The association between Chiari-like malformation, ventriculomegaly and seizures in cavalier King Charles spaniels.

Cavalier King Charles spaniels (CKCSs) with Chiari-like malformation (CM) and associated seizures are frequently diagnosed with idiopathic epilepsy. There could be an association between ventriculomegaly (V) or caudal fossa overcrowding (CCFP) and seizures. A retrospective case-control study was performed using MRI to investigate the possible association between these morphological abnormalities and seizures. Seizure semiology and, where possible, electroencephalographic (EEG) abnormalities were documented. Eighty-five CKCS with CM were included, 27 with seizures. There was no association between V or CCFP and seizures (P=0.10 and 0.71, respectively). Seizures were classified as having partial onset in 61% of individuals in the study population (95% CI 42.41-76.43%). Another cause of recurrent seizures in CKCS (such as familial epilepsy) is suspected, as previously reported.