence group, 2.05 vs. 0.73, p = 0.023). Conclusions: Neither the disappearance of MES nor the changes in NIHSS score correlated with the progression of infarct. Disappearance of MES indicated better neurological improvement in the acute phase.

A study of microemboli monitoring of atherosclerotic thrombotic cerebral infarction and artery stenosis

“…The mRS score did not show statistical differences just before and 3 months after discharge (P = 0.319), suggesting that the presence of microemboli had no significant effect on the improvement of neurological function after 3 months. Hao et al (2010) found that the NIHSS score improved more significantly in patients with microemboli and turned negative in patients with continuously positive detection of microemboli. Iosif et al (2008) and Schlaug et al (1999) re-examined MRI DWI and perfusion-weighted imaging (PWI) on patients within 1 week after stroke onset and found that asymptomatic cerebral perfusion was more likely to decrease in microembolus-positive patients and that small infarct lesions that could not be detected with MRI DWI also emerged.…”

“…These authors found that 43% of the patients were again detected as microemboluspositive one week later, and the total frequency of microembolus-positive patients in one week was 7%, which is close to our conclusion. Studies have shown that the ratio of microemboluspositivity peaks immediately after stroke, and the ratio decreases as time goes on (Sliwka et al, 1997;Iguchi et al, 2007;Hao et al, 2010).…”

“…It has been previously established that all enrolled patients admitted to hospital should receive microembolus detection as soon as possible within 48 h (Hao et al, 2010). Patients with positive microembolic signals would undergo microemboli detection again after one week.…”

“…If any of the TCD results of the head and neck artery, carotid ultrasound, and MRA imaging examination were in accordance with the criterion of diagnosis of vascular stenosis, the patient can be defined as having vessel stenosis (Hao et al, 2010).…”

Clopidogrel Load for Emboli Reduction in Patients With Symptomatic Carotid Stenosis Undergoing Urgent Carotid Endarterectomy

“…[1][2][3] MES have been used for risk stratification and assessment of therapeutic efficacy in these conditions. 4 Clopidogrel load (300 mg) combined with dual antiplatelet therapy reduces asymptomatic embolization in patients with symptomatic CARAS in 2 phase IIb randomized clinical trials.…”