Authors :
First Author: Yujiang Wang, PhD – Newcastle University
Presenting Author: Sarah Gascoigne, BSc, PGDip – Newcastle University
Mariella M.Panagiotopoulou2@newcastle.ac.uk, MSc – Newcastle University; Christopher Thornton, Dr – Newcastle University; Fahmida Chowdhury, Dr – UCL; Jane de Tisi, Mrs – UCL; Beate Diehl, Dr – UCL; John Duncan, Prof – UCL; Andrew McEvoy, Mr – UCL; Anna Miserocchi, Mr – UCL; Peter Taylor, Dr – Newcastle University
Rationale:
Modulatory biorhythms have long been associated with epilepsy, and this association is bi-directional. Multiple mechanisms are thought to underpin these associations; but functionally, in humans, little is known about their expression in the brain or their interaction with epilepsy. Specifically, although multiple biorhythms are recorded in ongoing brain activity, we currently do not know if these biorhythms are functionally altered in pathological tissue.
Methods:
We used continuous intracranial EEG recordings over multiple days in 39 people with focal refractory epilepsy. We extracted biorhythms of neural activity on circadian and ultradian timescales in simple signal properties such as band power. We analyzed if these biorhythms varied in the presence of pathology.
Results:
Circadian and multiple ultradian rhythms were diminished in magnitude in regions that were deemed to be pathological compared to healthy tissue (median AUC >0.7, p< 0.05 across subjects). This effect was persistent in time in most patients in circadian and multiple ultradian rhythms, independent of seizure occurrence.