Seizure & epilepsy

Seizure is a disorder of the nervous system, thought to be the result of faulty electrical activity in the brain which can lead to changes in behavior, movement, feelings, and/or levels of consciousness.

Description

Epilepsy studies involve seizure detection from EEG traces, but other parameters can be of interest, such as ECG, EMG, activity/behavior, or sleep scoring. For instance, researches have been suggesting that SUDEP (Sudden Unexpected Death in Epilepsy) could occur preferentially during sleep. Therefore, combining epilepsy and sleep analysis, through a unique analysis software, is a crucial advantage when studying SUDEP and other comorbidities.

Additionally, seizure detection can be useful when working in toxicology or safety pharmacology studies. The testing of various agents and drugs and their effects on seizure threshold or the induction of seizures can be useful when determining safety of said compounds and therapeutics.

Video monitoring, combined with biopotentials acquisition, is also recommended, to identify and characterize seizure movements and give insight to seizure development and intensity. EEG and synchronized video acquisition help to identify motor and non-motor seizures or behavioral artifacts.

Wireless technology permits a constant transfer of high volumes of digital data from freely moving animals. The advantages associated with this technique are well established; higher quality data obtained from naturally-behaving subjects, which reliably captures detailed physiological events.

Implantable telemetry options

Various sized options are available in our implantable telemetry systems.

Rodents

Fully implantable easyTEL+ system and rodentPACK head-mounted systems are both wireless and allow subjects to freely move around their cages with group housing options.

easyTEL+ system acquires a single biopotential and provides the options for activity and core body temperature recordings.
rodentPACK system can collect up to 4 biopotentials (EEG, EOG, ECG, EMG) in addition to activity recording. rodentPACK also provides the ability to reuse transmitters across subjects, cohorts, and/or studies for a cost-effective alternative to implantable telemetry.

Large animals

The fully implantable easyTEL+ system offers up to 4 biopotentials (EEG, EOG, ECG, EMG) with optional temperature and activity monitoring that can be paired with synchronized video recording.

All of our telemetry recording systems can be paired with synchronized video monitoring to assist with neurological assessments.

Non-invasive telemetry options

Non-invasive systems collect neurological and activity changes without surgical implantation of the telemeter. Subjects are equipped with an external transmitter housed in a jacket or a helmet with surface leads paced on the scalp. Physiological measurements are captured non-invasively and wirelessly transmitted by Bluetooth or radio frequency, to a receiver.

Analysis

Our powerful EEG analysis software helps researchers comb through the data and analyze their subject’s response to various agents, drugs, and disease models. It allows the analysis of EEG morphology with time-synchronized video for behavioral verification.

Automated sleep scoring allows for further behavioral analysis through sleep staging that can be overlaid on signal screen. FFT spectral information can also be overlaid on the signal screen to observe changes between epoch in relation to other variables.

AW: Active Wake; QW: Quiet Wake; SWS: Slow Wave Sleep ; REM: Rapid Eye Movement sleep

Epilepsy detection module

From the EEG signal, the seizure detection module automatically detects seizures, combining multiple user adjusted criteria and logical modes:

All detected seizures are logged in a table
Invalid seizures can be deleted
Undetected seizures can be created
Valid seizures can be exported to text or xls files

Heatmaps allow for easy identification of changes in signal over time or across leads and related to disease, activity, or incoherence across various leads or brain regions.

Protocol example

<a title="Use of a Wireless Video-EEG System to Monitor Epileptiform Discharges Following Lateral Fluid-Percussion Induced Traumatic Brain Injury" href="https://www.jove.com/video/59637/use-wireless-video-eeg-system-to-monitor-epileptiform-discharges">Use of a Wireless Video-EEG System to Monitor Epileptiform Discharges Following Lateral Fluid-Percussion Induced Traumatic Brain Injury</a> </p> <p>

McGuire, M. J., Gertz, S. M., McCutcheon, J. D., Richardson, C. R., Poulsen, D. J. Use of a Wireless Video-EEG System to Monitor Epileptiform Discharges Following Lateral Fluid-Percussion Induced Traumatic Brain Injury. J. Vis. Exp. (148), e59637, doi:10.3791/59637 (2019).