[Baroreflex function in patients with Binswanger's encephalopathy].

To analyze the baroreflex function in Binswanger's encephalopathy, we performed head-up tilting (HUT) in three steps (20 degrees, 40 degrees, and 60 degrees for 5 min.) and evaluated changes in blood pressure, heart rate, plasma noradrenaline (NA) and plasma arginine vasopressin (AVP) in 15 patients with Binswanger's encephalopathy (mean age; 70.1 +/- 5.6 years), 10 patients with lacunar infarction (mean age; 72.3 +/- 6.3 years) and eight normal controls (mean age; 69.0 +/- 4.3 years). In the patients with Binswanger's encephalopathy, the resting blood pressure was higher than that in the other two groups and the blood pressure decreased by more than 20 mmHg in five cases and by 15 mmHg in one case after HUT. In all groups, the heart rates and NA increased significantly after HUT, but the AVP levels were not significantly increased after HUT in the patients with Binswanger's encephalopathy. In conclusion, central baroreceptor pathways involved in the function of AVP release, brainstem-hypothalamic pathways are impaired in Binswanger's encephalopathy.