Abstracts

Rationale: It is known that, in adult diabetic patients, nonketotic hyperglycemia may precipitate seizures. To identify the proconvulsant effect of hyperglycemia, we induced limbic seizures by lithium-pilocarpine in streptozotocin-induced diabetic rats. Methods: Male rats (n=9) were injected with one dose of streptozocin (50mg/kg, IP) to induce diabetic hyperglycemia. Controls (n=9) were received normal saline intraperitoneally. After 7 days, we measured blood glucose level and induced status epilepticus by one dose of pilocarpine (30mg/kg, IP). We compared the occurrence of seizure, seizure latency (latency to the first forelimb clonus), seizure severity (Racine’s scale), dose of diazepam for cessation of seizure and mortality between two groups. P values of <0.05 considered to be statistically significant. Results: Streptozotocin-treated rats showed significantly higher blood glucose concentration than control rats (mean level: 453mg/dl versus 125mg/dl, P=0.01) Six rats (67%) among total control rats developed seizures (above fourth stage of Racine’s scale) by one dose of pilocarpine, on the other hand, all diabetic rats developed seizures by same dose. Diabetic rats revealed shorter seizure latency (mean latency: 30.8 minutes versus 19.2 minutes, P=0.33) and higher mortality. In seizure severity, the frequency of above stage 5 was higher in diabetic rat (P=0.13), but the maximal Racine’s scale showed no difference between two groups. There was no difference between two groups, in the dose of diazepam for cessation of seizure. Conclusions: These results indicated that high glucose concentrations are associated with proconvulsant effects in pilocarpine-induced status epilepticus model.