ABSTRACT. This study aimed to assess the relationship between the recurrence and prognosis of patients with acute middle cerebral artery infarction, atherosclerotic brain infarction, and the existence of microemboli. We continuously enrolled patients with acute atherosclerotic thrombotic cerebral infarction artery stenosis. We performed transcranial Doppler color ultrasound micro emboli monitoring, color Doppler ultrasound carotid artery tests, intracranial Microemboli monitoring study and carotid artery magnetic resonance angiography, impairment evaluation of nerve function, and registration of stroke recurrence and stroke mortality. Of the 49 patients enrolled in the study, 123 main arteries presented atherosclerotic stenosis or formed plaques, and 33 patients had symptomatic stenosis. Patients with symptomatic stenosis have a higher incidence of microemboli than patients with asymptomatic stenosis (P = 0.009). The microembolus-positive rate increased in patients with unstable plaques (P = 0.001). Patients who were microembolus-negative were more likely to show a neural function deficient NIHSS (National Institutes of Stroke Scale) score improvement than patients who were microembolus-positive at one week (P = 0.026). However, we found no significant difference between mRS (modified rankin scale) score (P = 0.319), relapse, and death (P = 0.179). The rate of microembolus-positivity increased in patients with atherosclerotic thrombotic cerebral infarction and unstable plaques. Patients who were microembolus-negative were more likely to show an improvement of neural function deficiency than patients with microembolus-positivity at one week (P = 0.026).

The aim of the present study was to investigate the effects of microembolic signals (MES) on post‑stroke neurological deficits, stroke recurrence and survival in patients with acute cerebral infarction (CI). Patients with acute CI were enrolled consecutively and classified etiologically into the following 4 subtypes using the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification: i) Cardioembolism (CE); ii) large‑artery atherosclerosis (LA); iii) small‑vessel disease (SVD); and iv) stroke of other etiology, including other and undetermined etiologies. The MES of cerebral arteries were monitored by transcranial doppler (TCD), carotid atherosclerotic lesions were detected by color Doppler sonography and extracranial and intracranial magnetic resonance angiography were performed. Next, the severity of neurological deficits was evaluated using National Institutes of Health Stroke Scale (NIHSS) scores. Cases of stroke recurrence and post‑stroke mortality were recorded. A total of 135 patients were recruited, including 33 with CE, 49 with LA, 24 with SVD and 29 with stroke of other etiology. A significant difference in the incidence of MES was identified between the 4 subtypes (P=0.025). The occurrence of positive MES was found to markedly correlate with a history of coronary heart disease (P<0.001) and antithrombotic treatment (P=0.045) and increased levels low density lipoprotein (P=0.036). Compared with patients with negative MES, no significant changes in NIHSS scores were found in patients with positive MES on days 1 and 7 following admission. The incidence of recurrent stoke and post‑stroke mortality was elevated 3 months from the onset of CI. In conclusion, a significant difference in the occurrence of MES was identified between subtypes of patients with acute CI. The incidence of recurrent stroke and mortality was increased among patients with positive MES 3 months from onset.