audiogenic seizures

Audiogenic Reflex Seizures, Anyone?

Crinkling wrapping paper, crackling fires, and music - can any of these things cause seizures? 

What are they?

Feline audiogenic reflex seizures (FARS) start in cats late in life (> 10 years of age) and are triggered by a sound or sounds. The seizure phenotype (appearance) has a myoclonic component (a rapid twitch) but may also have absence or generalized seizures, as well. Absence seizures don't have any muscle movement associated with them and generalized seizures are charicterized by tonic clonic movements.

What causes FARS?


Any noise, but usually a high frequency sound such as clinking a spoon in a tea cup triggers the seizures. Some cats will have spontaneous seizures in addition to FARS and others will purely have FARS. If you are seeing an older cat with new onset seizures, consider having the client keep a "sound diary" for a few weeks to see if there is a correlation. 

Why bother identifying this...you're going to tell me to give phenobarbital!


Au contraire mon frere! A sentinel study was published in 2017 by Lowrie, et al (https://doi.org/10.1177%2F1098612X15622806) that showed a marked improvement in cats on levetiracetam in a randomized, controlled, open-label study with phenobarbital. 100% of the cats in the levetiracetam group obtained seizure control compared to 3% in the phenobarbital group. So you're correct that I typically prefer phenobarbital for feline seizures...except for FARS!

What causes FARS?

Interestingly, the majority of cats diagnosed with FARS in the published studies have had idiopathic epilepsy with a small portion showing progressive signs suggestive of active forebrain disease (neoplasia, meningoencephalitis).  

Merry Christmas to those who celebrate! Wishing everyone a happy, healthy holiday season filled with family, friends and good food. Thanks for reading and I look forward to working with you soon! As a quick reminder, I am out of town December 25-January 2nd. See you in 2026!