Thalamic interictal epileptiform discharges in deep brain stimulated epilepsy patients

• Published in: Journal of neurology Vol. 263; no. 10; pp. 2120 - 2126
• Main Authors: Sweeney-Reed, Catherine M., Lee, Harim, Rampp, Stefan, Zaehle, Tino, Buentjen, Lars, Voges, Juergen, Holtkamp, Martin, Hinrichs, Hermann, Heinze, Hans-Jochen, Schmitt, Friedhelm C.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2016; Springer Nature B.V
• Subjects: Aged; Brain Mapping; Brain Waves; Deep Brain Stimulation - methods; Drug Resistant Epilepsy - diagnostic imaging; Drug Resistant Epilepsy - therapy; Electrodes; Electroencephalography; Epilepsy; Female; Functional Laterality; Humans; Magnetic Resonance Imaging; Male; Medicine; Medicine & Public Health; Neurology; Neuroradiology; Neurosciences; Online Systems; Original Communication; Thalamus - physiology; Tomography, X-Ray Computed; Interictal epileptiform discharges; Refractory epilepsy; Anterior nucleus of the thalamus; Dorsomedial nucleus of the thalamus; Deep brain stimulation
• ISSN: 0340-5354; 1432-1459
• DOI: 10.1007/s00415-016-8246-5

The relationships between interictal epileptiform discharges (IEDs) in the anterior (ANT) and dorsomedial nuclei (DMNT) of the thalamus and electro-clinical parameters in pharmacoresistant focal epilepsy patients receiving intrathalamic electrodes for deep brain stimulation (DBS) were investigated. Thalamus-localized IEDs (LIEDs) and surface EEG (sEEG)-IEDs were evaluated in eight patients who underwent ANT-DBS. Occurrence and frequency of ANT- and DMNT-LIEDs and pre-operative sEEG-IEDs were examined with respect to seizure onset location and seizure outcome following ANT-DBS. LIEDs were identified in all eight patients, in the ANT, DMNT, or both. ANT-LIEDs were observed in all patients with an unequivocal temporal seizure onset zone. The ANT-LIED frequency correlated with pre-surgical sEEG-IED frequency ( ρ  = 0.76, p  = 0.033) and predicted ANT-DBS responsiveness ( T  = −2.6; p  = 0.0428). Of the five patients with bilateral sEEG-IEDs, all had ANT-LIEDs, but only one patient had DMNT-LIEDs. All patients with no or unilateral sEEG-IEDs had DMNT-LIEDs. Observation of LIEDS in the ANT and DMNT supports the hypothesis that these nuclei are involved in propagation of focal epileptic activity. Their correspondence with differing electro-clinical features suggests that these nuclei are functionally distinguishable nodes within the epileptic networks of individual patients.