RT Journal Article
SR Electronic
T1 Ictal recruitment of anterior nucleus of thalamus in human focal epilepsy
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 788422
DO 10.1101/788422
A1 Emilia Toth
A1 Ganne Chaitanya
A1 Diana Pizarro
A1 Sachin S Kumar
A1 Adeel Ilyas
A1 Andrew Romeo
A1 Kristen Riley
A1 Ioannis Vlachos
A1 Olivier David
A1 Karthi Balasubramanian
A1 Sandipan Pati
YR 2019
UL http://biorxiv.org/content/early/2019/10/01/788422.abstract
AB The thalamic nuclei play diverse roles in the initiation, propagation, and termination of temporal lobe seizures. The role of the anterior nucleus of the thalamus (ANT) - a node that is integral to the limbic network is unclear. The objective of this study was to characterize temporal and - spectral patterns of ANT ictal recruitment in drug-resistant temporal lobe epilepsy (TLE). We hypothesized that seizures localized to the temporolimbic network are likely to recruit ANT, and the odds of recruitment were higher in seizures that had altered consciousness. Ten patients undergoing stereo-electroencephalography (SEEG) were recruited prospectively to record field potentials from the ANT. Using epileptogenicity index and line length, we computed the number of seizures that recruited the ANT (recruitment ratio), the recruitment latencies between the ANT and the epileptogenic zone (EZ), and latency of ANT recruitment to clinical manifestation for seventy-nine seizures. We observed that seizures localized to mesial temporal subregions (hippocampus, amygdala, anterior cingulate) have a higher predilection for ANT recruitment, and the recruitment was faster (ranged 5-12 secs) and preceded clinical onset for seizures that impaired consciousness. Seizures that recruited ANT lasted significantly longer (t=1.795, p=0.005). Recruitment latency was inversely correlated to seizure duration (r=-0.78, p=0.004). Electrical stimulation of the EZ induced seizures, in which early recruitment of ANT was confirmed. Stimulation of ANT did not induce a seizure. Finally, we tested the hypothesis that spectral and entropy-based features extracted from thalamic field potentials can distinguish its state of ictal recruitment from other interictal states (including awake, sleep). For this, we employed classification machine learning that discriminated thalamic ictal state from other interictal states with high accuracy (92.8%) and precision (93.1%). Among the features, the emergence of the theta rhythm (4-8 Hz) maximally discriminated the endogenous ictal state from other interictal states of vigilance. These results prompt a mechanistic role for the ANT in the early organization and sustaining of seizures, and the possibility to serve as a target for therapeutic closed-loop stimulation in TLE.ASDAnti-seizure drugsDWTDiscrete Wavelet TransferEIEpileptogenecity IndexESElectrographic SeizuresEZEpileptogenic ZoneFASFocal Onset Aware SeizuresFBTCSFocal to bilateral tonic-clonic seizuresFIASFocal onset seizures with impaired awarenessHAACHippocampus, Amygdala, Anterior Cingulate complexLLLine LengthMSEMultiscale EntropyRFRandom ForestRKSRandom Kitchen SinkRWERelative Wavelet EnergySEEGstereo-electroencephalographyTLETemporal lobe epilepsyUEOUnequivocal electrographic onset