中枢性眩晕脑血流量及血流动力学研究

Cerebral blood flow and hemodynamics in patients with dizziness resulting from central nervous system disorders

目的观察中枢性眩晕患者局部脑血流量及脑血液动力学改变。方法使用133Xe吸入法及经颅多普勒超声(TCD)分别测定经头颅CT或MRI检查证实无脑组织结构异常改变的86例中枢性眩晕患者的局部脑血流量(RCBF)及各主要脑动脉的脑血流速度,分为发作期组、间歇期组和健康人对照组。结果中枢性眩晕患者60.5%出现脑血流量减少,伴相应动脉脑血流速度减低。发作期异常的发生率明显高于间歇期(P<0.01),疾病组大脑半球血流量、各局部脑叶血流量及相应脑动脉血流速度均低于对照组(P<0.01, P<0.05)。结论中枢性眩晕患者在无脑内结构改变的情况下进行RCBF及TCD检测,有助于观察病变部位脑血流量及血流动力学变化的规律及程度,对于临床诊断和治疗有着重要意义。

Objective To investigate the changes in regional cerebral blood flow (RCBF) and cerebral hemodynamics in patients with dizziness resulted from disorders of the central nervous system. Method Using 133 Xe inhalation technique and transcranial Doppler ultrasonography(TCD), we measured RCBF and blood flow velocity in the major cerebral arteries in 86 such patients with dizziness, who were divided into persisting and intermittent groups according to the symptoms. Another 86 normal adult subjects were also included as the control group. All the patients were free from cerebral structural abnormalities as demonstrated by CT or magnetic resonance imaging. Result Decreased RCBF was found in 60.5% of the patients with also lowered cerebral blood flow velocity, and the abnormalities appeared more serious when the dizziness persisted. The RCBF in the cerebral hemisphere and each cerebral lobes, along with the blood velocity in the cerebral arteries, was significantly lower in the 2 patient groups than in the control group. Conclusion Measurement of RCBF and cerebral blood velocity in patients with central nervous system-related dizziness but without cerebral structural changes may facilitate the assessment of the degree of pathological changes in RCBF and hemodynamics in the affected area and help to better understand the patterns of these changes, which may consequently assist clinical decisions on the diagnosis and treatment of the disease.