Elderly Hypertensive Patients: Silent White Matter Lesions, Blood Pressure Variability, Baroreflex Impairment and Cognitive Deterioration

Agustin      J. Ramirez; Gianfranco      Parati; Paolo      Castiglioni; Damian      Consalvo; Patricia      Solis; Marcelo      R. Risk; Paola      Waissman; Marco      DiRienzo; Giusepe      Mancia; Ramiro      A. Sanchez

Abstract

Introduction: Hypertension may increase the risk for stroke and is frequently associated with subcortical and periventricular white matter lesions (WML). This is considered a prognostic factor for the development of stroke and cognitive impairment, particularly in attention processes. Additionally, in elderly subjects, it is known the implications of alterations in the neural cardiovascular regulation and the cardiovascular risk. Aims: To evaluate, in asymptomatic elderly hypertensives, the association of ambulatory blood pressure values and autonomic activity with neurocognitive impairment and WML. In addition, we also evaluated the role of the autonomic nervous system particularly the vagal component, in the pathogenesis of white matter lesions. Methods: We studied 22 elderly essential hypertensive patients (69±1.1y) and as control group, 16 normotensive elderly subjects (age 67±3.2y) were also enrolled. To each one of them, a cerebral MRI was performed to classify them, by a neuro-radiologist blinded of the subject clinical status, using a 0 to 9 scale where 0 denoted no WML and 9 the most severe lesions. Twenty four hours arterial blood pressure monitoring was performed to each one of the subjects under study. Office blood pressure was measured 3 times and the mean value reported. Beat to beat finger arterial pressure monitoring (Finapres) was performed for a 2h period. During the first hour the patient remained lying supine in a quiet darkened room and during the second hour four manoeuvres: stand-up, cold pressor test, handgrip and quiet activity were randomly performed. Mean blood pressure and pulse interval values, from the two periods, and their respective variabilities, baroreflex sensitivity and power spectral analysis were calculated. Regarding neuropsychological assessment: Minimental test, attention evaluation, RAVLT, visual memory, language and executive function, geriatric depression scale, cognitive deficit rate tests were performed in all subject.....

Keywords: White matter lesion, elderly subjects, essential hypertension, autonomic function, variability and barorreflex control, prognostic factor, neurological evaluation, Cerebral Magnetic Resonance Imaging, ambulatory blood pressure