Doppler examination and cerebral arterial stricture in patients with ischemic stroke

BACKGROUND: With the development of interventional therapy, it is necessary for evaluating cerebral vessels to instruct treatment and determine prognosis of patients with ischemic stroke; however, correlation of distribution of infarction focus and clinical symptoms with degrees of cerebrovascular stricture is still unclear. OBJECTIVE: To evaluate the characteristics of cerebral arterial stricture of patients with ischemic stroke with transcranial Doppler (TCD) and color duplex flow imaging (CDFI) and compare the correlation between distribution of cerebral infarction focus and clinical types with magnetic resonance imaging (MRI). DESIGN: Contrast observation. SETTING: Department of Neurology, the First Hospital of Jilin University. PARTICIPANTS: A total of 159 patients with ischemic stroke were selected from the Department of Neurology, the First Hospital of Jilin University from January to December 2005, including 106 males and 53 females aged from 27 to 88 years. Bases on diagnostic criteria of cerebrovascular disease established by Rao et al, clinical manifestations of all patients were evaluated with CT or nuclear magnetic resonance. All patients provided the confirmed consent. METHODS: The accepted patients received TCD and CDFI examination at 1 week after onset of ischemic stroke. Among them, 112 patients received cerebrovascular imaging examination simultaneously. MRI was used to check cerebral infarction focus and cerebrovascular stricture > 50% was regarded as the accepted vessels. In addition, DWI-T2 TCD (Germany) was used to check middle cerebral artery, and degrees of middle cerebral artery were classified into mild, moderate and severe stricture based on blood velocity (140 cm/s, 180 cm/s). Stroke was classified based on characteristics of infarction focus and clinical symptoms showed with MRI and correlation with degrees of cerebrovascular stricture was analyzed simultaneously. MAIN OUTCOME MEASURES: Correlation between the characteristics of ischemic stroke and clinical symptoms checked with TCD and CDFI. RESULTS: A total of 159 patients with ischemic stroke were involved in the final analysis; in addition, 112 cases received cerebrovascular imaging examination simultaneously. ① MRI results of 159 patients with cerebral artery occlusive disease (CAOD): There were 131 patients (82.3%) with cerebral infarction, 40 (25.2%) with transient ischemic attack and 4 (2.5%) with subclavian steal syndrome (SSS). ② Infarction types with MRI examination: There were 33 patients (20.8%) with solitary cerebral infarction and 98 (61.6%) with multiple-cerebral infarction. ③ Results of TCD, CDFI, MRI angiography, CT angiography and digital subtraction angiography (DSA): Among 112 patients, 181 lesion sites (61.8%) were located in cranium and 112 lesion sites were located out of cranium; especially, lesion site was mostly observed in stem of middle cerebral artery (31.2%) and watershed of basilar artery (7.2%) in cranium and the beginning site of internal carotid artery (21.4%) out of cranium. ④ Correlation of vascular stricture checking with TCD, MRI and clinical diagnosis: On one hand, MRI and clinical diagnosis demonstrated that 68 patients had a watershed infarction; meanwhile, TCD examination indicated that there were 3 patients with mild vascular stricture, 24 with moderate vascular stricture and 36 with severe vascular stricture. On the other hand, among 68 patients with non-watershed infarction, there were 27 patient with mild vascular stricture, 26 with moderate vascular stricture and 15 with severe vascular stricture. There were significant differences (χ2 =26.854, P =0.001). Clinical diagnosis indicated that 40 patients had transient ischemic attack and TCD examination demonstrated that there were 8 patient with mild vascular stricture, 12 with moderate vascular stricture and 20 with severe vascular stricture. There were significant differences as compared with 68 patients with watershed infarction (χ2 =21.258, P =0.001). ⑤ Correlation of vascular stricture checking with CDFI, MRI and clinical diagnosis: On one hand, among patients who were determined as watershed infarction with MRI and clinical diagnosis, CDFI examination indicated that there were 32 patients with mild vascular stricture at neck, 25 with moderate vascular stricture and 6 with severe vascular stricture. On the other hand, among patients with non-watershed infarction, there were 48 patient with mild vascular stricture, 18 with moderate vascular stricture and 2 with severe vascular stricture. There were significant differences (χ2 =6.018, P =0.019). Among patients with transient ischemic attack checking with clinical diagnosis, there were 23 patient with mild vascular stricture, 9 with moderate vascular stricture and 8 with severe vascular stricture. There were no significant differences as compared with patients with non-watershed infarction (χ2 =0.597, P =0.440). CONCLUSION: ① TCD and CDFI are effective marks to determine cerebral arterial stricture and hemodynamical changes. ② Infarction and transient ischemic attack at watershed are generally clinical phenotypes of CAOD patients and infarction at watershed is correlated with degrees of cerebrovascular stricture. ③ TCD, MRI and clinical analysis of stroke types are significant for instructing treatment and evaluate prognosis.