Abstract:

Objective To identify the different clinical characteristics between diffusion-weighted imaging negative and positive stroke treated with intravenous thrombolysis and analyse the cause of diffusion-weighted imaging (DWI) negative stroke. Methods Retrospective analysis was made upon data of patients with ischemic stroke who received intravenous thrombolysis during September 2013 and February 2015. The patients were divided into DWI positive group and DWI negative group based on head magnetic resonance imaging (MRI). The differences in baseline data, risk factors for cerebral vascular diseases, clinical manifestation and outcome at discharge were compared between the two groups. Results Among 119 patients, there were 94 cases of DWI positive and 25 cases of DWI negative with 21% of DWI negative rate. There were no obvious differences between the baseline characteristics of DWI negative stroke versus DWI positive stroke, including gender, age and risk factor for cerebral vascular diseases. No inter-group differences in NIHSS score were noted at  admission NIHSS. The discharge NHISS of DWI negative stroke was 0 (0, 1) which was obviously lower than that of DWI positive group's 1 (0, 4) (P =0.02). The discharge mRS of DWI negative stroke was 0 (0, 1) while DWI positive stroke was 1 (1, 3) (P <0.001). There were significantly statistical differences between them. The hemorrhagic transformation rate (2.1%) and mortality rate (1.1%) of DWI positive stroke were relatively low, and there were no hemorrhagic transformation or death occurring in DWI negative group. There were no obvious differences in hemorrhagic transformation or death outcome. Conclusion DWI negative stroke is milder and recover better than DWI positive stroke. As the intracranial hemorrhage rate and mortality are low in either DWI positive or negative stroke, rt-PA intravenous thrombolysis is safe in stroke.

Key words: Diffusion-weighted imaging; Negative; Stroke; Intravenous thrombolysis; Clinical characteristics

摘要：

目的 探讨静脉溶栓治疗中磁共振成像（magnetic r esonance i maging，MRI）弥散加权像（diffusion weighted imaging，DWI）阴性缺血性卒中的临床特征及可能原因。 方法 回顾性分析长海医院2013年9月-2015年2月单纯静脉溶栓的缺血性卒中患者，根据头颅MRI将 患者分为DWI阳性组和DWI阴性组，比较两组患者基线资料、脑血管病危险因素、临床症状和出院时结 局的差异。 结果 入组的119例患者中，DWI阳性94例，阴性25例，DWI阴性率为21%，DWI阳性组和阴性组患者 性别、年龄、脑血管病危险因素发生率无显著差异。两组入院时的美国国立卫生研究院卒中量表 （National Institutes of Health Stroke Scale，NIHSS）评分未见显著差异，出院时DWI阴性组的NIHSS评分 中位数为0（0，1），显著低于DWI阳性组NIHSS评分中位数1（0，4）（P =0.02）；改良Rankin量表（modified Rankin Scale，mRS）评分中位数为0（0，1），显著低于DWI阳性组mRS评分中位数1（1，3）（P <0.001）。 DWI阳性组出血转化率（2.1%）和死亡率（1.1%）均较低，而DWI阴性组未见出血转化和死亡病例，两 组的出血转化及死亡结局没有显著差异。 结论 与DWI阳性缺血性卒中相比，DWI阴性缺血性卒中出院时症状较轻，恢复较好。两组溶栓后颅 内出血的发生率及死亡率均较低且没有显著差异，静脉溶栓对于DWI阳性及阴性的缺血性卒中都是 安全的。

关键词: 弥散加权成像; 阴性; 缺血性卒中; 静脉溶栓; 临床特点