Audiogenic reflex seizures in cats
When the charity International Cat Care asked veterinary neurologists at Davies Veterinary Specialists, UK, for help with several enquiries it had received regarding cats having seizures, seemingly in response to certain high-pitched sounds, the answer was that the problem was not documented and little, if anything, was known about the occurrence.
Researchers compiled a questionnaire for owners to complete. Working with International Cat Care, and using the interest generated by the media, the story went worldwide (dubbed ‘Tom and Jerry syndrome’ after the cartoon character Tom who has a strong startle reflex and often reacts with involuntary jerks to sound stimuli). They received hundreds of replies from across the globe from people who had noticed the same problem in their cats in response to certain types of sound. This study has defined a previously unreported syndrome by using a carefully screened questionnaire and medical records. The geriatric nature of this condition is such that it may be overlooked in older cats, which may potentially suffer from other concurrent conditions. The hope is that publication of the paper will raise awareness among vets in practice about this syndrome. Meanwhile, work is ongoing to identify the genetic basis of this disorder and the team is now also working on a paper about treatment of these cases.
Objectives This study aimed to characterise feline audiogenic reflex seizures (FARS). Methods An online questionnaire was developed to capture information from owners with cats suffering from FARS. This was collated with the medical records from the primary veterinarian. Ninety-six cats were included.
Results Myoclonic seizures were one of the cardinal signs of this syndrome (90/96), frequently occurring prior to generalised tonic–clonic seizures (GTCSs) in this population. Other features include a late onset (median 15 years) and absence seizures (6/96), with most seizures triggered by high-frequency sounds amid occasional spontaneous seizures (up to 20%). Half the population (48/96) had hearing impairment or were deaf. One-third of cats (35/96) had concurrent diseases, most likely reflecting the age distribution. Birmans were strongly represented (30/96). Levetiracetam gave good seizure control. The course of the epilepsy was non-progressive in the majority (68/96), with an improvement over time in some (23/96). Only 33/96 and 11/90 owners, respectively, felt the GTCSs and myoclonic seizures affected their cat’s quality of life (QoL). Despite this, many owners (50/96) reported a slow decline in their cat’s health, becoming less responsive (43/50), not jumping (41/50), becoming uncoordinated or weak in the pelvic limbs (24/50) and exhibiting dramatic weight loss (39/50). These signs were exclusively reported in cats experiencing seizures for >2 years, with 42/50 owners stating these signs affected their cat’s QoL.
Conclusions and relevance In gathering data on audiogenic seizures in cats, we have identified a new epilepsy syndrome named FARS with a geriatric onset. Further studies are warranted to investigate potential genetic predispositions to this condition.
Mark Lowrie, Claire Bessant, Robert J Harvey, Andrew Sparkes, and Laurent Garosi
Audiogenic reflex seizures in cats
Journal of Feline Medicine and Surgery 1098612X15582080, first published on April 27, 2015 doi:10.1177/1098612X15582080