Brain Function, Cognition, and the Blood Pressure Response to Pharmacological Treatment

Abstract

Objective: To extend evidence suggesting that essential hypertension influences neuropsychological performance and that brain function before treatment is related to the success of pharmacological lowering of blood pressure (BP). Methods: A voxel-based examination of the whole brain was conducted among 43 hypertensive patients treated for 1 year with assessment pre and post treatment, using positron emission tomography and neuropsychological testing. Results: Neuropsychological performance improved over the year of treatment but was unrelated to change in regional cerebral blood flow (rCBF). Neither mean resting rCBF nor responsivity to a working memory task changed significantly with treatment. However, patients with greater lowering of systolic BP during treatment showed increased rCBF responsivity to a working memory task in medial and orbital frontal areas and decreased rCBF responsivity in mid frontal, parietal, thalamus, and pons (as well as lower thalamic rCBF pretreatment). Improved working memory performance over the treatment period was related to decreased responsivity in medial frontal, medullary, and parietal areas. Patients showing greater lowering of BP with treatment seemed to reduce excitatory and enhance inhibitory coupling between memory processing and BP more than those with less treatment success. Conclusion: Degree of treatment success for both BP and cognitive performance among hypertensives is related to differing patterns of rCBF. Overall, the results emphasize the relevance of brain function to the treatment of hypertension. BP = blood pressure; PET = positron emission tomography; rCBF = regional cerebral blood flow; MRI = magnetic resonance imaging; ROI = region of interest.