Authors :
Presenting Author: Starr Cameron, BVetMed, MS, DACVIM (Neurology) – University of Wisconsin - Madison, School of Veterinary Medicine
Caroline Seymour, BSc – Veterinary Student, Medical Sciences, University of Wisconsin - Madison, School of Veterinary Medicine; Sue Osting, BSc – Neurology – University of Wisconsin - Madison; Nicholaus Marino, BSc – Veterinary Student, Medical Sciences, University of Wisconsin - Madison; Paul Buckmaster, DVM, PhD – Professor, Comparative Medicine; Neurology & Neurological Sciences, Stanford University
Rationale:
Temporal lobe epilepsy (TLE) is common in people and has been well described in several other species. Over half of epileptic domesticated cats have a seizure presentation similar to people with TLE, including: hypersalivation, staring off, dilated pupils, and facial twitching. In people with TLE, hippocampal sclerosis, characterized by hilar neuron loss, mossy fiber sprouting, and interneuron loss within the dentate gyrus, is commonly found. We hypothesized that cats with TLE-like seizures would display changes within the hippocampus similar to people with TLE.
Methods:
To test this hypothesis, client-owned cats with a history of seizures that were being euthanized (for any reason, related or unrelated to seizure activity) were perfused immediately upon euthanasia with paraformaldehyde (n=6). Control cats were young (1 year old) research colony cats that were being euthanized as part of other research studies (n=6). Brains were isolated and sectioned (40mm) coronally. Tissue was mounted and slides were stained for Nissl, Timm’s, or immunohistochemistry, specifically parvalbumin.
Results:
For stereology, preliminary data showed that two cats with a history of seizures had significantly lower numbers of hilar neurons compared to control cats, suggesting evidence of epilepsy related neuron loss. Timm’s stain revealed moderate mossy fiber sprouting in the cats with a history of seizures and mild mossy fiber sprouting in the control cats.
Conclusions:
If confirmed, these findings would suggest that a subset of cats with a history of seizures have neuropathological similarities to people with TLE, including evidence of hippocampal sclerosis. Advanced treatment options, such as surgery or laser ablation, could then be trialed as therapy for cats with TLE-like seizures. In addition, cats with TLE-like seizures could be considered as another possible large animal model for investigating diagnostic and treatment modalities for TLE.
Funding:
Supported by: This study was supported by UW – Madison, School of Veterinary Medicine Companion Animal Fund & NIH T35 OD011078-12.