Abstracts

Rationale: In our previous studies, we demonstrated that focal brain cooling suppresses epileptiform discharges in rat. However, the clinical applicability of a focal brain cooling system on epileptic seizures still remains to be elucidated. We therefore addressed this issue by developing an implantable, automated cooling system in animals. Methods: A thermoelectric device using a Peltier chip (6.0x6.0 mm) was ipsilaterally applied on the SI-MI area of anesthetized/free-moving male spontaneously epileptic rats (NERs). The EEG, the ECG, cortical temperatures and the cerebral blood flow were monitored. The cooling system was completely automated; following the automatic detection of anticipating epileptic discharges through real-time multivariate analyses, the cortex was instantly cooled or rewarmed by a silicon coated Peltier device. Results: Seizures in anesthetized NERs were instantly suppressed by cooling below 25°C. Cooling was also effective in the free-moving NERs, where the onset of seizures, as well as both partial and generalized seizures in progress, were completely suppressed at 20°C. Excessive cooling (<15°C), however, caused a significant dysfunction of the sensori-motor systems. The cerebral blood flow decreased during cooling at 20°C, but thereafter it returned to normal soon after rewarming. Conclusions: These results showed the clinical effectiveness of this new cooling system, not just on intractable epilepsy with foci, but also on epilepsy without foci. Further clinical trials are presently in progress.