Neurology：重度无症状颈动脉狭窄增加认知损害风险

无症状颈动脉狭窄是脑血管病的危险因素，但对于认知损害的关系尚不明确。来自意大利的Simona Balestrini等医师研究了重度无症状颈动脉狭窄及脑血流动力学异常与认知损害的关系。该研究的目的是评价严重颈动脉狭窄及相关的血流动力学损害是否增加无症状患者的认知损害程度，发表在2013年6月4日的neurology杂志上。结果显示：重度无症状颈动脉狭窄增加认知损害风险。

研究共纳入210例单侧无症状严重颈动脉狭窄患者，109例健康对照者，两组人群进行为期36月的前瞻性随访评价。入组时记录两组人群的一般资料、血管性危险因素及药物治疗情况。采用经颅多普勒超声屏气试验测的屏气指数(BHI)评估脑血流动力学。在纳入及随访期内利用MMSE评价认知状态。认知损害定义为MMSE评分下降3分或随访期内下降超过整体水平。

颈动脉狭窄患者相比无狭窄的对照组增加认知损害的发生，优势比为[OR] 4.16，95%可信区间为1.89到9.11，p < 0.001。颈动脉狭窄同侧屏气指数异常与认知损害增加相关(OR 14.66 [95% CI 7.51–28.59]; p < 0.001)。

该研究显示在无36个月的随访期内，无症状但有严重颈动脉狭窄患者认知损害的发生风险增加。血流动力学损害明显增加认知损害风险。颈动脉狭窄的功能评估或可预测无症状颈动脉狭窄患者发生认知损害的风险，以期更好的避免无症状颈动脉狭窄患者出现认知损害。

Severe carotid stenosis and impaired cerebral hemodynamics can influence cognitive deterioration.
OBJECTIVE
To evaluate whether severe carotid stenosis and related hemodynamics impairment may increase the risk of cognitive deterioration in asymptomatic subjects.
METHODS
A total of 210 subjects with unilateral asymptomatic severe carotid stenosis and 109 healthy controls were included and prospectively evaluated for a 36-month period. At entry, demographics, vascular risk profile, and pharmacologic treatments were defined. Cerebral hemodynamics was assessed by transcranial Doppler-based breath-holding index (BHI) test. Cognitive status was evaluated with the Mini-Mental State Examination (MMSE) at entry and at the end of the follow-up period. Cognitive deterioration was defined as a decrease in the MMSE score of 3 points or more during the overall follow-up period.
RESULTS
Subjects with carotid stenosis showed an increased probability of developing cognitive deterioration compared with the group without stenosis (odds ratio [OR] 4.16 [95% confidence interval (CI) 1.89-9.11]; p < 0.001). The presence of an impaired BHI ipsilateral to the stenosis was associated with an increased incidence of reduction in cognitive performance (OR 14.66 [95% CI 7.51-28.59]; p < 0.001).
CONCLUSIONS
Our findings show that the presence of a severe carotid stenosis influences cognitive deterioration over a 36-month period in asymptomatic subjects. An associated hemodynamic impairment significantly increases the risk. Evaluation of functional consequences of carotid stenosis may offer the opportunity to select a group with an increased risk of developing cognitive impairment from subjects with asymptomatic severe carotid stenosis.