Clinical characterization of epileptic seizures in Pomeranians with idiopathic epilepsy or epilepsy of unknown cause

Electroencephalography: electrode arrays in dogs

Electroencephalography (EEG) is the gold standard for confirming epileptic seizures in both human and veterinary patients. Despite idiopathic epilepsy being one of the most common neurological conditions in dogs, our understanding of it in veterinary medicine lags that in human medicine. The relative underuse of EEG in dogs with seizures has potential causes including practical issues, financial concerns, lack of training/equipment, and questions of clinical value. This technological underuse may lead to, or result from, major gaps in our understanding of EEG in veterinary patients. This underutilization of EEG is of significant clinical relevance because the diagnosis of specific epilepsy syndromes in humans guides the treatment, namely pharmacological, dietary, or surgical. These epilepsy syndromes are diagnosed based on several factors, one of which is the characteristic electrical brain activity on EEG. The aim of this narrative literature review was to highlight the study of cortical brain activity to improve our understanding of EEG in veterinary medicine. Specifically, the utility of EEG with focus on the existing proposed electrode arrays and their current supporting evidence. A recent survey study confirmed that a variety of canine EEG protocols are concurrently in use, including diverse electrode arrays. By comparison, in humans there is a standardized 10-20 electrode array, with average localization error of 13-17 mm depending on the number of placed electrodes on the scalp. We offer a review of the factors that would contribute to the ideal canine EEG electrode array highlighting areas for improvement and future validation. This proposed level of understanding will facilitate the identification of cortical seizure foci with a known degree of error, paving the way for non-pharmaceutical interventions like epilepsy surgeries.

Suspected paroxysmal dyskinesia in four small-breed dogs: Clinical presentation, diagnosis, management and prognosis

This case report details the clinical presentation, diagnosis, management and prognosis of paroxysmal dyskinesia (PD) in four small-breed dogs, each weighing under 6 kg: A 7-year-old spayed female Pomeranian, an 8-year-old female mixed breed, a 1-year-old female Pomeranian and a 9-year-old castrated male Poodle. These dogs were referred to our hospital due to movement disorders. Diagnosis was facilitated by video recordings of the episodes, assessing motor activity, consciousness, episode duration, any pre- or post-episodic behaviour as well as the presence of autonomic signs. Magnetic resonance imaging conducted on two of the dogs returned unremarkable results. Treatment trials included a gluten-free diet for all four dogs, with two also receiving acetazolamide. This intervention led to a decrease in the frequency of abnormal movement in all patients. Our findings suggest that PD in dogs can be effectively diagnosed through detailed symptom description using videos and questionnaires. Furthermore, once diagnosed, a combination of nutritional and medical management can be beneficial.

The Potential of Bemegride as an Activation Agent in Electroencephalography in Dogs

The present study investigated the potential of bemegride as a pharmacological activation agent that elicits epileptiform discharges (EDs) in interictal electroencephalogram (EEG) recordings in dogs. Four laboratory dogs with idiopathic epilepsy and four without epilepsy were included. The dogs were anesthetized using sevoflurane during EEG recordings. Bemegride was administered intravenously and repeatedly until EDs were enhanced or induced, or until the maximum dose (20 mg/kg) had been administered. Bemegride activated EDs in all dogs with epilepsy. These EDs predominantly occurred in each dog's spontaneous irritative zones, which were identified without the administration of bemegride. EDs occurred after the administration of bemegride in 50% of dogs without epilepsy. The dose required for activation was significantly lower in dogs with epilepsy (median; 7.3 mg/kg) than in those without (median; 19.7 mg/kg) (p = 0.0294). The only suspected adverse effect associated with the administration of bemegride was vomiting in two dogs after awakening from anesthesia. There were no other adverse effects, including seizures. The present results demonstrated the potential of bemegride as a safe and effective pharmacological activation agent of EDs in anesthetized dogs with epilepsy and provided more options for the diagnosis and therapeutic planning of epilepsy, including presurgical evaluations, in dogs.