Medial occipital arteriovenous malformations. Surgical treatment.

In a consecutive operative series of 115 intracranial arteriovenous malformations (AVM's), 16 occupied the medial occipital region. Typically, the patients with medial occipital AVM's presented with bleeding often accompanied by homonymous visual field deficit, or with migrainous headache. The malformations were supplied principally by branches of the posterior cerebral artery. Through an occipital craniotomy, a surgical approach along the junction of the falx and tentorium provided access to the arteries feeding the AVM and facilitated excision of the malformation. There were no deaths in the series. The incidence of visual field deficit after the operation varied, but in only five cases was the visual field worsened postoperatively. All patients who had a history of intractable headache were cured or improved after surgery. These lesions are favorably situated for surgical treatment.