title: Early Detection of Human Epileptic Seizures Based on Intracortical Local Field Potentials.
abstract: The unpredictability of re-occurring seizures dramatically impacts the quality of life and autonomy of people with epilepsy. Reliable early seizure detection could open new therapeutic possibilities and thus substantially improve quality of life and autonomy. Though many seizure detection studies have shown the potential of scalp electroencephalogram (EEG) and intracranial EEG (iEEG) signals, reliable early detection of human seizures remains elusive in practice. Here, we examined the use of intracortical local field potentials (LFPs) recorded from 4×4-mm296-microelectrode arrays (MEA) for early detection of human epileptic seizures. We adopted a framework consisting of (1) sampling of intracortical LFPs; (2) denoising of LFPs with the Kalman filter; (3) spectral power estimation in specific frequency bands using 1-sec moving time windows; (4) extraction of statistical features, such as the mean, variance, and Fano factor (calculated across channels) of the power in each frequency band; and (5) cost-sensitive support vector machine (SVM) classification of ictal and interictal samples. We tested the framework in one-participant dataset, including 4 seizures and corresponding interictal recordings preceding each seizure. The participant was a 52-year-old woman suffering from complex partial seizures. LFPs were recorded from an MEA implanted in the participant's left middle temporal gyrus. In this participant, spectral power in 0.3-10 Hz, 20-55 Hz, and 125-250 Hz changed significantly between ictal and interictal epochs. The examined seizure detection framework provided an event-wise sensitivity of 100% (4/4) and only one 20-sec-long false positive event in interictal recordings (likely an undetected subclinical event under further visual inspection), and a detection latency of 4.35 ± 2.21 sec (mean ± std) with respect to iEEG-identified seizure onsets. These preliminary results indicate that intracortical MEA recordings may provide key signals to quickly and reliably detect human seizures.
authors.affiliation: School of Engineering and the Brown Institute for Brain Science, Brown University, Providence, RI 02912 USA.
authors.forename: Yun S
authors.initials: YS
authors.lastname: Park
authors.affiliation: Center for Neurorestoration and Neurotechnology, Rehabilitation R&D Service, Department of Veterans Affairs, Providence, RI 02908 USA; the School of Engineering, Brown University, Providence, RI 02912 USA; and the Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114 USA.
authors.forename: Leigh R
authors.initials: LR
authors.lastname: Hochberg
authors.affiliation: Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114 USA.
authors.forename: Emad N
authors.initials: EN
authors.lastname: Eskandar
authors.affiliation: Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114 USA.
authors.forename: Sydney S
authors.initials: SS
authors.lastname: Cash
authors.affiliation: Department of Neuroscience and the Brown Institute for Brain Science, Brown University, Providence, RI 02912 USA; the Center for Neurorestoration and Neurotechnology, Rehabilitation R&D Service, Department of Veterans Affairs, Providence, RI 02908 USA, phone: 401-863-5282; fax: 401-863-6481.
authors.forename: Wilson
authors.initials: W
authors.lastname: Truccolo