Fiermonte G, Aloe Spiriti M A, Latagliata R, Petti M C, Giacomini P
Institute of Clinical Nervous and Mental Diseases, La Sapienza University, Rome, Italy.
J Intern Med. 1993 Dec;234(6):599-602. doi: 10.1111/j.1365-2796.1993.tb01019.x.
The purpose of this study has been to investigate by ultrasonographic methods the flow velocities of cerebral arteries because increased blood viscosity due to haematocrit elevation can cause neurological symptoms in polycythaemia vera patients, because of the resulting decrease in cerebral flow.
Twenty newly diagnosed patients, with haemoglobin values of > 18 g dl-1 and/or an haematocrit of > 50%, were examined by transcranial Doppler. Recordings were performed in basal conditions and after pharmacological and/or phlebotomic treatment, when haematocrit values were < or = 50%. Blood velocities were evaluated in middle (MCA), anterior (ACA), posterior (PCA) cerebral arteries and in the basilar (BA) artery.
Basal recordings showed decreased velocities (MCA: 39.40 +/- 9.34 cm s-1; ACA: 34.05 +/- 10.25 cm s-1; PCA: 31.46 +/- 5.97 cm s-1; and BA: 27.47 +/- 7.42 cm s-1); pre- and post-treatment value differences observed in MCA, ACA and BA were highly significant (P < 0.001).
A decrease in cerebral flow could be a risk for multifocal micro-ischaemic cerebral infarctions leading, after several years, to a multi-infarct dementia; an early reduction in erythrocyte burden should be very useful in polycythaemic patients in preventing lacunar lesions.
本研究旨在通过超声检查方法研究脑动脉的血流速度，因为真性红细胞增多症患者由于血细胞比容升高导致血液粘度增加，进而引起脑血流量减少，可导致神经症状。
对20例新诊断患者进行经颅多普勒检查，这些患者血红蛋白值>18 g/dl和/或血细胞比容>50%。在基础状态下以及血细胞比容值≤50%时，经药物和/或放血治疗后进行记录。评估大脑中动脉（MCA）、大脑前动脉（ACA）、大脑后动脉（PCA）和基底动脉（BA）的血流速度。
基础记录显示血流速度降低（MCA：39.40±9.34 cm/s；ACA：34.05±10.25 cm/s；PCA：31.46±5.97 cm/s；BA：27.47±7.42 cm/s）；在MCA、ACA和BA中观察到的治疗前后值差异具有高度统计学意义（P<0.001）。
脑血流量减少可能是多灶性微缺血性脑梗死的危险因素，数年后可导致多发性梗死性痴呆；早期减轻红细胞负荷对真性红细胞增多症患者预防腔隙性病变非常有用。
