脑白质损害的认知功能研究

目的 :观察脑白质损害 (WML )与事件相关电位 P30 0变化关系 ,探讨 WML在认知功能降低中的作用。方法 :35例经 MRI证实的 WML ,进行影像学、简易智能状态检测 (MMSE)和事件相关电位 P30 0测定 ,依据 WML体积将其分为轻度 (<5 cm3)、中度 (5～ 15 cm3)和重度 (>15 cm3) ,并对 WML与 P30 0潜伏期变化进行相关分析。结果 :轻度 WML 11例 ,中度 17例 ,重度 7例 ,主要表现为 T2和质子密度加权像上高信号 ,分布在脑室周围、半卵园中心及皮层下白质。轻度及中度 WML时 MMSE测定值无降低 ,重度 WML时 MMSE也只降低为 2 6 .9。随 WML的程度加重 ,P30 0潜伏期延长越明显 ,相关分析提示两者具有正相关。结论 :观察老年性 WML主要依靠 T2像或质子密度加权像。MMSE在反应 WML导致的认知功能障碍时不够敏感。 WML能引起事件相关电位 P30 0延长 ,其损害程度与 P30 0潜伏期变化呈正相关。

The study of cognitive function in patients with cerebral white matter lesions

Objective:To observe the relation between cerebral white matter lesions (WML) and eventrelated potential (ERP) P300 in order to study the effect of WML on cognitive decline in elderly. Methods: There were 35 pateitns with WML that were confirmed by MRI. All ssubjects underwemt MRI, Mini Mental State Examination (MMSE), ERP examination. WML were divided into mild (<5cm 3), middle (5~15cm 3) and heavy (>15cm 3) degree by the volume of WML. The correlation analysis was made between the extent of WML and P300 latency. Results: The pateitns with mild, middle and heavy degree WML were 11,17 and 7cases respectively. The hyperintensities were present on T2 and proton density (PD) weighted image, which distributed around cerebral ventricle, in centrum semiovale and white matter under cortex. The scores of MMSE did not decrease in mild and middle WML. It only reduce to 26.9 scores in heavy WML. P300 latency increased progresively with the extent of WML. There are positive corelation between them. Conclusion: Only T2 and PD weighted images are suited for observing appearance of WML in elderly MMSE is not sensitive in estimating cognitive function decline. WML can lead to the increase of ERP P300 latency. The extent of WML have positive corelation with P300 latency.