ABSTRACT
BACKGROUND: To investigate the effect of body temperature on seizure and hippocampal damage in the lithium and pilocarpine-induced status epilepticus METHODS: We pretreated the Sprague-Dawley rats with lithium (3mEq/kg) and pilocapine (30 mg/kg) and divided into three groups by their body temperatures which were maintained at normothermia (36.5+/-0.5 degrees C), hyperthermia(40.0+/-0.5 degrees C) and hypothermia (320+/-0.5 degrees C). Each group was maintained in a state of status epilepticus with assigned body temperatyre for 4 hours. After 24 hours, the rats were sacrificed, the pattern of EEG changes and degree of hippocampal cellular damage were compared between different groups. RESULTS: (1) Progression of typical EEG pattern of status epilepticus were observed in normothermic group ; discrete ictal discharge with slowing (30 min), wax and waning ictal discharge (60 min), continuous ictal discharge (90 min), continuous ictal discharge with flat period (180 min) and periodic epileptiform discharge (240 min) in time orfer. In hyperthermic group, the progression of EEG pattern was more rapid tha that od normothermic group ; continuos ictal dischatge was appeared within 30 minutes and periodic epileptiform discharge was within 90 minutes. On the other hand, the hypothermic group showed delayed evolution and wax and waning ictal discharge persisted until 240 minutes. (2) The survived neuronal cellular counts at CA1 and CA3 area of ventral hippocampus were compared between each group. The survived neuronal cellular counts were 90.9+/-5.55 (CA1) and 73.9+/-5.15 (CA3) in hypithermic group, 56.1+/-5.38 (CA1) and 40.6+/-7.03 (CA3) in normothermic group and 42.7+/-4.08 (CA1) and 31.7+/-4.64 (CA3) in hyperthermic group (p<0.05). CONCLUSION: The body temperatyre might influence the severity of seizure and seizure-induced brain damage. Hyperthermia aggravated the severity of seizure and seizure induced hippocampal damage, while hypothermia inhibited them.