Cognitive function in relation to cerebral blood flow regulation after preeclampsia

Although the regulation of cerebral blood flow is known to be altered during
preeclampsia, little is known about the state of the control mechanisms after
the experience of preeclampsia. Nevertheless, several studies report evidence
for formerly preeclamptics having a higher risk to die from stroke and a
shorter life expectancy. Furthermore, our previous study shows that
neurovascular coupling is abnormal in a subgroup of formerly preeclamptics. The
question raised now is whether cognitive function and the persistent cognitive
complaints which are regularly reported by former preeclamptics are related to
these abnormalities in local blood flow regulation.
A few studies show that cognitive function is disturbed after severe
preeclampsia, but discuss that it is not known whether this effect is permanent
or temporal and whether it is caused by organic damage. Our working hypothesis
is that test-objectified cognitive function of formerly preeclamptics with or
without subjective cognitive complaints is correlated with dynamic
cerebrovascular control parameters measured by non-invasive techniques for
recording cerebral autoregulation and neurovascular coupling. The major
objective of the proposed study is to investigate whether cognitive functioning
of formerly preeclamptics is diminished and related to control of brain
perfusion (brain function). If cognitive function is diminished and related to
altered brain function, it could be hypothesized that this cognitive decline is
caused by organic cerebral damage and that abnormal CVC parameters may predict
a higher risk for future cerebrovascular complications such as stroke.

To evaluate whether cognitive function of formerly preeclamptics is diminished
and correlated with dynamic cerebrovascular control properties using
non-invasive measuring techniques (dynamic cerebral autoregulation,
neurovascular coupling). Question is whether these control parameters can serve
as screening tool for identifying formerly patients with increased risk on
future complications. Comparison of these findings with parameters
characterizing systemic blood vessel functioning (pulse wave velocity PWV,
pulse transit time PTT) and clinical patient neuropsychological status.

All subjects will be provided with objective information concerning the
research. In case of a positive decision after a number of days thinking over,
they will sign a form of consent.
In case the subject wishes, the partner is permitted to accompany her during
the recording session. The subject has the right to stop participation to the
study at any moment. This information will also be provided before the start of
the study.

Investigation load and risk for the participants are minimal.
Neuropsychological test battery takes about one hour. For the cerebrovascular
tests the participant is lying supine in a bed. During the study of
neurovascular coupling the participant has to actively view a dynamic visual
stimulus during 40 seconds followed with an eyes closed period of 20 seconds.
This sequence is repeated about 10 times. All measurements are non-invasive,
do not form a patient load and are painless. Between the different parts of
the research (neuropsychological tests, Duplex-investigation, neurovascular
coupling registration, cerebral autoregulation registration and pulse wave
velocity determination) patients will be given the opportunity to have breaks
and drink water. Participation therefore bears no risk.

Ethical aspects
All potential study participants will be informed both in writing and verbally
with objective information concerning the scientific research project. Enough
time (days to week) will be given to think about participation and to give
approval. In case of a positive decision a form of consent will be signed.

It will be made clear that participants may at any moment, without giving
reasons and without any further medical consequence, stop their participation
to the study.

At any moment the participant will be able to consult an independent physician
for further information. The name of this physician is dr. G. Koek (azM).

Participant privacy will be assured and the study data will be coded nameless
and anonymously by a coded serial number. Data will be stored for the legally
maximal period of medical data backup.
Only direct project staff members will have access to the measurement data.
Only these members will know the link between the coded patient data and the
patient private data.

It will be made clear that participants may choose to be informed about the
results at the end of the project.
The present research is not directly related to disease and will not result in
disease related aspects. Despite this, we will inform every participant whether
he/she and/or their family doctor wants to be informed about the results of the
study. In case abnormalities are found in a subject, which according to the
present medical standards should be treated, the general practitioner will be
informed.


Publication of research results
Results of the study will be published in peer reviewed scientific papers both
in case of positive but also in case of negative findings. Publication of
results will be done according to the CCMO-statement regarding publication
policy (march, 2002).
No (research) sponsoring authority has a right of veto regarding publication of
research results.