Transdural spinal cord herniation: imaging and clinical spectra.
OBJECTIVE
Transdural herniation of the spinal cord is a rarely reported clinical entity, and many of the existing reports were published before the advent of MR imaging. We describe five current cases and compare them with findings in 25 cases reported in the literature to delineate the clinical and imaging spectra of transdural spinal cord herniation.


METHODS
MR imaging, CT myelography, and conventional myelography were performed in five patients with transdural herniation of the spinal cord. These studies, along with clinical findings, are described. Intraoperative photographs are included for one case. The salient features of both the current and previously reported cases are summarized in tabular form.


RESULTS
In three cases, transdural spinal cord herniation occurred posttraumatically, in one case the cause was iatrogenic and in the others the herniation occurred spontaneously. Imaging features not previously reported include dorsally directed herniations at thoracolumbar levels (two patients), apparent (lacking surgical confirmation) syringomeyelia (one case), a vertebral body nuclear trail sign (one case), and intramedullary hyperintensities on MR images (two cases). Clinical features not previously reported include unilateral pyramidal-sensory deficits (one case) and isolated unilateral pyramidal signs (one case). Clinical findings similar to previous reports include progressive paraparesis (two cases) and progressive Brown-Séquard syndrome (one case).


CONCLUSIONS
Our five cases illustrate certain clinical and imaging findings not previously reported, and, together with the established features of the 25 cases in the literature, delineate the spectra of transdural spinal cord herniation.
Watters
M R
MR
Division of Neurology, University of Hawaii School of Medicine, USA.
Stears
J C
JC
Osborn
A G
AG
Turner
G E
GE
Burton
B S
BS
Lillehei
K
K
Yuh
W T
WT
D000328:Adult; D018437:Brown-Sequard Syndrome / Q000209:etiology; D002574:Cervical Vertebrae / Q000293:injuries; D003952:Diagnostic Imaging; D004388:Dura Mater / Q000473:pathology; D005260:Female; D006801:Humans; D007049:Iatrogenic Disease; D007405:Intervertebral Disc Displacement / Q000150:complications; D007430:Intraoperative Care; D008159:Lumbar Vertebrae / Q000293:injuries; D008279:Magnetic Resonance Imaging; D008297:Male; D008591:Meningomyelocele / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D008875:Middle Aged; D009192:Myelography; D010291:Paresis / Q000209:etiology; D010781:Photography; D011712:Pyramidal Tracts / Q000503:physiopathology; D012678:Sensation Disorders / Q000209:etiology; D013119:Spinal Cord Injuries / Q000150:complications; D016103:Spinal Fractures / Q000150:complications; D013595:Syringomyelia / Q000150:complications; D013904:Thoracic Vertebrae; D014057:Tomography, X-Ray Computed