Carotid-cavernous fistulas (CCFs) are pathologic, arteriovenous communications between the carotid artery and cavernous sinus. They cause various complex neuro-ophthalmic symptoms by shunting the flow of arterial blood into the venous system. In this study, a systematic review is conducted on the neuro-ophthalmic presentations associated with CCFs. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines were followed during the systematic review. We searched PubMed, Scopus, and Web of Science from inception to December 31, 2023. Articles written in English on patients with confirmed CCFs reporting clinical features, diagnostic modalities, treatment approaches, and outcomes were included. Abstracted data included demography, clinical presentations, venous flow dynamics, trauma history, investigative methodology, approaches to treatment, and outcomes. Overall, 33 studies with a total number of 403 patients were included. The mean age at presentation was 42.99 years for patients with direct CCFs and 55.88 years for those with indirect CCFs. Preponderance was observed in male patients with direct CCFs, constituting 51.56%, while females predominated in those with indirect CCFs, at 56.44%. The clinical symptoms in all patients with CCFs were proptosis in 58 cases (14.39%), conjunctival congestion in 29 patients (7.20%), diplopia in nine patients (2.23%), vision blurring in four patients (0.99%), eyelid swelling in five patients (1.24%), pain in the eye in three patients (0.74%), and an upper lid mass in one patient (0.25%). Endovascular treatments, including coil and Onyx embolization, have been effective in relieving clinical symptoms and arresting the progression of these symptoms. In conclusion, the common clinical features in CCFs usually underline proptosis, congestion, and diplopia, necessitating a comprehensive neuro-ophthalmological review. Prompt identification of the symptoms of blurred vision is crucial to avoid permanent damage. Lid swelling, ocular pain, and an upper lid mass are less common but equally essential presentations for comprehensive evaluation. The recognition of these variable presentations is essential not only for timely intervention but also for the improvement in patient outcomes, thus emphasizing the role of clinician awareness in managing CCF cases.

UNASSIGNED: The purpose of the study was to describe ocular blood flow changes in eyes affected by a carotid-cavernous fistula (CCF) using laser speckle flowgraphy. We hypothesized that imaging blood flow velocity waveforms in the retinal arterioles and venules simultaneously would reveal specific characteristics of an arteriovenous (AV) connection.
UNASSIGNED: The study was an observational case series, with a retrospective case-control analysis.
UNASSIGNED: Five patients with a CCF underwent measurement of ocular blood flow using laser speckle flowgraphy. The blood flow was compared retrospectively between a control group of healthy subjects (n = 32) and patients with an elevated intraocular pressure or venous outflow impairment without an AV fistula (n = 40). The outcomes were derived from the arteriole and venule blood flow velocity waveforms, including an A-V phase delay and flow pulsatility.
UNASSIGNED: The presence of an active CCF was associated with an increased delay in the peak velocity measured in the retinal venule (10.7% ± 2.2% of the cardiac cycle duration) compared with unaffected fellow eyes (1.8% ± 0.2%; p = 0.05) or control eyes of normal subjects (2.7% ± 0.3%; p = 0.02). This delay disappeared after fistula thrombosis and was not present in eyes with a central retinal vein occlusion (CRVO), glaucoma, non-arteritic anterior ischemic optic neuropathy (NAION), or papilledema. The venule blood flow velocity decreased during systole (and in some cases momentarily stopped), leading to a delayed pulse with a greater amplitude in the venules than in fellow eyes and normal controls after normalizing to the arteriole amplitude (1.71 ± 0.3 vs 0.54 ± 0.03 vs 0.59 ± 0.02; p = 8.0E-12). This specific AV delay could also be identified in a scanning laser ophthalmoscope (SLO; SPECTRALIS®) video.
UNASSIGNED: Laser speckle flowgraphy reveals dynamic retinal vascular changes in eyes affected by a CCF, which are not present in healthy controls or patients with other eye conditions, and which reverses with treatment.

Endovascular neurointervention is typically performed with iodinated contrast medium (ICM) under fluoroscopy. However, some patients may be contraindicated to such procedures based on their sensitivity to ICM. In this report, we describe a case of successful coil embolization of a direct carotid cavernous fistula using angiography with gadolinium-based contrast agents in a patient with severe allergic reaction to ICM. The clinical decision-making for this patient was further complicated by comorbidities of renal impairment, drug allergies, and previously severe gastrointestinal bleeding.

UNASSIGNED: Carotid cavernous fistulas are uncommon vascular abnormalities marked by anomalous connections between the carotid artery and the cavernous sinus. The authors present a case of a direct carotid cavernous fistula and its successful treatment in a 42-year-old female.
UNASSIGNED: A 42-year-old female presented with right eye painful swelling and visual disturbance. She had no known comorbidities or history of injury. Examination showed proptosis, chemosis, and orbital bruit. Carotid angiography confirmed a carotid cavernous fistula, which was managed endovascularly. The patient fully recovered after treatment.
UNASSIGNED: Carotid cavernous fistula occurs spontaneously or as a result of trauma or other vascular abnormalities. Common clinical manifestations include proptosis, chemosis, and orbital bruit, with vision loss being a feared complication. Diagnosis is typically confirmed through angiography, with digital subtraction angiography being the gold standard. Endovascular treatment is usually effective, although surgical management may be necessary in certain cases.
UNASSIGNED: Carotid cavernous fistula is a rare but potentially sight-threatening neurological condition. Treatment with a transvenous approach is effective for the management of direct carotid cavernous fistula.

An abnormal connection between the carotid artery and cavernous sinus is referred to as a carotid cavernous fistula (CCF). A direct CCF results when the connection occurs between the intracranial internal carotid artery (ICA) and the cavernous sinus. These events are typically the result of a head injury, but can also be iatrogenic, resulting from various intracranial procedures. Direct CCF occurrences rarely heal spontaneously due to the high flow rate across the fistula. In this report, we present an uncommon case involving a delayed iatrogenic direct CCF, which developed following the placement of a pipeline flow-diverting stent that was used to treat a cerebral aneurysm. Interestingly, this unusual iatrogenic direct CCF subsequently spontaneously resolved within a few months. To our knowledge, this is the only case of a delayed CCF occurring with the use of a flow-diverting sent, which then resolved on its own. This report recounts our experience with the case.

A female in her 70s presented with altered mental status, left eye pain, ophthalmalgia, and diplopia following a fall. Brain MRI demonstrated contrast-enhancing left peri-insular T2 hyperintense changes that was read as possible herpes simplex encephalitis by neuroradiology. Cerebral angiogram revealed a Barrow Type D left sided carotid cavernous fistula. The patient was subsequently treated with endovascular transvenous coil embolization of the left cavernous sinus resulting in complete occlusion of the fistula. The goal of this case is to present a unique case of a carotid cavernous fistula radiologically mimicking herpes simplex encephalitis. Early recognition of carotid cavernous fistula on neuroimaging is important for prompt treatment of symptoms.

Due to the anatomical proximity between the skull and the face, maxillofacial trauma can often cause injuries to cranial structures. Among these complications are carotid-cavernous fistulas (CCF), which are rare in maxillofacial trauma, although their etiology is usually traumatic. They are described as an atypical communication between the internal carotid artery and the cavernous sinus, which can generate a sudden change in the direction and distribution of blood flow between the brain and orbit. This paper aims to report a case of craniomaxillofacial trauma in which the patient evolved with diplopia, palpebral ptosis, and ophthalmoplegia of the left eye, diagnosed as traumatic CCF. The oral and maxillofacial surgery and traumatology team of the University Hospital of Western Paraná was observed these symptoms for the first time during post-operative follow-up after one day of surgery to repair mandibular fractures of the patient in question. With the identifying the signs and symptoms, a neurosurgery was requested for assessment and management. After clinical evaluation and imaging tests, they diagnosed the condition as CCF 5 days after the mandibular fractures and the patient was referred for treatment. Surgery was performed, in the same day, to resolve the CCF with the endovascularly by embolization with micromoles. The CCF was resolved and the patient continued on outpatient follow-up, progressing without sequelae from the CCF or mandibular fractures.

UNASSIGNED: To evaluate the prevalence and pattern of extraocular muscle enlargement and proptosis in patients with carotid cavernous fistulas (CCF).
UNASSIGNED: We conducted a retrospective study on patients with digital subtraction angiography (DSA) confirmed CCFs with neuroimaging (computed tomography or magnetic resonance imaging) performed prior to the DSA. The maximum extraocular muscle diameters were recorded. Extraocular muscles were considered enlarged if they were greater than two standard deviations above the normal muscle diameters. Proptosis was defined as the distance between the interzygomatic line to the anterior globe of ≥2 mm compared to the contralateral orbit or ≥21 mm.
UNASSIGNED: Forty orbits from 20 patients were included. The mean age of participants was 65 ± 15 years and 13 (65%) were female. Thirteen (65%) fistulas were indirect and seven (35%) were direct. There was enlargement of at least one muscle in 11 (27.5%) orbits, and this was not correlated with the type of fistula (direct/indirect). The inferior rectus was most commonly enlarged in seven orbits (17.5%), followed by the medial rectus in five orbits (12.5%). Proptosis was found in 17 (43%) orbits and was more common ipsilateral to the fistula (58% ipsilateral group vs 19% contralateral group, p < .01).
UNASSIGNED: Extraocular muscle enlargement was observed in over one-fourth of CCFs. When enlarged, the inferior and medial rectus muscles are most commonly involved. These findings may help clinicians and radiologists when evaluating the CT or MRI scans of patients with suspected CCFs.

UNASSIGNED: Carotid cavernous fistula (CCF) refers to the abnormal arteriovenous communication between the carotid system at the skull base and the sphenoid cavernous sinus, which is caused by trauma in almost 75% of cases. The drainage of venous blood to the spinal cord represents a distinctive mechanism, which is commonly observed in dural arteriovenous fistula (DAVF), and typically manifests clinically as progressive myelopathy. However, it is a rare occurrence in clinical practice that traumatic carotid cavernous fistula (TCCF) causes delayed quadriplegia through perimedullary venous drainage.
UNASSIGNED: We report the case of a 29-year-old male patient who was admitted to the hospital with a sudden onset of headache and quadriplegia. The patient had previously lost his right eye in a traffic accident 5 years ago. Cerebral angiography showed a high-flow direct CCF on the right side, accompanied by obvious drainage of cerebellar and perimedullary veins. We successfully performed coil embolization for the CCF, and the symptoms of the patient gradually improved after the operation. During follow-up at sixth-months, the patient regained the ability to walk independently.
UNASSIGNED: We experienced a rare case of TCCF with quadriplegia. Utilizing coil embolization, we achieved successful improvement in the patient\'s condition. However, the mechanism and the best treatment of CCF drainage through the perimedullary vein are still unclear. We need to further explore the pathophysiological information of CCF venous drainage.

Carotid cavernous fistulas (CCFs) are a rare but debilitating entity that may present with orbital or cerebral venous hypertension. CCFs may pose diagnostic and management pitfalls for clinicians as they can initially be misdiagnosed as primary orbital pathology or nonarteriovenous shunting-related cavernous sinus pathology. Furthermore, the resolution of pulsatile tinnitus could be an ominous sign in patients with untreated dural arteriovenous fistula. We describe a case of a 56-year-old male who presented with progressive right eye proptosis, congestion, decreased visual acuity, limited duction, exophthalmos, and pulsatile tinnitus. The patient had poor response to antibiotics and steroids. Magnetic resonance imaging brain showed significant inflammation involving the right orbit and atypical enhancement of the basal frontal lobe adjacent to the orbit. Cerebral angiography revealed an indirect right CCF and right sigmoid sinus thrombosis with stenosis of the right internal jugular vein. No clear predisposing factor was identified. Given the rapidly progressive nature of the condition, the patient successfully underwent endovascular treatment with transvenous approach to preserve flow in the internal carotid artery while ensuring occlusion of the fistula. A triad of proptosis, eye congestion, and signs of turbulent flow such as tinnitus or orbital bruit should raise suspicion for CCF. An interesting feature in this patient is that CCF may have occurred secondary to sigmoid sinus thrombosis with accompanying small cortical vein drainage. Our case highlights the importance of early recognition and timely intervention to ensure the resolution of orbital hypertension-related symptoms in rare cases of CCFs.