Unilateral contrast-enhancing pontomedullary lesion due to an intracranial dural arteriovenous fistula with perimedullary spinal venous drainage: the exception that proves the rule

Watch brain circulation in unexplained progressive myelopathy: a review of Cognard type V arterio-venous fistulas

BACKGROUND

Intracranial dural arterio-venous fistulas are pathological anastomoses between arteries and veins located within dural sheets and whose clinical manifestations depend on location and hemodynamic features. They can sometimes display perimedullary venous drainage (Cognard type V fistulas-CVFs) and present as a progressive myelopathy. Our review aims at describing CVFs' variety of clinical presentation, investigating a possible association between diagnostic delay and outcome and assessing whether there is a correlation between clinical and/or radiological signs and clinical outcomes.

METHODS

We conducted a systematic search on Pubmed, looking for articles describing patients with CVFs complicated with myelopathy.

RESULTS

A total of 72 articles for an overall of 100 patients were selected. The mean age was 56.20 ± 14.07, 72% of patients were man, and 58% received an initial misdiagnosis. CVFs showed a progressive onset in 65% of cases, beginning with motor symptoms in 79% of cases. As for the MRI, 81% presented spinal flow voids. The median time from symptoms' onset to diagnosis was 5 months with longer delays for patients experiencing worse outcomes. Finally, 67.1% of patients showed poor outcomes while the remaining 32.9% obtained a partial-to-full recovery.

CONCLUSIONS

We confirmed CVFs' broad clinical spectrum of presentation and found that the outcome is not associated with the severity of the clinical picture at onset, but it has a negative correlation with the length of diagnostic delay. We furthermore underlined the importance of cervico-dorsal perimedullary T1/T2 flow voids as a reliable MRI parameter to orient the diagnosis and distinguish CVFs from most of their mimics.

Transvenous coil embolization of a Cognard V transverse-sigmoid sinus dural arteriovenous fistula

Dural arteriovenous fistulas with drainage into the spinal veins, classified as Cognard type 5, can be challenging to diagnose and treat. Brainstem and cervical spinal cord signal abnormalities on magnetic resonance imaging result from venous congestion, and can mimic tumor, infection, or inflammation.1-3 Transarterial and transvenous embolization techniques can be used to treat dural arteriovenous fistulas endovascularly. Efficacious transvenous treatment relies on the ability to safely catheterize the draining vein at the dural arteriovenous fistula site. Transvenous access options may seem limited in the setting of occluded venous sinuses. This case highlights the technical aspects of the transvenous approach to embolization of a transverse-sigmoid sinus dural arteriovenous fistula within an isolated sinus,4,5 demonstrating traversal of the occluded venous sinus from a contralateral approach.6,7[Media: see text].

Dural arteriovenous fistulas misdiagnosed as intracranial neoplasms: illustrative case

BACKGROUND

Dural arteriovenous fistulas (dAVF) may induce imaging findings attributable to various disease entities including malignant neoplasms. In these cases, diagnosis and adequate treatment are often delayed and patients may be exposed to spurious treatments in addition to the risks inherent to an untreated dAVF with cortical venous drainage.

OBSERVATIONS

The authors report a case of a patient referred for surgical treatment of a supratentorial high-grade glioma. Thorough review of imaging data challenged the initial radiological diagnosis and led to proper angiographic workup. As a result, a high-grade dAVF was confirmed and successfully embolized. In addition to this case, we provide an extensive literature review on dAVF initially diagnosed as cerebral neoplasms, including clinical, imaging and follow-up data.

LESSONS

The literature provides diagnostic criteria for dAVF on magnetic resonance imaging; however, those criteria may be only partly applicable in many cases. Misdiagnosis of a neoplasm due to dAVF has been reported but remains rare, especially in supratentorial lesions. Digital subtraction angiography should be pursued to rule out an underlying vascular pathology if any doubt. This may prevent unnecessary interventions such as biopsies, pharmacological treatment and a delay in dAVF treatment, given its associated risk of hemorrhage and nonhemorrhagic neurological deficits.

A case series of intracranial dural arteriovenous fistulae mimicking cervical myelitis: a diagnosis not to be missed

Objective

To describe the diagnostic features of intracranial dural arteriovenous fistulae (DAVF) presenting with cervical cord or brainstem swelling.

Methods

Retrospective case note and neuroimaging review of patients with angiographically confirmed DAVF diagnosed during January 2015–June 2020 at a tertiary neuroscience centre (Walton Centre NHS Foundation Trust, Liverpool, UK).

Results

Six intracranial DAVF causing cervical cord or brainstem oedema (all males aged 60–69 years) and 27 spinal DAVF (88% thoracolumbar) were detected over a 5.5-year period. Significantly more patients with intracranial DAVF received steroids for presumed inflammatory myelitis than those with spinal DAVF (5/6 vs 1/27, p = 0.0001, Fisher’s exact test). Several factors misled the treating clinicians: atypical rostral location of cord oedema (6/6); acute clinical deterioration (4/6); absence (3/6) or failure to recognise (3/6) subtle dilated perimedullary veins on MRI; intramedullary gadolinium enhancement (2/6); and elevated CSF protein (4/5). Acute deterioration followed steroid treatment in 4/5 patients. The following features may suggest DAVF rather than myelitis: older male patients (6/6), symptomatic progression over 4 or more weeks (6/6) and acellular CSF (5/5).

Conclusion

Intracranial DAVF are uncommon but often misdiagnosed and treated as myelitis, which can cause life-threatening deterioration. Neurologists must recognise suggestive features and consider angiography, especially in older male patients. Dilated perimedullary veins are an important clue to underlying DAVF, but may be invisible or easily missed on routine MRI sequences.

Intracranial Dural Arteriovenous Fistulas With Brainstem Engorgement: An Under-Recognized Entity in Diagnosis and Treatment

Background: In rare circumstances, patients with intracranial (dural arteriovenous fistulas) DAVFs could be complicated with brainstem engorgement, which might lead to delayed or false diagnosis and subsequent improper management.

Methods: On July 2th, 2019, a systematic search was conducted in the PubMed database for patients with intracranial DAVFs complicated with brainstem engorgement.

Results: Sixty-eight articles reporting of 86 patients were included for final analysis. The patients were aged from 20 to 76 years (57.10 ± 12.90, n = 82). The female to male ratio was 0.68 (35:51). Thirty-three (40.2%, 33/82) patients were initially misdiagnosed as other diseases. The specific location distributions were cranio-cervical junction, cavernous sinus, superior petrosal sinus, transverse and/or sigmoid sinus, tentorium, and other sites in 27 (32.5%), 11 (13.2%), 9 (10.8%), 10 (12.0%), 21 (25.3%), and 5 (6.0%) patients, respectively. The Cognard classification of DAVFs were II, III, IV, and V in 9 (10.7%, 9/84), 1 (1.2%, 1/84), 1 (1.2%, 1/84), and 73 (86.9%, 73/84) patients. Eighteen (22%, 18/82) patients were demonstrated to have stenosis or occlusion of the draining system distal to the fistula points. The mean follow-up period was 7.86 (n = 74, range 0–60 months) months. Fifty-four (70.1%, 54/77) patients experienced a good recovery according to the mRS score.

Conclusions: Intracranial DAVFs complicated with brainstem engorgement are rare entities. Initial misdiagnosis and delayed definite diagnosis are common in the past three decades. The treatment outcome is still unsatisfactory at present. Early awareness of this rare entity and efficiently utilizing the up to date investigations are of utmost importance.

A rare case of spinal dural arteriovenous fistula mimicking malignant glioma of the medulla oblongata: Significance of cerebral angiography for accurate diagnosis of brain stem region

Background:

The findings of a hyperintense sign on T2-weighted imaging (T2-WI) and gadolinium (Gd) contrast enhancement on magnetic resonance imaging (MRI) of the brain stem suggest malignant glioma. However, this pathological condition is probably uncommon, and it may be unknown that a dural arteriovenous fistula (DAVF) can imitate this radiological pattern. In addition, it is extremely rare to be caused by a spinal DAVF. Here, a rare case of spinal DAVF that mimicked malignant glioma of the medulla oblongata is presented.

Case Description:

A 56-year-old woman was admitted with a progressive gait disturbance, vertigo, and dysphasia. MRI showed a hyperintense signal in the medulla oblongata on fluid-attenuated inversion recovery (FLAIR) and moderate contrast enhancement on Gd-enhanced MRI. Interestingly, Gd-enhanced MRI demonstrated abnormal dilated veins around the brain stem and cervical spinal cord. Cerebral angiography showed spinal DAVF at the left C4/C5 vertebral foramen fed by the C5 radicular artery. The fistula drained into spinal perimedullary veins and flowed out retrograde at the cortical vein of the posterior cranial fossa. Therefore, surgical disconnection of the spinal DAVF was performed by a posterior approach. The patient’s postoperative course was uneventful. Cerebral angiography showed complete disappearance of the DAVF, with marked reductions of the hyperintense sign of the medulla oblongata on FLAIR.

Conclusion:

This important case illustrates MRI findings mimicking brain stem glioma. In cases with the hyperintense sign-on T2-WI associated with contrast enhancement suspicious of brainstem glioma, careful checking for perimedullary abnormal vessels and additional cerebral angiography should be performed.

Dural arteriovenous fistula presenting with dementia and bulbar symptoms

Dural arteriovenous fistulas are relatively rare. Some cases are difficult to diagnose, leading to unnecessary investigations, treatments and delays, particularly if the presentation is atypical. We report a case of a man who presented with progressive dementia and bulbar symptoms, both under-recognised non-haemorrhagic neurological deficits, caused by cortical venous hypertension. Brain imaging showed unusual bilateral thalamic, tectal plate and midbrain oedema. The patient was investigated and treated for alternative aetiologies, before being correctly diagnosed and managed using angiographic embolisation. His clinical and radiological signs improved significantly following treatment, reducing his risk of neurological morbidity and mortality.

An Isolated Unilateral Pontomedullary Lesion Due to An Intracranial Dural Arteriovenous Fistula Mimicking A Brain Tumor - Case and Review

Intracranial dural arteriovenous fistula (DAVF) with perimedullary venous drainage may cause brainstem swelling and represent a diagnostic challenge. A 66-year-old man presented to the emergency room with recurrent vertigo, minimal truncal ataxia with a wide-based gait, and a slightly impaired tandem gait. Brain magnetic resonance imaging (MRI) revealed a hyperintense lesion in the left pontomedullary area on T2-weighted images (T2WIs) with partial gadolinium enhancement, but without increased signals on diffusion-weighted images. Abnormal serpentine flow void vessels surrounding the medulla and upper cervical spinal cord were initially overlooked but discovered later. An angiogram revealed DAVF with feeders from the right occipital artery and the meningeal branch of the right distal vertebral artery with drainage into the anterior medullary venous system and the perimedullary veins. The patient underwent a successful transarterial endovascular embolization and improved gradually. A brain MRI at 3-month follow-up revealed a residual hyperintense signal on the T2WIs in the left lower medulla. Six cases of patients exhibiting DAVF with isolated unilateral brainstem swelling from the literature were reviewed. Isolated unilateral brainstem swelling due to intracranial DAVF with perimedullary venous drainage is extremely rare and might mimic a tumor on MRI. Abnormal serpentine flow void vessels on the surface of the brainstem or spinal cord are crucial diagnostic clues.

Lessons to Be Remembered from a Dural Arteriovenous Fistula Mimicking Medulla and High Cervical Cord Glioma

The radiological signs of intracranial dural arteriovenous fistulas (ICDAVFs) are heterogenous. While it is commonly accepted that hyper intense T2 wedge magnetic resonance imaging of the brainstem and cervical cord mainly concern gliomas, it is so far uncommon and probably unknown that ICDAVFs can imitate similar radiological pattern, especially with gadolinium contrast enhancement and cord enlargement. Thus the angiography is poorly documented in the diagnostic workup. We report the unusual history of ICDAVFs, revealed by clinical and radiological features that mimicked a medulla or cervical spinal cord glioma. This observation provides information on the management of atypical lesions mimicking medulla or cervical cord glioma and arguments for a careful radiological study. Looking for dilated veins around the brainstem and the cord is mandatory in the workup of a supposed infiltrating brainstem or spinal cord lesion, in order to rule out an ICDAVF. Even if the hyperintense T2 images associated with contrast enhancement is in favor of a brainstem or spinal cord glioma, additional cerebral angiography should be mandatory. Moreover, this clinical case highlights the need for a multidisciplinary approach including neuroradiologist, oncologist and neurosurgeon.

Dural Arteriovenous Fistulas: A Characteristic Pattern of Edema and Enhancement of the Medulla on MRI

Medullary edema with enhancement is rarely reported at initial MR imaging in intracranial dural arteriovenous fistulas. We report a series of 5 patients with dural arteriovenous fistulas, all of whom demonstrated a characteristic pattern of central medullary edema and medullary enhancement at initial MR imaging. Cognard type V dural arteriovenous fistula, defined by drainage into the perimedullary veins and the veins surrounding the brain stem, is a rare yet well-described pathologic entity. Even more rarely reported, however, is its clinical presentation with predominantly bulbar symptoms and MR imaging findings of central medullary edema with enhancement. This constellation of findings frequently leads to a convoluted clinical picture, prompting work-up for alternative disease processes and delaying diagnosis. Because an expedited diagnosis is critical in preventing poor outcomes, it is paramount to make the referring physician and neuroradiologist more cognizant of this rare-yet-characteristic imaging manifestation of dural arteriovenous fistula.

Cognard Type V intracranial dural arteriovenous fistula presenting in a pediatric patient with rapid, progressive myelopathy

Cognard Type V dural arteriovenous fistulas (dAVFs) are a unique type of cranial vascular malformation characterized by congestion of the perimedullary venous system that may lead to devastating spinal cord pathology if left untreated. The authors present the first known case of a pediatric patient diagnosed with a Type V dAVF. A 14-year-old girl presented with a 3-week history of slowly progressive unilateral leg weakness that quickly progressed to bilateral leg paralysis, sphincter dysfunction, and complete sensory loss the day of her presentation. MRI revealed an extensive T2 signal change in the cervical spine and tortuous perimedullary veins along the entire length of the cord. An emergency cranial angiogram showed a Type V dAVF fed by the posterior meningeal artery with drainage into the perimedullary veins of the cervical spine. The fistula was not amenable to embolization because vascular access was difficult; therefore, the patient underwent urgent suboccipital craniotomy and ligation of the arterialized venous drainage from the fistula. The patient's clinical course immediately reversed; she had a complete recovery over the course of a year, and she remains asymptomatic at the 2-year follow-up. This report adds to a growing body of evidence that describes the diverse and unpredictable nature of Type V dAVFs and highlights the need to obtain a cranial angiogram in pediatric patients with unexplained myelopathy and cervical cord T2 signal change on MRI.

Transarterial Onyx embolization of jugular foramen dural arteriovenous fistula with spinal venous drainage manifesting as myelopathy-a case report and review of the literature

We report a rare case of jugular foramen dural arteriovenous fistula (DAVF) with spinal venous drainage. A 48-year-old woman suffered from progressive weakness of lower extremities and incontinence of urine and feces for 14 days. Magnetic resonance imaging (MRI) revealed a tortuous posterior medullary vein at C2-T2 and ischemic signal at C2-C4 of the spinal cord. Brain MRI revealed an abnormal high signal near the left jugular foramen. Digital subtraction angiography of the spinal vascular was negative, while brain angiography showed a left jugular foramen DAVF with spinal perimedullary venous drainage. The patient recovered completely soon after endovascular embolization with Onyx-18. Diagnosis of a DAVF presenting with myelopathy is challenging. Early diagnosis and treatment are essential for a favorable outcome.