On July 5th, Swetta Jansen will present on Optimization of a Mathematical Model of Cerebral Autoregulation studying AD pathology in room SP A1.08.
Cerebral autoregulation (CA) refers to the mechanism that maintains cerebral blood flow (CBF) at a physiological level during changes in blood pressure. Studies have demonstrated that CA is generally a robust mechanism across ageing and certain diseases, such as hypertension. However, Alzheimer’s patients show a significant reduction in overall CBF and an increase in cerebrovascular resistance. The exact mechanisms causing these reductions in CBF are unknown. Therefore, the aim of this research is to use mathematical modeling to investigate which mechanisms might be impaired in cognitive disorders that cause globally reduced CBF. This research relies on experimental data of CBFV recordings obtained from the Department of Geriatric Medicine at the Radboud University Nijmegen Medical Centre. This data includes Transcranial Doppler recordings of healthy older individuals and individuals that are diagnosed with mild cognitive impairment (MCI) or Alzheimer’s disease (AD). The model for CBF by Ursino and Lodi (1998) was fitted to the experimental data for these distinct groups, with the goal to investigate possible differences in parameter distributions. The mathematical model was successfully fitted to the time series data of the healthy and pathophysiological individuals, using a range of parameter optimization methods. The resulting parameter distributions are in line with earlier reported values. The results of this study strengthen the idea of the occurrence of increased cerebrovascular resistance and reduced cerebrovascular compliance in AD. Additionally, it suggests that autoregulation in AD may fail to timely compensate for fluctuations in CBF and instability of blood pressure leading to brain hypoperfusion under orthostatic stress.