Focal seizures: an unusual presentation of giant intracranial aneurysms. A report of four cases with comments on the natural history and treatment.

Four patients with partial epileptic seizures for several years, but without permanent neurological deficits, were found to have giant aneurysms of the middle cerebral artery. None had a history of subarachnoid hemorrhage. Operative findings included compression of the medial temporal and subfrontal cortex, infarction of the superior temporal gyrus, and evidence of previous hemorrhage from the aneurysms. In two patients, clipping of the aneurysm with decompression of the adjacent temporal lobe cured the seizure disorder. In the other two patients, the aneurysms could only be wrapped, and the seizures continued. It is postulated that focal compression of temporal lobe structures and local hemodynamic phenomena caused by the giant aneurysm predispose to epilepsy in these patients.