What If We Could See a Seizure Focus?

Idiopathic epilepsy is something we all see on a regular basis. However, when we diagnose something by exclusion, I often wonder what we are missing. Currently idiopathic epilepsy is diagnosed if dogs meet the following criteria:

Tier I

  • Normal neurologic examination

  • Normal CBC, serum biochemistry and bile acid test


Tier II

  • All of the above PLUS

  • Normal brain MRI

  • Normal CSF analysis results


(There is a Tier III, but it is rarely used.)

What if we could actually see a seizure focus?


This is the stuff of science-fiction, folks! A recent article in JVIM (https://doi.org/10.1111/jvim.16270) utilized an MRI technique that has been used in human epilepsy to try to visualize a seizure focus in dogs with idiopathic epilepsy. MRI works by affecting magnetic fields in the brain. With this new technique, neuronal currents are mapped with a specific oscillating magnetic field. This has been shown to be an effective mapping technique for humans with idiopathic epilepsy. The researchers applied the technique to a group of control dogs (those without seizures) and dogs diagnosed with idiopathic epilepsy with Tier II level confidence.

Results

There were three different frequencies used in the protocol however the authors combined the results from the different frequencies and found that 11 of 12 dogs with idiopathic epilepsy had a bright spot identified in their brain, with this technique. Even cooler, 4 of the 5 control dogs did NOT have any bright spots visualized in their brains. Perfect? No. Super cool? Yes!

Take Home Message

What does this mean for you and me? It means that as we test this new protocol a bit more we are one step closer to "seeing" the seizure focus in the brain. Who cares, you may ask? We all should!! If we can see it, we can remove it surgically (maybe), target it with radiation (already being done but this will improve accuracy), or start to identify different "types" of idiopathic epilepsy and assess how our drug protocols are affecting animals with specific forms of epilepsy. All of this allows us to target epilepsy much more specifically, and ultimately improve quality of life.

Thanks for reading! Hopefully you can use this new information to give your clients hope, when faced with a diagnosis of canine idiopathic epilepsy. Researchers (vets!) are working tirelessly to find a way to make life better for owners, and their pets with epilepsy.

Have a great week and be safe!