Periodic discharges in veterinary electroencephalography-A visual review

First described in human EEG over 60 years ago, there are very few examples of periodic discharges in the veterinary literature. They are associated with a wide variety of etiologies, both intracranial and systemic, making interpretation challenging. Whether these patterns are indicative of ictal, interictal, or postictal activity is a matter of debate and may vary depending on the clinical features in an individual patient. Periodic discharges have a repeated waveform occurring at nearly regular intervals, with varying morphology of individual discharges from simple sharp waves or slow waves to more complex events. Amplitudes, frequencies, and morphologies of the discharges can fluctuate, occasionally evolving, or resolving over time. This study presents a visual review of several veterinary cases with periodic discharges on EEG similar to those described in human EEG, and discusses the current known pathophysiology of these discharges.

Automated summary

Described in human EEG over 60 years ago, periodic discharges in veterinary literature are rare and challenging to interpret due to their association with various intracranial and systemic etiologies. The debate on whether these patterns indicate ictal, interictal, or postictal activity is ongoing, depending on individual clinical features. In this study, veterinary cases with periodic discharges on EEG, similar to those in human EEG, are visually reviewed and the current pathophysiology of these discharges is discussed.