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 is a fibrous connective tissue encasing and protecting the CNS, together with the BBB it provides a singular separate compartment in the body Attached to bony vertebral canal---- Peridural Membrane 1905 Fick german anatomist, virtual space between it and dura Epidural fat and veins are bright on FSE T2 images 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 Syndrome of spontaneous intracranial hypotension/ Familial intracranial hypotension Post-traumatic spine / whiplash injury / hydrops Anterior dural defects/anterior neuroenteric cysts Ideopathic spinal cord herniation (through the dura) Subtypes of dorsal degenerative disc disease, disc clefts Dorsal herniated disc and cord ischemia/ infarct /dural AVM Hirayama Disease (juvenile amyotrophy of the distal upper extremity) Radiologists and neuroradiologist spend lots of time evaluating spinal MRI, years of observation have led me to find similarities in imaging characteristics of diferent clinical entities, I will go over some examples, making enphasis on some common findings

Pathology of the Dura There are many similarities in these diseases thay may have abnormal peridural fluid, free or loculated Many more cases will be considered congenital if we investigate the dura and connective tissues Tarlov type I dural cysts, posterior cysts y scoliosis no mencionados

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. Reports en comunicacions de Chicago ASNR en 2007/8 Añadir más de la captación y liquido extra dural??? intracranial hypotension. Neuroradiology 2002;44:996-1003  

No intracranial FLAIR dural anomaly 45 yo male, orthostatic HA No intracranial FLAIR dural anomaly J Carlos Castro Ferrero 45 a. NO CONTRASTE x DATOS POSITIVOS MR y coinciden con la clínica, ingresado T2 TSE fat sat T2 TSE fat sat

T2 TSE fat sat T1 fat sat T2 TSE fat sat T1 fat sat Arregui mujer 43 años, cefalea ortostática frontal 1 semana antes con rotación del cuello chasquido. RM cerebral N salvo leve ingurg senos venosos. Dia siguiente ingresada columna completa con Gd eval dolor cervical y lumbar---quistes Sacro es Arriola hipotension Problema donde dirigir parches durals sino mejora con tto médico 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 Felix Alcaraz Gomez “Lemon shape” of the dura separated from the bony canal and surrounded by extradural fluid Also scoliosis?? Y vertebral scalloping!!! T2 fat sat

C Anterior Cysts Neuroenteric Broncogenic Bony defects, hemivertebrae… Congenital, spectrum of split notocord Could include anterior medular H I do not have a case of my own, Br J radiol 203

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. Again a congenital origin is refered T4-T7

T6 medula herniation Caso reciente, no op. se fue 12 Octubre. ESCASA PATOLOGIA DISCAL ASOCIADA, pero si hay una hernia intraespojosa Zurdo Jurado Varon 49 años Postcontrast sag T1 fat sat: no abnormal dural or intrathecal enhancement 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” El segundo párrafo es aplicable a toda la patologia degenerativa Quencer RM. Editorial Cord Herniation, AJNR 1998;19:1185.

Disc Disease and Cord H. Intraop. ultrasound Quiñones Poster at ESNR Barcelona 2005 Dural rent bout 15 mm long and 4-5 mm wide Progresive improvement, over the following year 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 Reviewed mielo-CT scans in 84 patients with 114 thoracic herniated disks. They found 46% of thoracic herniated disks had had a sclerotic trail usually from the central endplate posteriorly to the protruded fragment, and in 79% the density in the trail was similar to disk. 21% only had the hyperdense trail with no detectable herniation. Only 22 patients had MR with 35 thoracic disk herniations. Trails were also detected not completely extending to the disk margin and without herniation, but the authors do not give their incidence.

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 This 40 y0 females after gim with fitball, started with dorsal painand progresive loss of strength in the legs. The first RM 4-5 day after symptoms started showed 2 herniated discs D but no cord lesion. We cannot obtain Difusion.

40 yo female, 2 disc hernias T6-T7 and T8-T9 Caso Inmaculada BARQUERO 40 años paraparesia tras pilates, empeora 10 días, aparece en 2nda RM lesion medular además de las hernias, posible isquemia sobreañadida, Angio TC no se detecta eje espinal anterior, arteriografia alteraciones durales posteriores embolizadas Now 8 months after initial symptoms stabilized, but not reverted 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 H fexion Myelopathy or Nonprogressive Juvenile spinal muscular atrophy of the distal upper limbs

Hirayama, 26 yo male deltoid atrophy Focal atrophy of the left hemicord at C5-C6 28 yo male, trains with weights, that complains of loss of strength in left arm (and on physical exam has deltoid atrophy) Increased epidural space at cervico-thoracic junction

Follow up Flexion MRI Tambien peq lámina fluid C6C7 anterior!!! 1 month later to demonstrate dural detachment flexion MRI, with marked posterior epidural fatty tissue and venous engorgement Growth spurt, Surgery to fix-fuse vertebrae, duroplasty to increase thecal sac size… 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). Posterior inhomogeneosu fat sat, choose adecuate plane in each region Very useful hipotension and trauma Schievink VL, Torres VE. Spinal Meningeal diverticula in autosomal dominant polycstic kidney disease. Lancet 1997; 349:1223-4.

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. Biopsies dura / other connective tissue Clinical diagnosis of hyperlaxitude…