Retrospective analysis of the surgically treated temporal lobe arteriovenous malformations with focus on the visual field defects and epilepsy

Abstract

Background Authors investigate the surgical outcomes of the temporal lobe arteriovenous malformation (AVM) with focus on the visual field deficit and seizure. Methods Between 1981 and 2004, we experienced 294 cases of intracranial AVMs. Among the 294 cases, 45 (15.3%) were located in the temporal lobe. Twenty-six of the 45 cases underwent microsurgical excisions of the AVMs. Results The male-female ratio of 26 surgically treated temporal lobe AVMs was 15:11. The mean age was 34.2 years, ranging from 7 to 63 years. The sites of lesion were classified as polar in 1, dorsal in 2, laterobasal in 15, and mediobasal in 8. The initial symptoms were hemorrhage in 22 and epilepsy in 4 cases. Arteriovenous malformations were totally removed in all 26 patients and there was no surgical mortality. The visual field deficits were identified in 17 of 22 patients with hemorrhage. Massive hematoma cases that needed emergency operation were 5. Visual field deficits improved in only 2 of the 5 patients after surgery. Among the 7 quadrantanopia patients, 3 resulted in hemianopia after surgery. Seven of 22 hemorrhage patients had history of epilepsy. Although one patient had new postoperative epilepsy, the medical controls of the seizure were good in all 8 patients. Four patients underwent AVM excision for epilepsy without hemorrhage. In two patients, seizures disappeared after surgery. The other two patients had typical psychomotor seizures after the total excision of AVMs. Conclusions Improvement of visual field deficit due to hematoma was difficult in most cases. Emergency craniotomy for global neurological deterioration due to massive hematoma had improved the visual field deficit in two cases. Although the outcome of seizure associated with hemorrhage was acceptable, the postoperative intractable seizures would remain in cases with epilepsy without hemorrhage. Intraoperative electrocorticography might be requisite for nonruptured temporal lobe AVM cases with epilepsy.