PMC4025157_01
Brain MRI at initial diagnosis. MRI images show high intensity in the right middle cerebellar peduncle (a) and the globus pallidus (b). Dilated cortical veins are revealed as a flow void from the left cerebellum to the bilateral parieto-temporo-occipital lobe (a, b).
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F1
T2-weighted MRI showed high intensity in the right middle cerebellar peduncle (fig. 1a), the right globus pallidus (fig. 1b), and the corona radiata.
Right external carotid arteriogram in the lateral (a, b) and anterior-posterior views (c) confirming the definitive diagnosis of dural transverse-sigmoid sinus fistula; the right common carotid arteriogram shows a complete obliteration of the fistula after endovascular treatment (d). Early arterial phase of the external carotid arteriogram shows the right occipital artery, middle meningeal artery, and the ascending pharyngeal artery as main feeders in (a). In the late arterial phase, most drainage flow runs off retrograde from the straight sinus to the basal vein of Rosenthal and to the inferior sagittal sinus, with a severe venous congestion in the cerebellum, medial deep cerebrum, and parieto-temporo-occipital lobe (b, c).
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F2
The right occipital artery, the middle meningeal artery, and the ascending pharyngeal artery were the main feeders (fig. 2a). Especially the reflux of the dilated cortical veins was remarkable in the left cerebellum, medial deep cerebrum, and in the parieto-temporo-occipital lobes, suggesting severe venous congestion (Boden type II, Cognard type IIa+b, Larwani Grade 2; fig. 2b, c). Transvenous embolization with platinum coils delivered through the right transverse-sigmoid sinus completely occluded the fistula (fig. 2d), which was followed by a significant improvement of her cognitive function with a normalization of CBF.
Three-dimensional 99mTc-ethylcysteine dimer SPECT imaging before (a) and after (b) endovascular embolization. The relative reduction of cerebral blood flow in the bilateral posterior cingulate gyrus, precuneus (broad arrows) and the left parieto-occipital cortex (narrow arrows) (a) has improved to a normal extent after treatment (b).
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F3
Three weeks after the embolization, three-dimensional 99mTc-ethylcysteine dimer single photon emission computed tomography imaging, using an easy Z-score imaging system analysis, revealed that the pretreatment reduction of CBF in the bilateral posterior cingulate gyrus, precuneus, and the left parieto-occipital cortex (fig. 3a) had improved to normal levels (fig. 3b).