What are seizures in dogs and cats and how are they treated?

A seizure is a symptom of certain diseases affecting the brain.  In medical terms, it's also referred to as 'hypersynchronous cerebrocortical discharge'.  That's because, in a healthy animal, the cells in the brain send electrical signals over relatively long distances and don't 'fire' all at once in any particular area.  On an EEG, this looks like little squiggly lines in health, but if enough cells fire together (hypersynchronous discharge) it looks like a big 'spike' on the EEG readout.

This is our Electroencephalogram in action ...

Like we said, seizures are a symptom of disease.  The most common disease to cause seizures in dogs is Idiopathic Epilepsy.  But liver disease, kidney disease, changes in calcium or sodium in the blood, even brain tumors and auto-immune diseases can cause seizures.  That's why we often recommend an MRI and a spinal tap to look at your pet's brain and determine the underlying cause.

Still, seizures as a symptom (even if the underlying cause isn't progressive - like Idiopathic Epilepsy or a 'stroke') are often progressive.  That means that, the more a pet has seizures, the more likely they are to have more seizures and the more severe the seizures are likely to become.

For this reason, we treat seizures to maintain a certain level of control.  While it is possible to make seizures go away completely; in many cases, the adverse effects of the drugs make this a terrible option.  You see,  the more we give drugs to control seizures, the more we sedate the patient.  If we go to far with the medications, there won't be any seizures but your pet might be mistaken for a doormat!

There are many different options for treating seizures in our pets.  First, we attempt to identify and treat the underlying cause of the seizures.  Then we try to find the right drug or combination of drugs for that particular pet and your particular situation.  That's why we call it the 'art of seizure management'.

What is an EEG?

EEG is the acronym for electroencephalography.  

Which is definitely a word that needs an acronym ....

Electroencephalography is a method of using electrodes that can sense the flow of electricity within biological tissues to look at brain function.  The brain, spinal cord, heart, and some other special tissues in the body use electrical signals to communicate rapidly between the cells that make up those particular tissues.  With these special electrodes, we can watch this electrical current and deduce information from them with regard to certain diseases.  

The machine shows us the electrical activity as several lines on a screen.  In animals and people, EEG is primarily used to evaluate an individual for seizures or, sometimes, sleep disorders.  

Seizures look like 'spikes' followed by 'waves' as you can see here...

We also use it for patients that are in status epilepticus.  This is a condition when a seizure lasts longer than 20 minutes or there are multiple seizures without a return to consciousness in between.  Left untreated, this can cause permanent brain damage!

We've actually had two patients at LOVN this year that were in status epilepticus when they came in, but weren't having any outward signs.  This is called non-convulsive status epilepticus and without our EEG we wouldn't have been able to recognize it.  What's more, we were able to treat both of these patients with medications and use the EEG to monitor the effect of the drugs.

When patients are having such prolonged seizures, we often have to put them under general anesthesia to stop the seizures.  Then we have to decide when to try and wake them up.  Without the EEG this would just be a guess.  But with our EEG we can monitor the read-out for continued seizures even though the patient is completely asleep.  So, now, we don't have to guess when it's safe to wake a patient up.  We know...