These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Maladaptation of vascular response in frontal area of patients with orthostatic hypotension.
    Author: Hayashida K, Nishiooeda Y, Hirose Y, Ishida Y, Nishimura T.
    Journal: J Nucl Med; 1996 Jan; 37(1):1-4. PubMed ID: 8543976.
    Abstract:
    UNLABELLED: To clarify the relationship between abnormalities in cerebral blood flow (CBF) and in blood pressure regulation, we performed 99mTc-HMPAO brain SPECT in association with measurement of plasma norepinephrine and blood pressure in both the upright and supine positions. METHODS: We studied six patients with orthostatic hypotension and six normal patients. No patient had any significant stenosis of the carotid arteries on echocardiography-Doppler ultrasound and no abnormalities on brain MRI or CT. Changes in systolic blood pressure were monitored during the upright test, and 8-ml blood samples were taken at baseline and at 1 and 5 min after the upright position. RESULTS: Systolic blood pressure decreased by a mean of 38 +/- 10 and 9 +/- 3 mmHg in the orthostatic hypotension and normal groups, respectively. Compared with baseline values, plasma norepinephrine levels at 1 and 5 min after the upright test did not increase in the orthostatic hypotension group but did increase significantly in the normal group. In the orthostatic hypotension group, 99mTc-HMPAO brain SPECT showed postural cerebral hypoperfusion in the bilateral frontal areas, of which the mean count ratio of the frontal-to-cerebellar area between the upright and supine positions significantly changed from 0.871 +/- 0.029 to 0.942 +/- 0.067 and from 0.881 +/- 0.035 to 0.954 +/- 0.073 in the right and left areas, respectively. No postural change in CBF was evident in other areas in the orthostatic hypotension group. In the normal group, there were no such changes in CBF, blood pressure and plasma norepinephrine levels during the upright test. CONCLUSION: Postural cerebral hypoperfusion in the frontal areas in the orthostatic hypotension group might relate to maladaptation of the vascular response during the upright test.
    [Abstract] [Full Text] [Related] [New Search]