This document discusses brain stimulation as a treatment for epilepsy. It describes a responsive neurostimulator device that detects abnormal brain activity associated with seizures and delivers stimulation to prevent seizures from occurring. It also discusses using intracranial electrodes to map epileptic networks in the brain and locate the seizure onset zone. Finally, it envisions future devices that can continuously monitor brain activity at high resolution using wireless sensors and use artificial intelligence to anticipate and respond to seizures.

2. Brain Stimulation for The Treatment Of Epilepsy Associate Professor of Neurology and Bioengineering University of Pennsylvania Brian Litt, MD Disclosure

7. NeuroPace Responsive Stimulator

8. Stimulating Electrode, 4 contacts Electrode (4 contacts )

9. Anthony Murro, M.D. Medical College of Georgia

10. Stimulated Temporal Lobe Epileptiform Activity Stimulation Courtesy of NeuroPace Inc.

11. eRNS Sample Data

12. Seizure -5 -4 -3 -2 0 -1 -6 Hours 0 hrs: Seizure - 2 hrs: “Chirps” start & build Accumulated Energy 50 min epochs Raw EEG: 6 sec burst Energy Accumulates - 1 hour EEG: 10 sec shown - 8 hrs: bursts increase Raw EEG: 15 min epoch Energy over time to Seizure Onset (A) (B) (C) (D)

13. Gamma Precursors in Neocortical Epilepsy ~85 Hz Sz onset (in red) Worrell, et al., Brain , in press

14. Interictal HFEO: Seizure Precusors? Worrell et al., 2004 50  V 100 ms ~70-100 Hz oscillation

15. Ictal Recording/ Mapping Defining the Network Dysplasia (stealth) Ictal onset zone Rapid Sz spread Epileptogenic Zone Brocca’s area HFEOs

16. Hippocampal Interneurons Diversity & characteristic anatomy Images reproduced from Freund TF, Buzsaki G: Interneurons of the Hippocampus . Hippocampus 1996, 6(4):345-470.

18. Hippocampal Neuromodulation Intrinsic and subcortical sources Neuromodulator Receptor Source Glutamate mGluR Intrinsic GABA GABA B Intrinsic Acetylcholine m1 Medial septal nucleus m2 Diagonal band of Broca m3 m4 Serotonin 5HT-3 Median raphé nucleus 5HT-2 Dorsal raphé nucleus 5HT-1A Norepinephrine  1 Locus coeruleus  2  1 Dopamine D1 Ventral tegmental area D2 Histamine H2 Tuberomamillary nucleus Adenosine Intrinsic Somatostatin Intrinsic NPY Intrinsic CRF Hypothalamus