BLOOD-PRESSURE REGULATION IN ALZHEIMERS-DISEASE

Brain neurons which regulate brood pressure (BP), including the C-l to nic vasomotor neurons, degenerate in Alzheimer's disease (AD). This st udy determines whether BP is decreased in AD. We reviewed records of t hree autopsy proven AD patients. Medical causes for decreased BP were investigated. Yearly averages for systolic (SBP), diastolic (DBP), mea n arterial (AP) blood pressure and pulse pressure (PP) were calculated . BP in the year of diagnosis was compared to the sum of all BP in sub sequent years. In addition, each yearly measurement through the course of AD was compared to its counterpart in the year of diagnosis. Three BP measurements were significantly decreased by from 6.9% to 15.9% in all patients when BP in the year of diagnosis was compared to the sum of each pressure in subsequent years. Sustained BP declines started i n the third to fourth year after diagnosis of AD and continued for up to 9 years. The PP was decreased by 19.9% in one patient, There was a strong correlation between the number of C-l neurons in these cases an d their AP and SBP in the years after diagnosis. Hypothalamic phenylet hanolamine N-methyltransferase activity was decreased by 63% in AD com pared to control cases. Neurofibrillary tangles were found in the para ventricular nucleus of the hypothalamus in an AD case. We postulate th at BP is altered in AD as neurons which regulate it degenerate.