Orthostatic hypotension is a sharp, prolonged drop in blood pressure when standing up that is common in the elderly. Orthostatic hypotension may be accompanied by dizziness, which can cause falls. That is why it is important to properly diagnose and monitor orthostatic hypotension using blood pressure measurements while the person is standing up. This PhD thesis shows that these measurements are often not performed consistently, making it difficult, for example, to draw conclusions about the relationship between anti-hypertensive medication and orthostatic hypotension. The thesis investigates near-infrared spectroscopy (NIRS), a method for measuring cerebral blood flow, as a potential alternative measurement method, both in a controlled hospital setting and in elderly people's homes. In both situations, it proved feasible to use NIRS to measure the response of blood pressure and cerebral blood flow to standing up. Cerebral blood flow recovered more slowly in people with orthostatic hypotension than in people without orthostatic hypotension. Elderly people with dizziness complaints while standing up showed a stronger decrease in their cerebral blood flow than those without such complaints. These results suggest that NIRS has potential for monitoring orthostatic hypotension. Follow-up research is required to confirm this in a larger cohort of elderly people with and without orthostatic hypotension and dizziness symptoms.
Marjolein Klop (1996) completed her Master's degree in Technical Medicine at the University of Twente in 2020 with a thesis project conducted at the Geriatrics Department of Radboud university medical center. She went on to complete her PhD at the Donders Institute and at the Geriatrics Department. She is currently working as a postdoc at the Geriatrics Department of Radboud university medical center.