Acute painful cavernous sinus syndrome in unruptured intracavernous aneurysms of the internal carotid artery. Possible pathogenetic mechanisms.

Three cases of painful ophthalmoplegia with acute onset due to an unruptured aneurysm of the intracavernous portion of the internal carotid artery are reported. The possible pathogenetic mechanisms responsible for this unusual mode of clinical manifestation are discussed and the neurovascular relationships of the cavernous sinus are analyzed in respect of ischemic versus compressive damage to the intracavernous neural structures.