Vasoregulatory activity in patients with Huntington's chorea

Vasoregulatory activity has been assessed in 11 patients with Huntington's chorea and 13 control subjects by intra-arterial pressure studies. There was no significant difference in the resting mean blood pressure or its response to the Valsalva manoeuvre in the 2 groups. However, with rapid tilting of subjects into a 60° head-up position there was a fall in mean blood pressure which was significantly greater in patients with Huntington's chorea than in control subjects (p < 0.005). The significance of this defect in postural vasoregulatory mechanisms is considered. Our observations are also discussed in the light of the recent suggestion by others that the caudate nuclei have an important role in modulating vasomotor activity.