Cluster headache syndrome associated with middle cerebral artery arteriovenous malformation.

Cluster headache (CH) is an idiopathic cephalalgic syndrome, although several pathological processes have been described in association with this syndrome. We report two cases of cluster headache in hospitalized patients with middle cerebral artery dependent arteriovenous malformation (AVM). After surgical removal of the AVM the headache completely resolved, suggesting that complementary studies and treatment of the underlying aetiology may be indicated for secondary forms of cluster headache.