[Peripheral facial palsy after embolization of a dural arteriovenous fistula with Onyx®]

Facial Nerve Paralysis Following Endovascular Embolization: A Case Report and Review of the Literature

OBJECTIVE

We report a case of facial nerve paralysis post-endovascular embolization of a sigmoid sinus dural arterio-venous fistula from initial presentation to current management and discuss the merits of observation versus decompression through a systematic review of relevant literature.

PATIENT

61 F with right facial palsy.

INTERVENTION

Following a single intravenous dexamethasone injection with oral steroids over 2 months, patient was observed with no additional treatment other than Botox chemodenervation and facial rehabilitation.

OUTCOME AND RESULTS

The patient initially presented with complete right facial palsy (HB 6/6). Post-op CT imaging indicated Onyx (ev3, Irvine, California, USA) particles present at the geniculate segment of the facial nerve. Observation was chosen over surgical intervention. At the most current follow up of 8 months, facial function has improved substantially (HB 2/6).

CONCLUSION

Facial palsy is a serious, though rare, complication of transarterial endovascular embolization. With our case report and literature review, we highlight not only how conservative observation is the recommended treatment, but also that facial nerve recovery should be expected to reach near complete recovery, but not sooner than in 3 months.

Vagal Nerve Palsy After Transarterial Embolization of Transverse-Sigmoid Dural Arteriovenous Fistula Using Onyx

OBJECTIVE

We report a case of a 70-year-old man who developed a transverse-sigmoid dural arteriovenous fistula (TS-DAVF) that was successfully treated by transarterial embolization (TAE) with Onyx.

CASE PRESENTATION

The patient presented with sudden and progressive disturbance of consciousness and left hemiparesis. Magnetic resonance imaging (MRI) revealed venous infarction and hemorrhagic changes with brain swelling in the right parietal lobe. Angiography revealed a right TS-DAVF and multiple occlusions with retrograde leptomeningeal venous drainage into the cortical veins. The TS-DAVF was graded as Borden type III and Cognard type IIa+b. Because of its progressive clinical nature and wide distribution of DAVF in the occluded sinus wall, he underwent emergent TAE with liquid embolic materials including n-butyl cyanoacrylate and Onyx under informed consent by his family. Complete obliteration of the TS-DAVF was achieved, leading to a marked amelioration of symptoms, and MRI after treatment confirmed a decrease in the brain swelling. However, he suffered transient dysphagia due to right vagal nerve palsy caused by occlusion of vasa nervorum of ascending pharyngeal artery. He returned home 5 months later with a modified Rankin Scale of 1.

CONCLUSIONS

TAE with Onyx appears to be effective for aggressive TS-DAVF with a widely distributed shunt. However, the blood supply to the cranial nerves and potentially dangerous anastomoses between the external-internal carotid artery and vertebral artery should be taken into account to avoid serious complications.

Cranial Nerve Palsy after Onyx Embolization as a Treatment for Cerebral Vascular Malformation

The Onyx liquid embolic system is a relatively safe and commonly used treatment for vascular malformations, such as arteriovenous fistulas and arteriovenous malformations. However, studies on possible complications after Onyx embolization in patients with vascular malformations are limited, and the occurrence of cranial nerve palsy is occasionally reported. Here we report the progress of two different types of cranial nerve palsy that can occur after embolization. In both cases, Onyx embolization was performed to treat vascular malformations and ipsilateral oculomotor and facial nerve palsies were observed. Both patients were treated with steroids and exhibited symptom improvement after several months. The most common types of neuropathy that can occur after Onyx embolization are facial nerve palsy and trigeminal neuralgia. Although the mechanisms underlying these neuropathies are not clear, they may involve traction injuries sustained while extracting the microcatheter, mass effects resulting from thrombi and edema, or Onyx reflux into the vasa nervorum. In most cases, the neuropathy spontaneously resolves several months following the procedure.

Facial palsy after embolization of dural arteriovenous fistula: A case report and literature review

Background

Dural arteriovenous fistulas (DAVF) are unusual intracranial vascular malformations consisting of anomalous connections between meningeal arteries and dural sinuses or the veins that pass through them. They have variable clinical presentation and prognosis, which depend on their location and venous hemodynamics. Treatment is based on the closure of the abnormal connections, which is usually conducted via arterial and/or transvenous endovascular techniques.

Case Description

We present a male patient who complained of headaches and left-sided pulsatile tinnitus due to DAVF from the external carotid artery branches draining directly into the ipsilateral sigmoid sinus. Embolization with Onyx^® was successful, obtaining angiographic occlusion and symptom remission. However, on postoperative day 4, the patient presented with left facial palsy and spontaneous regression.

Conclusion

Although embolization is an effective and safe procedure, complications may occur. Reflux of the embolic agent to the vasa nervorum of the cranial nerve may lead to ischemic neuropathy. Here, we reported a case of embolized DAVF presenting with a postoperative peripheral facial palsy where the two embolized pedicles were branches of the middle meningeal and occipital arteries involved in the vascularization of the extratemporal segment of the facial nerve. We discuss the etiopathogenic, anatomical, and pathophysiological aspects of this complication.

Dural arteriovenous fistulas of the hypoglossal canal: systematic review on imaging anatomy, clinical findings, and endovascular management

Dural arteriovenous fistulas (DAVFs) of the hypoglossal canal (HCDAVFs) are rare and display a complex angiographic anatomy. Hitherto, they have been referred to as various entities (for example, “marginal sinus DAVFs”) solely described in case reports or small series. In this in-depth review of HCDAVF, the authors describe clinical and imaging findings, as well as treatment strategies and subsequent outcomes, based on a systematic literature review supplemented by their own cases (120 cases total). Further, the involved craniocervical venous anatomy with variable venous anastomoses is summarized. Hypoglossal canal DAVFs consist of a fistulous pouch involving the anterior condylar confluence and/or anterior condylar vein with a variable intraosseous component. Three major types of venous drainage are associated with distinct clinical patterns: Type 1, with anterograde drainage (62.5%), mostly presents with pulsatile tinnitus; Type 2, with retrograde drainage to the cavernous sinus and/or orbital veins (23.3%), is associated with ocular symptoms and may mimic cavernous sinus DAVF; and Type 3, with cortical and/or perimedullary drainage (14.2%), presents with either hemorrhage or cervical myelopathy. For Types 1 and 2 HCDAVF, transvenous embolization demonstrates high safety and efficacy (2.9% morbidity, 92.7% total occlusion). Understanding the complex venous anatomy is crucial for planning alternative approaches if standard transjugular access is impossible. Transarterial embolization or surgical disconnection (morbidity 13.3%–16.7%) should be reserved for Type 3 HCDAVFs or lesions with poor venous access. A conservative strategy could be appropriate in Type 1 HCDAVF for which spontaneous regression (5.8%) may be observed.