Pål G. Larsson

4Orvar Eeg-Olofsson
2Knut Stavem
2Edna Røssberg
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An extension of transfer entropy, called partial transfer entropy (PTE), is proposed to detect causal effects among observed interacting systems, and particularly to distinguish direct from indirect causal effects. PTE is compared to a linear direct causality measure, the Partial Directed Coherence (PDC), on known linear stochastic systems and nonlinear(More)
  • Michael Scherg, Nicole Ille, Dieter Weckesser, Arndt Ebert, Andrea Ostendorf, Tobias Boppel +4 others
  • 2012
PURPOSE The burden of reviewing long-term scalp electroencephalography (EEG) is not much alleviated by automated spike detection if thousands of events need to be inspected and mentally classified by the reviewer. This study investigated a novel technique of clustering and 24-h hyper-clustering on top of automated detection to assess whether fast review of(More)
OBJECTIVE Clinically, intra-subject variability of the alpha frequency is well known, but sparsely documented and practically not used in the evaluation of the electroencephalogram (EEG). In cognitive science, however, the peak alpha frequency (PAF) variations are implemented. The aim of the present study was to document the clinical notion of differences(More)
We report comparison and assessment of the clinical utility of different automated methods for the estimation of the alpha frequency in electroencephalograph (EEG) and compare them with visual evaluation. A total of 56 consecutive patients, aged 17 to 78 years, who had a routine EEG recording, were included, and they were grouped as patients with epilepsy(More)
PURPOSE To compare three methods of localizing the source of epileptiform activity recorded with magnetoencephalography: equivalent current dipole, minimum current estimate, and dynamic statistical parametric mapping (dSPM), and to evaluate the solutions by comparison with clinical symptoms and other electrophysiological and neuroradiological findings. (More)
BACKGROUND The Chronic Sinusitis Survey (CSS) is a valid, disease-specific questionnaire for assessing health status and treatment effectiveness in chronic rhinosinusitis. In the present study, we developed a Norwegian version of the CSS and assessed its psychometric properties. METHODS In the pooled data set of 65 patients from a trial of treatment for(More)
The purpose of this study was to investigate changes in utilisation of antiepileptic drugs (AEDs) in epilepsy and non-epilepsy disorders in Norway and furthermore to study the retention rates of the most commonly used AEDs in these indications in long-term use. The data consisted of all prescriptions of AEDs from Norwegian pharmacies in the Norwegian(More)
BACKGROUND Symptoms of attention deficit hyperactivity disorder (ADHD) are more common in children with epilepsy than in the general paediatric population. Epileptiform discharges in EEG may be seen in children with ADHD also in those without seizure disorders. Sleep enhances these discharges which may be suppressed by levetiracetam. AIM To assess the(More)
The sleep EEGs of many children with neurodevelopmental disorders reveal epileptiform activity. The aim of this study was to compare spike index (SI) in full-night recordings with SI in sleep-deprived EEGs in the morning; EEGs were obtained over 24 hours using ambulatory equipment. Sixteen children between the ages of 7 and 12 years were included in the(More)
Different neuroimaging techniques (fMRI, spectroscopy, PET) are being used to evaluate candidate drugs in pharmacological development. In patients with epilepsy fast propagation of the epileptiform activity between different brain areas occurs. Electric Source Imaging (ESI), in contrast to the aforementioned techniques, has a millisecond time resolution,(More)