Electroencephalography Findings in Healthy and Finnish Spitz Dogs with Epilepsy: Visual and Background Quantitative Analysis

Abstract

Background: Qualitative and quantitative electroencephalography (EEG) parameters of healthy and Finnish Spitz dogs with epilepsy have not been determined.Objective: To determine if EEG can provide specific characteristics to distinguish between healthy dogs and dogs with epilepsy.Animals: Sixteen healthy and 15 Finnish Spitz dogs with epilepsy.Methods: A prospective clinical EEG study performed under medetomidine sedation. Blinded visual and quantitative EEG analyses were performed and results were compared between study groups.Results: Benign epileptiform transients of sleep and sleep spindles were a frequent finding in a majority of animals from both groups. The EEG analysis detected epileptiform activity in 3 Finnish Spitz dogs with epilepsy and in 1 healthy Finnish Spitz dog. Epileptiform activity was characterized by spikes, polyspikes, and spike slow wave complexes in posterior‐occipital derivation in dogs with epilepsy and with midline spikes in control dog. The healthy dogs showed significantly less theta and beta activity than did the dogs with epilepsy (P< .01), but the only significant difference between healthy dogs and dogs with untreated epilepsy was in the alpha band (P< .001). Phenobarbital treatment increased alpha, beta (P< .001), and theta (P< .01), and decreased delta (P< .001) frequency bands compared with dogs with untreated epilepsy.Conclusions and Clinical Importance: Benign epileptiform transients of sleep could be easily misinterpreted as epileptiform activity. Epileptiform activity in Finnish Spitz dogs with epilepsy seems to originate from a posterior‐occipital location. The EEG of dogs with epilepsy exhibited a significant difference in background frequency bands compared with the control dogs. Phenobarbital treatment markedly influenced all background activity bands. Quantitative EEG analysis, in addition to visual analysis, seems to be a useful tool in the examination of patients with epilepsy.