短暂性脑缺血发作患者认知功能与脑血流量改变

背景有实验表明短暂性脑缺血发作后可遗留一定的认知功能障碍,提出脑血流量及其分布与认知活动关系密切的假说.目的观察短暂性脑缺血发作患者的认知功能改变,验证其与脑血流灌注的关系.设计病例-对照实验.单位解放军兰州军区乌鲁木齐总医院老年病科、神经电生理室、核磁室.对象选择2002-01/2003-06在解放军兰州军区乌鲁木齐总医院老年病科住院和门诊的短暂性脑缺血发作患者35例,均为男性,右利手,年龄45～78岁,平均(68.1±8.4)岁.对照组33例,为同期本院健康体检者.男性,均为右利手,年龄45～77岁,平均(67.8±8.6)岁.方法应用事件相关电位、老年认知功能量表[包括定向、识记、广度、回忆1(有无联系)、长记忆、动物名、划销与计算、分类与类同、临摹、语言和回忆2(有无关系)等11项内容,根据原始分查不同年龄组的T分转换表,消除年龄因素的影响;再根据受试者的教育水平查教育T'分表,消除教育因素的影响;这样就可根据T'分及百分位水平对受试者的认知功能进行评估,得分越低,认知功能越差]对两组对象进行检测评估,并对短暂性脑缺血发作患者进行磁共振血管成像检查.主要观察指标①事件相关电位检测结果.②老年认知功能量表检查结果.③脑血管磁共振血管成像检查结果.结果35例短暂性脑缺血发作患者,33例正常体检者,均进入结果分析.①事件相关电位检测结果短暂性脑缺血发作患者的P300潜伏期明显长于对照组[(336.2±34.2)ms,(311.3±44.2)ms,t=5.945 3,P＜0.05 ].②老年认知功能量表检查结果短暂性脑缺血发作组广度、回忆1、长记忆、动物名、计算、回忆2评分均低于对照组[(39.7±11.9),(47.4±12.0)分;(54.5±14.8),(61.8±14.5)分;(61.1±7.8),(64.7±1.7)分;(59.4±11.0),(64.7±8.8)分;(50.0±14.7),(58.1±14.2)分;(44.6±15.4),(53.2±17.8)分,t=4.151 0～7.292 8,P＜0.05～0.01].③脑血管磁共振血管成像检查结果短暂性脑缺血发作组33例(94%,33/35)脑动脉有异常改变,主要表现为狭窄和闭塞.其中椎动脉广泛性狭窄占54%(19/35);大脑前动脉(双侧)、中动脉(双侧)、后动脉(双侧)狭窄和闭塞的分别为40%(28/70)、59%(41/70)、47%(33/70);基底动脉和颈内动脉(双侧)狭窄和闭塞的分别为5.71%(2/35),5.71%(4/70).结论①短暂性脑缺血发作患者P300潜伏期明显延长,并有多种认知功能障碍,尤以记忆损害突出.②磁共振血管成像显示脑动脉狭窄和闭塞,提示短暂性脑缺血发作患者有持久的脑血流低灌注与此密切相关认知功能损害.

Cognitive function and hemodynamic compromise in patients with transient ischemic attacks

BACKGROUND: Researches suggest that transient ischemic attack (TIA)can induce cognitive dysfunction, and cerebral blood flow and its distribution are hypothesized to be closely related to cognitive activities.OBJECTIVE: To investigate the alteration of cognitive function and provide insights into its relations with cerebral perfusion in TIA patients.DESIGN: A case-control study.SETTING: Departments of Geriatrics, Electrophysiology and Magnetic Resonance of Urumqi General Hospital of Lanzhou Military Area Command of Chinese PLA.PARTICIPANTS: Totally 35 male right-handed TIA patients aged 45-78 years with an average of (68.1±8.4) years were selected from the inpatients and outpatients in the Department of Geriatrics, Urumqi General Hospital of Lanzhou Command of Chinese PLA between January 2002 and June 2003. Another 33 healthy right handed male subjects aged 45-77 years with an average of (67.8±8.6) years coming for physical examination were recruited to serve as the control group.METHODS: Patients and control subjects were tested with event-related potentials (ERPs) and the scale of elderly cognitive function (SECF) to examine the orientation, learning and memory, span, recall 1 (association),long-term memory, naming of animals, calculation, classification, copying,language and recall 2 (relation). According to the T score transformation table, the original scores were transformed into T scores relative to the age to eliminate the impact of age, and also into T'score to eliminate the interference by the patients'education, so that cognitive function of the patients could be evaluated with T'score, and the lower the score, the poorer the cognitive function. Cases in the two groups were all tested, and TIA patients were also examined with magnetic resonance angiography (MRA).MAIN OUTCOME MEASURES: Results of ERPs, SECF and MRA.RESULTS: Of the 35 TIA patients and 33 control subjects all completed the trial. Examination of ERPs reveled significantly prolonged latency of P300 components of ERP in the TIA group [(336.2±34.2) ms] than that in the control group [(311.3±44.2) ms, P ＜ 0.05]. The scores of span, recall 1,long-term memory, naming of animals, calculation, and recall 2 in SECF in TIA group were all lower than those in control group (39.7±11.9 vs 47.4±12.0; 54.5±14.8 vs 61.8±14.5; 61.1±7.8 vs 64.7±1.7; 59.4±11.0 vs 64.7±8.8; 50.0±14.7 vs 58.1±14.2; 44.6±15.4 vs 53.2±17.8, t=4.151 0-7.292 8, P ＜ 0.05-0.01). MRA identified abnormalities in 33 of the 35 TIA patients (94%), manifested mainly by stenosis and occlusion involving the vertebral artery (54%, 19/35), bilateral anterior, middle and posterior cerebral arteries (40% ,28/70;59% ,41/70;47% ,33/70), basilar artery (5.71%, 2/35) and bilateral internal carotid artery (5.71%, 4/70) respectively.CONCLUSION: TIA patients are characterized by prolonged P300 latency with multiple cognitive impairments especially in memory and cerebral artery stenosis and occlusion as shown by MRA, suggests that TIA patients have persistent low cerebral perfusion and frequently, cognitive dysfunction in the presence of local blood supply disorder in the hemispheres.