Abnormalities of the Dura Mater:
Are multiple Clinical Syndromes with
dural lesions associated to abnormal
connective tissue?
Dr. Diana Quiñones and Dr. Juan Viaño
Neuroradiologists
Resonancia Magnética Hospital del Rosario
Madrid, Spain.
The dura mater in the spine
The dura attaches anteriorly to the V. by Hoffman ligaments (to the
superficial layer of the PLL above annulus), and lateraly to the N root sleeve.
Wiltse LL. Anatomy of the extradural compartments of the lumbar spinal canal.
Peridural membrane and circumneural sheath. Radiologic Clinics of NA
2000;38(6):1177-1206.
Clinical and radiological entities
related to dura mater lesions
A.
Syndrome of spontaneous intracranial hypotension/ Familial
intracranial hypotension
B.
Post-traumatic spine / whiplash injury / hydrops
C.
Anterior dural defects/anterior neuroenteric cysts
D.
Ideopathic spinal cord herniation (through the dura)
E.
Subtypes of dorsal degenerative disc disease, disc clefts
F.
Dorsal herniated disc and cord ischemia/ infarct /dural AVM
G.
Hirayama Disease (juvenile amyotrophy of the distal upper
extremity)
Pathology of the Dura
A
Intracranial Hypotension
 The so called “spontaneous hypotension syndrome” in
many cases is preceded by exertion.
 Familial hypotension patients have sometimes a
“Marphanoid phenotype”
 Some cases reported have huge anterior dural
defects, others vertebral endplate abnormalities just
at the level of the dural tear.
 These dural defects and vertebral abnormalities could
have a congenital origin, similar to neuroenteric cysts
where a stalk or cleft remains connecting to the spinal
canal.
45 yo male, orthostatic HA
No intracranial FLAIR dural anomaly
T2 TSE fat sat
T2 TSE fat sat
T2 TSE fat sat
T1 fat sat
T2 TSE fat sat
T1 fat sat
B
trauma and whiplash
injury
 Positional post-traumatic whiplash headache occurs
early after the accident, and lasts a long time.
 50 % have direct signs of CSF leakage on in the thoracic
or lumbo-sacral spine on MRI
 Most patients do not have a decreased ICP, and MRI
does not show dural enhancement
Takagi “Chronic headache after cranio-cervical trauma. Hypothetical
pathomechanism based upon neuroanatomical considerations” Eur
J Med Res 2007; 12:249-254.
Hypotension vs trauma
“lemon shape” colapsed dura
T2 fat sat
C Anterior Cysts
 Neuroenteric
 Broncogenic
 Bony defects, hemivertebrae…
Congenital, spectrum of split notocord
 Could include anterior medular H
D Idiopathic Cord
Herniation
 First noted in a surgical report by Wortzman 1974
 Case reports bloomed in the last decades after
widespread use of MRI (over 100)
 All cases occur between T2 and T8 levels
 The “nuclear trail sign” is frequently noted (sclerosis
of the vertebral end plates)
Imaging of Ideopathic spinal cord herniation. Radiographics 2008,
28(2): 511-8.
Transdural Spinal Cord herniation: imaging and clinical spectra.
AJNR 1998 19: 1337-1344.
T6 medula herniation
 A 46 yo male with years of L. leg
weakness, dorsal pain and
altered sensation. Slight dorsal
disc degenerative disease.
Quencer, Editorial Cord Herniation,
AJNR 1998;19:1185.
 “It is probably unrealistic to accept that prior disc
herniation caused a dural defect through which the cord
herniated. With such a mechanism, one would expect to
find not only an intradural disc fragment but a higher
incidence of cord herniation in the cervical area”
 “It is reasonable to believe that cord herniation of and by
itself would not cause a myelopathy. Vascular
compromise, adhesions, or a focal compression of the
cord provide the probable explanation of the myelopathy
in these patients”
Disc Disease and Cord H.
Intraop.
ultrasound
D Quiñones, Poster at ESNR Barcelona 2005
E Degenerative Disc Disease
Disk Clefts and “the nuclear trail”
 “The nuclear trail sign” an abnormal straight or curvilinear
hiperdensity, oriented A-P, located at the vertebral
endplate, and associated with thoracic disk herniation was
described 1992 by Awwad ( The nuclear trail sign in thoracic
herniated disks AJNR 1992;13:137-143).
we never find this trail in the cervical or lumbar spine
 Unique force vectors in the dorsal region may predispose
weak areas of the cartilaginous endplates to evolve into this
subset of Schmorl´s nodes.
 Or there could be a genetic connective tissue predisposition
F Degenerative / cord ischemia
 Some patients with thoracic
herniated discs may have
acquired dural lesions.
 Disc bulges may cause local
microtrauma and inflammation
of the dura, causing intrathecal
complications affecting the cord
vascularization.
 Dorsal kyphosis, and ventral cord
contact may influence
40 yo female, 2 disc
hernias T6-T7 and T8-T9
No ASA
Disc disease and cord ischemia
 Acute vertical disc herniation can lead to spinal cord
infarction by retrograde disk embolus to the spinal
artery, related to increased discal pressure and
Valsalva maneuver
 Embolus from Schmorls node to venous sinusoids, then
to the epidural vertebral venous plexus, and to the
arterial side though A-V anastomosis
JJ Han ” Fibrocartilaginous embolism: an un common cause of Spinal
cord infarction” Arch Phys Med Rehabil 2004; 85:153-157
Toro G, et al “Natural history of spinal cord infarction caused by
nucleous pulposus embolism” Spine 1994;60:360-6
G Hirayama Disease
 A focal cervical myelopathy occurring in young
patients, the dura looses posterior attachment to
the vertebrae
 with flexion of the spine the dura thightens,
separating from the osseous spinal canal and
compressing the cord, while the extradural space
engorges (similar to the venous engorgement
and fluid accumulation found in the spinal canal
of hypotension patients).
 local cord ischemia may contribute to symptoms
Hirayama, 26 yo male deltoid atrophy
Focal atrophy of
the left hemicord
at C5-C6
Increased epidural
space at cervicothoracic junction
Follow up Flexion MRI
 Flexion increases the extradural space posterior to the
dorsal thecal sac, fat sat would increase detection
Spine MR Imaging
 Sequences that enhance
fluid detection and dural
pathology such as FLAIR
and T2 fat sat are not
routinely obtained in
spinal imaging
 To evaluate extradural
fluid I propose FLAIR or T2
fat saturation should be
included in spine MRI
protocols (at least in one
plane).
In Conclusion:
 I encourage neuroradiologists, neurosurgeons
and others to search for these dural lesions, and
study the dura or other connective tissues in
these groups of patients to find possible genetic
variations related to dural pathology.