Introduction
: Charles Bonnet Syndrome is characterized by visual hallucinations that can occur following severe visual insult, rarely due to dural arteriovenous fistulas (DAVF) or cerebral venous sinus thrombosis (CVST). Prompt differentiation between DAVF and CVST is important since treatments may differ and inadequate treatment may result in blindness. We highlight a patient who presented with Charles Bonnet Syndrome initially misdiagnosed with CVST by MR venography and later correctly diagnosed with a massive DAVF with superimposed CVST by digital subtraction angiography and underwent DAVF embolization with complete resolution.
Methods
: Case Report.
Results
: A 78 year‐old man with hypertension and hyperlipidemia presented with three weeks of bilateral vision loss associated with formed hallucinations exacerbated by dark rooms. Neurological exam revealed decreased visual acuity of 20/400 and grade five papilledema bilaterally. Non‐Contrast (TOF) MR venogram revealed lack of flow in the superior sagittal sinus (SSS), straight sinus (SS) and deep venous system, and partial flow of the left transverse and sigmoid sinus and left jugular vein. MR brain without gadolinium was unremarkable. Cerebral angiography revealed a high‐grade DAVF predominantly supplied by the occipital branch of the left external carotid artery [Figure 1; A‐C], with retrograde flow into the left sigmoid, transverse, superior sagittal, and straight sinuses, as well as retrograde flow into the right vein of Trolard [Figure 1; A‐D]. The left distal sigmoid sinus and left jugular bulb were occluded. The left transverse and proximal left sigmoid venous sinuses were compartmentalized from non‐occlusive thrombus, while the SSS and bilateral transverse sinuses where patent [Figure 1; A, B]. Embolization using coils and onyx was performed with complete occlusion of the left transverse and sigmoid sinuses, the points of main drainage of the fistula, as there was no single trans arterial pedicle suitable for embolization. Postembolization angiography demonstrated a Cognard Grade 1 fistula with some residual fistulous shunting of the occipital artery to the torcula. Follow up angiogram at six weeks showed interval occlusion of the residual shunt. He had minimal improvement in his vision at three months of follow up.
Conclusions
: This case highlights a patient with Charles Bonnet Syndrome due to a high flow DAVF. The MR venogram failed to capture the DAVF since the retrograde flow was interpreted as thrombosis on MRV. DAVF and CVST have a complex cause‐effect relationship, since thrombosis may open up venous channels that can lead to a fistula and sluggish blood flow from a fistula may stimulate thrombus formation. Treatments between CVST and DAVF differ since high grade DAVF often require endovascular embolization and anticoagulation may increase the risk of intracerebral hemorrhage in a subset of patients. Digital subtraction angiography and/or contrast enhanced MRV should be considered in cases of suspected extensive thrombosis to help differentiate between thrombosis and DAVF.
Successful presurgical endovascular management of venous sinus thrombosis associated with high-grade cerebral arteriovenous malformation: A case report
