Frequenzdynamik epileptischer Netzwerke: Eine systemneurophysiologische Funktionsanalyse

• Applicant: Professor Dr. Hermann Stefan
• Subject Area: Clinical Neurology; Neurosurgery and Neuroradiology
• Term: from 2010 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 185800476

The main aim of the study is a new non-invasive surrogate marker for localization and understanding of epileptic networks. Seizure activity and between seizures occurring spikes are characteristic for epileptic networks. Source analysis of these signals contributes for example to the planning of epilepsy surgery. Current studies now suggest new markers: high- (“high frequency oscillations” – HFO) and low-frequency oscillations (“slow waves”). Analysis of these enables localization and investigation of epileptic networks and their temporal dynamics independent of spikes and seizures. Therefore, even in patients without spikes (~20-30%) and without the need of seizures such information can be obtained. HFO are strongly correlated with epileptic networks, which promises more accurate localizations. So far, studies were mainly conducted using invasive methods, which limits clinical application. The presented study now aims to investigate HFO/slow wave with simultaneous invasive and non-invasive methods. For this purpose, simultaneous invasive-/surface-EEG and MEG is recorded in patient with pharmacoresistant focal epilepsies. Activity in high- and low-frequency bands is localized and compared with the gold-standard of long-term invasive EEG and resection volume after epilepsy surgery. A quantitative comparison is performed with the norm, acquired from healthy controls.

• DFG Programme: Research Grants
• Participating Person: Privatdozent Dr. Stefan Rampp