Variants of radiculomeningeal vascular malformations of the spine

1987 ◽  
Vol 66 (3) ◽  
pp. 333-337 ◽  
Author(s):  
Leslie D. Cahan ◽  
Randall T. Higashida ◽  
Van V. Halbach ◽  
Grant B. Hieshima
Keyword(s):  
Spinal Cord ◽  
Vascular Malformations ◽  
Venous Pressure ◽  
Venous Drainage ◽  
Venous System ◽  
Low Flow ◽  
Neurological Deficits ◽  
Content Type ◽  
Dorsal Nerve ◽  
Intraspinal Hemorrhage

✓ In recent years, it has become evident that the most common form of arteriovenous malformation to involve the spinal cord in adults is a low-flow fistula with its nidus located on the dura in relation to the dorsal nerve root. This lesion, termed “radiculomeningeal fistula” (RMF), is drained by the intradural coronal venous system and most likely causes neurological deficits due to raised venous pressure within the spinal cord. The therapy that was formerly recommended was multilevel laminectomy with microsurgical stripping of the intradural vessels. However, that procedure focused on the draining veins rather than the nidus, and it has been replaced by direct treatment of the nidus or by disconnecting the nidus from the coronal venous system. This paper reports variants of RMF's that show a wider spectrum of the clinical and radiological findings than has been previously reported. Three patients presenting with extradural venous drainage, intraspinal hemorrhage, and/or sudden non-hemorrhagic neurological decline are reported. A more complete understanding of RMF facilitates the radiological and clinical evaluation of these patients and enables the surgeon to modify the therapy in a significant way.

scholarly journals The antireflux mechanism – Angiographic anatomy and clinical implications

2020 ◽  
Vol 26 (6) ◽  
pp. 691-702 ◽  
Author(s):  
Philippe Gailloud
Keyword(s):  
Spinal Cord ◽  
Clinical Features ◽  
Venous Pressure ◽  
Venous Drainage ◽  
Low Flow ◽  
Clinical Implications ◽  
Clinical Expression ◽  
Arteriovenous Fistulas ◽  
Arteriovenous Shunts ◽  
Retrograde Filling

Background Early anatomists suspected that the radiculomedullary veins draining the spinal cord had valves preventing their retrograde filling with anatomical casting material. Modern investigations have discarded the presence of true valves and introduced instead the notion of a pseudo-valvular configuration for which the term antireflux mechanism was coined in the 1970s. The angiographic anatomy of the antireflux mechanism has not been well documented so far. Methods This article discusses anatomical and clinical features of the antireflux mechanism with a series of 12 angiographic observations documenting the antireflux mechanism under normal and pathological circumstances. Results The antireflux mechanism divides radiculomedullary veins into intradural and extradural segments. While the structure of the antireflux mechanism is not yet fully clarified, it includes at least a tight narrowing of the radiculomedullary vein at its point of passage through the thecal sac, which is angiographically detectable and likely protects the intradural venous system from transient or persistent surges in venous pressure (e.g. sneezing, pregnancy). This tight narrowing of the antireflux mechanism likely also represents an obstacle to normal anterograde flow, potentially leading to venous stagnation and thrombosis. Conclusions The antireflux mechanism includes at least a tight narrowing of the radiculomedullary vein, which likely influences the development and clinical expression of low-flow spinal arteriovenous fistulas and might impact the spinal venous drainage even in the absence of arteriovenous shunts.

Split spinal cord malformations in children

1998 ◽  
Vol 88 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Yusuf Ersşahin ◽  
Saffet Mutluer ◽  
Sevgül Kocaman ◽  
Eren Demirtasş
Keyword(s):  
Spinal Cord ◽  
Neurological Deficits ◽  
Single Type ◽  
Type I ◽  
Type Ii ◽  
Content Type ◽  
Spinal Lesion ◽  
The Mean ◽  
Fine Print

Object. The authors reviewed and analyzed information on 74 patients with split spinal cord malformations (SSCMs) treated between January 1, 1980 and December 31, 1996 at their institution with the aim of defining and classifying the malformations according to the method of Pang, et al. Methods. Computerized tomography myelography was superior to other radiological tools in defining the type of SSCM. There were 46 girls (62%) and 28 boys (38%) ranging in age from less than 1 day to 12 years (mean 33.08 months). The mean age (43.2 months) of the patients who exhibited neurological deficits and orthopedic deformities was significantly older than those (8.2 months) without deficits (p = 0.003). Fifty-two patients had a single Type I and 18 patients a single Type II SSCM; four patients had composite SSCMs. Sixty-two patients had at least one associated spinal lesion that could lead to spinal cord tethering. After surgery, the majority of the patients remained stable and clinical improvement was observed in 18 patients. Conclusions. The classification of SSCMs proposed by Pang, et al., will eliminate the current chaos in terminology. In all SSCMs, either a rigid or a fibrous septum was found to transfix the spinal cord. There was at least one unrelated lesion that caused tethering of the spinal cord in 85% of the patients. The risk of neurological deficits resulting from SSCMs increases with the age of the patient; therefore, all patients should be surgically treated when diagnosed, especially before the development of orthopedic and neurological manifestations.

Histopathology of experimental hematomyelia

1991 ◽  
Vol 75 (6) ◽  
pp. 911-915 ◽  
Author(s):  
Thomas H. Milhorat ◽  
David E. Adler ◽  
Ian M. Heger ◽  
John I. Miller ◽  
Joanna R. Hollenberg-Sher
Keyword(s):  
Spinal Cord ◽  
Tissue Injury ◽  
Central Canal ◽  
Microglial Cells ◽  
Neurological Deficits ◽  
Thoracic Spinal Cord ◽  
Content Type ◽  
Thoracic Spinal ◽  
Cellular Debris ◽  
Dorsal Columns

✓ The pathology of hematomyelia was examined in 35 rats following the stereotactic injection of 2 µl blood into the dorsal columns of the thoracic spinal cord. This experimental model produced a small ball-hemorrhage without associated neurological deficits or significant tissue injury. Histological sections of the whole spinal cord were studied at intervals ranging from 2 hours to 4 months after injection. In acute experiments (2 to 6 hours postinjection), blood was sometimes seen within the lumen of the central canal extending rostrally to the level of the fourth ventricle. Between 24 hours and 3 days, the parenchymal hematoma became consolidated and there was an intense proliferation of microglial cells at the perimeter of the lesion. The cells invaded the hematoma, infiltrated its core, and removed erythrocytes by phagocytosis. Rostral to the lesion, the lumen of the central canal was found to contain varying amounts of fibrin, proteinaceous material, and cellular debris for up to 15 days. These findings were much less prominent in the segments of the canal caudal to the lesion. Healing of the parenchymal hematoma was usually complete within 4 to 6 weeks except for residual hemosiderin-laden microglial cells and focal gliosis at the lesion site. It is concluded that the clearance of atraumatic hematomyelia probably involves two primary mechanisms: 1) phagocytosis of the focal hemorrhage by microglial cells; and 2) drainage of blood products in a rostral direction through the central canal of the spinal cord.

Spinal cord mapping with evoked responses for accurate localization of the dorsal root entry zone

1995 ◽  
Vol 82 (4) ◽  
pp. 587-591 ◽  
Author(s):  
Mahmood Fazl ◽  
David A. Houlden ◽  
Zelma Kiss
Keyword(s):  
Spinal Cord ◽  
Dorsal Root ◽  
Neurological Deficits ◽  
Intractable Pain ◽  
Specific Stimulus ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Accurate Localization

✓ Direct spinal cord stimulation and recording techniques were used intraoperatively to localize the dorsal root entry zone (DREZ) in four patients with brachial plexus avulsion and severe intractable pain. The spinal cord was stimulated by a cordotomy needle placed on the pia-arachnoid at the DREZ or the dorsal or dorsolateral aspect of the spinal cord. Recordings were obtained from a subdural silver ball electrode placed rostral or caudal to the stimulation site. Spinal cord conduction velocity was significantly faster following dorsolateral stimulation than dorsal stimulation (mean = 66 and 45 m/sec respectively). The spinal cord evoked potential was significantly larger in amplitude following dorsolateral stimulation than dorsal stimulation at a specific stimulus intensity. Stimulation at the DREZ failed to evoke a response. These neurophysiological phenomena helped to accurately localize the DREZ before DREZ lesioning was undertaken. There were no untoward neurological deficits related to the DREZ lesions and all patients had satisfactory pain relief following the procedure. Intraoperative spinal cord mapping facilitates accurate DREZ localization when the DREZ cannot be visually identified.

Evaluation of experimental spinal cord injury using cortical evoked potentials

1973 ◽  
Vol 39 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Stephen H. Martin ◽  
James R. Bloedel
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cortical Response ◽  
Neurological Deficits ◽  
Cystic Degeneration ◽  
Post Injury ◽  
Content Type ◽  
Cord Injury ◽  
Cortical Responses ◽  
Control Response

✓ Experiments were performed to determine if changes in cortical evoked responses could be used to predict the extent of the neurological deficits following spinal cord injury by sudden inflation of a Fogarty balloon in the epidural space cephalad to a laminectomy. The cortical responses to stimulation of the posterior tibial nerve were recorded over the sigmoid gyrus at various times following the lesion and compared with the control response. Severe, irreversible neurological deficits occurred in cats in which the cortical response either could not be evoked immediately after injury or disappeared rapidly during this period. At the end of at least 6 weeks following injury, all of these animals were paraplegic and showed severe cystic degeneration of the spinal cord. In animals in which the post-injury cortical response did not completely disappear, only mild changes were observed in a spinal cord 6 weeks following injury. This technique may be helpful in ascertaining the severity and irreversibility of a traumatic spinal cord lesion; because the technique is simple, the method may prove helpful in the clinical management of patients with spinal cord injury.

Intramedullary ependymoma of the spinal cord

1990 ◽  
Vol 72 (4) ◽  
pp. 523-532 ◽  
Author(s):  
Paul C. McCormick ◽  
Roland Torres ◽  
Kalmon D. Post ◽  
Bennett M. Stein
Keyword(s):  
Spinal Cord ◽  
Mr Imaging ◽  
Tumor Recurrence ◽  
Neurological Deficits ◽  
Functional Improvement ◽  
Consecutive Series ◽  
Intramedullary Spinal Cord ◽  
Content Type ◽  
Fine Print

✓ A consecutive series of 23 patients underwent operative removal of an intramedullary spinal cord ependymoma between January, 1976, and September, 1988. Thirteen women and 10 men between the age of 19 and 70 years experienced symptoms for a mean of 34 months preceding initial diagnosis. Eight patients had undergone treatment prior to tumor recurrence and referral. Mild neurological deficits were present in 22 patients on initial examination. The location of the tumors was predominantly cervical or cervicothoracic. Radiological evaluation revealed a wide spinal cord in all cases. Magnetic resonance (MR) imaging was the single most important radiological procedure. At operation, a complete removal was achieved in all patients. No patient received postoperative radiation therapy. Histological examination revealed a benign ependymoma in all cases. The follow-up period ranged from 6 to 159 months (mean 62 months) with seven patients followed for a minimum of 10 years after surgery. Fourteen patients underwent postoperative MR imaging at intervals ranging from 8 months to 10 years postoperatively. No patient has been lost to follow-up review and there were no deaths. No patient showed definite clinical or radiological evidence of tumor recurrence during the follow-up period. Recent neurological evaluation revealed functional improvement from initial preoperative clinical status in eight patients, no significant change in 12 patients, and deterioration in three patients. The data support the belief that long-term disease-free control of intramedullary spinal ependymomas with acceptable morbidity may be achieved utilizing microsurgical removal alone.

Reflections upon the nature and management of intracranial and intraspinal vascular malformations and fistulae

1994 ◽  
Vol 80 (4) ◽  
pp. 606-616 ◽  
Author(s):  
Sean Mullan
Keyword(s):  
Sinus Thrombosis ◽  
Vascular Malformations ◽  
Venous Malformation ◽  
Venous Pressure ◽  
Venous Occlusion ◽  
Vein Of Galen ◽  
Content Type ◽  
Permanent Cure ◽  
Glue Embolization ◽  
Fine Print

✓ Evidence is presented that dural fistulae are preceded by sinus thrombosis and that their danger lies in arterialized venous pressure within the cranium or the orbit. Arterial side occlusion leads to recurrence, while venous side occlusion leads to permanent cure. Vein of Galen aneurysms embrace some features of cerebral arteriovenous malformations (AVM's), namely a reticulum, and some features of dural fistulae, namely evidence of previous sinus anomaly and direct drainage into a sinus. These aneurysms are also permanently cured by venous side thrombosis, although the dangers inherent in their reticulum demand that this be done in stages or preceded by arterial side embolization. A very limited experience with venous end occlusion of cerebral (and spinal) AVM's suggests that they, too, can be permanently cured by venous side occlusion without excision. Their reticulum demands maximum, multistage, preliminary arterial side embolization together with intraoperative hypotension during the venous occlusion stage in order to minimize intracerebral hemorrhage or swelling. Schematic models of both fistulae and malformations are presented, together with reasons why particulate embolization is safer than glue embolization. The theory is advanced that dural fistulae, vein of Galen aneurysms, and AVM's are venous- rather than arterial-based lesions, which is consistent with the experience that permanent cure has been effected by venous side occlusion without excision in all three anomalies. It is speculated that there may be a developmental link between AVM and the venous malformation, the AVM being essentially a fistulized venous malformation.

Modified classification of spinal cord vascular lesions

2002 ◽  
Vol 96 (2) ◽  
pp. 145-156 ◽  
Author(s):  
Robert F. Spetzler ◽  
Paul W. Detwiler ◽  
Howard A. Riina ◽  
Randall W. Porter
Keyword(s):  
Spinal Cord ◽  
Classification System ◽  
Arteriovenous Malformations ◽  
Vascular Malformations ◽  
Relevant Literature ◽  
Vascular Lesions ◽  
Cavernous Malformations ◽  
Content Type ◽  
Arteriovenous Fistulas ◽  
Fine Print

The literature on spinal vascular malformations contains a great deal of confusing terminology. Some of the nomenclature is inconsistent with the lesions described. Based on the experience of the senior author (R.F.S.) in the treatment of more than 130 spinal cord vascular lesions and based on a thorough review of the relevant literature, the authors propose a modified classification system for spinal cord vascular lesions. Lesions are divided into three primary or broad categories: neoplasms, aneurysms, and arteriovenous lesions. Neoplastic vascular lesions include hemangioblastomas and cavernous malformations, both of which occur sporadically and familially. The second category consists of spinal aneurysms, which are rare. The third category, spinal cord arteriovenous lesions, is divided into arteriovenous fistulas and arteriovenous malformations (AVMs). Arteriovenous fistulas are subdivided into those that are extradural and those that are intradural, with intradural lesions categorized as either dorsal or ventral. Arteriovenous malformations are subdivided into extradural-intradural and intradural malformations. Intradural lesions are further divided into intramedullary, intramedullary-extramedullary, and conus medullaris, a new category of AVM. This modified classification system for vascular lesions of the spinal cord, based on pathophysiology, neuroimaging features, intraoperative observations, and neuroanatomy, offers several advantages. First, it includes all surgical vascular lesions that affect the spinal cord. Second, it guides treatment by classifying lesions based on location and pathophysiology. Finally, it eliminates the confusion produced by the multitude of unrelated nomenclatural terms found in the literature.

Pure sylvian fissure arteriovenous malformations

2000 ◽  
Vol 92 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Gary Zimmerman ◽  
Adam I. Lewis ◽  
John M. Tew
Keyword(s):  
Arteriovenous Malformations ◽  
Short Term Memory ◽  
Vascular Malformations ◽  
Neuropsychological Testing ◽  
Memory Loss ◽  
Complete Removal ◽  
Sylvian Fissure ◽  
Neurological Deficits ◽  
Content Type ◽  
Fine Print

Object. Pure sylvian fissure arteriovenous malformations (AVMs) are vascular malformations confined to the sylvian fissure without parenchymal involvement. Because the branches of the middle cerebral artery are arteries of passage and the margins between the AVM and the insula cortex may be ill defined, many surgeons regard pure sylvian fissure AVMs as inoperable. The authors reviewed their surgical experience with eight patients harboring pure sylvian fissure AVMs to determine the incidence of operative morbidity.Methods. All eight patients experienced seizures, five (63%) had headaches, and three (38%) experienced hemorrhages. Preoperatively, six patients (75%) were normal neurologically and two (25%) had neurological deficits. Five (63%) of eight sylvian fissure AVMs were located in the dominant hemisphere. The size of the nidus ranged from 6 to 27 cm3 (mean 14 cm3).Complete removal of the AVM was documented by postoperative angiography in every case. Seizures were reduced or eliminated and headaches were relieved in all affected patients. Transient neurological deficits, which included aphasia, short-term memory loss, and hemiparesis, occurred in four patients (50%). Within 3 months, all patients were functioning independently with no new neurological deficits. The status of two patients who had had preoperative neurological deficits improved postoperatively. Neuropsychological testing showed no new cognitive deficits.Conclusions. With appreciation for transient instances of postoperative morbidity, the outcome was excellent in all patients. The authors thus advocate microsurgery as the primary treatment for pure sylvian fissure AVMs.

Management of dural arteriovenous malformations of the anterior cranial fossa

1990 ◽  
Vol 72 (5) ◽  
pp. 692-697 ◽  
Author(s):  
Neil A. Martin ◽  
Wesley A. King ◽  
Charles B. Wilson ◽  
Stephen Nutik ◽  
L. Phillip Carter ◽  
...  
Keyword(s):  
Arteriovenous Malformations ◽  
Vascular Malformations ◽  
Venous Drainage ◽  
Anterior Cranial Fossa ◽  
Venous Aneurysm ◽  
Content Type ◽  
Cortical Vein ◽  
Sagittal Sinus ◽  
Feeding Vessels ◽  
Cranial Fossa

✓ Eight patients with dural arteriovenous malformations (AVM's) of the anterior cranial fossa are presented, and the pertinent literature is reviewed. Unlike cases of dural AVM's in other locations, sudden massive intracerebral hemorrhage was the most frequent reason for presentation. Other symptoms included tinnitus, retro-orbital headache, and a generalized seizure. The malformations were supplied consistently by the anterior ethmoidal artery, usually in combination with other less prominent feeding vessels. The lesion's venous drainage was through the superior sagittal sinus via a cortical vein; in addition, in two cases a subfrontal vein drained the AVM. A venous aneurysm was encountered near the site of anastomosis with the dural feeder in most cases, and was found in all patients who presented with hemorrhage. The AVM was obliterated surgically in six patients, with favorable results achieved in five. One patient died postoperatively from a pulmonary complication. Because of their anatomy and proclivity for hemorrhage, these vascular malformations represent a unique group of dural AVM's. Surgical management of anterior fossa dural AVM's carries low morbidity, and is indicated when the lesions have caused hemorrhage or when there is an associated venous aneurysm.

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