Traumatic Retropharyngeal Pseudomeningocele with Atlanto ...

The Neuroradiology Journal 20: 694-698, 2007 www. centauro. it

Traumatic Retropharyngeal
Pseudomeningocele with Atlanto-Occipital
Dislocation in a Neurologically Intact Patient

M.S. MATHEWS*, C.M. OWEN*, A.N. HASSO**, D.K. BINDER*

* Department of Neurological Surgery and ** Radiology, University of California; Irvine, Orange, California, USA

Key words: traumatic pseudomeningocele, asymptomatic, retropharyngeal

SUMMARY – Traumatic retropharyngeal pseudomeningoceles occur rarely, are associated with se-
vere trauma, and have been reported in patients with significant neurologic deficits at presentation.
We report the rare occurrence of a pseudomeningocele following a high-speed motor vehicle accident.
Neurological examination showed the patient to be briskly following commands, with intact cranial
nerve, motor, and sensory function. CT/MR imaging showed subarachnoid hemorrhage involving
the interpeduncular cistern, a clivus fracture, a right occipital condyle fracture, an atlanto-occipital
subluxation, aortic arch transection (stable and contained on CT angiogram), multiple rib fractures
on the right side with associated pneumothorax, hemothorax and pulmonary contusions. His cervi-
cal spine was stabilized in a halo. He was subsequently managed in the intensive care unit and re-
mained neurologically intact. A repeat MRI showed the interval development of a 2×1.5 cm pseudo-
meningocele at the craniocervical junction medial to the left occipital condyle communicating with
the left anterolateral aspect of the spinal canal. Traumatic pseudomeningoceles are associated with
large deceleration forces at the time of injury and are usually associated with significant neurologic
deficits at presentation. However, they can arise and give rise to symptoms in a delayed fashion in
trauma patients who are neurologically intact at initial presentation.

Introduction Case Report
Traumatic retropharyngeal pseudomenin- A 40-year-old male was brought to the emer-

goceles are rare findings associated with severe gency department following a high speed motor
trauma and have consistently been reported in vehicle accident. There was no Battle sign, rac-
patients with significant neurologic deficits at coon eyes, no external hematomas, swelling or
presentation. other obvious signs of trauma to the head and
neck. Physical examination showed bilaterally
Most cases have been associated in patients symmetric chest movements, a soft, nontender
with atlanto-occipital dislocation and hydro- abdomen, and a stable pelvis. His neurologic
cephalus .1,2,3,4 function was entirely intact.

Although traumatic pseudomeningoceles of CT imaging demonstrated subarachnoid he-
the cervical spine can be asymptomatic, they morrhage involving the interpeduncular cis-
can give rise to delayed symptoms such as tern, a clivus fracture, a right occipital condyle
airway compromise 1, dysphagia 3, suboccipital fracture (figures 1A,B), an atlanto-odontoid
pain 5, and delayed neurological deficits 6. subluxation, stable aortic arch transection,
multiple rib fractures on the right side with as-
This makes it important to recognize this
condition in trauma patients.

694

M.S. Mathews Traumatic Retropharyngeal Pseudomeningocele with Atlanto-Occipital Dislocation in a Neurologically Intact Patient

AB
Figure 1 A) Reformatted paramedian sagittal CT scan of the craniocervical junction shows a fracture of the distal clivus (arrow)
and occipital condyle with downward displacement of the fracture fragments towards the anterior arch of C2. B) Coronal refor-
matted CT scan shows the widely separated occipital condyle lying beneath the right side of the clivus (arrow). The left atlanto-
occipital joint is disarticulated consistent with ligamentous disruption.

sociated pneumothorax, hemothorax and pul- ated traumatic injuries, the patient was man-
monary contusions. aged conservatively for his retropharyngeal
pseudomeningocele.
The patient was intubated in the ED sec-
ondary to progressive tongue swelling that re- Discussion
sulted in airway obstruction. His cervical spine Pseudomeningoceles are abnormal outpouch-
was stabilized in a halo.
ings of the arachnoid membrane through a du-
Repeat MRI at two weeks showed the in- ral defect and are usually of congenital or iatro-
terval development of a fluid collection at the genic (postsurgical) origin 6. Traumatic pseudo-
craniocervical junction most prominent on the meningoceles are uncommon, and rarely seen
left, just medial to the left occipital condyle in the cervical spine. When present they have
where it measured 2×1.5 cm (figures 2A-C). been described in varying anatomical locations
The fluid collection communicated with the such as retropharyngeal ,1,2,3 posterolateral 4 and
left anterolateral aspect of the spinal canal at intracanalicular 5. The first documented trau-
the craniocervical junction suggesting pseu- matic cervical pseudomeningocele was reported
domeningocele. Also seen was an extensive by Louw in 1992 5, while the first retropharyn-
ligamentous injury at the craniocervical junc- geal pseudomeningocele was reported by Wil-
tion and C1/C2, including injury to the tecto- liams et Al in 1995 1.
rial membrane, anterior atlanto-occipital mem-
brane, posterior atlanto-occipital membrane, Retropharyngeal pseudomeningoceles are
posterior atlanto-axial membrane, and the left rare complications of high velocity blunt
alar ligament (figure 2C). Due to the absence of
neurologic deficits and the presence of associ-

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Traumatic Retropharyngeal Pseudomeningocele with Atlanto-Occipital Dislocation in a Neurologically Intact Patient M.S. Mathews

A B
C
696
Figure 2 A) Left parasagittal T2-weighted MR scan showing a
sausage shaped CSF density lying between and separating the
occipital condyle and atlas. B) Left parasagittal T2-weighted
MR scan showing the connection between the CSF collection
and ventral subarachnoid space adjacent to the left vertebral
artery (arrow). C) Axial T2-weighted scan at the craniocervi-
cal junction showing the disrupted atlanto-occipital ligament
(arrow) and the connection (asterisk) between the spinal ca-
nal and pseudomeningocele.

www. centauro. it The Neuroradiology Journal 20: 694-698, 2007

Table 1 Age Neurological Associated Time (weeks) to Treatment
Authors (yrs) exam spine injury pseudomeningocele Hydrocephalus
and year presentation
Atlanto-
Williams et 03.5 Quadriparesis occipital 04 Yes VP shunt
Al 1995 dislocation
Bilateral
Naso et Quadriparesis, occipital 14 Yes VP shunt
Al 1997 26.0 multiple lower condyle
Naso et fractures 05 Yes None
Al 1997 CN palsies. Atlanto-
Natale et Quadriparesis, occipital
Al 2004 11.0 progressed to dislocation
Reed et death.
Al 2005 Sensory loss No obvious <1 No LP shunt
Cognetti et 33.0 on the left C2 bony injury
Al 2006 region
Paresis of Atlanto- 04 Yes, delayed None
09.0 both upper occipital 06
extremities dislocation Immediate No LP shunt
Atlanto-
19.0 Quadriparesis occipital
dislocation
Achawal et Surgical
Al 2006 Atlanto-axial drainage+
38.0 Quadriplegia dislocation No lumbar drain

placement

Mathews et 40.0 Normal Atlanto-axial 02 No Observation
Al 2007 subluxation

trauma and have been described in association Management strategies for pseudomenin-
with atlanto-odontoid dislocation and hydro- gocele are controversial and include conserva-
cephalus .3,6 Thus far only five reports appear tive management, lumboperitoneal shunting,
to be available from the literature 1-4,7 with an and open surgical repair. Regarding lumbar
additional case with questionable trauma at pseudomeningoceles, Kitchen advocated con-
onset 8. Probably secondary to the nature and servative management with bed rest as the
severity of the underlying trauma, all retro- first approach with surgical repair of the tear
pharyngeal pseudomeningoceles have been re- in case of failure. However he considered lum-
ported in patients with neurological deficits. boperitoneal shunting to be an alternative 9. In
Our case demonstrates that a retropharyngeal retropharyngeal pseudomeningoceles, if con-
pseudomeningocele may occur in a neurologi- servative management is not effective the sur-
cally intact patient. geon must carefully weigh the options of CSF
diversion with surgical dural defect repair. Be-
Since traumatic pseudomeningoceles are cause of the anatomical complexity of the ret-
rare, arise in a delayed fashion, and may be ropharyngeal space and because of the location
asymptomatic, it is entirely possible that pseu- of the dural tear a surgical approach can be dif-
domeningoceles may arise following trauma ficult and risky (sepsis) 4.
more frequently than reported, and go unde-
tected in neurologically intact patients lacking In previous cases of retropharyngeal pseudo-
indications for delayed imaging of the spine meningoceles with co-existing obstructive hy-
(table 1). drocephalus, placement of ventriculoperitoneal

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Traumatic Retropharyngeal Pseudomeningocele with Atlanto-Occipital Dislocation in a Neurologically Intact Patient M.S. Mathews

shunts has been used to decrease intracranial Conclusion
pressure and secondarily help to heal the pseu- Retropharyngeal pseudomeningocele is a rare
domeningocele (table 1). Others, in the absence
of hydrocephalus, have placed lumboperitoneal complication of blunt occipitocervical trauma.
shunts resulting in progressively reduced size However, it should be considered in the differ-
of the CSF collection and improvements in ential diagnosis of delayed onset respiratory,
clinical state .3,4 More aggressive surgery is best swallowing, or neurological disturbances, even
reserved for the cases unresponsive to less in- in patients who are neurologically intact at
vasive treatment. presentation.

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101 The City Drive South
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2006. Fax: (714) 456-8284.
E-mail: [email protected]
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