Invasive EEG in Presurgical Evaluation of Epilepsy

2011 IEEE Biomedical Circuits and Systems Conference (BioCAS)

Desgent

Duss

et al. 2011

In this paper, we propose new subdural electrode contacts to improve signal-to-noise ratio (SNR) for intracerebral electroencephalographic (icEEG) recording. We describe the proposed electrodes material composition, fabrication process, electro-chemical impedance spectroscopy analyses, and in vitro comparative studies with commercial electrodes (microelectrodes -MRE, depth electrodes -DPE, and subdural electrodes -SDE). The proposed subdural electrode contacts are made of Platinum (Pt) or Gold (Au). Compared to the DPE/SDE and MRE, the proposed Pt or Au electrodes feature reduced impedances of ~116 kΩ and ~8.89 MΩ respectively. In vivo icEEG recordings for three weeks in an adult Sprague Dawley rat demonstrated signal stability, 50% noise reduction and up to 3 dB SNR improvement. Following the long-term icEEG recording, brain histological result showed no abnormal tissue reaction in underlying cortex.

Section: Introductionmentioning

confidence: 99%

New subdural electrode contacts for intracerebral electroencephalographic recordings: Comparative studies on neural signal recording in vivo

2011 IEEE Biomedical Circuits and Systems Conference (BioCAS)

Desgent

Duss

et al. 2011

“…Epilepsy is a common chronic neurological disorder characterized by a predisposition to unprovoked recurrent seizures. A seizure is the manifestation of an abnormal, hypersynchronous discharge of a population of cortical neurons [1]. Several causes may disturb the normal pattern of brain activity and trigger an epileptic seizure, such as head injury, brain infection, developmental malformations, brain tumors, cerebrovascular disease, vascular malformations, genetic disorders, and hippocampal sclerosis.…”

Section: Introductionmentioning

confidence: 99%

“…However, electrographically, many seizure patterns are seen at seizure onset and there is variability in the seizure pattern depending on the localization and etiology of the seizure. The most common seizure onset patterns are low-voltage fast activity, highvoltage fast activity, and the rhythmic spiking [1]. Clinically, these ictal discharges usually lead to behavioral manifestations but may also be clinically silent (i.e., electrical seizures), especially if the ictal discharges remain very focal (without spread), are brief (a few seconds) and occur in non-eloquent cortex.…”

Section: Introductionmentioning

confidence: 99%

Low‐Power Implantable Device for Onset Detection and Subsequent Treatment of Epileptic Seizures: A Review

Journal of Healthcare Engineering

Nguyen

2010

Over the past few years, there has been growing interest in neuro-responsive intracerebral local treatments of seizures, such as focal drug delivery, focal cooling, or electrical stimulation. This mode of treatment requires an effective intracerebral electroencephalographic acquisition system, seizure detector, brain stimulator, and wireless system that consume ultra-low power. This review focuses on alternative brain stimulation treatments for medically intractable epilepsy patients. We mainly discuss clinical studies of long-term responsive stimulation and suggest safer optimized therapeutic options for epilepsy. Finally, we conclude our study with the proposed low-power, implantable fully integrated device that automatically detects low-voltage fast activity ictal onsets and triggers focal treatment to disrupt seizure progression. The detection performance was verified using intracerebral electroencephalographic recordings from two patients with epilepsy. Further experimental validation of this prototype is underway.

“…They may secondarily generalize as the epileptic discharge spreads contralaterally. Electrographically, several patterns can be seen at seizure onset such as low-voltage fast-activity, high-voltage fast-activity or rhythmic spiking [1]. Ictal discharges usually lead to a variety of behavioral manifestations but may sometimes be clinically silent (i.e.…”

Section: Introductionmentioning

confidence: 99%

Epileptic seizure onset detection prior to clinical manifestation

2010 Annual International Conference of the IEEE Engineering in Medicine and Biology

Nguyen

2010

In this paper, we present the design of an epilepticseizure detector. This circuit is part of an implantable device used to continuously record intracerebral electroencephalographic signals through subdural and depth electrodes. The implemented seizure detector is based on a detection algorithm validated in Matlab tools and the circuits were implemented using CMOS 0.18-microm process. The proposed system was tested using intracerebral EEG recordings from two patients with drug-resistant epilepsy. Four seizures were assessed by the proposed CMOS building blocks and the required delays to detect these seizures were 3, 8, 11, and 11 sec, respectively after electric onset. The simulated total power consumption of the detector was 6.71 microW. Together, these preliminary results indicate the possibility of building implantable ultra-low power seizure-detection devices.