CASE REPORT

Cervical Spine Dural Arteriovenous Fistula With
Coexisting Spinal Radiculopial Artery Aneurysm
Presenting as Subarachnoid Hemorrhage:
Case Report
Joshua W. Lucas, BS
Jesse Jones, MD
Azadeh Farin, MD
Paul Kim, MD
Steven L. Giannotta, MD
Department of Neurosurgery, Keck School
of Medicine, University of Southern
California, Los Angeles, California
Correspondence:
Joshua W. Lucas, BS,
1200 N State St,
Suite 3300,
Los Angeles, CA 90089.
E-mail: joshualu@usc.edu
Received, September 14, 2010.
Accepted, February 22, 2011.
Published Online, June 28, 2011.
Copyright ª 2011 by the
Congress of Neurological Surgeons

BACKGROUND AND IMPORTANCE: We present a patient with a cervical spine dural
arteriovenous fistula associated with a radiculopial artery aneurysm at the same vertebral level presenting with subarachnoid hemorrhage.
CLINICAL PRESENTATION: A 45-year-old Native American man presented with suddenonset severe headache, lethargy, and right hemiparesis. Computed tomography (CT) of
the head showed subarachnoid hemorrhage and hydrocephalus. A subsequent CT of the
neck showed an anterior spinal subdural hematoma from C2 to C4 causing mild cord
compression. Carotid and vertebral angiography failed to demonstrate an intracranial
aneurysm, but showed a spinal dural arteriovenous fistula originating from the right
vertebral artery at the C5 neuroforamen. The severity of the patient’s symptoms, atypical
for rupture of a dural arteriovenous fistula, prompted more thorough angiographic
evaluation. Thus, injection of the right thyrocervical trunk was performed, demonstrating
a 4-mm spinal radiculopial artery aneurysm. Following ventriculostomy, a hemilaminectomy from C4 to C7 was performed with disconnection of the fistula from its
drainage system. Subsequent resection of the aneurysm, which was determined to be
the cause of the hemorrhage, was accomplished. The patient improved neurologically
and was discharged to rehabilitation.
CONCLUSION: Spinal cord aneurysms from a separate vascular distribution may coexist
with spinal dural arteriovenous fistulas. In the setting of spinal hemorrhage, especially in
situations with an atypical clinical presentation, comprehensive imaging is indicated to
rule out such lesions.
KEY WORDS: Aneurysm, Dural arteriovenous fistula, Subarachnoid hemorrhage
Neurosurgery 70:E259–E263, 2012

DOI: 10.1227/NEU.0b013e31822ac0fb

S

pinal dural arteriovenous fistulas (dAVFs)
are the most common type of spinal vascular malformations, comprising 60 to
80% of such lesions.1,2 Spinal dAVFs are acquired
lesions representing an abnormal connection
between a dural branch of a radicular artery and
vein along the spinal dural surface, forming in
response to poorly understood pathophysiologic
mechanisms.2-4 Most dAVFs are found at the
neural foramina of the thoracolumbar junction,
but they may arise at any spinal level.2,3
ABBREVIATIONS: dAVF, dural arteriovenous fistulas;
SAH, subarachnoid hemorrhage

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Lesions in the thoracolumbar region manifest
as progressive myelopathy with spastic paraparesis, sensory disturbances, or genitosphincteric dysfunction.1,3 Craniocervical spinal
dAVFs can present with similar symptoms, but
are distinguished by a propensity for causing
subarachnoid hemorrhage (SAH) and cranial
nerve dysfunction.3,5,6 Rupture of craniocervical
dAVFs, although rare, typically produces lowgrade subarachnoid hemorrhage. Here, we
present an unusual case of a dAVF originating
from branches of the vertebral artery and a
coexisting aneurysm of the spinal pial circulation
in a patient presenting with moderate-grade
SAH.

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LUCAS ET AL

CASE REPORT
A 45-year-old Native American man presented with sudden-onset
severe headache. The patient also reported light sensitivity, neck pain and
stiffness, nausea, and one episode of emesis. He was confused and
lethargic with a Glasgow Coma Score of 13, and 2/5 strength in his right
upper extremity with 4/5 strength in his right lower extremity. The
patient admitted to a 10-year history of daily intravenous drug abuse. Of
note, he denied a history of fevers, chills, or other symptoms of acute
infection.
A noncontrast head computed tomography (CT) revealed extensive
SAH in the upper cervical region and the basilar cisterns, and intraventricular hemorrhage with hydrocephalus (Figure 1). Subsequently,
a CT angiogram of the head and neck to assess for a vascular etiology
revealed an anterior spinal subdural hematoma extending from C2 to C4
causing mild cord compression (Figure 2). Also, a prominence of vessels
surrounding the cord suggestive of a vascular malformation within the
spinal canal was identified. A separate focus of hyperdensity at the C4/C5
level suggestive of an aneurysm was also noted (Figure 3). Magnetic
resonance imaging of the cervical spine was strongly supportive of these
findings (Figure 4).
Comprehensive cerebral and spinal cord angiography was subsequently performed. Injection of the right vertebral artery demonstrated
an abnormally enlarged radicular artery at the C5 level and a dAVF at the
C5 neuroforamen with a cranially directed draining vein extending to
the suboccipital region (Figure 5). Based on the presence of posterior
fossa SAH with an anterior spinal subdural hematoma, and the focus of
hyperdensity seen on CT, injection of the right thyrocervical trunk was
performed. This demonstrated a radiculopial artery aneurysm measuring
4 mm in diameter located anteriorly within the spinal canal at the level
of the C4/C5 disc (Figure 6A and 6B). No intracranial vascular abnormalities or other anomalies were identified. These findings were
consistent with a category IV subtype III spinal dAVF at the C5 neuroforamen and a radiculopial artery aneurysm at the level of the subdural
hematoma fed by distal branches of the thyrocervical trunk.

FIGURE 1. Axial CT scan of the head showing subarachnoid
hemorrhage and intraventricular hemorrhage.

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FIGURE 2. Sagittal CT scan of the cervical spine with contrast demonstrating
an anterior subdural mass extending from C2 to C4 and a focus of enhancement
at the C4/C5 disc.

On postbleed day 4, the patient underwent a C4 to C7 right-sided
hemilaminectomy with ligation of the dAVF and resection of the radiculopial artery aneurysm. Intraoperative angiography showed occlusion
and absence of both lesions (Figure 7). The patient subsequently
improved to a Glasgow Coma Score of 15 with 4+/5 strength in his right

FIGURE 3. Axial CT scan with contrast through C4/C5 showing the anterior
focus of enhancement later determined to be a radiculopial aneurysm and the
posterior draining vein of the dAVF.

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CERVICAL dAVF WITH RADICULOPIAL ANEURYSM

FIGURE 4. Sagittal T2-weighted magnetic resonance imaging of the cervical
spine demonstrating a hyperintense ovoid lesion at the levels of C2 to C4 and
multiple flow voids in the same location.

upper extremity and 5/5 strength in his right lower extremity, and was
discharged to rehabilitation. Histologic evaluation of the aneurysm
demonstrated an arterial wall without evidence of infection, excluding
the possibility of a mycotic aneurysm or pseudoaneurysm.

DISCUSSION
Craniocervical dAVFs, although uncommon, have been wellcharacterized in the literature. SAH has been reported to occur in
34 to 45% of cases.2,5,6 When associated with hemorrhage, cases
of dAVF rupture are usually characterized by a more benign
clinical course than with aneurysm rupture. Fassett et al3 found
that 95% of patients with craniocervical dAVF-related SAH
presented with Hunt and Hess grade I or II hemorrhage, and no
patients presented with Hunt and Hess grade IV or V hemorrhage. A large percentage of these patients had lesions with
a cephalad or intracranially directed drainage pattern.5,6 Comparatively, 50 to 60% of patients with aneurysm-related SAH
present with Hunt and Hess grade I or II hemorrhage, while 17 to
30% present with Hunt and Hess grade IV or V hemorrhage.7,8
This patient, however, presented with moderate- to severegrade SAH necessitating a ventriculostomy, clearly atypical for
a craniocervical dAVF rupture. Upon discovery of the dAVF with
injection of the right vertebral artery, this case could easily have
been misdiagnosed as a dAVF alone. The discrepancy between

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FIGURE 5. Injection of the right vertebral artery revealing
a spinal dural arteriovenous fistula with a large feeding vessel
originating from the level of C5 and a posterior cranially
directed draining vein.

the patient’s severity of SAH and that diagnosis, along with key
findings on CT, heightened our suspicion that some other
process might be responsible for the hemorrhage. Thus, injection
of the right thyrocervical trunk was performed, demonstrating the
coexisting radiculopial artery aneurysm.
We were confident, based on the anterior location of both the
spinal subdural hematoma and the aneurysm, that the aneurysm
was the source of the hemorrhage. The radiculopial artery
aneurysm in this patient arose anteriorly from pial branches fed
by the thyrocervical trunk. The dAVF, while located at the same
vertebral level, arose posteriorly from right vertebral artery
branches. Intraoperatively, the aneurysm was determined to be
the lesion that ruptured based on its appearance and proximity to
the anterior spinal subdural hematoma.
There is no definite explanation for the presence of the
simultaneous lesions found in this patient. An association
between dAVFs and aneurysms has only rarely been reported in
the literature.9 However, other complex vascular structures such
as arteriovenous malformations and multiple dAVFs have been
found to coexist with dAVFs more frequently.10 As low-flow
lesions, dAVFs rarely produce enough hemodynamic stress on the
arterial walls to induce aneurysm formation of feeding arteries.
Isolated aneurysms of the anterior spinal artery proper or

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LUCAS ET AL

FIGURE 6. Injection of the right thyrocervical trunk demonstrating a radiculopial artery aneurysm within the spinal canal
measuring 4 mm in diameter at the level of C4/C5. A, anteroposterior view. B, lateral view.

branches of the anterior spinal artery are also rare lesions, but
when present are often associated with SAH.11,12
The decision to proceed with an open microsurgical technique
was made to allow for complete treatment of both the aneurysm
and dAVF. The subdural hematoma was large enough to compress

the cervical spinal cord, so a longer laminectomy was performed
to aid in decompression. Based on the patient’s long history of
intravenous drug abuse, we were suspicious that the radiculopial
artery aneurysm might have actually been a mycotic aneurysm.
However, no active infection was identified, and final pathological
analysis of the aneurysm wall confirmed that the aneurysm was
not mycotic.
The lesions in this patient highlight the possibility that
craniocervical dAVFs and aneurysms of the spinal cord may
coexist. Without additional clues from the CT scan and the
patient’s uncharacteristic presentation, the SAH and spinal
hemorrhage might have mistakenly been attributed to rupture of
the dAVF, leaving the true cause of the hemorrhage undiscovered.
Thus, it is reasonable to conclude that early progression to more
comprehensive vascular imaging studies in the diagnostic
algorithm may be indicated to assess for the presence of such
simultaneous lesions.
Disclosure
The authors have no personal financial or institutional interest in any of the
drugs, materials, or devices described in this article.

REFERENCES

FIGURE 7. Postoperative angiogram of the right vertebral
artery displaying complete resolution of the spinal dural arteriovenous fistula.

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review. Eur J Neurol. 2010;17(5):684-691.
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literature review and case presentation. Neurosurg Focus. 2009;26(1):E4.

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CERVICAL dAVF WITH RADICULOPIAL ANEURYSM

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COMMENT

T

he authors present an interesting case of spinal dural arteriovenous
fistula (SDAVF) presenting with intracranial subarachnoid (SAH)
and cervical spinal subdural hemorrhage (SDH). In and of itself, SAH is
a rare presenting symptom for SDAVF, although recently a clinical series
from Toronto reported a relatively high incidence of hemorrhagic presentation of cervical DAVFs (Kim et al, AJNR 2010;31:1512-1515).
Feeding artery aneurysms to a SDAVF have been reported previously by
UCSF (Malek et al, Neurosurgery 1999;44:877-880), with pathologic
correlation. The current case report also offers pathology confirming
a true arterial aneurysm as opposed to a dissection or mycotic aneurysm.
This case underscores the importance of performing complete cervicocerebral angiography in order to delineate all possible feeding arteries
to cervical spinal AV fistulas. Detailed angiography is essential prior to
either endovascular or surgical treatment of these rare but important
vascular malformations so that all arterial feeders to the AVF are identified as well as the pial supply to the spinal cord itself.
Steven W. Hetts
San Francisco, California

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