Report of 4 cases
Kittipong Srivatanakul, Dittapong Songsaeng, Augustin Ozanne, Frédérique Toulgoat and Pierre Lasjaunias
The authors describe 4 cases of syringomyelia-associated spinal cord arteriovenous malformation (AVM). All cases were managed with embolization of the AVM. Treatments were aimed to stabilize the AVM itself and not directed toward the syrinx. In 3 of the 4 cases the syringomyelia resolved after treatment. Reports concerning AVM as a cause of syringomyelia is very scarce and lacks posttreatment clinical information. In light of the clinical course and imaging findings, the authors propose a theory that venous hypertension in the spinal cord is the trigger for the development of syringomyelia, which may reverse after AVM treatment.
Pierre Lasjaunias, Georges Rodesch, Phillippe Pruvost, Françoise Grillot Laroche and Pierre Landrieu
✓ The authors report the case of a vein of Galen aneurysmal malformation in a 1-year-old baby presenting with an enlarging head. The lesion was a direct arteriovenous fistula in a dilated vein of Galen and was treated by complete embolization in one session. Four months after occlusion of the shunt, the ectatic vein of Galen and torcular were normal, and the head circumference had stabilized. This case serves as an opportunity to emphasize the quality of results that can be obtained with endovascular techniques. Proper analysis of the vein of Galen angioarchitecture allows planning for appropriate treatment with the lowest possible risk of morbidity and mortality.
Roberto C. Heros, Gerard M. Debrun, Robert G. Ojemann, Pierre L. Lasjaunias and Pierre J. Naessens
✓ A patient presenting with progressive paraparesis was found to have a spinal arteriovenous fistula at the T3–4 vertebral level. The lesion consisted of a direct communication of the anterior spinal artery with a very distended venous varix that drained mostly superiorly to the posterior fossa and simulated a posterior fossa arteriovenous malformation (AVM) on vertebral angiography. The patient was treated by surgical ligation of the fistula through an anterior transthoracic approach. He deteriorated abruptly on the 4th postoperative day, probably because of retrograde thrombosis of the enlarged anterior spinal artery. Over the next few months, he improved to the point of being able to walk with crutches. He has also regained sphincter control.
The different types of spinal AVM's are reviewed. Our case does not fit into any of these groups. A new category, Type IV, is proposed to designate direct arteriovenous fistulas involving the intrinsic arterial supply of the spinal cord.
Dittapong Songsaeng, Kittipong Srivatanakul, Timo Krings, Sasikhan Geibprasert, Augustin Ozanne and Pierre Lasjaunias
The purpose of this study is to analyze the clinical presentation, morphological characteristics, angio-architecture, and outcome of vertebrobasilar dissection (VBD) in the pediatric population.
The authors retrospectively reviewed 29 consecutive cases involving children younger than 16 years of age who were diagnosed with symptomatic VBDs. Data were gathered with respect to the patient's age, sex, clinical history, associated underlying disease, and symptoms (headache, vertigo) as well as the location of the dissection and the imaging appearance.
The patients' mean age was 8.24 years (range 2 months–15 years). There was an overall 3:1 male predominance, although among children older than 8 years, girls and boys were similarly affected. Hemorrhagic dissections occurred in 10 of 29 cases. In nonhemorrhagic dissections, stroke occurred in 16 cases, with the most common presenting symptoms being headaches and vertigo; in the other 3 cases, mass effect due to a chronic dissecting aneurysm was present. In 7 children an underlying vessel wall disease was found. The location of the dissection was extradural in 11 cases and intradural in the remainder. There was no preference with respect to side. The basilar artery was affected in 9 patients.
The imaging appearance and clinical presentation of symptomatic VBDs in the pediatric population differs from that in adults. Boys are more often affected, especially at younger ages, and hemorrhagic presentation is more common, presumably owing to the fact that the basilar artery is more commonly involved. Depending on the pathogenetic mechanism underlying the dissection, different clinical symptoms will evolve, necessitating individually tailored treatment.
Pierre Lasjaunias, Ming Chiu, Karel Ter Brugge, Atul Tolia, Michel Hurth and Mark Bernstein
✓ The authors describe their experience with four cases of dural arteriovenous malformation (AVM) which led them to analyze the clinical aspects of these lesions in an attempt to understand their pathophysiology. An additional 191 previously reported cases of dural AVM's were reviewed with special attention to the mechanism of intradural, central, and peripheral nervous system manifestations. Apart from the peripheral cranial nerve symptoms, which are most likely due to arterial steal, the central nervous system (CNS) symptoms appear to be related to passive venous hypertension and/or congestion. Generalized CNS symptoms can be related to cerebrospinal fluid malabsorption due either to increased pressure in the superior sagittal sinus, to venous sinus thrombosis, or to meningeal reaction resulting from minimal subarachnoid hemorrhages. These phenomena are not related to the anatomical type of venous drainage. On the other hand, focal CNS symptoms are specifically indicative of cortical venous drainage. Seizures, transient ischemic attacks, motor weakness, and brain-stem and cerebellar symptoms can be encountered depending on the territory of the draining vein or veins. Therefore, the localizing value of focal CNS symptomatology relates to the venous territory and not to the nidus or to the arterial supply characteristics of dural AVM's. Furthermore, the venous patterns of various dural AVM's at the base of the skull are expressed by differences in their clinical presentation. Dural AVM's of the floor of the anterior cranial fossa and of the tentorium are almost always drained by the cortical veins and, therefore, have a high risk of intradural bleeding.
The remarkable similarities in the manifestations of dural and brain AVM's and the differences in the manifestations of dural and spinal dural AVM's are pointed out. High-quality angiograms and a multidisciplinary approach to the study of dural AVM's will provide the best understanding of their symptoms and, therefore, the most appropriate treatment strategy.
Anatomy, normal variations, and angiographic aspects
Pierre Lasjaunias, Bernard Vallee, Hervé Person, Karel Ter Brugge and Ming Chiu
✓ The lateral spinal artery corresponds to the most rostral extent of the posterolateral arterial axis of the spinal cord. It supplies the posterior and lateral aspects of the spinal cord, and courses anterior to the posterior roots of the upper cervical spinal nerves (C-1 to C-4), and posterior to the dentate ligament. The lateral spinal artery anastomoses rostrally with the branches of the posterior inferior cerebellar artery (PICA) at the restiform body and laterally with the extraspinal arteries at the emergence of each nerve. It may originate either from the vertebral artery or from the PICA lateral to the medulla. Certain variations will cause an unusual but normal enlargement of the vessel in a specific portion of its course; these variations include vertebral artery duplication, a C-1 or C-2 vertebral origin of the PICA, a C-1 or C-2 occipital origin of the PICA, and an intradural course of the vertebral artery at C-2. Knowledge of these variations in the arterial supply to the area allows for an understanding of the different anatomic peculiarities present and their angiographic importance.
Sasikhan Geibprasert, Vitor Pereira, Timo Krings, Pakorn Jiarakongmun, Pierre Lasjaunias and Sirintara Pongpech
The goal in this study was to present possible pathological mechanisms, clinical and imaging findings, and to describe the management and outcome in patients with hydrocephalus due to unruptured pial brain arteriovenous malformations (AVMs).
Medical records and imaging findings in 8 consecutive patients with hydrocephalus caused by AVMs and treated between June 2000 and September 2007 were retrospectively reviewed to determine clinical symptoms, AVM location, venous drainage, level/cause of obstruction, and degree of hydrocephalus. Management of hydrocephalus, AVM treatment, complications, and follow-up results were evaluated.
Headaches were the most common clinical symptom (7 of 8 patients). Deep venous drainage was identified in all patients. Mechanical obstruction by the draining vein or the AVM nidus was seen in 6 patients, in whom obstruction occurred at the interventricular foramen (2 patients) or the aqueduct (4 patients). Hydrodynamic disorders following venous outflow obstruction and venous congestion of the posterior fossa led to hydrocephalus in the remaining 2 patients. Ventriculoperitoneal (VP) shunts were placed in 6 of 8 patients with a moderate to severe degree of hydrocephalus. Regression of hydrocephalus was noted in 4 patients, whereas in 2 the imaging findings were stable, 1 of whom had decreased hydrocephalus only after AVM size reduction. In 2 patients with mild hydrocephalus who were not treated with shunt insertion, 1 improved and 1 was clinically stable after AVM treatment.
The most common cause of hydrocephalus in unruptured brain AVMs is mechanical obstruction by the draining vein if it is located in a strategic position. Management should be aimed at treatment of the AVM; however, VP shunts may be necessary in acute and severe cases of hydrocephalus.
Dominique Fournier, Karel G. TerBrugge, Robert Willinsky, Pierre Lasjaunias and Walter Montanera
✓ The authors report the results of treatment in 49 consecutive patients with brain arteriovenous malformations (AVM's) who underwent therapeutic embolization with liquid adhesive agents between 1984 and 1988 at the Toronto Western Hospital. Thirty-three patients had no other treatment and were followed up with angiography at 2 years and clinically from 2 to 6 years. Of the other 16 patients, 10 had adjunctive radiosurgery and six underwent surgical resection following embolization. Seven (14%) of the 49 patients had a morphological cure effected by embolization as evidenced on their 2-year follow-up angiograms; these have remained clinically stable. Twelve patients developed neurological deficits after embolization; eight (16% of the series) were transient and four (8%) were permanent. Two patients (4%) had a delayed hemorrhage after incomplete obliteration of their malformations. Endovascular treatment resulted in clinical improvement in 15 (33%) of the other 46 patients. None of the patients who initially presented with hemorrhage had a rebleed following embolization. It is concluded that endovascular treatment with liquid embolic material can be an integral part of the multidisciplinary treatment protocol for patients with brain AVM's.