A case of cervical myelopathy due to dural arteriovenous fistula at the craniocervical junction]

A 70-year-old woman noted paresthesia ascending from both legs to her thighs 27 months previously. She also suffered from urinary urgency and incontinence. Thereafter, weakness in both legs developed and gradually became worse. At the time of admission, a neurological examination revealed diffuse atrophy and mild spasticity in all four extremities, bilateral mild weakness in both upper extremities, and severe weakness in both lower extremities. Her superficial sensation was moderately impaired below the Th 3 level on her right side, and below the Th 4 level on her left side along with a mildly decreased sense of vibration in her left leg. Marked hyperreflexia in all four extremities and bilateral pathological reflexes were also observed. Pollakisurea, urinary incontinence and constipation were also present. Cervical MRI showed a swelling of the spinal cord at the C3 to C7 levels. Inside the spinal cord, low signal intensity lesions were seen on the T1-weighted MRI, and high signal intensity lesions were observed on the T2-weighted MRI, and the rim of the cervical cord was also enhanced by gadolinium-DTPA. MR angiography revealed enlarged and tortuous vessels at the craniocervical junction, thus suggesting the presence of a dural arteriovenous fistula (AVF). Vertebral arteriography demonstrated abnormal vessels at the spinomedullary junction supplied by the right vertebral artery, which drained into the anterior and posterior spinal veins. After surgically treating the dural AVF, the swelling of the spinal cord, the abnormal signals on MRI, and the clinical symptoms all markedly improved. Although most of the spinal dural AVF were located at the thoracic and lumbar levels, the present case was considered to be a very rare case of dural AVF, since it was located at the craniocervical junction and thus led to the development of cervical myelopathy.     

Venous congestive myelopathy of the cervical spinal cord: An autopsy case showing a rapidly progressive clinical course

We report a rapidly progressive myelopathy in a 74‐year‐old Japanese man who was admitted to our hospital with a 4‐month history of progressive gait disturbance and died of pneumonia followed by respiratory failure on the 22nd day of admission. During the course of his illness, magnetic resonance imaging (MRI) revealed intramedullary lesions with edematous swelling from the medulla oblongata to the spinal cord at the level of the fourth vertebra. After administration of contrast medium, the ventral portion of the lesion was mildly and irregularly enhanced and a dilated vessel was recognized along the ventral surface of the upper cervical cord. At autopsy, ischemic changes were observed in the upper‐to‐middle cervical cord segments, with so‐called arterialized veins in the subarachnoid space. No neoplastic lesions were found within or outside the brain and spinal cord. These pathological findings were essentially those of venous congestive myelopathy (VCM) associated with dural arteriovenous fistulae (AVF), formerly known as Foix–Alajouanine syndrome. VCM associated with dural AVF, which is now considered to be treatable in the early stages, is rare found in the cervical spinal cord. The present autopsy case, with MRI findings, provides further information that might be useful for recognition and diagnosis.     

A case of spinal dural AVF treated by endovascular embolization]

Here we report a case of spinal dural arteriovenous fistula(AVF) treated by endovascular embolization. A 58-year-old female presented with progressive intermittent claudication and numbness of the lower extremities. MRI showed swelling of the spinal cord with intramedullary high signal intensity on T2-weighted image and intramedullary enhancement, suggested spinal cord myelopathy. Myelography demonstrated the dilated serpentine vessels in the subarachnoid space and focal filling defect. Angiography showed spinal dural AVF fed by bilateral lateral sacral artery. The draining vein was posterior spinal vein. Endovascular embolization using liquid material was performed under general anesthesia. The injection of glue included the distal feeding artery, the shunt itself and the initial part of draining vein. A complete cure was achieved, with a normal postoperative angiogram. MRI returned to normal with complete disappearance of T2 high signal, cord enlargement and enhancement by contrast medium. It was suggested that venous congestion induced the transient spinal ischemia, manifested as intermittent claudication. Endovascular embolization using liquid material was safe and quite effective for spinal dural AVF.     

A case of spinal dural arteriovenous fistula draining to the ventral coronal venous plexus]

Here we report a case of spinal dural areteriovenous fistula (AVF) draining to the anterior spinal vein. An 80-year-old female presented with progressive weakness of lower extremities. MRI showed spinal enlargement at the Th10 to L1 with high intensity signals on T2-weighted image and multiple flow voids on the dorsal and ventral surface of the spinal cord. Angiogram of the left L2 lumbar artery demonstrated a hairpin-shaped vessel with ascending and descending limbs, mimicking radiculomedullary artery. Oblique view angiogram of the left L2 lumbar artery showed that radiculomedullary vein drained to the dilated anterior spinal vein, which then drained cranially and caudally on the anterior and posterior surface of the spinal cord. The patient underwent T9-L2 laminectomy. Several large tortuous dilated veins in the subarachnoid space were found. Examination of the inner surface of the dura revealed an arterialized vein that began at the level of L2 and coursed superiorly. The arterialized vein was coagulated and interrupted. The postoperative angiogram demonstrated the obliteration of the fistula. Postoperative MRI returned to normal with complete disappearance of T2 high signal, cord enlargement. In most spinal dural AVF, the venous drainage is predominantly upward on the posterior surface of the spinal cord. The spinal dural AVF draining to the anterior spinal vein is atypical, and cause difficulty in differentiating the anterior spinal artery from the anterior spinal vein. Oblique view angiogram may be helpful to differentiate the anterior spinal vein from anterior spinal artery.     

Case of spinal thoracic-lumbar dural arteriovenous fistula with polyneuropathy type sensory impairment]

A 57-year-old man had progressive paresthesias ascending from both legs together with paraparesis. Distal paresthesias of the upper extremities developed earlier than segmental sensory impairments. At transfer to our hospital, a neurological examination detected bilateral lower limb weakness predominant in the distal part; severe glove and stocking paresthesias in addition to superficial sensory impairment below the Th8 level; and micturition problems. T2-weighted thoracolumbar MRI showed a hyperintense spinal cord lesion between Th5 and L1. At the L4 level, a spinal arteriogram showed enlarged and tortuous vessels extending from the lumbar artery which drains to the spinal vein. These findings led to the diagnosis of spinal dural arteriovenous fistula. Anatomical substrates for this sensory impairment may be produced by development from the side to forward parts of lesions in the outer circumference of the anterior funiculi, resulting in the dominating sensory impairment in the distal parts of the upper extremities. Physicians need to be aware of patients who have polyneuropathy-like sensory impairment without segmental sensory signs, and must consider the possibility of spinal dural arteriovenous fistula.     

Atypical spinal dural arteriovenous fistula with supply from the lateral sacral artery.

We report a dural arteriovenous fistula (AVF) that developed at a site on the midline dorsal surface of the dura mater that had been damaged by repeated lumbar punctures. A 61-year-old male patient had undergone repeated lumbar punctures and discectomy for severe lumbago 40 years before the present admission. After surgery, the lumbago symptoms resolved. However, 30 years after the operation, he started to experience dysaesthesia, motor weakness in both legs, and urinary disturbance. Physical examination revealed bilateral leg weakness, diminished deep tendon reflexes in the patellar and Achilles tendons bilaterally, and decreased superficial sensation below L1. Magnetic resonance imaging revealed swelling with intramedullary high intensity and multiple flow voids around the conus and spinal cord on T(2)-weighted images, and adhesive arachnoiditis. Spinal angiography revealed an AVF between the left lateral sacral artery and the S1 radicular vein at the site of the previous operation. Surgery was conducted to carry out excision of the dural AVF at the shunting point, the arterialized intradural vein, and lysis of the arachnoiditis. This case of dural AVF may have been caused by repeated lumbar punctures.     

硬脊膜动静脉瘘(附1例临床分析)

目的探讨硬脊膜动静脉瘘(SDAVF)的病因、发病机制、临床表现、诊断及治疗。方法回顾性分析了1例患者的相关临床资料。结果本例患者以双下肢渐进性麻木、无力1年余,加重伴大小便障碍9个月为主要临床表现,脊髓MRI显示T9~L1髓内以长T2长T1为主之异常信号,超选择DSA造影可见位于入LT12椎管处一硬脊膜动静脉之瘘口,成功地进行了经单侧椎板开窗夹闭瘘口术。结论SDAVF为一具有直接的动静脉交通性病变,常伴有小型畸形团,多发生于中年男性,误诊率高,主要表现为渐进性的肢体麻木、无力及大小便障碍,MRI有助于诊断,但仍须DSA确诊。阻断连接瘘口与冠状静脉丛的引流静脉是治疗SDAVF的有效方法,显微外科手术效果可靠、复发率低,尽早地确诊和治疗是取得良好疗效的根本前提。     

Venous congestive myelopathy: Three autopsy cases showing a variety of clinicopathologic features

We describe three patients with progressive myelopathy, in whom autopsy revealed spinal cord pathology compatible with that of venous congestive myelopathy (VCM) associated with dural arteriovenous fistula (AVF), formerly known as angiodysgenetic necrotizing myelopathy (Foix–Alajournine syndrome). In these three patients, common symptoms were gait disturbance and sensory disturbance of the extremities, and these symptoms slowly worsened. The clinical diagnoses varied and included spinal cord intramedullary tumor, cervical spondylosis and multiple sclerosis. At autopsy, all the patients showed enlarged, tortuous venous vessels on the dorsal surfaces of the spinal cord at the affected levels. In the affected spinal cord parenchyma, necrotic lesions manifested by various degrees of neuronal loss and gliosis, with increased numbers of hyalinized vessels, were evident. The presence or absence of associated spinal dural AVF could not be identified histopathologically. Even with the help of modern neurological examination methods, early and accurate clinical diagnosis of VCM is sometimes difficult. When encountering patients with progressive myelopathy, VCM, although recognized as rare, should be considered as an important differential diagnosis.     

A case of spinal dural arteriovenous malformation associated with the broad lesion within spinal cord--diagnostic value of MRI with Gd-DTPA enhancement

A 70-year-old man, with slowly progressive gait disturbance, numbness in his lower limbs and dysuria, was admitted to our hospital in July, 1988. Neurological examination revealed flaccid paraparesis, hyperesthesia below the level of Th-10 combined with the disturbance of pain and temperature sensations below the level of Th-11, and neurogenic bladder. Midsagittal Tl-weighed image of MRI did not reveal any abnormal finding except for a mild enlargement of the conus medullaris. With Gadolinium (Gd)-DTPA injection, however, the spinal cord was diffusely enhanced below the level of the 9th thoracic spine. This enhancement effect was particularly remarkable at the periphery of the spinal image showing several high intensity spots in the posterior aspect of the spinal cord, which was thought to be incompatible with the spinal cord neoplasm. The angiographic examination of the selective Th-7 intercostal artery on the left showed vascular malformation lying adjacent to the 7th intervertebral foramen with markedly dilated tortuous spinal veins going upwards and downwards, which was compatible with spinal dural arteriovenous malformation (AVM). After the artificial embolization, draining veins as well the nidus of AVM had completely disappeared on angiogram. There was an improvement on his neurological findings and Gd-DTPA enhancement had been diminished on MRI. It was suggested that Gd-DTPA enhancement on MRI was due to the dilated and remarkably congestive spinal veins, and that both the elevated venous pressure and reduction of intramedullary arteriovenous pressure gradient were the cause of the development of clinical symptoms.     

Spontaneous resolution of an idiopathic cervical direct vertebral arteriovenous fistula after partial coil embolization in a patient presenting with myeloradiculopathy

A 53-year old female presented with paresis of the left upper extremity. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) disclosed a single high-flow vertebral arteriovenous fistula (AVF) with vertebral artery (VA) transection. The AVF was also fed by steal flow from the contralateral VA. The left posterior inferior cerebellar artery (PICA) branched just distal to the fistula. The fistula drained into the neighboring paravertebral veins and refluxed into the intradural venous systems. The dilated drainers compressed the spinal cord. Embolization was attempted at the drainer just behind the fistula orifice using platinum coils. The fistula was still fed slightly by right VA after the embolization, but spontaneous complete obliteration was achieved after one week. The clinical symptoms and signs disappeared. Although, detachable balloon embolization is the quickest and most effective procedure to obliterate a fistula, stepwise embolization using GDC can be considered, and may avoid the normal pressure perfusion break-through phenomenon. Spontaneous obliteration of the fistula after partial embolization in our case may result from intravenous embolization just behind the fistula orifice. It may therefore be a useful approach to the embolization of an AVF to begin the embolization at the venous side of the fistula.     

Intracranial dural arteriovenous fistula with spinal venous drainage]

Two cases of intracranial dural arteriovenous fistulae draining into the medullary veins are reported. One patient was a 68-year old man who experienced brief and repeated episodes of paraplegia, followed by a permanent spinal cord syndrome. The other patient was a 74-year-old woman who rapidly developed a syndrome of the medulla and spinal cord. In both cases spinal cord angiography failed to show vascular malformations, but myelography revealed venous imprints and magnetic resonance imaging of the cervical spinal cord disclosed a pre-medullary signal. Cerebral angiography showed an intracranial arteriovenous fistula fed by the external carotid artery and draining into the veins of the posterior fossa and the spinal venous network. Complete occlusion of the fistula was achieved by embolization with microparticles. Intracranial dural arteriovenous fistulae draining into the medullary veins are rare: to our knowledge, only 4 cases have been reported. Such lesions must be considered whenever a spinal cord syndrome has no detectable cause.     

表现为蛛网膜下腔出血的高颈段硬脊膜动静脉瘘

目的对表现为蛛网膜下腔出血的高颈段硬脊膜动静脉瘘发病机制进行分析,预测出血因素,避免漏诊,指导治疗。方法对5例表现为蛛网膜下腔出血的高颈段硬脊膜动静脉瘘的临床资料进行总结。结果5例瘘口均位于枕大孔区～颈2节段,由椎动脉脊膜支供血．通过髓周静脉引流。所有5例引流静脉均向颅内引流,有不同程度扩张,3例伴有静脉瘤样改变。手术后复合瘘口均消火,4例治愈,1例死亡。结论高颈段硬脊膜动静脉瘘向颅内引流并伴有引流静脉扩张易出血,颅内压增高可能是诱发出血的因素。血管造影应全面,避免小部分蛛网膜下腔出血的患者造影假阴性。手术夹闭瘘口并切断近端引流静脉是可靠的治疗方法。     

Computed tomography (CT) angiography with multidetector row helical CT for detecting spinal dural arteriovenous fistula]

A 59-year-old man had have dysuria and left thigh pain for 2 months. He also experienced transient weakness of both legs twice, which recovered within a few hours. One month ago, he had bowel disturbance. Lumbar MRI showed a swelling of the conus medullaris. Enlarged and tortuous vessels behind the spinal cord on lumbar MRA and CT myelography was demonstrated. Though angiogram through intercostal and lumbar arteries revealed no abnormal findings, CT angiography with multidetector row helical CT (MDCT) showed abnormal vessel in intradural space at sacral level. Angiogram through left internal iliac artery revealed abnormal vessel fed by branches of the lateral sacral artery at the early arterial phase. Thus, diagnosis of dural arteriovenous fistula (DAVF) at the left S1 level was confirmed. It was indicated that CT angiography with MDCT was useful in detecting spinal DAVF especially at sacral level.     

Neuroimaging of Tuberculous Myelitis: Analysis of Ten Cases and Review of Literature

We retrospectively reviewed the clinical and neuroimaging features of 10 patients with tuberculous myelitis. The most common presenting symptoms were fever (70%) and paraplegia (60%). Bladder and bowel symptoms were present in 90% patients. On MRI, the involvement of the cervical/thoracic segment of the spinal cord was most commonly seen (90%). The most consistent finding was hyperintense signals on T2-weighted MRI. T1-weighted images showed isointense (n= 5) and hypointense (n= 4) signals in the spinal cord lesions. Post-contrast enhancement was present in 6 patients, epidural enhancement in 4 patients, and cord swelling in 2 patients. We reviewed more than 250 published cases with the diagnosis of tuberculous myelitis and radiculomyelitis with special attention to MRI findings. It is predominantly a disease of the thoracic spinal cord. Most spinal cord lesions appear as hyperintense on T2 and iso- or hypointense on T1-weighted images. MRI findings in patients with spinal cord tuberculosis have both diagnostic and prognostic significance. Cord atrophy or cavitation and the presence of syrinx on MRI may be associated with poor outcome.     

Spinal dural arteriovenous fistulae: exacerbation after myelography with metrizamide

Metrizamide dorsal myelography was performed in two patients with minor to moderate sensorimotor paraparesis. Direct and indirect myelographic signs of spinal arteriovenous aneurysm were seen and spinal cord angiography showed thoracic dural arteriovenous fistulae (AVF) in both cases. Within 24 hours following myelography, clear neurological worsening occurred, associated with cephalalgia, nausea and transient diplopia in one case, leading to paraplegia in a few days. Paraplegia was complete six months after surgery in one case, and had resolved after embolization of fistula in the other patient. The mechanism of neurological worsening may include: substraction of cerebrospinal fluid, sitting position during and after myelography and local increase of metrizamide concentration secondary to impaired resorption caused by the fistula. Water-soluble myelography is of invaluable aid in the diagnosis of dural AVF and must be followed by early angiography, thus allowing prompt therapeutic embolization.     

Clinical study of spinal dural arteriovenous fistula-with special reference to neurological symptoms and magnetic resonance imaging]

We have evaluated the backgrounds, neurological symptoms, signs, and magnetic resonance images (MRI) in six cases of spinal dural arteriovenous fistula. The subjects were 2 males and 4 females, and the mean age was 67.2 years old. The cardinal subjective symptoms were progressive motor weakness of lower extremities (2 cases), paroxyomal weakness of lower extremities (3 cases), sensory disturbance of polyneuritic type (2 cases), and intermittent claudication (1 case). Administration of beverages and drugs, which might include vasodilators and taking baths, worsened the symptoms and signs in 3 cases and 2 cases respectively. Concerning to MRI findings, high signal intensities or swellings were observed at mid-thoracic area to upper conus of the spinal cord in all cases. These changes, which would be induced by edema caused by high venous pressure, were especially prominent in the central area of the cords. By these mechanisms, sensory disturbance like polyneuritic type caused by the disturbance in deep areas of posterior columns might more prominent than the disorder of spinothalamic tracts placed in superficial areas of cord in the early stage of the disease. These abnormal intensities of MRI were higher than the level of clinical symptoms and signs. The difference was about 6.5 segments. For this reason, the upper border of the spinal cord lesions could not be identified by the neurological symptoms. Although the clinical features and MRI findings are relatively characteristic, flow void signs by high resonance MRI and abnormal blood vessels by spinal angiography will be necessary to diagnose this disease confidently.     

Spinal extradural arteriovenous fistulas with retrograde intradural venous drainage: Diagnostic features in digital subtraction angiography and time-resolved magnetic resonance angiography

Spinal extradural arteriovenous fistulas (AVFs) may be more difficult to prospectively identify than dural AVFs because they are less common than dural AVFs. The primary purpose was to further characterize the diagnostic imaging of spinal extradural AVFs with intradural retrograde venous drainage. The magnetic resonance (MR) imaging and angiographic results of 23 patients with suspected spinal dural AVFs were analyzed in order to distinguish dural and extradural AVFs. The diagnostic accuracy of MR angiography was retrospectively compared between dural and extradural AVFs. All 23 patients showed high intensity in the spinal cord on T2-weighted MR images. Eighteen out of 23 patients were diagnosed with dural AVFs, while the remaining 5 were diagnosed with extradural AVFs by angiography. Extradural AVFs were fed by a branch of the segmental artery to the vertebral body, characterized by a fistula located in the ventral extradural space, and drained retrogradely via an epidural venous pouch into intradural veins. The segmental artery was localized within 1 vertebral level using MRA in 12 out of 18 patients (67%) with dural AVFs and in 1 out of 5 patients (20%) with extradural AVFs (p = 0.09). The reasons behind the lower accuracy was mainly the image misinterpretation. Congestion of the spinal cord in spinal extradural AVFs with intradural retrograde venous drainage was similar to that in dural AVFs, whereas its angioarchitecture differed from that of dural AVFs. A clearer understanding of the imaging features of extradural AVFs is important for improving the diagnostic accuracy and clarifying treatment targets.     

Symptomatic venous congestion of the brain stem after embolization for dural fistula of the cavernous sinus

We report the case of a 60-year old woman presenting, 3 days after arterial embolization of a dural arteriovenous fistula, with diplopia and gait disturbance in relation with right oculomotor nerve palsy and cerebellar dysfunction. On T2 weighted MR images, several hyperintense areas appeared in the pons and the midbrain. After one month, clinical symptoms and diffuse hyperintense areas resolved spontaneously, as the patient was treated by anti-vitamin K. This complication probably corresponds to reversible pontine venous congestion caused by poor venous drainage of the dural arteriovenous fistula.     

Abnormal somatosensory evoked potentials indicate compressive cervical myelopathy in mucopolysaccharidoses

Compressive myelopathy at the cranio-cervical junction is a complication of mucopolysaccharidoses (MPS). To detect cervical myelopathy we recorded median and posterior tibial nerve SEPs in 15 patients aged 2.4-33.4 years (median 8.8 years) with MPS I-S (n = 3), MPS IVA (n = 8) and MPS VI (n = 4). In addition to the cortical waveforms we recorded the subcortical median nerve SEPs N13b and P13 generated near the cranio-cervical junction and the lemniscal P30 after posterior tibial nerve stimulation. MRI studies in 13 subjects revealed spinal cord compression at the cranio-cervical junction in 10 patients; 5 patients had an increased signal intensity on the T2-weighted initial MRI indicating high cervical myelomalacia and 4 patients had clinical signs of cervical myelopathy. We did not find a relationship between the SEPs and spinal cord compression. Abnormal SEPs were found in the patients with MRI evidence of myelomalacia (sensitivity 1.0, specificity 1.0) and correspondingly in the patients with clinical signs (sensitivity 1.0, specificity 0.91). The SEPs consequently deteriorated in 2 subjects of 7.3 and 10.3 years of age. Abnormal SEPs indicated subclinical cervical myelopathy in 3 subjects. Cervical cord compression may be present before occurrence of clinical or electrophysiological evidence of myelopathy. However, we feel that the SEP analysis is useful to detect functional impairment of the cervical cord in patients with MPS.     

Surgical treatment of spinal dural arteriovenous fistulas

Increased understanding of the epidemiology, pathophysiology, and anatomy of vascular lesions affecting the spinal cord over the past 2 decades has permitted identification of subdivisions based on distinct biological features. The dural arteriovenous fistula (AVF) is the most common type of spinal vascular malformation and the most amenable to treatment. Venous congestion, the cause of myelopathy in these lesions, is effectively treated by interruption of the medullary vein as it enters the subarachnoid space between the dural nidus and the coronal venous plexus. Embolization of an untreated dural AVF in an acutely deteriorating patient stabilizes the neurological deficit and provides adequate time for definitive surgical treatment. The outcome after treatment of dural AVFs depends not only on the type and location of the lesion but also on the preoperative neurologic function. Patients who are ambulatory before treatment are usually ambulatory after treatment. Optimal outcome depends on early diagnosis and intervention.