The purposes of this study were to review historical changes in the classification of spinal arteriovenous (AV) shunts and to propose a practical classification system. The associated literature ...regarding the classification of spinal AV shunts was reviewed in the angiography era between 1967 and 2015. The classification systems of spinal AV shunts and a proposed classification system were presented with neuroradiological imaging and medical illustrations. There have been seven major classification systems based on the evolution of diagnostic methods as well as treatments for spinal AV shunts: the first description of spinal AV shunts diagnosed and classified using spinal angiography in 1971; the second classification based on a case report of intradural direct perimedullary arteriovenous fistulas (AVFs) treated by microsurgery in 1987; the third classification based on a case series of intradural perimedullary AVFs treated by endovascular interventions in 1993; the fourth and fifth classification systems based on a case series of spinal AVFs and arteriovenous malformations (AVMs) treated by microsurgery or endovascular interventions in 2002; the sixth classification based on a case series of cranio-spinal dural AV shunts in 2009; and the seventh classification based on a case series of extradural AVFs treated by microsurgery and endovascular interventions in 2011. Based on historical reports, the author proposed a classification system according to the sites (dural, intradural, and extradural) and types (AVF and AVM) of AV shunts. By learning the historical background, we may obtain a clearer understanding of the complex and confusing classification system of spinal AV shunts.
Background : Spinal dural arteriovenous fistulas (DAVFs) are rare and can cause gait and micturition disturbances as well as paresthesias of lower extremities. Misdiagnosis may result in poor ...clinical outcomes. Methods : Fifty patients treated at the Tokyo Metropolitan Neurological Hospital were retrospectively analyzed. Results : Forty patients (80%) initially received misdiagnosis. At the initial hospital, most patients who underwent thoracic MRI were diagnosed correctly as spinal DAVFs, whereas most patients who underwent lumbar MRI received misdiagnosis such as lumbar stenosis, although they showed thoracic myelopathy, epiconus syndrome, and conus medullaris syndrome. Patients with delayed diagnosis of spinal DAVFs resulted in high rates of additional disability. Conclusion : When common lumbar stenosis fails to explain the symptoms, the possibility of spinal DAVFs should be considered, and thoracic MRI should be performed to confirm the diagnosis.
Objective
Superficial siderosis of the central nervous system is a rare intractable disease induced by chronic subarachnoid hemorrhage. Neurological deficits, such as cerebellar ataxia and hearing ...difficulties, gradually progress if left undiagnosed. Hemosiderin deposition is irreversible because standard medical treatment has not yet been established. Interventions at the source of bleeding may be the key to a preferable outcome of treatment for chronic subarachnoid hemorrhage; however, the source is not clear in many cases.
Methods
Among the consecutive cases diagnosed with a spontaneous cerebrospinal fluid (CSF) leak, cases of superficial siderosis associated with a CSF leak due to a ventral dural defect were retrospectively analyzed.
Results
Among 77 cases of a CSF leak, 7 cases (9%) of superficial siderosis were identified (median age of 59 years, male, 4 cases). Defects were diagnosed on 1-mm sliced fast imaging employing steady-state acquisition MRI (
n
= 5), conventional myelographic CT (
n
= 1), or dynamic myelographic CT (
n
= 1) at high thoracic levels (T1–T4). All defects were repaired by direct neurosurgery. During surgery, continuous bleeding from the epidural veins of the internal vertebral venous plexus was identified as the source of subarachnoid hemorrhage. Epidural CSF pulsations through the defect prevented clot formation by the epidural veins. Dural repair stopped free communication between the subarachnoid and epidural spaces, leading to the disappearance of chronic subarachnoid hemorrhage.
Conclusion
Bleeding from the epidural venous plexus may be the cause of superficial siderosis associated with ventral dural defects. Neurosurgical repair may stop the progression of this condition.
Spinal dural arteriovenous fistulas (DAVFs) are rare but can cause serious gait and micturition disturbances. Delays in diagnosis and treatment result in poor clinical outcomes; however, the process ...of misdiagnosis is unknown.
Forty consecutive patients were retrospectively analyzed.
Thirty-one patients (78%) were initially misdiagnosed with lumbar spinal stenosis or other diseases, mostly by orthopedic surgeons, even though most patients (85%) had specific symptoms or characteristic neuroimaging findings of spinal DAVFs: they often presented with spastic gait (thoracic myelopathy), progressive ascending numbness that begins in the distal lower extremities (epicous syndrome), and urinary tract symptoms (conus medullaris syndrome); initial lumbar MRI showed T2 signal change in the conus medullaris and vascular flow voids around the cord. The median time from onset to treatment was longer in patients with a misdiagnosis than in those with the correct diagnosis (11 vs 4 months). In all patients, the fistula was completely obliterated by the direct microsurgical procedure; however, patients with a misdiagnosis had developed additional disabilities by the time a correct diagnosis was made (Aminoff-Logue gait grade of 3.6 ± 1.4 vs 2.1 ± 1.5 p = 0.013), and achieved markedly smaller improvements after the treatment (Aminoff-Logue gait grade of 3.0 ± 1.6 vs 1.1 ± 1.5, p = 0.006) than those with the correct diagnosis of spinal DAVFs.
When common spinal stenosis fail to explain the symptoms such as thoracic myelopathy, epiconus syndrome, and conus medullaris syndrome, the possibility of spinal DAVFs should be considered. If lumbar MRI shows conus medullaris lesions, thoracic MRI should be performed to confirm the diagnosis.
Objective: The purpose of this study was to provide an update on recent developments in the diagnosis and treatment of arteriovenous fistulas at the craniocervical junction (CCJ AVFs).Methods: ...Associated literature published between 2009 and 2018 on the PubMed database was reviewed.Results: The systematic review identified 97 lesions in 92 cases of CCJ AVFs. These lesions were divided into three groups according to their angioarchitecture: 56 lesions of dural AVFs, 34 of intradural AVFs, and 7 of extradural AVFs. Clinical features, neuroimaging findings, treatments, and outcomes were compared among the three groups. Cases of dural AVFs were commonly associated with myelopathy and/or brainstem dysfunction due to venous congestion in the spinal cord (38%) and/or brainstem (21%). Cases of intradural AVFs had a more complex angioarchitecture than those of dural AVFs and were associated with a hemorrhagic presentation (83%). Of the 34 intradural AVFs, 25 lesions (74%) had a feeder aneurysm (n = 20) or varix (n = 5). The development of the aneurysm/varix may be attributed to hemodynamic and flow-related phenomena. The surgical obliteration of the intradural drainer and/or feeder was effective in most cases of dural and intradural AVFs. Endovascular embolization may be more effective in cases of extradural AVFs than in those of dural or intradural AVFs. No permanent neurologic complications occurred in 80 cases treated by surgery; however, brain infarction occurred in 2 (9%) of 22 cases treated by endovascular embolization. Good recovery was more frequently achieved in cases of intradural (79%) and extradural AVFs (100%) than in those of dural AVFs (61%) because cases with hemorrhagic presentation had fewer permanent neurologic deficits than those with venous congestion.Conclusion: A differential diagnosis among dural, intradural, and extradural AVFs is important because clinical features, neuroimaging findings, and treatment outcomes markedly differ among the three groups.
The purpose of this study is to compare the angiographic and clinical characteristics of spinal epidural arteriovenous fistulas (SEAVFs) and spinal dural arteriovenous fistulas (SDAVFs) of the ...thoracolumbar spine.
A total of 168 cases diagnosed as spinal dural or extradural arteriovenous fistulas of the thoracolumbar spine were collected from 31 centers. Angiography and clinical findings, including symptoms, sex, and history of spinal surgery/trauma, were retrospectively reviewed. Angiographic images were evaluated, with a special interest in spinal levels, feeders, shunt points, a shunted epidural pouch and its location, and drainage pattern, by 6 readers to reach a consensus.
The consensus diagnoses by the 6 readers were SDAVFs in 108 cases, SEAVFs in 59 cases, and paravertebral arteriovenous fistulas in 1 case. Twenty-nine of 59 cases (49%) of SEAVFs were incorrectly diagnosed as SDAVFs at the individual centers. The thoracic spine was involved in SDAVFs (87%) more often than SEAVFs (17%). Both types of arteriovenous fistulas were predominant in men (82% and 73%) and frequently showed progressive myelopathy (97% and 92%). A history of spinal injury/surgery was more frequently found in SEAVFs (36%) than in SDAVFs (12%;
=0.001). The shunt points of SDAVFs were medial to the medial interpedicle line in 77%, suggesting that SDAVFs commonly shunt to the bridging vein. All SEAVFs formed an epidural shunted pouch, which was frequently located in the ventral epidural space (88%) and drained into the perimedullary vein (75%), the paravertebral veins (10%), or both (15%).
SDAVFs and SEAVFs showed similar symptoms and male predominance. SDAVFs frequently involve the thoracic spine and shunt into the bridging vein. SEAVFs frequently involve the lumbar spine and form a shunted pouch in the ventral epidural space draining into the perimedullary vein.
There is currently no consensus regarding surgical indications for symptomatic sacral perineural cysts.
Nine patients with symptomatic sacral perineural cysts underwent microsurgery. All patients ...fulfilled the following criteria: (1) cyst sizes larger than 15 mm; (2) cysts show the “delayed inflow” and/or “delayed outflow” of contrast on myelographic computed tomography (CT), and (3) neurological symptoms correlate with the primary cyst.
On myelographic CT, all primary cysts showed the “delayed inflow” of contrast; the average cyst/thecal sac Hounsfield units (HU) ratio was 0.17. In 7 patients, the primary cyst showed “delayed outflow”; the average cyst/thecal sac HU ratio increased to 3.12 on images obtained 24 hours after contrast injection.
Regarding the modified Rankin Scale, 67% of patients reported that their overall symptoms improved to normal activities after surgery. The most improved symptom was coccydynia (75% improvement, P = 0.017), followed by leg radiation pain (67% improvement, P = 0.027) and buttock pain (50% improvement, P = 0.068). Bowel/bladder dysfunction improved in 100% of patients, but newly developed in 1 patient (P = 0.32). Perineal pain only decreased in 33% (P = 0.41).
To the best of our knowledge, this is the first study to have performed a quantitative analysis of the dynamics of cerebrospinal fluid in sacral perineural cysts using myelographic CT. Sixty-seven percent of patients benefited from surgery; however, our criteria may not be a necessary and sufficient condition for patient selection because 33% did not respond to surgery despite the successful elimination of the check-valve.
The purpose of this study was to describe significant CT myelography findings for determination of the leak site and outcome of targeted epidural blood patch (EBP) in patients with spontaneous CSF ...leaks.
During 2005-2013, spontaneous CSF leaks were diagnosed for 12 patients with orthostatic headaches. The patients received targeted EBP on the basis of CT myelography assessments.
Computed tomography myelograms revealed ventral extradural collection of contrast medium distributed over multiple spinal levels (average 16 levels). Intraforaminal contrast medium extravasations were observed at multiple spinal levels (average 8.2 levels). For 8 (67%) of 12 patients, spinal lesions were noted around the thecal sac and included calcified discs with osteophytes, an ossified posterior longitudinal ligament, and an ossified yellow ligament; lesions were mostly located ventral to the thecal sac and were in close contact with the dura mater. The levels of these spinal lesions were considered potential leak sites and were targeted for EBP. For the remaining 4 patients who did not have definite spinal lesions around the thecal sac, leak site determination was based primarily on the contrast gradient hypothesis. The authors hypothesized that the concentration of extradural contrast medium would be the greatest and the same as that of intradural contrast medium at the leak site but that it would decrease with increased distance from the leak site according to the contrast gradient. Epidural blood patch was placed at the level of spinal lesions and/or of the greatest and same concentration of contrast medium between the intradural and extradural spaces. For 10 of the 12 patients, the orthostatic headaches decreased significantly within a week of EBP and disappeared within a month. For the remaining 2 patients, headaches persisted and medical treatment was required for several months. For 3 patients, thick chronic subdural hematomas caused severe headaches and/or disturbed consciousness because of the mass effect of the hematomas, which were removed by bur hole drainage surgery. For 1 patient, bur hole drainage before EBP on the day of admission to hospital resulted in subdural tension pneumocephalus. The patient's headache immediately disappeared after EBP, and the hematoma did not recur. The other 2 patients underwent EBP followed by bur hole drainage, which resulted in improvements and disappearance of the hematomas. Over the follow-up period (mean 39 months), no CSF leaks or chronic subdural hematomas had recurred in any patient after EBP; by the final follow-up visit, all patients had returned to their jobs.
The most significant finding of this study was that spinal ventral calcified or ossified lesions, which may be associated with a dural tear, were present in approximately 70% of patients. Targeted EBP to these lesions resulted in good outcomes.
Craniocervical junction (CCJ) arteriovenous fistulas (AVFs) are treated using neurosurgical or endovascular options; however, there is still no consensus on the safest and most effective treatment. ...The present study compared the treatment results of neurosurgical and endovascular procedures for CCJ AVFs, specifically regarding retreatment, complications, and outcomes.
This was a multicenter cohort study authorized by the Neurospinal Society of Japan. Data on consecutive patients with CCJ AVFs who underwent neurosurgical or endovascular treatment between 2009 and 2019 at 29 centers were analyzed. The primary endpoint was the retreatment rate by procedure. Secondary endpoints were the overall complication rate, the ischemic complication rate, the mortality rate, posttreatment changes in the neurological status, independent risk factors for retreatment, and poor outcomes.
Ninety-seven patients underwent neurosurgical (78 patients) or endovascular (19 patients) treatment. Retreatment rates were 2.6% (2/78 patients) in the neurosurgery group and 63% (12/19 patients) in the endovascular group (p < 0.001). Overall complication rates were 22% and 42% in the neurosurgery and endovascular groups, respectively (p = 0.084). Ischemic complication rates were 7.7% and 26% in the neurosurgery and endovascular groups, respectively (p = 0.037). Ischemic complications included 8 spinal infarctions, 2 brainstem infarctions, and 1 cerebellar infarction, which resulted in permanent neurological deficits. Mortality rates were 2.6% and 0% in the neurosurgery and endovascular groups, respectively (p > 0.99). Two patients died of systemic complications. The percentages of patients with improved modified Rankin Scale (mRS) scores were 60% and 37% in the neurosurgery and endovascular groups, respectively, with a median follow-up of 23 months (p = 0.043). Multivariate analysis identified endovascular treatment as an independent risk factor associated with retreatment (OR 54, 95% CI 9.9-300; p < 0.001). Independent risk factors associated with poor outcomes (a postoperative mRS score of 3 or greater) were a pretreatment mRS score of 3 or greater (OR 13, 95% CI 2.7-62; p = 0.001) and complications (OR 5.8; 95% CI 1.3-26; p = 0.020).
Neurosurgical treatment was more effective and safer than endovascular treatment for patients with CCJ AVFs because of lower retreatment and ischemic complication rates and better outcomes.
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