Review reframes feline hippocampal necrosis as a shared endpoint

A new review in The Veterinary Journal argues that feline hippocampal necrosis, or FHN, should be understood as a histopathologic endpoint rather than a single disease, and that it overlaps with, but is not the same as, hippocampal sclerosis and feline temporal lobe epilepsy. The paper, published in early May 2026, revisits about 25 years of literature and reinforces that cats with temporal lobe seizure patterns, especially focal seizures with orofacial signs, may have hippocampal injury driven by multiple underlying processes, including neoplasia, vascular disease, seizure-related injury, developmental abnormalities, and increasingly, autoimmune limbic encephalitis. Earlier studies linked these cases to bilateral hippocampal and sometimes piriform lobe lesions, while more recent work has highlighted LGI1/VGKC-complex antibody–associated disease in some cats. (sciencedirect.com)

Why it matters: For veterinary professionals, the review is a reminder not to treat FHN as a tidy standalone diagnosis. Cats presenting with staring, facial twitching, lip smacking, hypersalivation, chewing, swallowing, head turning, or behavioral change may fit a temporal lobe epilepsy phenotype, but the underlying cause still needs workup. Prior literature suggests MRI can identify hippocampal signal changes, yet many cats are refractory to conventional antiseizure therapy, and some cases may represent autoimmune encephalitis rather than idiopathic epilepsy. That has implications for differential diagnosis, client counseling, prognosis, and how aggressively clinicians pursue imaging, CSF testing, pathology, or referral. (journals.sagepub.com)

What to watch: Expect continued debate over definitions, plus more focus on antibody testing, MRI-pathology correlation, and whether subsets of cats with temporal lobe seizures may benefit from more targeted diagnostic and treatment approaches. (sciencedirect.com)