[Preliminary results of PET activation study in cerebral arteriovenous malformation (AVM), using C15O2 and 18F-FDG]

The authors applied PET activation study to two patients with arteriovenous malformation (AVM) to localize primary motor cortex before surgery or embolization. The change in regional cerebral blood flow (rCBF) was measured during foot movements in Case 1 who had a 2-cm AVM located in the post-central gyrus. Superimposed PET/MRI images revealed that the rCBF increase was located in the pre-central gyrus. Its validity was confirmed by intraoperative cortical mapping using electrical median nerve stimulation. The patient safely underwent total removal of AVM. The change in regional cerebral metabolic rate for glucose (rCMRglc) was measured during hand movements in Case 2 who had a huge AVM over the central sulcus. Superimposed PET/MRI images revealed that hand movements significantly increased rCMRglc in the frontal cortex, which was separated from the original primary motor area. The patient safely underwent partial embolization, although he suffered transient weakness of the face after embolization. The preliminary results strongly suggest that PET activation study is useful to localize precisely cortical functions of the patients with AVM, thus reducing morbidity after treatment. The results also suggest that cortical functions may undergo translocation when huge AVM involves the eloquent area.