no neurologic deficit after trephination and EBP treatment. In
addition, the patient had no residual symptoms or recurrence at
A 55-year-old male had a three-month history of progressive
headaches and neck pain without history of trauma. Brain mag-
netic resonance (MR) imaging revealed a subdural hematoma in
the fronto-parietal region, and cervical MR imaging at that time
showed dural thickening enhancement of the spinal canal (Fig.
1). This patient was diagnosed with a chronic subdural hemato-
ma after SIH. The patient underwent a computed tomography
(CT) myelography of the entire spinal column, which localized a
generous leak at the C1-2 level, with contrast extravasation in the
epidural space (Fig. 2). The patient had progressive symptoms
and increased subdural hematoma in subsequent CT imaging.
A trephination of the subdural hematoma was performed
and the hematoma was drained for three days. After two days
of trephination, a direct cervical blood patch was performed
under CT guidance at the C1-2 level to prevent a recurrence of
subdural hematoma. With the patient resting in a supine posi-
tion on the CT gantry, we guided a 22-gauge needle into the left
lateral epidural compartment at the C1-2 level. We positioned
the needle adjacent to the thecal sac, matching the site of the
leak seen on the CT myelography (Fig. 3). We also confirmed
the needle position with an injection of 0.5 mL of iohexol (Om-
Spontaneous intracranial hypotension (SIH) is characterized
by an orthostatic headache in the absence of a history of trauma
or dural puncture. SIH is caused by spontaneous cerebral spinal
fluid (CSF) leakage of unknown etiology at the level of the spine.
Most SIH patients recover after bed rest, hydration, applying an
abdominal binder and administration of caffeine and steroids.
Application of epidural blood patches (EBP) at the CSF-leak
site offers another treatment option. Some SIH patients en-
counter a subdural hematoma (SDH) as severe complication
with neurologic deficits.
In SIH with CSF leak at the high cervical region, EBP has tra-
ditionally been performed in the lumbar area or in the thoracic
and lower cervical area4,13,14). Because a direct EPB at the leak
site may present challenges due to the narrow space of region
and its proximity to important neural structures, the medical
literature has reported only two cases involving an EBP proce-
dure performed at the C1-2 level7,13).
We report the case of a bilateral SDH patient with SIH who
came to our hospital and was discharged two weeks later with
J Korean Neurosurg Soc 50 : 274-276, 2011
Copyright © 2011 The Korean Neurosurgical Society
Print ISSN 2005-3711 On-line ISSN 1598-7876
Chronic Subdural Hematoma after Spontaneous
Intracranial Hypotension : A Case Treated
with Epidural Blood Patch on C1-2
Byung-Won Kim, M.D., Young-Jin Jung, M.D., Min-Su Kim, M.D., Byung-Yon Choi, M.D.
Department of Neurosurgery, Yeungnam University College of Medicine, Daegu, Korea
Spontaneous cerebrospinal fluid (CSF) leak is a recognized cause of spontaneous intracranial hypotension (SIH). Subdural hematoma (SDH) is a seri-
ous but rare complication of SIH. An autologous epidural blood patch at the CSF-leak site can effectively relieve SIH. We report a case of bilateral SDH
with SIH caused by a CSF leak originating at the C1-2 level. A 55-year-old male complained of orthostatic headache without neurological signs. His
symptoms did not respond to conservative treatments including bed rest, hydration and analgesics. Magnetic resonance imaging showed a subdural
hematoma in the bilateral fronto-parietal region, and computed tomography (CT) myelography showed a CSF leak originating at the C1-2 level. The
patient underwent successful treatment with a CT-guided epidural blood patch at the CSF-leak site after trephination for bilateral SDH.
Key Words : Blood patch · Epidural · Intracranial hypotension · Subdural hematoma.
• Received : March 29, 2011 • Revised : May 9, 2011
• Accepted : September 5, 2011
• Address for reprints : Min-Su Kim, M.D.
Department of Neurosurgery, Yeungnam University College of Medicine,
317-1 Daemyeong 5-dong, Nam-gu, Daegu 705-717, Korea
Tel : +82-53-620-3790, Fax : +82-53-620-3770
E-mail : email@example.com
Chronic Subdural Hematoma after Spontaneous Intracranial Hypotension | BW Kim, et al.
nerve root sheaths and around small defects due to small trau-
mas, a fall, severe exercise, or a cough that tears the dura or
Some studies have reported that connective tissue disorders
such as Marfan syndrome, Ehlers-Danlos syndrome type 2, and
autosomal dominant polycystic kidney disease play a signifi-
cant role in causing SIH9,14).
While the pathophysiology of SDH in patients with SIH re-
mains unknown, studies have proposed several mechanisms.
Downward displacement of the brain due to low CSF pressure
may produce tears in the bridging veins of the dural border cell
layer, causing these veins to rupture. Alternatively, as subdural
CSF collections gradually enlarge the subdural space, the bridg-
nipaque 240, Nycomed Amersham, Oslo, Norway). We then
performed the blood patch by an injection of the patient’s autol-
ogous blood obtained from the right brachial vein. The injec-
tion was stopped at 5 mL, at which point the patient noticed an
increased pressure sensation in his neck. Findings of a neuro-
logic examination performed after the procedures were normal.
The patient’s neurological signs were observed for a period of
two weeks. At the time of discharge, his headache was almost
completely relieved. His headache had completely dissipated
three months after the EBP.
An MR imaging of the brain taken three months after the
procedure showed no more dural enhancement and no fluid
collection in the subdural space (Fig. 4). A CT myelography at
the six-month follow-up revealed no
contrast extravasation in the epidural
space (Fig. 5). At present, the patient is
in good health condition and reports
Spontaneous intracranial hypoten-
sion, as the name implies, is caused by
low CSF pressure, usually secondary to
an occult leak. A CSF leak occurs in
weak areas around the dura mater and
Fig. 1. Preoperative magnetic resonance imaging. Brain non-contrast T1-weighted (A) and T2-
weighted (B) axial images show a subdural hematoma over both frontal and parietal convexity.
Cervical contrast-enhanced T1-weighted (C) sagittal image shows dural thickening enhancement.
Fig. 2. Coronal (A) and axial (B) computerized tomographic scanning
shows epidural contrast material accumulation at the C1-2 levels.
Fig. 3. An axial computerized tomographic (CT) scanning (A) shows nee-
dle placement in the left lateral epidural compartment at the upper C2
level followed by administration of the blood patch. An axial CT scanning
(B) shows that contrast material injected to confirm the epidural location
is identified with mild flattening of the lateral thecal sac margin.
Fig. 4. Brain magnetic resonance imaging three months after epidural
blood patch. Axial T2-weighted (A) and contrast-enhanced T1-weighted
(B) images show no subdural hematoma and pachymeningeal thicken-
Fig. 5. Axial computerized tomographic scanning (A and B) six months
after epidural blood patch show no epidural contrast material accumula-
tion at the C1-2 levels.
J Korean Neurosurg Soc 50 | September 2011
We report the case of a bilateral SDH as a severe complication
of SIH with a CSF leak originating at the C1-2 level. The au-
thors believe that an EBP performed directly at the site of the
leak as the initial treatment can more effectively seal the defect.
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2. Buvanendran A, Byrne RW, Kari M, Kroin JS : Occult cervical (C1-2)
dural tear causing bilateral recurrent subdural hematomas and repaired
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ing veins may stretch and rupture in some cases14).
Although the most common presenting symptom in SIH is or-
thostatic headaches, the exact mechanism of orthostatic head-
aches in CSF leak is unknown. The total volume of the brain,
CSF, and the intracranial blood remains constant inside the rig-
id skull. Therefore, a decrease in one of these components should
cause a reciprocal increase in either or both of the remaining
two8). The intracranial venous structures are pain-sensitive, and
their dilatation in turn may lead to headaches.
MR imaging represents the method of choice to depict intra-
cranial manifestations; the neuroimaging features include dif-
fuse meningeal enhancement, acquired Chiari malformation,
and subdural fluid collections11). The Monro-Kellie hypothesis
is the mechanism frequently used to explain MRI findings with
aforementioned conditions8). A reduction in the volume of the
CSF requires an increase in volume of one or both of the other
components. The most reliably demonstrated area of increased
volume on imaging is the pachymeninges, which show diffuse
thickening and enhancement with gadolinium-enhanced MRI
due to lack of a blood-brain barrier and an increase in the vol-
ume of venous blood in this compartment15). In cases of SIH,
the site of the CSF leak rests predominantly in the cervical or
thoracic region, and the diagnosis is typically established by CT
myelography or radionuclide imaging4,6). In our patient, CT
myelography was instrumental in identifying the leak site.
Although supportive measures and medical therapy such as
hydration, bed rest, caffeine, steroid and parenteral fluid may
provide temporary relief, a more durable treatment is to seal the
site of the leak. The mainstay of the treatment is the injection of
autologous blood (10-20 mL) into the spinal epidural space. Re-
lief of symptoms is often dramatic after EBP. If EBP fails the
first time, it can be repeated3). Complications of cervical EBP
include spinal cord and nerve root compression, chemical men-
ingitis, intrathecal injection of blood, seizures, and stiffness of
the neck2). Cases of large subdural hemorrhage require surgical
drainage and treatment of the underlying cause of SIH10). With
the current technology, we can perform imaging-guided proce-
dures in the spine with relative safety and minimal discomfort
to the patient. In cases of cervical leaks, it is reasonable to offer a
cervical blood patch as the initial treatment13). In our patient,
after trephination of subdural hematoma, we performed EBP at
the C1-2 level.