Population of the ictal-interictal zone: The significance of periodic and rhythmic activity

Seizures contribute to patient mortality and are usually treated aggressively. Rhythmic and periodic patterns – the “ictal-interictal continuum” – are often associated with seizures, yet the optimum method of treating these patterns is not known: should they be aggressively suppressed, or monitored without treatment? Understanding which patterns are more strongly associated with seizures and which are highly associated with mortality is important to help the clinician decide how to treat these findings. We present an overview of the etiologies, association with seizures, and mortality of periodic and rhythmic patterns, and one approach to treatment.