Effect of parenteral magnesium sulfate on penicillin-induced seizure foci in anesthetized cats.

The use of magnesium sulfate as an anticonvulsant remains controversial. The effect of parenteral magnesium sulfate on established penicillin-induced seizure foci in anesthetized cats was studied. After induction of an epileptic focus by application of penicillin to the cerebral cortex, experimental animals were infused intravenously with magnesium sulfate, whereas control animals received normal saline solution at an equivalent rate. Experimental animals achieved a mean serum magnesium level of 11.73 +/- 2.00 mg/dl. Analysis of the electroencephalogram recordings demonstrated no significant difference in epileptic spike activity between the experimental and control groups. The critical importance of adequate controls in studies of this type is stressed.