Increased cerebral perfusion after detachable balloon embolization of carotid cavernous fistula on technetium-99m-HMPAO brain SPECT.

Most symptoms and signs associated with a carotid cavernous fistula (CCF) are thought to be related to regurgitation of flow into cortical veins and to venous congestion. Arteriovenous shunting and secondary perfusion insufficiency is regarded as less important in causing symptoms. We describe a 27-yr-old male patient who had improvement of neurologic symptoms and signs after detachable balloon embolization of traumatic CCF. The pre- and postocclusion 99mTc-HMPAO brain SPECT scan showed improved cerebral blood flow after occlusion. The CCF had shown marked arteriovenous shunting without significant venous congestion on pre-occlusion cerebral angiogram. The postocclusion cerebral angiogram revealed complete occlusion of the CCF with increased blood flow in the ipsilateral middle cerebral artery distribution. These findings suggest that cerebral dysfunction may be related to perfusion insufficiency from the CCF. Brain SPECT scanning can assess the functional status of cerebral perfusion and may be a useful, noninvasive adjunct to angiography.