Activity: Participating in or organising an event types › Participation in conference
SEIZURES AND OTHER INVOLUNTARY MOVEMENTS IN CATS
Katia Marioni-Henry, DVM, PhD, DACVIM (Neurology), ECVN, MRCVS
Edinburgh, United Kingdom
Recent advances in feline neurology have generated new approaches for the investigation and treatment of seizures and other types of feline involuntary movements.
A peculiar form of feline epilepsy characterized by complex partial seizures with orofacial involvement and hippocampal lesions has been recently associated with voltage-gated potassium channel (VGKC) complex antibody found in cases of limbic encephalitis in people.1, 2 This type of feline epilepsy was first described fifteen years ago, when it was characterized by post-mortem findings of necrosis of the hippocampus and piriform lobe.3 Initially, only cats from central Europe appeared to be affected and the prognosis for recovery was considered poor. The presence of clusters of cases from the same area or household led to hypothesize a possible toxic cause.3 However, in recent studies cats diagnosed with hippocampal necrosis were successfully treated1 and cases of feline hippocampal necrosis were reported also in United Kingdom4, United States5, Australia6 and Finland7. The presence of clusters of cases from the same area has yet to be explained. In human patients, limbic encephalitis are usually autoimmune conditions associated with distant tumours, however, the VGKC- complex antibodies have limited specificity and may be found in non-autoimmune encephalitis, including Creutzfeldt–Jakob disease (CJD).8
Increased awareness of feline hippocampal necrosis and the introduction of novel terminology and diagnostic tools such MRI, have influenced our knowledge of feline epilepsy. 9, 10 In a recent retrospective study on feline epilepsy including 81 cats with MRI or post-mortem examination, epilepsy of unknown cause was diagnosed in 22% of cats with recurrent seizures, compared to 38% and 66% previously reported by authors who called this entity primary or suspected idiopathic epilepsy combining genetic epilepsy and epilepsy of unknown cause. 9, 11, 12 Cats with epilepsy of unknown cause had a significantly longer survival rate compared with cats with epilepsy secondary to structural brain lesions or acute symptomatic seizures with 73% of the cats alive after 1 year and 44% of the cats achieving remission with phenobarbital treatment. 9
Other conditions that will be discussed in this video-based presentation are permetrin toxicosis13, REM sleep behaviour disorder 14 and feline hyperaesthesia syndrome15. Particular emphasis will be given to clinical features that help differentiating these conditions.