Q&A Report: Evaluation of Novel Therapies Using Spontaneous Seizure Models

Cameron Metcalf and Katrina Irey answer questions from a recent webinar on technical requirements and benefits of spontaneous seizure models and epilepsy therapy development.

The answers to these questions have been provided by:

Cameron Metcalf, PhD
Associate Director
ADD Program
University of Utah

Katrina Irey, BS
Kaha Sales Specialist
North American Sales
ADInstruments, Inc.

Have you looked into using machine learning methods (eg., Deeplabcut) to detect convulsion/seizures from the video? Also, how long after Kainate induced kindling is the model "viable" (ie., does spontaneous seizure state result in long-term damage)?

First, we agree that machine learning/artificial intelligence can be beneficial to video monitoring for seizures. There are multiple groups that are working on this and we have developed our own algorithm for seizure quantification using rat telemetry. Second – to clarify we were speaking about the kainate model, which is not the same as kindling. Tissue damage following kainate in our paradigm is consistent with human mesial temporal lobe epilepsy and rats develop spontaneous seizures in the weeks and months that follow.

Is there a limit to how long I can record data from my animals with the telemetry system?

The short answer is weeks-months at least. We have been able to extend the life of our telemeters by explanting and re-implanting. Another thing to note is that this will also be dependent on your computer and the software you use. Continuous recordings of multiple animals will create very large files that will need to be managed accordingly depending on the processing and storage capabilities of your computer.

What effect size do you expect to see for a successful experimental drug in these models? How many animals are required to be properly powered to see such an effect?

An effect size of 50% (or more) reduction in seizures is preferred. Also, given the variability in seizure frequency, to detect such a change group sizes of 12 or more are required.

What is the range of the telemeter once implanted?

Several feet (depending on charge) – to further expand on this, the manual states that the transmission range of the rat telemeters is 5 meters, but this can vary depending on the configuration of your laboratory.

Can this telemetry technology can be virtually use in other vertebrate (for example fish)?

Not likely in fish until implantable telemeters are sufficiently miniaturized, but the telemeters can be used in rodents similar in size to mice and rats such as guinea pigs, hamsters, voles, etc.