短暂性脑缺血发作间期局部脑血流及细胞功能影像学分析

背景短暂性脑缺血发作(transient ischemic attack,TIA)间期的脑血流及脑功能状态的研究国内外均处于初期阶段,国外应用单光子发射电子计算机断层显像(SPECT),正电子发射计算机断层扫描( PET)等项检查手段进行了初步单一脑血流或脑功能的观察,分别提出TIA间期存在脑血流低灌注状态;间期亦可见脑功能局部减低区,但两者之间的关系仍是未知数.目的通过对 TIA患者发作间期局部脑血流及脑细胞功能状态的同期观察,探讨TIA的有效干预治疗依据. 设计横断面观察研究. 地点和对象 41例首都医科大学宣武医院神经内科2001-06/2002-07诊断 TIA住院患者( TIA组), 45例同期正常体检无神经系统疾病人员(对照组),排除糖尿病及严重心肝肾疾病.干预距末次发作后 1～ 7 d内行 SPECT和 CTPI,PET检查. 主要观察指标对两组SPECT和 CTPI,PET检查结果进行对比相关分析. 结果 41例 TIA患者 SPECT显示放射稀疏和(或)缺损检出率为 95% (39/41), CTPI显示灌注异常检出率为63% (26/41),提示 TIA发作间期仍有半数以上存在相应区域局部脑血流动力异常,而对于CTPI显示脑血流正常者, SPECT仍显示有放射稀疏和(或)缺损,考虑为局部脑细胞功能减低所致,同期PET检测结果亦显示局部脑细胞葡萄糖代谢减低异常. 结论 TIA发作间期患者虽无临床症状及体征,但脑细胞功能未完全恢复正常,部分患者仍处于脑血流低灌注异常状态.即使脑血流恢复正常者,仍存在局部脑细胞功能减低区.提示对TIA患者的治疗,不仅要改善脑血流,亦要保护脑细胞功能状态,对于防止TIA复发及阻止脑梗死的发生有重要作用.

Imaging analysis offocal cerebral flow and cellular function during the interphase of transient ischemicattacks

BACKGROUND:Studies on focal cerebral blood flow and brain behavior during the interphase of transient ischemic attack(TIA) are still in the preliminary stage.Singlephoton emission computed tomography(SPECT) and positivephoto emission tomography(PET) have been used in some developed countries to observe the brain blood flow and behavior and revealed cerebral hypoperfusion and focal neurological dysfunction during the interphase of TIAs. But their correlation is poorly known. OBJECTIVE:To explore basis for effective intervention and treatment by observing the focal cerebral blood flow and corresponding brain behavior during the interphase of TIAs. DESIGN:Crosssectional observation. SETTING and PARTICIPANTS:Forty-one TIA inpatients were confirmed between June 2001 and July 2002 at the Department of Neurology,Xuanwu Hospital,Capital University of Medical Sciences.Fortyfive people without neurological diseases,which were confirmed by from routine physical examinations, were enrolled as controls.Patients with diabetes or severe heart,liver and kidney diseases were excluded. INTERVENTIONS: Patients underwent SPECT,CTPI,and PET examinations within 1-7 days following the last attack of TIA. MAIN OUTCOME MEASURES:Focal cerebral blood flow and brain function by SPECT,CTPI,and PET examinations. RESULTS:Radiosparsity or defect rate or both was 95% (39/41) by SPECT examination in 41 patients, and perfusional dysfunction rate was 63% (26/41) by CTPI,indicating that more than half of patients with TIA had focal cerebral blood flow abnormality at corresponding regions during the interphase.Subjects who had normal blood flow but with radiosparsity or defect or both were considered due to the reduced regional cerebral function.Glucose metabolism decrement was also found in focal brain by PET at the same time. CONCLUSION:Although no clinical signs and symptoms can be found in patients during the interphase of TIAs,neuronal function is not completely restored, and some patients still have cerebral hypoperfusion.Even those whose blood flow return to normal still have focal functional defects.Therefore,treatment of TIA shall not focus only on improving blood flow but also on protecting brain function, which is important for preventing recurrent TIA and brain stroke.