Cyclosporin A aggravates electroshock-induced convulsions in mice with a transient middle cerebral artery occlusion.

1. To test whether an ischemic insult increases the susceptibility to cyclosporine A (CsA)-induced neurotoxicity, we examined the effect of CsA on the minimal electroshock-induced convulsions in mice treated with a transient middle cerebral artery occlusion (MCAO) for a short period (2 h). 2. This MCAO produced small to mid-sized infarcted regions in the cerebral hemisphere with increasing post-operative days. In MCAO mice, CsA (30 mg/kg, i.p.) elevated the incidence of minimal electroshock-induced convulsions to 90-100% over that in sham mice (20-30%) at 1-7 days but not 14 days post-surgery. 3. In light of these findings, the possibility that CsA increases the risk of convulsions in patients with cerebral infarction and/or at an early stage following focal cerebral ischemia would have to be considered.