Development of a fMRI memory task for epilepsy surgery candidates

For patients with drug-resistant focal epilepsy neurosurgery could be a helpful
treatment in terms of seizure reduction. However, these patients are at risk
for disruption of the language or memory networks and deficits of these
cognitive functions postoperatively. To minimize this risk, it is important to
assess the lateralization of language and memory networks preoperatively.
Currently, an invasive test, the Wada test, is used. Research is now focused on
using the non-invasive method fMRI. FMRI language lateralization has already
proven to be possible, but for memory this is more complicated. In the
Netherlands there is no proper memory task available that can be used in fMRI
to localize memory functions in patients with epilepsy.
The challenge is to develop a task that will provoke specific memory network
activations, namely bilateral hippocampal activity. A promising fMRI memory
task is the face-name association task. However, this task is currently used in
research involving students and has to be adjusted to be suitable for patients.

The main object of this study is:
Optimization of the face-name association task, such that this task can be used
to examine the prediction of postoperative memory failure in preoperative
patients with epilepsy.

Sub Objectives:
- Investigation and adaptation of the difficulty of the task, such that the
participants under study perform well on the task
- Replication of the results of prior research (de Vogelaere et al., 2010) and
provoke bilateral hippocampal activation
- Control for physiological processes using a photoplethysmogram (PPG)

The primary outcome is a fMRI memory task that can map the memory function
bilaterally in healthy controls. Based on the outcome of this project, further
research can be performed to assess the predictive value of memory fMRI in
preoperative temporal lobe epilepsie (TLE) patients.

This is an observational study with healthy volunteers. The study is a
feasibility study of the face-name association task in a clinical setting. The
task will be adjusted and tested in the MRI on ten healthy volunteers, varying
in age and education level. A lateralization index score will be computed,
using significant Bold response strengths of the fMRI data. We anticipate that
the fMRI memory task will subsequently be tested on epilepsy patients during a
pre-surgical workup and that the results will be compared to the Wada test,
currently in clinical use.

The healthy volunteers will undergo one MR scanning session (about 30 minutes
in duration). There is no extra benefit for the participants themselves. The
extra risk for the participants in this study are negligible.