F. S. S. Leijten

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The conductivity of the human skull plays an important role in source localization of brain activity, because it is low as compared to other tissues in the head. The value usually taken for the conductivity of skull is questionable. In a carefully chosen procedure, in which sterility, a stable temperature, and relative humidity were guaranteed, we measured(More)
One of the critical issues in brain-computer interface (BCI) research is how to translate a person's intention into brain signals for controlling computer programs. The motor system is currently the primary focus, where signals are obtained during imagined motor responses. However, cognitive brain systems are also attractive candidates, in that they may be(More)
Diagnosing psychogenic non-epileptic seizures (PNES) is a clinical challenge. There is neither a standard in diagnosing PNES nor a comprehensive theoretical framework for this type of seizure. The diagnosis of PNES must be made by excluding epilepsy. However, epilepsy cannot always be determined and PNES and epileptic seizures may coexist. In this study,(More)
The purpose of this study was to evaluate the contribution of posterior circulation to memory function by comparing memory scores between patients with and without a foetal-type posterior cerebral artery (FTP) during the intracarotid amobarbital procedure (IAP) in epilepsy patients. Patients undergoing bilateral IAP between January 2004 and January 2010(More)
INTRODUCTION Epilepsy associated with tuberous sclerosis complex (TSC) is drug resistant in more than half of the patients. Epilepsy surgery may be an alternative treatment option, if the epileptogenic tuber can be identified reliably and if seizure reduction is not at the expense of cognitive or other functions. We report the pre-surgical identification of(More)
For some TLE patients that do not respond the pharmacological treatment, epilepsy surgery is an option. In those cases, the determination of the location of the sources and the sequence in which they become active is of prime importance. In this paper, we investigate the interpretability and validity of dipole source localization based on EEG, MEG and(More)
In EEG correlated fMRI interictal spikes as identified in the EEG during scanning of an epilepsy patient are used as events in an event related fMRI design. Spike identification, whether automatic or by a human observer, is accompanied by uncertainty and inevitably leads to false detections and missed events. This situation is not common in event related(More)
OBJECTIVE High frequency oscillations (HFOs; > 80 Hz), especially fast ripples (FRs, 250-500 Hz), are novel biomarkers for epileptogenic tissue. The pathophysiology suggests enhanced functional connectivity within FR generating tissue. Our aim was to determine the relation between brain areas showing FRs and 'baseline' functional connectivity within EEG(More)
We describe two patients who showed snapping of the right hand fingers during invasive intracranial EEG evaluation for epilepsy surgery. We correlated the EEG changes with the finger-snapping movements in both patients to determine the underlying pathophysiology of this phenomenon. At the time of finger snapping, EEG spread from the supplementary motor area(More)
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