Carotid-Cavernous Fistula Associated with an Intracranial Lesion Caused by Cortical Venous Reflux

Abstract

<jats:p> Digital subtraction angiography (DSA) and magnetic resonance imaging (MRI) findings in 20 patients with carotid-cavernous fistula (CCF; 3 direct CCFs and 17 indirect CCFs) were retrospectively reviewed to evaluate venous drainage patterns that may cause intracerebral haemorrhage or venous congestion of the brain parenchyma. </jats:p><jats:p> We evaluated the relationship between cortical venous reflux and abnormal signal intensity of the brain parenchyma on MRI. Cortical venous reflux was identified on DSA in 12 of 20 patients (60.0%) into the superficial middle cerebral vein (SMCV; n=4), the uncal vein (n=2), the petrosal vein (n=2), the lateral mesencephalic vein (LMCV; n=1), the anterior pontomesencephalic vein (APMV; n=1), both the APMV and the petrosal vein (n=1) and both the uncal vein and the SMCV (n=1). Features of venous congestion, such as tortuous and engorged veins, focal staining and delayed appearance of the veins, were demonstrated along the region of cortical venous reflux in the venous phase of internal carotid or vertebral arteriography in six of 20 patients (30.0%). These findings were not observed in the eight CCF patients who did not demonstrate cortical venous reflux. MRI revealed abnormal signal intensity of the brain parenchyma along the region with cortical venous reflux in four of 20 indirect CCF patients (20%). Of these four patients, one presented with putaminal haemorrhage, while the other three presented with hyperintensity of the pons, the middle cerebellar peduncle or both on T2-weighted images, reflecting venous congestion. The venous drainage routes were obliterated except for cortical venous reflux in these four patients and the patients without abnormal signal intensity on MRI had other patent venous outlets in addition to cortical venous reflux. </jats:p><jats:p> CCF is commonly associated with cortical venous reflux. The obliteration or stenosis of venous drainage routes causes a converging venous outflow that develops into cortical venous reflux and results in venous congestion of the brain parenchyma or intracerebral haemorrhage. Hyperintensity of brain parenchyma along the region of cortical venous reflux on T2-weighted images reflects venous congestion and is the crucial finding that indicates concentration of venous drainage into cortical venous reflux. </jats:p>

Neuropsychiatric Presentation in Indirect Carotid-Cavernous Fistula: A Case Report

“…This patient's DSA findings (Figure 4 ) revealed the presence of cortical venous reflux (CVR) with indirect communication between the bilateral middle meningeal and terminal internal maxillary branches of the bilateral ECA in the cavernous sinus. The obliteration or stenosis of venous drainage routes leads to a converging venous outflow that develops into CVR and results in venous congestion of the brain parenchyma [ 11 ]. Our patient's cognitive decline can be attributed to venous congestive encephalopathy, a term introduced in 1994 that describes cranial neurologic deficits caused by venous hypertension [ 12 ].…”

Bilateral Carotid-Cavernous Fistula: A Diagnostic and Therapeutic Challenge

“…Intracranial hemorrhage or hemorrhagic infarcts are rare but dangerous complications of CCF and are associated with cortical venous reflux (CVR). 7 , 9 , 10 Cortical venous reflux has been found to be more common in patients with diplopia, cranial nerve palsy, elevated IOP, chemosis, and bruit. 7 Traditional 4-vessel angiography (digital subtraction angiography) is the gold standard to diagnose CCF and CVR, which may show tortuous and engorged veins, delayed appearance of the veins and focal staining, along the region of CVR in the venous phase of vertebral or internal carotid arteriography.…”

“… 9 Additional imaging clues to aid diagnosis include enlarged SOVs, thick extraocular muscles, enlarged cavernous sinus showing convexity of the lateral wall on brain CT and Magnetic Resonance Imaging (MRI), increased signal intensity of the brain parenchyma in the region and CVR on brain MRI, and decreased cerebral blood flow on the region of CVR on single-photon emission computerized tomography (SPECT). 9 …”

“…7 Traditional 4-vessel angiography (digital subtraction angiography) is the gold standard to diagnose CCF and CVR, which may show tortuous and engorged veins, delayed appearance of the veins and focal staining, along the region of CVR in the venous phase of vertebral or internal carotid arteriography. 9 Additional imaging clues to aid diagnosis include enlarged SOVs, thick extraocular muscles, enlarged cavernous sinus showing convexity of the lateral wall on brain CT and Magnetic Resonance Imaging (MRI), increased signal intensity of the brain parenchyma in the region and CVR on brain MRI, and decreased cerebral blood flow on the region of CVR on single-photon emission computerized tomography (SPECT). 9 Exophthalmos with conjunctival chemosis secondary to CCF can be confused for Graves' exophthalmos, especially in bilateral disease such as our patient.…”

“…9 Additional imaging clues to aid diagnosis include enlarged SOVs, thick extraocular muscles, enlarged cavernous sinus showing convexity of the lateral wall on brain CT and Magnetic Resonance Imaging (MRI), increased signal intensity of the brain parenchyma in the region and CVR on brain MRI, and decreased cerebral blood flow on the region of CVR on single-photon emission computerized tomography (SPECT). 9 Exophthalmos with conjunctival chemosis secondary to CCF can be confused for Graves' exophthalmos, especially in bilateral disease such as our patient. 11 Other diseases such as orbital pseudotumor, orbital vasculitis secondary to granulomatosis with polyangitis, polyarteritis nodosa, Tolosa-Hunt syndrome, and intracranial sarcoidosis may mimic CCF symptoms.…”