Radicular Vein Research Articles

Anatomical considerations regarding a high-flow arteriovenous fistula below the conus medullaris in a patient with hereditary hemorrhagic telangiectasia: Case report.

Cauda equina radicular arteriovenous fistulas are rare "low flow" shunting lesions characterized by direct communication between the radicular artery and vein of a cauda equina nerve root. None have been associated with hereditary hemorrhagic telangiectasia and a high-flow cauda equina radicular arteriovenous fistula has never been reported. We present a unique case of a high-flow cauda equina radicular arteriovenous fistula in a patient with hereditary hemorrhagic telangiectasia. Marked flow-induced vascular remodeling posed significant diagnostic and therapeutic challenges which will be highlighted in this report. A 39-year-old female with genetically confirmed hereditary hemorrhagic telangiectasia presented with progressive thoracic myelopathy secondary to a high-flow single-hole arteriovenous fistula below the conus. The feeding artery, arising from the anterior spinal artery, and draining vein had a paramedian course, favoring the diagnosis of a cauda equina radicular arteriovenous fistula (supplied by a proximal radicular artery) over a filum terminale arteriovenous fistula. Transarterial embolization was attempted but significant elongation and tortuosity of the anterior spinal artery precluded microcatheter access to the fistulous point. Surgical disconnection was successfully performed. The intraoperative findings supported the diagnosis of cauda equina radicular arteriovenous fistula. Delayed neurologic deterioration secondary to overshooting venous thrombosis was observed. She recovered after the initiation of therapeutic anticoagulation. To the best of our knowledge, we hereby report the first high-flow cauda equina radicular arteriovenous fistula. The accurate differentiation of cauda equina radicular arteriovenous fistula from filum terminale arteriovenous fistulas, while challenging, is important to avoid treatment-related complications. Careful preoperative planning, the use of specialized endovascular and surgical techniques, and meticulous postoperative care can ensure the safe and complete disconnection of high-flow cauda equina radicular arteriovenous fistulas.

MRI characteristics of lumbosacral dural arteriovenous fistulas.

Spinal dural arteriovenous fistulas located in the lumbosacral region are rare and present with nonspecific clinical signs. The purpose of this study was to find out the specific radiologic features of these fistulas. We retrospectively reviewed the clinical and radiological data of 38 patients diagnosed with lumbosacral spinal dural arteriovenous fistulas in our institution from September 2016 to September 2021. All patients underwent time-resolved contrast-enhanced three-dimensional MRA and DSA examinations, and were treated with either endovascular or neurosurgical strategies. Most of the patients (89.5%) had motor or sensory disorders in both lower limbs as the first symptoms. On MRA, the dilated filum terminale vein or radicular vein was seen in 23/30 (76.7%) patients with lumbar spinal dural arteriovenous fistulas and 8/8 (100%) patients with sacral spinal dural arteriovenous fistulas. T2W intramedullary abnormally high signal intensity areas were found in all lumbosacral spinal dural arteriovenous fistula patients, with involvement of the conus present in 35/38 (92.1%) patients. The "missing piece sign" in the intramedullary enhancement area was seen in 29/38 (76.3%) patients. Dilatation of the filum terminale vein or radicular vein is powerful evidence for diagnosis of lumbosacral spinal dural arteriovenous fistulas, especially for sacral spinal dural arteriovenous fistulas. T2W intramedullary hyperintensity in the thoracic spinal cord and conus, and the missing-piece sign could be indicative of lumbosacral spinal dural arteriovenous fistula.

Technical video: Onyx-18 embolization of spinal epidural arteriovenous Fistula using the scepter-Mini balloon catheter.

Spinal arteriovenous fistulas (AVFs) account for approximately 70% of all vascular spinal malformations and commonly develop in the lateral epidural space at the epidural /radicular venous junction. The fistula is located close to the spinal nerve root where a radiculomeningeal artery shunts to a radicular vein. Increased venous pressure leads to decreased spinal venous drainage and venous congestion causing progressive myelopathy, bowel/bladder incontinence and erectile dysfunction. Treatment consists of surgical occlusion of the intradural vein, or endovascular embolization, which has a reported success rate of 25%-75%.1 Endovascular failure can occur with inadequate embolic penetration of the nidus and the proximal segment of the draining vein, or premature reflux of the liquid embolic agent.The use of a dual-lumen balloon microcatheter offers advantage in these cases given the ability to push liquid embolysate more distally during balloon inflation. The Scepter Mini is a new dimethyl-sulfoxide (DMSO)-compatible dual-lumen balloon microcatheter with a distal-tip outer diameter of 1.6 Fr and a nominal balloon diameter of 2.2 mm, facilitating atraumatic navigation and safer balloon inflation. Limited neurointerventional experience using the Scepter Mini in predominantly cerebrovascular cases has reported favorable navigability and flow arrest2, 3 Although Onyx is rarely used for spinal AVF embolization, success has been reported considering the well-known favorable experience in cerebral cases.1, 4, 5We present one of the first cases of Onyx embolization of a spinal dural AVF through a Scepter Mini in a patient with progressively worsening lower extremity sensorimotor dysfunction. Operators should be aware of radiculomedullary arteries arising at the same level or at adjacent levels to avoid unintentional Onyx migration during balloon inflation.

Recognition of the variant type of spinal dural arteriovenous fistula: a rare but important consideration.

Spinal dural arteriovenous fistulas (SDAVFs) typically represent abnormal shunts between a radiculomeningeal artery and radicular vein, with the point of fistulization classically directly underneath the pedicle of the vertebral body, at the dural sleeve of the nerve root. However, SDAVFs can also develop in atypical locations or have more than one arterial feeder, which is a variant of SDAVF. The aim of this study was to describe the incidence and multidisciplinary treatment of variant SDAVFs in a single-center case series. Following institutional review board approval, the authors retrospectively analyzed their prospectively maintained database of patients with SDAVFs who presented between 2008 and 2020. For all patients, spinal digital subtraction angiograms were reviewed and variant SDAVFs were identified. Variant types of SDAVFs were defined as cases in which the fistulous point was not located underneath the pedicle. Patient demographics, angiographic features, clinical outcomes, and treatment modalities were assessed. Of 59 patients with SDAVFs treated at the authors' institution, 4 patients (6.8%) were identified as having a variant location of the shunt zone, pinpointed on the dura mater at the intervertebral level, further posteriorly within the spinal canal. In 3 cases (75%), a so-called bimetameric arterial supply was demonstrated. Recognition of the variant type of SDAVF is crucial for management, as correct localization of the fistulous point and bimetameric supply are critical for successful surgical disconnection, preventing delay in achieving definitive treatment.

Natural History and Clinical Outcomes of Paravertebral Arteriovenous Shunts.

Paravertebral arteriovenous shunts (PVAVSs) are rare. Whether the intradural venous system is involved in drainage may lead to differences in clinical characteristics through specific pathophysiological mechanisms. This study aims to comprehensively evaluate the natural history and clinical outcomes of PVAVSs with or without intradural drainage. Sixty-four consecutive patients with PVAVSs from 2 institutes were retrospectively reviewed. Lesions were classified as type A (n=28) if the intradural veins were involved in drainage; otherwise, they were classified as type B (n=36). The clinical course from initial presentation to the last follow-up was analyzed. The patients with type A shunts were older at presentation (52.5 versus 35.5 years, P<0.0001) and more likely to have lower spinal segments affected than patients with type B PVAVSs (67.8% versus 13.9%, P=0.00006). After presentation, the deterioration rates related to gait and sphincter dysfunction were significantly higher in patients with type A than type B shunts (gait dysfunction: 71.8%/y versus 17.0%/y, P=0.0006; sphincter dysfunction: 63.7%/y versus 11.3%/y, P=0.0002). According to the angiogram at the end of the latest treatment, 79% of type A and 75% of type B PVAVSs were completely obliterated. If the lesions were partially obliterated, a significantly higher clinical deterioration rate was observed in patients with type A shunts than those with type B shunts (69.9%/y versus 3.2%/y, P=0.0253). Type A PVAVSs feature rapid progressive neurological deficits; therefore, early clinical intervention is necessary. For complex lesions that cannot be completely obliterated, surgical disconnection of all refluxed radicular veins is suggested.

Early Diagnosis of Spinal Dural Arteriovenous Fistula

Spinal dural arteriovenous fistulas (SDAVF) are rare and most commonly affect men aged >50 years. Patients with SDAVF develop an abnormal vascular dural shunt between the dural branch of a segmental artery and a subdural radicular vein that drains the perimedullary venous system, leading to venous hypertension and secondary congestive myelopathy. Most SDAVFs are located in the thoracolumbar region, and usually patients present with slowly progressive paraparesis and urinary disturbances. SDAVF is diagnostically challenging; this condition may be misdiagnosed as lumbar spinal stenosis or myelitis. Clinicians should be aware of fluctuating symptoms in the early stages to avoid misdiagnosis of SDAVF. Claudication is associated with various activities including walking, bathing, drinking, and singing. On T2-weighted magnetic resonance imaging of the spinal cord, SDAVFs show a high signal intensity with a low signal intensity peripherally and dilated spinal cord veins in the subarachnoid space.

Revisiting Intrathecal Dorsal Venous Patterns of the Spinal Cord at Thoracolumbar Level as Probable Factor for Post Lumbar Puncture Spinal Hematoma.

The spinal cord is drained by three interconnected venous systems. Among them the extrinsic venous system of the dorsal thoracolumbar region with its radicular communications is liable to get injured due to its anatomical position. With increasing case reports of post puncture hematomas, revisiting the intrathecal extrinsic venous system of spinal cord has become a necessity. In a tertiary teaching institution, 25 adult cadavers were dissected by standard dissection procedure and spinal cord was removed with meninges. The dorsal aspect was further dissected out and layers of meninges were removed carefully to expose the extrinsic venous system in the dorsal region. The specimens that showed engorged veins were further studied for their extent, pattern, presence of radicular veins, their level and route of exit. Five specimens showed variant dorsal venous pattern of the extrinsic system of veins in the thoracolumbar region. The main dorsal spinal vein was seen to be engorged, tortuous and more than 2mm with engorged radicular veins. Out of 8 engorged radicular veins observed, 6 exited through the dorsal nerve root foramen and 2 exited through a separate foramen. The variant anatomy of intrathecal extrinsic venous system with engorgement of the thoracolumbar region veins might get injured during lumbar puncture procedure. The exit of radicular veins and the dorsal nerve root through the same foramen also makes the veins susceptible to post procedural spinal hematomas.

Spinal Epidural Arteriovenous Fistula with Perimedullary Venous Reflux: Clinical and Neuroradiologic Features of an Underestimated Vascular Disorder.

The purpose of this study was to discuss the clinical and radiologic characteristics of spinal epidural arteriovenous fistulas (SEAVF) and demonstrate their specific angiomorphology in a single-center series. Thirteen consecutive patients were diagnosed with SEAVF at RWTH Aachen University Hospital between 2006 and 2018 and were included in this study. All patients had MR imaging and DSA before treatment; 10 of these 13 patients received contrast-enhanced MRA (CE-MRA). The mean patient age was 72 ± 8 years. Paraparesis was present in 12 (92%) patients. Sphincter dysfunction and sensory symptoms were observed in 7 (54%) and 6 (46%) patients, respectively. The mean duration of symptoms was 6 ± 8 months. Congestive myelopathy on MR imaging was present in all patients. Prominent arterialized perimedullary veins were demonstrated in only 3 cases. CE-MRA revealed arterialized perimedullary veins and an arterialized epidural pouch in 9/10 (90%) patients, mostly located ventrolaterally. DSA demonstrated a multisegmental extension of the arterialized ventrolateral epidural pouch in 6 (46%) cases. An intradural radicular drainage vein was localized distant from the original fistula point in 3 (23%) patients. Congestive myelopathy with an acute/subacute clinical course was the dominant finding in spinal epidural arteriovenous fistulas. CE-MRA is a powerful diagnostic tool for identifying arterialized perimedullary veins as well as an arterialized epidural pouch. While arterialized perimedullary veins frequently present with only mild enlargement and elongation in spinal epidural arteriovenous fistulas, the arterialized epidural pouch is frequently located ventrolaterally and may extend over several vertebral levels. DSA remains the criterion standard to precisely visualize a spinal epidural arteriovenous fistula and its intradural radicular drainage vein, which may be located distant from the fistulous point.

Clinical and Radiologic Characteristics of Deep Lumbosacral Dural Arteriovenous Fistulas.

Spinal dural arteriovenous fistulas located in the deep lumbosacral region are rare and the most difficult to diagnose among spinal dural arteriovenous fistulas located elsewhere in the spinal dura. Specific clinical and radiologic features of these fistulas are still inadequately reported and are the subject of this study. We retrospectively evaluated all data of patients with spinal dural arteriovenous fistulas treated and/or diagnosed in our institution between 1990 and 2017. Twenty patients with deep lumbosacral spinal dural arteriovenous fistulas were included in this study. The most common neurologic findings at the time of admission were paraparesis (85%), sphincter dysfunction (70%), and sensory disturbances (20%). Medullary T2 hyperintensity and contrast enhancement were present in most cases. The filum vein and/or lumbar veins were dilated in 19/20 (95%) patients. Time-resolved contrast-enhanced dynamic MRA indicated a spinal dural arteriovenous fistula at or below the L5 vertebral level in 7/8 (88%) patients who received time-resolved contrast-enhanced dynamic MRA before DSA. A bilateral arterial supply of the fistula was detected via DSA in 5 (25%) patients. Clinical symptoms caused by deep lumbosacral spinal dural arteriovenous fistulas are comparable with those of spinal dural arteriovenous fistulas at other locations. Medullary congestion in association with an enlargement of the filum vein or other lumbar radicular veins is a characteristic finding in these patients. Spinal time-resolved contrast-enhanced dynamic MRA facilitates the detection of the drainage vein and helps to localize deep lumbosacral-located fistulas with a high sensitivity before DSA. Definite detection of these fistulas remains challenging and requires sufficient visualization of the fistula-supplying arteries and draining veins by conventional spinal angiography.

Surgical ligation of spinal dural arteriovenous fistula.

Spinal dural arteriovenous fistulas (SDAVFs) are abnormal arteriovenous shunts between a radicular artery and the radicular vein, located in the dorsal surface of the dura sleeve, which drains in a retrograde manner into the coronal venous plexus of the spinal cord without an interposed capillary network. This result is a venous hypertension that reduces spinal cord perfusion and leads to ischemia and edema. Spontaneous resolution is extremely rare and, once symptomatic, the typical course is further progression with increased neurological impairment. Therefore, once a fistula is diagnosed, treatment is recommended. The fistula is placed at the level of intervertebral foramen and surgical ligation is performed through a laminectomy. After dural opening, the area is inspected, and the arterialized vein is identified and ligated. Laminectomy and arteriovenous fistula ligation is a safe and reliable approach for accessing and treating spinal dural arteriovenous fistulas.

Stretching of roots contributes to the pathophysiology of radiculopathies

PurposeTo perform a synthesis of articles addressing the role of stretching on roots in the pathophysiology of radiculopathy. MethodsReview of relevant articles on this topic available in the PubMed database. ResultsAn intraoperative microscopy study of patients with sciatica showed that in all patients the hernia was adherent to the dura mater of nerve roots. During the SLR (Lasègue's) test, the limitation of nerve root movement occurs by periradicular adhesive tissue, and temporary ischemic changes in the nerve root induced by the root stretching cause transient conduction disturbances. Spinal roots are more frail than peripheral nerves, and other mechanical stresses than root compression can also induce radiculopathy, especially if they also impair intraradicular blood flow, or the function of the arachnoid villi intimately related to radicular veins. For instance arachnoiditis, the lack of peridural fat around the thecal sac, and epidural fibrosis following surgery, can all promote sciatica, especially in patients whose sciatic trunks also stick to piriformis or internus obturator muscles. Indeed, stretching of roots is greatly increased by adherence at two levels. ConclusionsAs excessive traction of nerve roots is not shown by imaging, many physicians have unlearned to think in terms of microscopic and physiologic changes, although nerve root compression in the lumbar MRI is lacking in more than 10% of patients with sciatica. It should be reminded that, while compression of a spinal nerve root implies stretching of this root, the reverse is not true: stretching of some roots can occur without any visible compression.

First-Pass Contrast-Enhanced MRA for Pretherapeutic Diagnosis of Spinal Epidural Arteriovenous Fistulas with Intradural Venous Reflux.

Spinal epidural AVFs are rare spinal vascular malformations. When there is associated intradural venous reflux, they may mimic the more common spinal dural AVFs. Correct diagnosis and localization before conventional angiography is beneficial to facilitate treatment. We hypothesize that first-pass contrast-enhanced MRA can diagnose and localize spinal epidural AVFs with intradural venous reflux and distinguish them from other spinal AVFs. Forty-two consecutive patients with a clinical and/or radiologic suspicion of spinal AVF underwent MR imaging, first-pass contrast-enhanced MRA, and DSA at a single institute (2000-2015). MR imaging/MRA and DSA studies were reviewed by 2 independent blinded observers. DSA was used as the reference standard. On MRA, all 7 spinal epidural AVFs with intradural venous reflux were correctly diagnosed and localized with no interobserver disagreement. The key diagnostic feature was arterialized filling of an epidural venous pouch with a refluxing radicular vein arising from the arterialized epidural venous system. First-pass contrast-enhanced MRA is a reliable and useful technique for the initial diagnosis and localization of spinal epidural AVFs with intradural venous reflux and can distinguish these lesions from other spinal AVFs.

The Transdural Course of Radicular Spinal Cord Veins--A Microangiographical and Microscopical Study.

This study focuses on the following questions: What are the morphological features at the transdural course of radiculomedullary veins? How are these short transdural segments that may harbour pathological arteriovenous shunts connected to the internal vertebral venous plexus? Is the conception of a reflux-impeding mechanism at the transdural segment indispensable and convincing? A total of 102 radiculospinal veins were studied microscopically at various levels of the spinal canal using serial paraffin and semi-thin sections. In addition, 26 vessels were investigated microangiographically following orthograde (12) or attempted retrograde (14) opacification of the intradural venous segment with barium sulphate. After paraplast-embedding, contact-microradiographs were taken using high-resolution spectroscopic plates. At their transdural course, the veins showed narrowing of their lumen accompanied by changes in the vessel wall composition and a tortuous course. Two structurally distinct arrangements of the transdural segment could be identified: A slit type was seen in 60% of the veins studied and a bulge- or nodular type was seen in 35% of the veins. In total, 5% of cases could not be assigned to either one of these types. Reflux to radicular veins from the outside of the dura mater could be produced in 2 out of 14 specimens. The extradural venous plexus, which primarily receives the radicular vein, was composed more frequently of lacunar spaces rather than plexiform blood vessel convolutions. Rare observations were fibrotic, blind ending radiculomedullary veins and continuation of a distinct venous blood vessel after crossing the dura. Reflux from the epidural plexus to radicular veins is not reliably stopped at the dural level and possibly physiological. Different arrangements of the transdural course of the veins appear to be at least appropriate to modulate flow. The purpose for two different types of radicular vein exit is unclear. The clinical impact of disturbed reflux-control is uncertain, which is in stark contrast to the severe consequences resulting from dural arteriovenous shunts. The functional role of the probably predominant epidural venous plexus for the spinal cord blood circulation remains poorly understood.

Ways to optimize the treatment of patients with discogenic-venous lumbosacral radiculomyeloischemia

Treatment of patients with neurological manifestations of degenerative-dystrophic lesions of the spine must be integrated and optimized from the perspective of pathogenesis. Antiedematous therapy is an important moment that takes into account the development of localized swelling affected the spinal structures. We studied the efficacy of L-lysine aescinat in the treatment of patients with discogenic-venous lumbosacral radiculomyelopathy. We analyzed the therapeutic efficacy of antitumor therapy with the drug L-lysine aescinat in 40 patients with discogenic-venous lumbosacral radiculomyelopathy in comparison with a control group of 40 patients treated with conventional therapy in a neurological hospital. The age of the patients ranged from 30 to 60 years. In total, there were 36 (45 %) women and 44 (55%) men. Herniated discs were visualized by MRI in all patients, attention was drawn to the condition of radicular veins of the cauda equina. We assessed muscle strength of lumbosacral myotomes, their trophicity and state of segmental-conductor apparatus sensitivity with the quantitative determination of the time of vibration of a tuning fork. The comparison of neurological status dynamics during treatment of inpatients has shown that neurological symptoms reduce more effectively in patients treated with L - lysine aescinat (by 75% during the first 3-5 days) and in a greater number of the patients (77.5% vs 55% in the control group). The authors' experience has shown that venous micro- and macro-circulation disorders play an important role in the pathogenesis of lower lumbar disk hernia. Clinical manifestations of these disorders are segmental and conductive spinal motor disorders in myotomes and sensitivity. Quantitative determination of vibration sensitivity (tuning fork test) is pathognomonic for radiculomyeloischemia. Vein tonics and antiedemics, including L - lysine aescinat as one of the most effective drugs, exert a pathogenetic effect on spondylic and discogenic nervous system disturbances.

Spinal Dural Arteriovenous Fistula: Imaging Features and Its Mimics.

Spinal dural arteriovenous fistula (SDAVF) is the most common spinal vascular malformation, however it is still rare and underdiagnosed. Magnetic resonance imaging findings such as spinal cord edema and dilated and tortuous perimedullary veins play a pivotal role in the confirmation of the diagnosis. However, spinal angiography remains the gold standard in the diagnosis of SDAVF. Classic angiographic findings of SDAVF are early filling of radicular veins, delayed venous return, and an extensive network of dilated perimedullary venous plexus. A series of angiograms of SDAVF at different locations along the spinal column, and mimics of serpentine perimedullary venous plexus on MR images, are demonstrated. Thorough knowledge of SDAVF aids correct diagnosis and prevents irreversible complications.

Spinal dural arteriovenous fistula with intramedullary cord hemorrhage

Spinal dural arteriovenous fistula (SDAVF) consists of an acquired arteriovenous shunt between a dural artery and perimedullary veins.1 This results in arterialization of radicular veins, venous hypertension, and decreased spinal cord perfusion.1 The condition has a male predominance and presents as a myelopathy in the fifth or sixth decade. Initial misdiagnosis is common.1–3 We present a man with a SDAVF and associated intramedullary cord hemorrhage.

The venous system of the human foetal spinal cord. Scanning electron microscope of vascular corrosion casts.

The investigation was carried out on 16 human foetal cadavers at the age of 17-23 weeks from the time of conception. The foetal vascular system was injected with the synthetic resin MERCOX CL-2R and analysed in scanning electron microscope.The vascular system of the foetal spinal cord was studied. The foetal vascular system was characterised by high variability concerning the number, course and localisation of blood vessels. It contained numerous anastomoses with the internal spinal venous plexuses, which included anterior and posterior radicular veins. Large arteries running on the surface of the spinal cord are accompanied by the homoname veins. The venous system of the investigated foetuses was divided into 2 categories of veins: internal veins responsible for the drainage of blood from the central area, that is central and peripheral veins coming radially to the surface of the spinal cord and external veins, which form the venous system of the surface of the spinal cord. The venous system of the foetal spinal cord was also examined as to the presence of the valves.

Spinal dural arteriovenous fistula presenting with paraplegia following lumbar puncture

Spinal dural arteriovenous fistulas are rare lesions with an annual incidence of 1 per 100,000 population. In patients with this disease, an abnormal vascular dural shunt exists between a dural branch of a segmental artery and a subdural radicular vein that drains the perimedullary venous system, leading to venous hypertension and secondary congestive myelopathy. Generally, patients present with progressive paraparesis, urinary disturbances, and gait ataxia. In this report the authors describe a 61-year-old woman with a spinal dural arteriovenous fistula who developed an acute paraplegia after a nontraumatic lumbar puncture. The possible underlying mechanisms and treatment options are discussed.

Side effects of corticosteroid injections: What's new?

The risk of sepsis with a hip or knee implant does not seem to be increased by prior joint injections, as long as the injection and surgery are separated by at least two months. Calcifications have been reported after intradiscal injection in the coccygeal region for coccydynia. Complete rest for 24hours after injection of triamcinolone hexacetonide into the knee had no effect on systemic diffusion of the product. Patients infected by HIV who are treated with ritonavir are at much greater risk for Cushing syndrome after epidural injection. Problems with menstruation after corticosteroid injection seem to be related to a transient decrease in estradiol levels, without alterations in FSH and LH levels. The risk of central serous chorioretinopathy and acute necrosis of the retina after injection is not known, even by ophthalmologists. Transient dysphonia occurs in 12% of patients receiving corticosteroid injections. The impressive Tachon's syndrome seems to be the venous counterpart to Nicolau's syndrome for arteries. Injections into C1-C2 should be abandoned because of the neurological risks. Since serious neurological events after foraminal injections could be the result of an overly fast injection into the arterialized radicular veins rather than in the arteries, only slow injections with products having a low risk of embolism or vascular complications should be allowed. Dexamethasone-based preparations seem to contain no particles or crystals, and have not induced any neurological accidents in various animal models, even after direct administration into vertebral or carotid arteries.

Developmental Venous Anomaly Associated with Hemi-Parkinson’s Syndrome

Objective and Importance: Developmental venous anomalies (DVAs) are common congenital anomalies of intracranial venous drainage. In general, it is felt that DVAs replace the normal venous drainage system and, unless associated with another lesion such as a cavernous malformation, should not produce symptoms. The present case raises important questions regarding the potential for DVAs to become symptomatic and the role of venous hypertension in this process. Clinical Presentation: We present the case of a 23-year-old woman who presented with rapidly progressive hemi-parkinsonism consisting of unilateral tremor, micrographia, gait difficulty, and cogwheel rigidity. MRI demonstrated a large DVA draining the region of the contralateral basal ganglia with associated high signal intensity on T2-weighted MR imaging and gadolinium enhancement. Arteriography demonstrated only the DVA with the trunk of the angioma draining forward toward the inferior petrosal sinus instead of into the deep venous system. A focal stricture of the main venous trunk was noted. Retrograde venography confirmed a tight stricture at the entrance of the venous trunk into the cavernous sinus. Conclusions: Although DVAs are generally considered benign variants of normal venous drainage, it is possible that in select cases, venous outflow restriction may result in symptomatic venous hypertension. This may be particularly problematic in the setting of a large DVA when multiple radicular veins drain into a single large venous channel.