Surgical Neurology 64 (2005) 341 – 345
www.surgicalneurology-online.com

Vascular

Brain stem ischemia from intracranial dural arteriovenous fistula:
Case report
Motoyoshi Satoh, MDa,T, Mitsuo Kuriyama, MDa, Takashi Fujiwara, MDa,
Koji Tokunaga, MDb, Kenji Sugiu, MDb
b

a
Department of Neurological Surgery, Kure Kyosai Hospital, Kure, Hiroshima 737-8505, Japan
Department of Neurological Surgery, Okayama University Graduate School of Medicine and Dentistry, Okayama 700-8558, Japan
Received 11 October 2004; accepted 20 December 2004

Abstract

Background: Intracranial dural arteriovenous fistulas (AVFs) with spinal perimedullary venous
drainage are rarely reported, but most of the patients initially have presented with myelopathy or
subarachnoid hemorrhage. This is the first report of the intracranial dural AVF patient who presented
with brain stem infarction.
Case Description: A 38-year-old woman experienced nausea and vomiting with an acute onset,
followed by vertigo. Magnetic resonance imaging showed ischemic lesion in the medulla oblongata, and she was then sent to our hospital. On admission, she had nystagmus, swallowing difficulties, Horner syndrome, and right hemiparesis and hemisensory disturbance. Cerebral angiography
revealed dural AVF draining into spinal perimedullary veins at the left transverse-sigmoid sinus. The
patient was treated by transvenous embolization under local anesthesia. A microcatheter proceeded
to the left sigmoid sinus via the internal jugular vein, and embolization of the sinus was performed
using coils without complications. The patient’s swallowing difficulties improved over a few days
after the embolization, and 1 month later, there remained only a right mild hemiparesis and
hemisensory disturbance. Six months after the onset, there was no ischemic lesion in the brain stem
on magnetic resonance imaging.
Conclusions: In this case, we showed the possibility of brain stem infarction, caused by the
intracranial dural AVF.
D 2005 Elsevier Inc. All rights reserved.

Keywords:

Brain stem ischemia; Dural arteriovenous fistula; Transvenous embolization

1. Introduction
Intracranial dural arteriovenous fistulas (AVFs) account
for approximately 12% of all intracranial arteriovenous
malformations [8], but the type of intracranial dural AVF
with spinal perimedullary venous drainage is rare [2,4]. Most
of such patients have presented with myelopathy or
subarachnoid hemorrhage, and in case of myelopathy, brain
stem signs appear to occur at a later stage of the clinical
course [1,2,4,5,9]. We, however, have experienced an intracranial dural AVF patient who had brain stem infarction,

T Corresponding author. Department of Neurological Surgery,
Okayama Kyokuto Hospital, Okayama 703-8265, Japan. Tel.: +81 86
276 3231; fax: +81 86 274 1028.
E-mail address: motoyoshisato@hotmail.com (M. Satoh).
0090-3019/$ – see front matter D 2005 Elsevier Inc. All rights reserved.
doi:10.1016/j.surneu.2004.12.029

which was not accompanied by myelopathy. A transvenous
embolization was performed, and the symptoms of the brain
stem were improved. To our knowledge, this is the first case
report of the intracranial dural AVF presenting with brain
stem infarction.
2. Case presentation
A 38 -year-old woman experienced nausea and vomiting with a sudden onset, followed by vertigo. She initially
presented to her general practitioner, and a stroke was
suspected. Magnetic resonance imaging (MRI) showed
ischemic lesion in the medulla oblongata, and she was then
sent to our hospital. On admission, she had nystagmus,
swallowing difficulties, and Horner syndrome on the right
side. In addition, she complained of right paresthesia in her

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M. Satoh et al. / Surgical Neurology 64 (2005) 341 – 345

Fig. 1. T1-weighted axial image showing low signal over the right half area in the medulla oblongata (A). T2-weighted (B) and FLAIR (C) axial images
showing high signal over the right half area in the medulla oblongata.

upper and lower extremities. Mild weakness affected her
right upper and lower limbs, but her upper and lower limbs
on the left side were neurologically normal.
Her medical history consisted of schizophrenia. She
was orally on major tranquilizers such as phenothiazine
and benzamide derivatives. They were injected intramuscularly after admission because her swallowing difficulties
were severe.
MRI (T1- and T2-weighted sequences and FLAIR
[fluid-attenuated inversion recovery] sequence) showed

ischemic lesion over the right half area of the medulla
oblongata (Fig. 1). Cerebral angiography revealed a dural
AVF draining into spinal perimedullary veins at the left
transverse-sigmoid sinus. Left external carotid artery
angiogram demonstrated a dural AVF fed by the petrosal
and posterior branches of the middle meningeal artery,
transosseous dural branch of the occipital artery, and
ascending pharyngeal artery (Fig. 2A). In addition, the
dural AVF was supplied by the meningohypophyseal trunk
of the left internal carotid artery (Fig. 2B) and posterior

Fig. 2. Left external carotid artery angiogram demonstrating a AVF fed by the petrosal (small arrow) and posterior branch (large arrow) of the middle meningeal
artery, transosseous dural branch of the occipital artery (small arrowhead), and ascending pharyngeal artery (large arrowhead) (A). Left internal carotid artery
(B) and right vertebral artery angiograms (C) demonstrating a dural AVF supplied by the meningohypophyseal trunk of the left internal carotid artery (open
small arrow) and posterior meningeal branch of the right vertebral artery (open small arrowhead), respectively. The fistulas were located on the left superior
petrosal sinus (open large arrowhead) and transverse-sigmoid sinus (open large arrow) junction and drained into the posterior spinal perimedullary vein (half
arrowheads) through the sigmoid sinus (D). The left transverse sinus was occluded (E).

M. Satoh et al. / Surgical Neurology 64 (2005) 341 – 345

343

Fig. 3. T1-weighted (A) and T2-weighted (B) sagittal images showing high signal in the medulla oblongata. T2-weighted sagittal image demonstrating the
enlarged posterior perimedullary vein behind the cervical cord as flow-void sign (arrows). The cervical cord was intact on MRI.

meningeal branch of the right vertebral artery (Fig. 2C).
The fistulas were located on the left transverse-sigmoid
sinus (Fig. 2A) and drained into the posterior spinal
perimedullary vein through the sigmoid sinus (Fig. 2D).
The left transverse sinus was occluded, whereas proximal
sigmoid sinus and internal jugular vein were intact
(Fig. 2E).
Cranial and cervical MRIs were followed up before
the endovascular surgery. T1- and T2-weighted images
showed high intensity in the medulla oblongata, which
meant hemorrhage (Fig. 3A and B). T2 -weighted sequences

demonstrated the enlarged posterior perimedullary vein
behind the cervical and thoracic cord as flow - void sign
(Fig. 3B). The cervical cord was intact on MRI.
Embolization was performed to occlude the affected
sigmoid sinus using coils transvenously. The affected sinus
was successfully occluded with platinum coils. The dural
AVF was completely obliterated, and venous hypertension
of the posterior fossa and spinal cord was released (Fig. 4).
The patient’s swallowing difficulties improved over a few
days after the embolization, and 1 month later, there
remained only a right slight hemiparesis and hemipares-

Fig. 4. Left common carotid artery (A) and right vertebral artery (B) angiograms after embolization. The dural AVF was completely obliterated.

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M. Satoh et al. / Surgical Neurology 64 (2005) 341 – 345

3. Discussion

Fig. 5. T1-weighted (A), T2-weighted (B) and FLAIR (C) axial images after
embolization. The low signals on T1-weighted sequences or high signals on
T2-weighted and FLAIR sequences were remarkably reduced in the
medulla oblongata.

thesia. Follow-up angiography was carried out 1 month
later, and the dural AVF was completely obliterated.
On MRI, the high signals on T1- and T2 - weighted
sequences and FLAIR sequence were remarkably reduced
in the medulla oblongata (Fig. 5).

We have experienced a dural AVF with spinal perimedullary venous drainage. This belongs to type V in the
classification of Cognard et al [2]. In type V dural arteriovenous malformation, both anterior and posterior spinal
perimedullary veins via pontomesencephalic vein have been
observed as draining veins from AVFs [1,2,4,9]. Gobin et al
[4] previously suggested that the venous drainage around
the brain stem such as the pontomesencephalic vein might
be related to brain stem signs. Indeed, in cases of
intracranial dural AVFs draining into the spinal veins, the
occurrences of myelopathy are attributable to the venous
congestion of the spinal cord [1,12]. In the present case, we
observed posterior spinal perimedullary vein through the
sigmoid sinus, but anterior spinal perimedullary and
pontomesencephalic veins were not seen. Moreover, the
bulbar ischemia occurred on the opposite side from the dural
AVM. This indicates that brain stem ischemia without
myelopathy may not only be ascribed to anatomic connection of the draining veins, but also to hemodynamic
mechanism at the onset.
As the cause of cerebral or spinal ischemia by AVFs,
there are 3 possibilities: venous hypertension, arterial steal,
and direct compression by enlarged veins. In the intracranial dural AVF patients with myelopathy, edema by the
venous congestion is the main cause of the spinal ischemia
because intracranial feeding arteries do not flow into the
spinal cord. Some of the patients have been reported to
have had sinus thrombosis simultaneously, and the
symptom of increased intracranial pressure such as
headache or nausea with acute onset preceded myelopathy
in such cases [4]. This means that the venous drainage into
the spinal perimedullary veins may proceed gradually after
sinus thrombosis and subsequently lead to ascending
myelopathy owing to edema of the spinal cord. Meanwhile, in our case, intracranial hypertension and brain stem
signs appeared at approximately the same time. We
suppose that she had nausea and vomiting when the
transverse sinus was thrombosed. Sundt and Piepgras [10]
postulated that, as the cause of increased intracranial
pressure, there is the impairment of venous runoff from
associated major sinus occlusion besides intrasinus hypertension by high flow into the draining sinus. The former
mechanism seems to induce acute onset of headache or
vomiting, comparing with the latter.
The dural AVF existed on the left transverse-sigmoid
sinus, but the draining vein was posterior spinal perimedullary vein through the sigmoid sinus. This may explain the
occurrence of the bulbar ischemia on the opposite side from
the dural AVF because there is no guarantee that all the
veins draining into the posterior spinal perimedullary vein
exist on the same side of the dural AVF. On MRI before
embolization, we observed a hemorrhage in the ischemic
territory of the medulla oblongata. Considering that hemorrhage occurs near the malformation or aneurysmally dilated

M. Satoh et al. / Surgical Neurology 64 (2005) 341 – 345

draining veins [11], there might be a possibility of the
hemorrhage owing to the dilated draining veins in this case.
Besides venous hypertension, there might be a possibility
of the steal of right posterior inferior cerebellar artery
(PICA) for the bulbar ischemia. Indeed, there was a fistula
between posterior meningeal branch of the right vertebral
artery and the transverse sinus. We, however, could identify
PICA on angiogram. In addition, the arterial feeder was not
a direct branch of PICA, and Kosnik et al [6] reported that
flow problems were created by increased venous pressure
more than by arterial steal. Considering these points, there
might be little possibility of arterial steal. Meanwhile, brain
stem compression by enlarged veins was not observed in
this case.
Transvenous embolization was performed in the present
case. Mullan [7] has pointed out that dural AVFs can be
permanently cured by venous side occlusion because these
malformations are primarily venous-based lesions. Transvenous embolization is now recognized as 1 of the most
effective treatment of dural AVFs [3], and we also
observed the complete obliteration of the dural AVF and
spontaneous disappearance of arterial input after transvenous embolization.
To our knowledge, there has been no report of
intracranial dural AVF patients who initially have presented with brain stem ischemia. This case has indicated
ischemic lesion in the brain stem by dural AVF without the
spinal cord lesion. In patients who have brain stem
symptoms and who exhibit the ischemic lesion over a wide
brain stem area on MRI, a cerebral angiography should be
undertaken, taking dural AVFs into consideration.
References
[1] Bret P, Salzmann M, Bascoulergue Y, et al. Dural arteriovenous
fistula of the posterior fossa draining into the spinal medullary
veins — an unusual cause of myelopathy: case report. Neurosurgery
1994;35:965 - 9.

345

[2] Cognard C, Gobin YP, Pierot L, et al. Cerebral dural arteriovenous
fistulas: clinical and angiographic correlation with a revised classification of venous drainage. Radiology 1995;194:671 - 80.
[3] Endo S, Kuwayama N, Takaku A, et al. Direct packing of the isolated
sinus in patients with dural arteriovenous fistulas of the transversesigmoid sinus. J Neurosurg 1998;88:449 - 56.
[4] Gobin YP, Rogopoulos A, Aymard A, et al. Endovascular treatment of
intracranial dural arteriovenous fistulas with spinal perimedullary
venous drainage. J Neurosurg 1992;77:718 - 23.
[5] Kalamangalam GP, Bhattacharya J, Teasdale E, et al. Myelopathy
from intracranial dural arteriovenous fistula. J Neurol Neurosurg
Psychiatry 2002;72:816 - 8.
[6] Kosnik EJ, Hunt WE, Miller CA. Dural arteriovenous malformations.
J Neurosurg 1974;40:322 - 9.
[7] Mullan S. Reflections upon the nature and management of intracranial
and intraspinal vascular malformations and fistulae. J Neurosurg
1994;80:606 - 16.
[8] Newton TH, Cronqvist S. Involvement of the dural arteries in
intracranial arteriovenous malformations. Radiology 1969;93:1071 - 8.
[9] Ricolfi F, Manelfe C, Meder JF, et al. Intracranial dural arteriovenous
fistulae with perimedullary venous drainage. Anatomical, clinical and
therapeutic considerations. Neuroradiology 1999;41:803 - 12.
[10] Sundt Jr TM, Piepgras DG. The surgical approach to arteriovenous
malformations of the lateral and sigmoid dural sinuses. J Neurosurg
1983;59:32 - 9.
[11] Viñuela F, Fox AJ, Pelz DM, et al. Unusual clinical manifestations of
arteriovenous malformations. J Neurosurg 1986;64:554 - 8.
[12] Wrobel CJ, Oldfield EH, di Chiro G, et al. Myelopathy due to intracranial dural arteriovenous fistulas draining intrathecally into spinal
medullary veins: report of three cases. J Neurosurg 1988;69:934 - 9.

Commentary
The authors report an excellent case of dural fistula of the
left sigmoid sinus complicated by brain stem ischemia and
medullary venous drainage. As the left sigmoid sinus was
already thrombosed, the decision for coil embolization of
the sinus was excellent, with complete cure of the fistula.
Gerard Debrun, MD
Interventional Neuroradiologist
29360 Paris, France