[Seizures as a late complication of bromocriptine therapy in patients with prolactin-producing macroadenomas: correlation between lateral extension of the adenoma and seizure onset].

Seizures have been reported as a late complication of medically treated prolactin-producing macroadenomas with lateral extension. Nine prolactin-producing macroadenomas with lateral extension to the cavernous sinus were treated with bromocriptine alone. In all cases, rapid decrease of serum prolactin level was recognized and in eight cases, evidence of tumor shrinkage on CT or MRI was demonstrated. During medical treatment, symptomatic seizures occurred in three cases. MRI showed small residual tumors on the medial surface of the temporal lobe in all these patients. Additionally, a hypointense signal on both T1- and T2-weighted images was recognized around the residual tumor. It was consistent with hemosiderin, a result of intratumoral hemorrhage caused by bromocriptine. On the contrary, the remaining six patients without seizures during treatment did not show abnormal hypointense signals on the medial surface of the temporal lobe. Seizures occur with a high incidence as a late complication of medical treatment of prolactin-producing macroadenomas with intradural supracavernous extension. The patients with seizure show hemosiderin deposit, which may be the trigger of the seizure, within the medial surface of the temporal lobe after bromocriptine therapy.