Diffusion tensor MRI correlates with executive dysfunction in patients with ischaemic leukoaraiosis
Diffusion tensor MRI correlates with executive dysfunction in patients with ischaemic leukoaraiosis
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DOI：
10.1136/jnnp.2003.014910
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发表时间：
2004-03-01
影响因子：
11
通讯作者：
Markus, HS
中科院分区：
文献类型：
--
作者：
O'Sullivan, M;Morris, RG;Markus, HS
背景：脑部小血管疾病是血管性痴呆的常见病因。在T2加权磁共振成像(MRI)上，既有离散的腔隙性脑梗塞，也有弥漫性的脑缺血改变，表现为汇合性高信号(脑白质疏松)。然而，T2损伤负荷与认知功能损害之间的相关性很弱。弥散张量磁共振成像(DTI)是一种可以提供更好的脑白质损伤指标的新技术。目的：确定在T2加权图像上，弥散张量成像与认知功能的相关性是否比病变负荷更强，以及这些相关性是否独立于常规MRI参数。方法：36例缺血性脑白质疏松(脑白质疏松伴腔隙性卒中)患者和19名健康志愿者接受了DTI、常规MRI和神经心理学评估。结果：DTI显示病灶内和正常外观白质的扩散率均增加。正常脑白质的平均弥散率与总分智商、执行功能测验呈负相关(r=-0.46，p=0.009)。在控制了年龄、性别、脑体积和T1/T2病变体积后，这些相关性仍然显著。T2损伤负荷与智商或神经心理评分之间没有明显的相关性。在常规测量中，脑体积与认知功能的相关性最好。结论：弥散张量测量与认知功能的相关性比常规MRI测量更好。它们可能在监测疾病进展和作为治疗试验的替代标记物方面有用。这一发现支持了脑白质损伤和白质连接中断在脑小血管疾病认知障碍发病机制中的作用。
Background: Cerebral small vessel disease is a common cause of vascular dementia. Both discrete lacunar infarcts and more diffuse ischaemic changes, seen as confluent high signal (leukoaraiosis) on T2 weighted magnetic resonance imaging (MRI), occur. However, there is a weak correlation between T2 lesion load and cognitive impairment. Diffusion tensor MRI (DTI) is a new technique that may provide a better index of white matter damage.Objectives: To determine whether DTI measures are correlated more strongly with cognitive performance than lesion load on T2 weighted images, and whether these correlations are independent of conventional MRI parameters.Methods: 36 patients with ischaemic leukoaraiosis (leukoaraiosis plus a previous lacunar stroke) and 19 healthy volunteers underwent DTI, conventional MRI, and neuropsychological assessment.Results: On DTI, diffusivity was increased both within lesions and in normal appearing white matter. Mean diffusivity of normal appearing white matter correlated with full scale IQ (r = -0.46, p = 0.009) and tests of executive function. These correlations remained significant after controlling for age, sex, brain volume, and T1/T2 lesion volumes. No significant correlation was identified between T2 lesion load and IQ or neuropsychological scores. Of conventional measures, brain volume correlated best with cognitive function.Conclusions: Diffusion tensor measurements correlate better with cognition than conventional MRI measures. They may be useful in monitoring disease progression and as a surrogate marker for treatment trials. The findings support the role of white matter damage and disruption of white matter connections in the pathogenesis of cognitive impairment in cerebral small vessel disease.