Teaching NeuroImages: Spontaneous regression of AVM feeding pedicle pseudoaneurysms

A 34-year-old woman had sudden left-sided weakness shortly after delivery. Head CT showed a small hemorrhage (figure, A) secondary to an arteriovenous malformation (figure, B) with 2 small pseudoaneurysms (figure, C). Angiography 2 months later documented obliteration of one of the 2 pseudoaneurysms but growth of the other (figure, D). Embolization of the pedicle bearing the pseudoaneurysm was planned but delayed by 1 month because of patient hesitation to undergo the procedure. Repeat angiogram showed spontaneous resolution (figure, E). Feeding pedicle pseudoaneurysms are dynamic lesions probably secondary to dissection. As remodeling occurs, interval growth, spontaneous regression, or both can be observed.1