title: Transcranial magnetic stimulation (TMS) coupled with electroencephalography (EEG): Biomarker of the future.
abstract: BACKGROUND
  In recent years, a number of novel brain-stimulation techniques have been developed (such as TMS-EEG, TMS-fMRI and TMS-NIRS), yet they remain underutilized in the field of epilepsy. Accumulating evidence suggests that transcranial magnetic stimulation (TMS) combined with electroencephalography (TMS-EEG) is a highly relevant technique for exploration of the pathophysiology of human epilepsies as well as a promising biomarker with diagnostic and prognostic potential.
  
  
  RESULTS
  In genetic generalized epilepsies, TMS-EEG has provided pathophysiological insight by revealing quasi-stable, covert states of excitability, a subclass of which is associated with the generation of TMS-induced epileptiform discharges (EDs). In focal epilepsy, TMS-induced EDs were successfully employed to identify the epileptogenic zone. In addition, TMS trains applied during focal EDs can terminate them, and appear to restore the effective connectivity of the brain network significantly altered by EDs. This abortive effect of TMS on EDs may possibly serve as a biomarker of response to invasive neuromodulatory techniques.
  
  
  CONCLUSIONS
  TMS-EEG-based stimulation paradigms can provide insight into the mechanisms underlying human epilepsies and, thus, warrant further study as diagnostic and prognostic biomarkers.
authors: Laboratory of Clinical Neurophysiology, Aristotle Univertasity of Thessaloniki, AHEPA University Hospital, 1 St Kiriakidi Street, 54636 Thessaloniki, Greece. Electronic address: kimiskid@med.auth.gr.
authors: V K
authors: VK
authors: Kimiskidis
mesh_terms: D015415:Biomarkers / Q000032:analysis*; D001921:Brain / Q000503:physiopathology; D003943:Diagnostic Techniques, Neurological / Q000639:trends*; D004569:Electroencephalography / Q000379:methods / Q000639:trends; D004827:Epilepsy / Q000175:diagnosis* / Q000628:therapy; D006801:Humans; D011379:Prognosis; D050781:Transcranial Magnetic Stimulation / Q000379:methods / Q000639:trends
chemical_list: D015415:Biomarkers
keywords: Brain connectivity; Epilepsy; Neuromodulation; TMS–EEG; TMS–EMG