Abstracts

Rationale: Most patients display a circadian and multidien regulation of their seizures. Similar results have been found in experimental models. Our goal was to determine whether circadian and multidien rhythms are also present in the cardio-respiratory and gastric systems in control and epileptic rats.

Methods: We recorded EEG, electrocardiogram, breathing, gastric activity, core body temperature, and activity in control and epileptic (pilocarpine model) group housed rats with an OSI telemetry system 24/7 during more than 2 months.

Results: Sleep/wake patterns, core temperature, all heart activity parameters (RR, HRV, LF, HF, LF/HF), breathing frequency, and gastric period displayed a strong circadian modulation in control and epileptic animals. All parameters were strongly phase-locked. In control animals, several of these parameters also showed a multidien regulation. In epileptic animals, interictal acitivity was also regulated in a multidien manner, allowing the identification of high and low seizure risk times as previously reported. Preliminary data show that the activity in peripheral organs also shows a multidien regulation.

Conclusions: Multidien rhythms appear to reflect internal biological processes as they are present in control animals. The multdien rhythmicity of seizures may be overriding these processes.

Funding: none