1. Retroclival Hemorrhage Where is the Blood?
eEdE-243
M Qandeel, S Ali, A Al-Saraf, E Ramos, S Lee
University of Chicago Medical Center
Chicago, IL

2. Nothing to Disclose

3. Background: Retroclival Hemorrhage
Retroclival hemorrhage (rcHage) is rare but can pose a diagnostic dilemma for localization.
mostly case reports and case series
mostly post traumatic and in pediatric patients
The retroclival blood can be localized to one of the three spaces:
subdural or intradural space
epidural space
subarachnoid space

4. Purpose Review & Understand the Complex Anatomy of Retroclival region.
Demonstrate an approach to subclassify retroclival hemorrhage into subdural (rcSDH), epidural (rcEDH), and subarachnoid (rcSAH) through CT and MR imaging analysis.
Demonstrate MIMICS of retroclival hemorrhage.

5. Methods Retrospectively review. 2011 to 2015
16 consecutive patients with retroclival hemorrhage.

6. Imaging Review
Two board-certified neuroradiologists independently categorized these cases as rcSDH, rcEDH, and rcSAH.
Discrepancy was resolved with consensus
Four key imaging criteria were used :
Extension beyond retroclival region along the tentorium and falx
Integrity of the tectorial membrane
Confinement of hemorrhage to the attachments of the tectorial membrane
Presence of intervening clear subarachnoid space between the hematoma and brainstem and/or encasement of the basilar artery.

7. Anatomy Review

8. Tectorial Membrane (1) of atlanto-axial joint
a broad, strong band which covers the dens and its ligaments
upward extension of the posterior longitudinal ligament
The tectorial membrane of atlanto-axial joint (occipitoaxial ligaments) is situated within the vertebral canal.
It is a broad, strong band which covers the dens and its ligaments, and appears to be a prolongation upward of the posterior longitudinal ligament of the vertebral column.
It is fixed, below, to the posterior surface of the body of the axis, and, expanding as it ascends, is attached to the basilar groove of the occipital bone, in front of the foramen magnum, where it blends with the cranial dura mater.
Its anterior surface is in relation with the transverse ligament of the atlas, and its posterior surface with the dura mater.

9. Anatomy of Tectorial Membrane(2) of atlanto-axial joint
attached to the basilar groove of the occipital bone where it blends with the cranial dura mater
The tectorial membrane of atlanto-axial joint (occipitoaxial ligaments) is situated within the vertebral canal.
It is a broad, strong band which covers the dens and its ligaments, and appears to be a prolongation upward of the posterior longitudinal ligament of the vertebral column.
It is fixed, below, to the posterior surface of the body of the axis, and, expanding as it ascends, is attached to the basilar groove of the occipital bone, in front of the foramen magnum, where it blends with the cranial dura mater.
Its anterior surface is in relation with the transverse ligament of the atlas, and its posterior surface with the dura mater.
anterior to the dura mater
posterior to the transverse ligament of the atlas
fixed to the posterior surface of the body of the axis
upward extension of the posterior longitudinal ligament
By Henry Vandyke Carter - Henry Gray (1918) Anatomy of the Human Body (See "Book" section below)Bartleby.com: Gray's Anatomy, Plate 308, Public Domain,

10. Cruciate Ligament of atlanto-axial joint
Transverse ligament
Superior longitudinal band
Inferior longitudinal band
tectorial membrane removed
these combined form the cruciate ligament

11. Transverse ligament of atlas
firmly attached on either side to a small tubercle on the medial surface of the lateral mass of the atlas
arches across the ring of the atlas, and retains the odontoid process in contact with the atlas
By Henry Vandyke Carter - Henry Gray (1918) Anatomy of the Human Body (See "Book" section below)Bartleby.com: Gray's Anatomy, Plate 306, Public Domain,

12. Apical and Alar Ligaments of the Dens
Apical ligament of the dens
Alar ligaments
cruciate membrane removed

13. MR Anatomy Tectorial Membrane Apical Ligament Transverse Ligament
By Henry Vandyke Carter - Henry Gray (1918) Anatomy of the Human Body (See "Book" section below)Bartleby.com: Gray's Anatomy, Plate 308, Public Domain,

14. Subclassifications of Retroclival Hemorrhage
Can be in one of three compartments:
epidural
subdural
subarachnoid
Pathogenesis and neuroimaging findings differ by the compartment.
Unlike in the supratentorium, the CONFIGURATION of the retroclival hemorrhage does NOT definitively HELP in determining the subclassification.

15. Retroclival Epidural Hemorrhage
Among the posterior fossa EDH, % are rcEDH.
Often as a result of traumatic disruption of the tectorial membrane or the other ligaments from hyperextension/hyperflexion of the craniocervical junction (CCJ)1.
Traction applied during stripping of the tectorial membrane can shear nearby vessels of the basilar venous plexus and dorsal meningeal branch of the meningohypophyseal trunk2.
Rarely, can be the result of fracture of the clivus3.
Meoded et al. demonstrated tectorial membrane injury, either stretching or disruption, in 70 % (7/10) of their patient group and transverse and posterior atlantooccipital membrane injury in 1 patient each (20 %), respectively [1].
Meoded A, Singhi S, Poretti A, et al. Tectorial membrane injury: frequently overlooked in pediatric traumatic head injury. American Journal of Neuroradiology 2011;32:1806–11.
Koshy J, Scheurkogel MM, Clough L, et al. Neuroimaging findings of retroclival hemorrhage in children: a diagnostic conundrum. Child's Nervous System 2014;30:835–9.
Guillaume D, Menezes AH. Retroclival hematoma in the pediatric population. Report of two cases and review of the literature. Journal of neurosurgery 2006;105:321–5.

16. Retroclival Epidural Space
Retroclival epidural space is a potential space between the dura mater and the tectorial membrane.
By Henry Vandyke Carter - Henry Gray (1918) Anatomy of the Human Body (See "Book" section below)Bartleby.com: Gray's Anatomy, Plate 308, Public Domain,

17. Retroclival Epidural Hemorrhage Imaging Findings
Often associated with tectorial membrane rupture or stretching
which is better assessed by MRI
Hemorrhage posterior to the clivus but anterior to the dura with lifting of the tectorial membrane
the hemorrhage can be both anterior and posterior to the tectorial membrane
inferiorly, limited to the C2 level
where PLL is attached to the intervertebral disc at the C2–C3 level

18. Retroclival Epidural Hemorrhage Imaging Findings
MRI is superior in evaluating ligamentous injury.
intact ligaments are uniformly T2-hypointense
because of fluid or blood products, injured ligaments become relatively T2- hyperintense.
The tectorial membrane may be elevated or disrupted with the presence of blood products and fluid in the region.
the other ligaments at the CCJ might also be affected.
The standard sequences include sagittal and axial T1- and T2- weighted MRI sequences as well as T2-weighted sequences.
The cervicomedullary junction, brain stem, and upper cervical cord may also be evaluated for signal changes or abnormality with the STIR pulse sequence.

19. Retroclival Epidural Hemorrhage
Among our 16 patients with rcHage, one had rcEDH.
3-year-old boy who had craniocervical ligamentous disruption (including the tectorial membrane) after a motor vehicle accident.
He needed surgical fixation but recovered fully.
Meoded et al. demonstrated tectorial membrane injury, either stretching or disruption, in 70 % (7/10) of their patient group and transverse and posterior atlantooccipital membrane injury in 1 patient each (20 %), respectively [1].

20. Retroclival Epidural Hemorrhage
CCJ ligamentous disruption, including the tectorial membrane and apical ligament
intraventricular and subarachnoid hemorrhage
extensive prevertebral effusion
3-year-old boy hit by automobile
the child fully recovered

21. Retroclival Epidural Hemorrhage
Clinical Manifestations
Imaging Findings
rcEDH in isolation is typically managed conservatively with follow-up imaging to assess stability.
The presence of brainstem or cranial nerve compression may dictate surgical evacuation or even posterior fossa decompression1.
For associated ligamentous injury, either conservative or surgical cervical immobilization, depending on the severity of the instability, are needed.
Headache, nausea, and cranial nerve palsy (particularly of the sixth cranial nerve) have been reported1.
Because of its course, CN VI is particularly vulnerable to shearing forces in the retroclival region.
It exits the brain stem at the pontomedullary junction, courses superiorly within the subarachnoid space between the pons and clivus and pierces the dura at the level of Dorello’s canal.
Koshy J, Scheurkogel MM, Clough L, et al. Neuroimaging findings of retroclival hemorrhage in children: a diagnostic conundrum. Child's Nervous System 2014;30:835–9.
Tubbs RS, Griessenauer CJ, Hankinson T, et al. Retroclival epidural hematomas: a clinical series. Neurosurgery 2010;67:404–6–discussion406–7.

22. Retroclival Subdural Hemorrhage
1% of all SDH are in the posterior fossa. rcSDH is even more rare with only few reported cases1.
Might be the result of shear injury of the bridging petrosal and small veins near the foramen magnum.
Koshy J, Scheurkogel MM, Clough L, et al. Neuroimaging findings of retroclival hemorrhage in children: a diagnostic conundrum. Child's Nervous System 2014;30:835–9.

23. Retroclival Subdural Hemorrhage Imaging Findings
The tectorial membrane remains intact
Hemorrhage posterior to the clivus within the dura without lifting of the tectorial membrane
remains adherent to the clivus
can also extend/redistrubute both cranially and caudally
not limited by the attachments of the tectorial membrane and can extend inferiorly below C2 level

24. Retroclival Subdural Hemorrhage Imaging Findings
Given the location of the hemorrhage, the tectorial membrane remains intact and adherent to the clivus, unlike rcEDHs.
the hemorrhage is not bounded by the margins of the tectorial membrane and may extend/redistribute into the cranial and the spinal subdural spaces.
The simultaneous presence of subdural blood in the posterior fossa would be more suggestive of RSDH.

25. Retroclival Subdural Hemorrhage Etiology and Outcomes
Among our 16 patients with rcHage, 14 met the imaging criteria for rcSDH.
Etiology (14 patients)
Trauma (n=6)
Spontaneous (n=5)
Post-procedure (n=2)
AVM (n=1)
Final Outcome
Full recovery in 57% (n=8): trauma (n=6), spontaneous (n=1), post-procedure (n=1)
Residual Deficits in 14% (n=2): AVM (n=1), spontaneous (n=2)
Mortality in 36% (n=5): spontaneous (n=3) and post-procedure (n=2)
Highest mortality rate in spontaneous rcSDH (60%)
No mortality in traumatic rcSDH

26. Retroclival Subdural Hemorrhage
note the thin clear subarachnoid space between the rcHage and the brainstem
rcSDH extending superiorly beyond the basilar groove
resulting effacement of prepontine and premedullary cisterns
Complete interval resolution
1 month later
3-year-old boy chronic hydrocephalus
status post VP shunt placement

27. Retroclival Subdural Hemorrhage
Cerebral convexity SDH with midline shift
Also note the thin clear subarachnoid space between the rcHage and the brainstem
rcSDH with intact tectorial membrane
62-year-old female with left sided weakness
and history of multiple myeloma
Patient died soon after presentation

28. Retroclival Subdural Hemorrhage
Keep in mind that only few case reports are available.
CN VI palsy have been described.
If traumatic, look for the presence of hemorrhage elsewhere in the posterior fossa or supratentorial compartment1.
Prognosis has been described as good when isolated. Therefore, expectant management might be a reasonable method unless there is brainstem compression, which would then require surgical evacuation2.
Sridhar K, Venkateswara PG, Ramakrishnaiah S, et al. Posttraumatic retroclival acute subdural hematoma: report of two cases and review of literature. Neurol India 2010;58:945–8.
Koshy J, Scheurkogel MM, Clough L, et al. Neuroimaging findings of retroclival hemorrhage in children: a diagnostic conundrum. Child's Nervous System 2014;30:835–9.

29. Retroclival Subarachnoid Hemorrhage
Can be spontaneous or posttraumatic, just like SAH elsewhere.
Tectorial membrane and other CCJ ligaments are usually intact, unless accompanied by other traumatic injuries.
rcSAH surrounds the basilar artery.
Will see also blood in the prepontine, premedullary, and cervicomedullary cisterns.
The retroclival subarachnoid space is in continuity with the intracranial and spinal subarachnoid compartments.
Blood can redistribute into or from the retroclival region

30. Retroclival Subarachnoid Hemorrhage Imaging Findings
The blood encases the basilar artery, and there is no clear subarachnoid space between the brainstem and the hematoma
Basilar artery
Hemorrhage posterior to the clivus within the subarachnoid space without lifting of the tectorial membrane
remains adherent to the clivus
blood can redistribute into or from the retroclival region
the retroclival subarachnoid space is in continuity with the intracranial and spinal subarachnoid compartments

31. Retroclival Subarachnoid Hemorrhage
intraventricular and subarachnoid hemorrhage
Fig.5 A2-year-oldgirlpresentedwithretroclivalsubarachnoidhemor- rhage after a television fell on the head. a Axial CT scan demonstrates hyperdense blood in the retroclival region (arrow) and a left occipital region scalp hematoma. b Axial FLAIR shows increased signal surround- ing the vertebral arteries consistent with subarachnoid hemorrhage (arrow). In addition, there is a left anterior cerebellar contusion (arrowhead) with a mastoid effusion. c Sagittal T2-weighted image of the cervical spine demonstrates an intact tectorial membrane (arrow) and presence of T2-hypointense blood adjacent to the basilar artery in the subarachnoid space. d Sagittal T1-weighted image of the cervical spine shows T1-hyperintense blood in the subacute phase surrounding the basilar artery (arrowhead), confirming the presence of retroclival sub- arachnoid hemorrhage. Intraventricular hemorrhage in the fourth ventri- cle is shown (arrow)
rcSAH with disrupted tectorial membrane
coexisting rcEDH is also present
Patient needed operative craniocervical fixation but recovered.
Young boy involved in MVA

32. Retroclival Subarachnoid Hemorrhage
Clinical Manifestations and Management
Similar to rcEDH and rcSDH, rarely may present with bilateral CN VI palsy.
If non-traumatic, need to look for source (e.g. aneurysm or AVM).
Prognosis depends on the primary cause of the hemorrhage and associated with findings.
Like SAH elsewhere, vasospasm is a serious complication.

33. Where is the blood?
Despite overlap, localizing rcHage to one of the three compartments carries implications for the etiology and perhaps the outcome.
Imaging features useful in localization of retroclival hemorrhage include:
rcSDH: extension of hemorrhage beyond retroclival region along the tentorium and falx with intact tectorial membrane;
rcEDH: confinement of hemorrhage to the attachment of the tectorial membrane; the tectorial membrane may be disrupted or lifted;
rcSAH: absence of intervening subarachnoid space between the hematoma and brainstem and/or encasement of the basilar artery by hematoma.

34. Where is the blood? suggested algorithm
Retroclival Hemorrhage
surrounds the basilar artery?
yes no
tectorial membrane intact and adherent to the clivus?
rcSAH
may see SAH elsewhere; usually intact CCJ ligaments
yes no
please note that different types od rcHage may coexist, especially when posttraumatic.
rcSDH
rcEDH
not limited by the attachments of the tectorial membrane; can extend beyond C2 level; may see SDH elsewhere
tectorial membrane injured commonly; usually limited by the attachments of the tectorial membrane

35. Mimics Potentially mimickers of retroclival hemorrhage include
engorgement of the basilar venous plexus
tumors, like meningiomas, chordoma.

36. Mimickers: Venous Engorgement
60 yo M. Lung cancer with brain mets.
8 hours later (immediate postop)
Baseline (for operative planning)
19 hours later!

37. Mimics: Tumors 26 yo Male. Chordoma.
Note the osseous destruction and the large anterior, prevertebral component.
26 yo Male. Chordoma.

38. Conclusion Retroclival hemorrhage is rare, but an important entity.
Placing the hemorrhage accurately in its appropriate compartment can be difficult, but appropriate localization allows assessment of associated findings and complications including ligamentous instability, vasospasm, or underlying brain and spinal cord injury1.
Koshy J, Scheurkogel MM, Clough L, et al. Neuroimaging findings of retroclival hemorrhage in children: a diagnostic conundrum. Child's Nervous System 2014;30:835–9.

39. Bibliographic Sources
Meoded A, Singhi S, Poretti A, et al. Tectorial membrane injury: frequently overlooked in pediatric traumatic head injury. American Journal of Neuroradiology 2011;32:1806– 11.
Vassiou K, Eftichia K, Marinos K, et al. Magnetic resonance imaging of the ligaments of the craniocervical region at 3Tesla magnetic resonance unit: Quantitative and qualitative assessment. JBiSE 2012;05:901–9.
Tubbs RS, Hallock JD, Radcliff V, et al. Ligaments of the craniocervical junction. Journal of Neurosurgery: Spine 2011;14:697–709.
Koshy J, Scheurkogel MM, Clough L, et al. Neuroimaging findings of retroclival hemorrhage in children: a diagnostic conundrum. Child's Nervous System 2014;30:835–9.
Krakenes J, Kaale B, Rorvik J, et al. MRI assessment of normal ligamentous structures in the craniovertebral junction. Neuroradiology 2001;43:1089–97.
Guillaume D, Menezes AH. Retroclival hematoma in the pediatric population. Report of two cases and review of the literature. Journal of neurosurgery 2006;105:321–5.
Dean NA, Mitchell BS. Anatomic relation between the nuchal ligament (ligamentum nuchae) and the spinal dura mater in the craniocervical region. Clin Anat 2002;15:182– 5.
Tubbs RS, Griessenauer CJ, Hankinson T, et al. Retroclival epidural hematomas: a clinical series. Neurosurgery 2010;67:404–6–discussion406–7.
Sridhar K, Venkateswara PG, Ramakrishnaiah S, et al. Posttraumatic retroclival acute subdural hematoma: report of two cases and review of literature. Neurol India 2010;58:945–8.
Bibliographic Sources