Clinical Outcomes of Patients with Delayed Diagnosis of Spinal Dural Arteriovenous Fistulas

Laboratory parameters as diagnostic indicators in venous hypertensive myelopathy

BACKGROUND CONTEXT

Venous hypertension is a rare cause of myelopathy that can be misdiagnosed as myelitis and be worsened by glucocorticosteroids.

PURPOSE

This study is aims to identify a fluid biomarker with diagnostic value in Venous Hypertensive Myelopathy (VHM).

STUDY DESIGN

a retrospective diagnostic study.

PATIENT SAMPLE

The patients diagnosed as having myelopathy between December 2020 and June 2022 were divided into a VHM group (n=71) and an inflammatory myelopathy (IM) group (n=123). A noninflammatory neurological disorders (NIND) group (n=53) was also acquired as baseline control.

OUTCOME MEASURES

The primary outcome was the diagnostic accuracy of the fluid biomarkers in the VHM and IM groups.

METHODS

The albumin, immunoglobulins, oligoclonal bands, neuron-specific enolase, myelin basic protein, and S100β were measured in their cerebrospinal fluid (CSF) and paired serum samples. Potential diagnostic biomarkers were screened through univariate and collinearity analyses. The diagnostic performance of these biomarkers was assessed by plotting the receiver-operating characteristic curves. Additionally, the predictive value of clinical factors and biomarkers for diagnosis was evaluated using multivariable logistic regression analysis.

RESULTS

The quantitative and normalized CSF-S100β values were significantly lower in the VHM group (p<.05). Analysis of receiver-operating characteristic curves adjusted for age and sex showed that the normalized CSF-S100β discriminated between VHM and IM (area under the curve (AUC) 0.884, 95% confidence interval [CI] 0.817-0.938). Particularly, it performed well in the AUC for normalized CSF-S100β (AUC 0.9400, 95% CI 0.8621-1.000) when oligoclonal bands and flow-void sign were negative.

CONCLUSIONS

The normalized CSF-S100β can differentiate between VHM and IM.

Surgical management of spinal dural arteriovenous fistulae: systematic review of current practices and open questions

BACKGROUND

Spinal dural arteriovenous fistulae(sDAVF) represent the most common spinal vascular malformation. Therapeutic strategies include both surgical and endovascular approaches. Surgical interruption of the fistula is crucial to prevent the onset and progression of neurological symptoms. Despite a range of surgical techniques, little research has evaluated their relative efficacy. This review aims to summarize the available surgical techniques and identify open questions for future research.

METHODS

A systematic review was conducted on PubMed, Ovid, and Web of Science databases to identify surgically treated cohorts of sDAVF. Five commonly reported surgical steps were analyzed: type of approach, temporary clipping, shunt disruption method, fistulous vein management, and epidural vessel management. In addition, open questions lacking consensus or evidence were identified for pre, intra and postoperative stages.

RESULTS

63 of 115 analyzed cohorts described surgical techniques. The most commonly used approach was single-level laminectomy (52.4%). Temporary clipping was used in 11.1% of cases, while 15.9% of studies reported excision of intradural arterialized veins. There was wide variation in the methods used to close the fistula, with the most frequent being coagulation alone (27.5%). The management of epidural vessels was reported in 11.1% of studies. Sixteen major open questions were identified with a wide variety of technical nuances.

DISCUSSION

Surgical treatment of sDAVF is not a standardized procedure but rather encompasses significantly different techniques. The lack of controlled trials leaves many questions unanswered, including optimal surgical strategies and the role of adjunct imaging and monitoring techniques. Further research is required to address these gaps and refine treatment protocols.

Vascular Pathologic Conditions in and around the Spinal Cord

Diagnosing and differentiating spinal vascular pathologic conditions is challenging. Small structures, lengthy imaging examinations, and overlapping imaging features increase the difficulty. Yet, subtle findings and helpful protocols can narrow the differential diagnosis. The authors aim to help radiologists make accurate and timely diagnoses of spinal vascular pathologic conditions in and around the spinal cord by highlighting spinal vascular anatomy, imaging findings, and three broad categories of abnormalities: infarcts, anomalies, and tumors. ©RSNA, 2024.

'Pressure cooker' and 'balloon pressure' techniques significantly increase 3-month complete occlusion rate after spinal arteriovenous fistula embolization as compared to glue: single center evaluation on 38 consecutive patients

BACKGROUND

Spinal arteriovenous fistulas can be treated either by surgery or by endovascular means, using different strategies. The main drawback of embolization is the risk of recurrence. Our objective is to evaluate the angiographic occlusion rate and the predictive factors of angiographic cure of spinal arteriovenous fistulas at 3 months or more after embolization.

METHODS

This is a retrospective single-center study including 38 consecutive patients with spinal arteriovenous fistulas treated by embolization as first-line treatment. We reviewed clinical and imaging data, complications, and the immediate angiographic occlusion rate of the fistulas, and at 3 months or more after the embolization.

RESULTS

A total of 45 embolization procedures were performed: 30 procedures using glue, 15 using Onyx by 'pressure cooker' or 'balloon pressure' techniques. We observed no statistically significant difference between the two groups concerning the immediate angiographic occlusion rate (87% in both groups; P>0.9), as well as for periprocedural complication rates. The angiographic occlusion rate at 3 months or more was higher in the Onyx 'combined' techniques treated group (87% vs 40%, P=0.007). The use of Onyx 'combined' techniques was independently associated with angiographic cure at 3 months after embolization (P=0.029). No other factors were identified as predictive of angiographic cure and clinical recovery after embolization procedures, nor were any predictive factors identified for the occurrence of periprocedural complications.

CONCLUSION

Embolization of spinal arteriovenous fistulas with Onyx using 'combined' techniques appears to be safe and associated with a higher rate of angiographic occlusion at 3 months than regular embolization with glue.

Risk factors for postoperative late deterioration in patients with spinal dural arteriovenous fistulas

Background

Approximately 86% of patients with spinal dural arteriovenous fistulas (SDVAFs) exhibit clinical improvement after surgery. However, 12%-55.8% of these patients experience late deterioration (LD) after an initial period of improvement. The risk factors for LD remain unclear. The aim of this study was to explore the risk factors for LD in SDVAF patients.

Methods

The clinical data of patients who were admitted to two tertiary hospitals between June 2014 and May 2022 were reviewed. Patients were divided into two groups: the LD group and the no LD group. The severity of neurological dysfunction (NDF) was evaluated using the Modified Aminoff and Logue Scale. Univariable and multivariable Cox regression analyses were performed.

Results

A total of 105 eligible patients were enrolled, with a mean age of 57.55 ± 9.42 years. The LD group comprised 37 individuals, while the no LD group consisted of 68 individuals. According to the univariable analysis, preoperative NDF severity and treatment strategy were associated with the risk of LD. According to the multivariable analysis, patients who underwent microsurgery (MS) had a lower risk of LD than did those who underwent endovascular treatment (EVT; HR 0.197, 95% CI 0.085-0.457), and patients with severe NDF had a higher risk of LD than did those with mild NDF (HR 3.604, 95% CI 1.226-10.588), whereas the risk of LD in patients with moderate NDF was similar to that of patients with mild NDF (HR 1.352, 95% CI 0.519-3.524).

Conclusion

EVT and severe preoperative NDF are independent risk factors for LD.

An Update on Spinal Dural Arteriovenous Fistulae: Case Series and Systematic Review

Spinal dural arteriovenous fistulae (sDAVFs) are rare entities with delayed diagnosis, potentially dramatic clinical manifestations, and complex management. We aim to present our mini case series and perform an updated systematic review of the usual patient profile, to search for established prognostic factors, to compare the effectiveness and safety of surgical and endovascular intervention, and to discuss trends in therapeutic strategy. We retrospectively collected data from patients treated in our department in the last decade (2014-2024) and we systematically reviewed the literature according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria and searched the PubMed database for relevant articles published in the same period. Epidemiologic data, imaging modalities, prognostic factors, and treatment modalities were assessed. Firstly, we identified four illustrative cases from our institution. In addition, our search yielded 559 studies and our review included 82 original studies. 3130 patients were identified (mean age 61; male-to-female ratio 3:1). Most commonly, the fistula level was in the thoracic spine (65%). Surgery was provided to 1837 patients (1213 as primary treatment) and embolism to 1085 (932 as primary treatment). Initial fistula occlusion rate and recurrence rate were 98.1% and 1.9% for surgery and 71.1% and 9.6% for embolism, respectively. No difference between the two modalities with respect to clinical outcome was observed. SDAVFs remain a challenge for neurosurgeons concerning both diagnosis and management. Surgery remains superior to embolism with respect to success as an initial treatment. Embolism can be offered if certain contraindications do not coexist. All symptomatic patients should be offered treatment, whereas asymptomatic patients could be conservatively managed only if the close patient follow-up can be secured.

Specific electromyography characteristics can distinguish longitudinally extensive transverse myelitis from congestive myelopathy due to spinal dural arteriovenous fistula: a retrospective study

Aims/Background Although electromyography has been extensively used in the diagnosis of neurological diseases, there is no comprehensive understanding of the electromyography manifestations of spinal dural arteriovenous fistula. Given the widespread use of electromyography in the diagnosis of neurological conditions, it is worthwhile to holistically analyse the electromyography findings of spinal dural arteriovenous fistula to differentiate it from neurological diseases that share similar clinical manifestations. The aim of this study is to evaluate whether electromyography can distinguish spinal dural arteriovenous fistula from longitudinally extensive transverse myelitis. Methods We holistically reviewed files of all patients who were diagnosed with spinal dural arteriovenous fistula or longitudinally extensive transverse myelitis at The First Medical Centre of PLA General Hospital from 1 January 2010 to 31 December 2020. We compared the symptomology, epidemiology, and imaging results of patients with spinal dural arteriovenous fistula and longitudinally extensive transverse myelitis, placing emphasis on their electromyography manifestations. Student's t test was used to analyse normally distributed data, while Chi-square test was used to compare classification statistics. Results Lesions of spinal dural arteriovenous fistula shown on images tend to appear at lower lumbar and sacral segments, whereas lesions of the cervical and upper thoracic segments are more characteristic of longitudinally extensive transverse myelitis. Spinal dural arteriovenous fistula patients and longitudinally extensive transverse myelitis patients overlap in terms of clinical manifestations. After comparison, the two groups of patients had different demographics (age, sex), onset mode, predisposing factors before onset, and electromyographic features. The electromyographic features of patients with spinal dural arteriovenous fistula were associated with neurogenic damage (p < 0.001). Conclusions In patients with spinal dural arteriovenous fistula, electromyography can help clinicians to identify early disease, avoid patient treatment delay, and eliminate unnecessary treatment.

A Case Report of Spinal Arteriovenous Fistula: Vague Presentation and Successful Outcome

Spinal arteriovenous fistula (spinal AVF) malformation is one of the rare spinal vascular diseases. Its presentation could be misleading as the patient presents with spinal cord dysfunction, including motor power loss.  Early detection is essential and requires a high suspicion by the providing physician so the patient can be rightfully directed to the proper team with vascular intervention resources. Efficient management leads to promising outcomes with patient recovery. We are presenting a case with progressing motor and sensory neurological deficits that had a vague clinical course. After a prompt diagnosis of spinal AVF, the patient was referred to the neuro-vascular specialist, who performed an embolization of the spinal AVF. The patient had an excellent outcome and was discharged to a rehabilitation facility.

Knowledge, attitudes and practices regarding spinal vascular malformations among doctors in China: a cross-sectional study

OBJECTIVE

Knowledge, attitude and practice (KAP) models are essential tools for assessing healthcare professionals' understanding, beliefs and behaviours towards specific health issues. This study aimed to explore the KAP of Chinese doctors in diagnosing and treating spinal vascular malformations (SVM).

DESIGN

A web-based cross-sectional survey.

SETTING

This study was conducted between October and December 2022 through a self-administered questionnaire.

PARTICIPANTS

Participants include full-time doctors who voluntarily participate. Doctors in advanced training, regular training or internships were excluded.

PRIMARY AND SECONDARY OUTCOME MEASURES

The KAP scores of Chinese doctors in diagnosing and treating SVM measured by the questionnaire.

RESULTS

A total of 517 doctors participated in the study, mostly in Shaanxi, China, working in SVM-relevant departments (n=396) or other departments (n=121). The doctors achieved an average knowledge score of 9.66±1.95 (range: 0-12), attitude score of 22.16±1.71 (range: 6-30) and practice scores of 46.13±5.35 for those in SVM-relevant departments (neurosurgery, orthopaedics and neurology) and 8.50±1.25 for those in other departments, respectively, revealing doctors have adequate knowledge, positive attitude and good practice, and those in SVM-relevant departments showing more adeptness compared with those in other departments. Moreover, multivariate logistic regression analysis showed that knowledge about SVM (OR=1.72, 95% CI 1.11 to 2.65, p=0.015), holding a master's degree (OR=1.85, 95% CI 1.14 to 3.00, p=0.013) and working in orthopaedics (OR=0.34, 95% CI 0.13 to 0.88, p=0.026) were independently associated with good attitude.

CONCLUSION

Chinese doctors showed adequate knowledge, moderate attitudes and good practice regarding SVM. A continuing education programme may improve clinical practitioners' ability to manage SVM.

Delayed Diagnosis of Spinal Dural Arteriovenous Fistula: A Case Report and Scoping Review

Spinal dural arteriovenous fistula (SDAVF) is among the most common arterial shunt diseases typically found in middle aged or older men. Herein, we aimed to clarify the reasons for misdiagnoses and delayed diagnoses of SDAVF, determine how these affect prognoses, and establish how they can be prevented. We conducted a PubMed/MEDLINE literature search using "spinal dural arteriovenous fistula", "delayed diagnosis", "late diagnosis", and "misdiagnosis" terms. We identified 18 articles, including 965 SDAVF cases. Patients were predominantly males (71.8-100.0%) (mean age: 53.5-71.0 years). Misdiagnoses rates varied (17.5-100.0%) and encompassed many conditions. The mean time between early manifestations and confirmed diagnosis was approximately 10-15 months and from the first radiologic image revealing dural arteriovenous fistula (DAVF) features to diagnosis was 9.2-20.7 months. Posttreatment outcomes showed a significant improvement in motor functions, gait, and micturition, particularly in patients exhibiting preoperative symptoms over a short period. SDAVF is frequently misdiagnosed or subject to delayed diagnosis, causing poor clinical outcomes. SDAVF symptoms including progressive lower-limb weakness, paresthesia, and vesicorectal dysfunction are indications for spinal magnetic resonance imaging with subsequent spinal angiography, wherein DAVF is evidenced by extensive T2 hyperintensity and flow-void abnormalities. We reported a representative case with delayed diagnosis.

Usefulness of time-resolved MR angiography in spinal dural arteriovenous fistula (SDAVF)-a systematic review and meta-analysis

Spinal dural arteriovenous fistulas (SDAVFs) constitute the most common type of spinal vascular malformations. Their diagnosis requires spinal digital subtraction angiography (DSA), which is time-consuming, requires catheterizing many vessels, and exposes patient to a high radiation and contrast doses. This study aims to evaluate the usefulness of time-resolved MR angiography (TR-MRA) in SDAVF diagnosis. We performed a systematic review of the PubMed and EMBASE databases followed by a meta-analysis. TR-MRA was an index test, and spinal DSA was a reference. Of the initial 324 records, we included 4 studies describing 71 patients with SDAVFs. In 42 cases, TR-MRA was true positive, and in 21 cases, it was true negative. We found 7 false-positive cases and 1 false negative. TR-MRA allowed for shunt level identification in 39 cases. Of these, the predicted level was correct in 23 cases (59%), to within 1 level in 38 cases (97.4%) and to within 2 levels in 39 cases (100%). The diagnostic odds ratio was 72.73 (95% CI [10.30; 513.35]), z = 4.30, p value < 0.0001. The pooled sensitivity was 0.98 (95% CI [0.64; 1.00]), and the pooled specificity was 0.79 (95% CI [0.10; 0.99]). The AUC of the SROC curve was 0.9. TR-MRA may serve as a preliminary study to detect SDAVFs and localize the shunt level with sensitivity and specificity as high as 98% and 79%, respectively. Unless the TR-MRA result is unequivocal, it should be followed by a limited spinal DSA.

Vascular Myelopathies

There are many vascular disorders that can affect the spinal cord, and their prevalence and etiology are highly influenced by age, sex, and risk factors. This article reviews the embryology and anatomy of the spinal cord, as well as several vascular conditions, describing their clinical and imaging presentation, emphasizing the different imaging modalities' contributions to increasing specificity and better defining the most appropriate therapy strategy for improving the patient's prognosis.

Spinal Dorsal Intradural Arteriovenous Fistulas: Natural History, Imaging, and Management

In this review, we describe the pathophysiology, diagnosis, and treatment of spinal dorsal intradural arteriovenous fistulas (DI-AVFs), focusing on novel research areas. DI-AVFs compose the most common subgroup of spinal arteriovenous lesions and most commonly involve the thoracic spine, followed by lumbar and sacral segments. The pathogenesis underlying DI-AVFs is an area of emerging understanding, thought to be attributable to venous congestion and hypertension that precipitate ascending myelopathy. Patients with DI-AVFs typically present with motor, sensory, or urinary dysfunction, although a wide swath of other less common symptoms has been reported. DI-AVFs can be subdivided by spinal region, which in turn is associated with 4 distinct clinical phenotypes: craniocervical junction (CCJ), subaxial cervical, thoracic, and lumbosacral. Patients with CCJ and lumbosacral DI-AVFs have particularly interesting presentations and treatment considerations. High-value diagnostic findings on MRI include flow voids, missing-piece sign, and T2-weighted intramedullary hyperintensity. However, digital subtraction angiography is the gold standard for diagnosis and localization of DI-AVFs and for definitive treatment planning. Surgical disconnection of DI-AVFs is almost universally curative and frontline treatment, especially for CCJ and lumbosacral DI-AVFs. Endovascular techniques evolve in promising ways, such as improved visualization, distal access, and liquid embolic techniques. The pathophysiology of DI-AVFs is better understood using newly identified radiologic diagnostic markers. Despite new techniques and devices introduced in the endovascular field, surgery remains the gold-standard treatment for DI-AVFs.

Surgical evolution in spinal dural arteriovenous fistula treatment-a 7 years monocentric experience

Accounting for 70% of all spinal vascular malformations, spinal dural arteriovenous fistulas (SDAVF) are the most common type of malformation. Interruption of the fistulous arterialized vein point is the goal of surgical treatment. The aim of the study was to compare open surgery (laminectomy) versus minimal invasive surgery (MIS) in SDAVF treatment. Between March 2013 and March 2020, we retrospectively collected 21 consecutive adult patients with SDAVF. Since March 2017, MIS has been routinely used for surgical treatment. Pre- and post-operative clinical evaluations used Aminoff-Logue score (ALS). Complication rate was noted. Post-operative occlusion of the malformation was confirmed by digital subtraction angiography (DSA) in all patients. MIS was compared to open surgery in terms of efficacy and complications with statistical evaluation. Standard laminectomy was performed in 12 patients and MIS technique in 9 patients. No difference was noted on pre-operative parameters. ALS and MRI signs of myelopathy were improved in all cases except for 1 patient in each group. All SDAVFs were excluded based on post-operative DSA. Significant differences were noted between the 2 groups in terms of perioperative blood loss (p<0.001), post-operative pain visual analog scale values (p<0.001), and first time out of bed (p<0.001). Wrong level surgery occurred in one patient in each group; patients were re-operated using the same technique. No infection or cerebrospinal fluid (CSF) leak was noted. In our experience, MIS is a safe alternative to open laminectomy for SDAVF treatment. MIS contributes to patient comfort and minimizes blood loss without increasing complication rate.

Our Experience of Eight Patients with Dural Arteriovenous Fistula's at Foramen Magnum with Respect to Presentation, Angioarchitecture, and Endovascular Treatment Outcomes

Background Dural arteriovenous fistulas (DAVFs) around foramen magnum (FM) with peri medullary venous drainage, are uncommon and have wide spectrum of presentation. Literature about this lesion is sparse. We intent to analyze and report our experience with these cases with respect to presentation, evaluation, and endovascular treatment outcomes.

Materials and Methods All the eight patients who were diagnosed with DAVFs at FM and treated with transarterial embolization using ethylene viny alcohol were included in this study. Clinical record sheets, radiological, and angiographic data of these patients were retrieved from our departmental database.

Results Duration of symptoms ranged from 1 day to 3 years. Presentation with progressive ascending sensory symptoms and weakness (N = 4), acute headache (N = 2) acute quadriplegia (N = 1), and right ear bruit (N = 1) was seen. Exclusive feeders from occipital artery (OA) and vertebral artery (VA) were seen in two and four patients, respectively. Dual feeders from a combination of ascending pharyngeal artery and VA; from a combination of OA and VA were seen in one patient each. The exclusive venous drainage to spinal peri medullary veins (N = 3), brain stem peri medullary veins (N = 1), and both combined (N = 4). Two patients had a draining vein aneurysm. Complete obliteration of fistula was achieved in all patients. Complete resolution of symptoms was seen in six patients; two patients had significant improvement.

Conclusion The clinical presentation of dural AVF at foramen magnum is wide ranging and these lesions can be treated effectively and safely by transarterial embolization. Duration of symptoms strongly influences the final patient outcome.

Spinal dural arteriovenous fistula masquerading as a herniated disc: illustrative case

BACKGROUND

Spinal dural arteriovenous fistula (SDAVF) is a rare disorder with an unknown etiology. Often, the clinical presentation and imaging findings are misleading, causing this condition to be mistaken for other entities, such as demyelinating or degenerative spinal lesions.

OBSERVATIONS

The authors report a challenging case of SDAVF in which the patient's symptoms were initially thought to be attributable to a herniated disc based on his imaging studies at another institution. He sought the authors for a second opinion, which yielded a confirmed diagnosis of SDAVF. Due to his rapidly progressive neurological manifestations, he underwent a surgical division of the fistula using intraoperative video angiography via indocyanine green injections. His symptoms progressively improved over a 3-month period. He regained full sphincter control by 4 months, which gave him a better recovery than seen in other patients with SDAVFs, who do not generally fully regain sphincter control.

LESSONS

SDAVF is a critical spinal vascular pathology that should not be overlooked in the differential diagnosis of any patient presenting with signs of progressive myelopathy. Despite its associated vague initial clinical symptoms, SDAVF typically, but not always, demonstrates a characteristic imaging appearance on magnetic resonance (MR) imaging studies; therefore, MR angiography is still required for definitive diagnosis. Surgical treatment for SDAVF is almost always definitive and curative.

Spinal epidural arteriovenous fistula with nerve root enhancement mimicking myeloradiculitis: a case report

BACKGROUND

Gadolinium enhancement of spinal nerve roots on magnetic resonance imaging (MRI) has rarely been reported in spinal dural arteriovenous fistula (SDAVF). Nerve root enhancement and cerebrospinal fluid (CSF) pleocytosis can be deceptive and lead to a misdiagnosis of myeloradiculitis. We report a patient who was initially diagnosed with neurosarcoid myeloradiculitis due to spinal nerve root enhancement, mildly inflammatory cerebrospinal fluid, and pulmonary granulomas, who ultimately was found to have an extensive symptomatic SDAVF.

CASE PRESENTATION

A 52-year-old woman presented with a longitudinally extensive spinal cord lesion with associated gadolinium enhancement of the cord and cauda equina nerve roots, and mild lymphocytic pleocytosis. Pulmonary lymph node biopsy revealed non-caseating granulomas and neurosarcoid myeloradiculitis was suspected. She had rapid and profound clinical deterioration after a single dose of steroids. Further work-up with spinal angiography revealed a thoracic SDAVF, which was surgically ligated leading to clinical improvement.

CONCLUSIONS

This case highlights an unexpected presentation of SDAVF with nerve root enhancement and concurrent pulmonary non-caseating granulomas, leading to an initial misdiagnosis with neurosarcoidosis. Nerve root enhancement has only rarely been described in cases of SDAVF; however, as this case highlights, it is an important consideration in the differential diagnosis of non-inflammatory causes of longitudinally extensive myeloradiculopathy with nerve root enhancement. This point is highly salient due to the importance of avoiding misdiagnosis of SDAVF, as interventions such as steroids or epidural injections used to treat inflammatory or infiltrative mimics may worsen symptoms in SDAVF. We review the presentation, diagnosis, and management of SDAVF as well as a proposed diagnostic approach to differentiating SDAVF from inflammatory myeloradiculitis.

Spinal dural arteriovenous fistula: A rare but treatable disease that should not be missed by orthopedic surgeons

Objective

Spinal dural arteriovenous fistula (SDAVF) is a rare disease that is often misdiagnosed by orthopedic surgeons. We analyzed the reasons for the misdiagnosis and proposed countermeasures.

Methods

Twenty-two SDAVF patients who were initially treated in orthopedics were included. The patients were divided into a correct diagnosis group (A) and a misdiagnosis group (B). The clinical data and prognosis were evaluated.

Results

There were 10 patients in group A and 12 patients in group B. The clinical manifestations included limb numbness, weakness, and bladder and bowel dysfunction. Among these patients without spinal degenerative diseases which had typical magnetic resonance imaging (MRI) features in Group A were more than Group B (P < 0.05). More patients had spinal degenerative diseases in group B. In group A, seven patients were primarily diagnosed with a SDAVF after multidisciplinary teamwork (MDT). In group B, five patients were misdiagnosed with lumbar spinal stenosis, four with lumbar disc herniation, two with thoracic spinal stenosis, and one with cervical spinal stenosis and lumbar spinal stenosis and underwent cervical spinal canal and lumbar spinal canal decompression. The length of time for confirming the diagnosis was 7 months longer in group B than in group A. All patients underwent microsurgery treatment. The average follow-up duration was 11 months. The modified Aminoff-Logue Disability Scale scores showed a statistically significant difference in improvement between the two groups (P < 0.05).

Conclusion

when patients with dysuria especially, have intermittent spinal nerve dysfunction, the possibility of SDAVF should be considered. Awareness of the specific clinical and spinal cord edema and flow voids on MRI of a SDAVF needs to be promoted for orthopedic surgeons. Timely MDT is an important measure for reducing misdiagnosis, and steroids or inappropriate surgery should be avoided until a SDAVF is completely excluded.

Imaging characteristics, misdiagnosis and microsurgical outcomes of patients with spinal dural arteriovenous fistula: a retrospective study of 32 patients

Background

Spinal dural arteriovenous fistula (SDAVF) is an extremely rare spinal vascular malformation. As SDAVF exhibits no specific clinical manifestations nor diverse imaging results, it is easily misdiagnosed, resulting in delayed treatment and irreversible neurological damage. Most patients were initially misdiagnosed, but there were few reports on reducing misdiagnosis.

Methods

A total of 32 consecutive patients, who presented to our institution (Shanghai Deji Hospital) with SDAVF between June 2013 and January 2016 were retrospectively analyzed. Data were collected on demographics, clinical presentation, imaging findings, follow-up, and clinical outcomes. The Aminoff-Logue scale (ALS) was used to assess clinical outcomes.

Results

Of the 32 enrolled patients (3 females, mean age 59.1±3.8 years), 23 patients (71.9%) were misdiagnosed as acute myelitis (11 patients), intramedullary tumors (6 patients), lumbar disc herniation (4 patients), and other conditions (2 patients). All patients underwent surgical procedures under electrophysiological monitoring. Fistulas were found in all 32 patients and were successfully occluded. The mean follow-up period was 19.22±8.21 months (ranging from 2 weeks to 30 months). One year later, 20 patients underwent magnetic resonance imaging (MRI), and 14 showed no T2 edema, and the edema was relieved in 6 patients. A total of 10 patients underwent enhancement MRI and no enhancement signs were detected. Among the 27 patients with long-time follow-up, the fistula had no residual or recurrence, 21 patients showed decreased ALS scores (P<0.05). Six patients exhibited nonsignificant improvement. No aggravating patient was found. Prognosis differed significantly between patients with ALS <6 and those with ALS ≥6 (P<0.05).

Conclusions

Spinal angiography should be performed with full intubation, and microcatheter angiography can reduce misdiagnosis. SDAVF must be differentiated from acute myelitis, intramedullary tumor, and other spinal vascular malformations. Microsurgical treatment is effective with a low recurrence rate.

[Clinical outcomes following microsurgery and endovascular embolization in the management of spinal dural arteriovenous fistula: A meta-analysis study]

OBJECTIVE

To compare the clinical effect of microsurgery and endovascular embolization in the treatment of spinal dural arteriovenous fistula (SDAVF) by meta-analysis.

METHODS

A systematic review was performed to retrieve all relevant literature about surgical treatment or endovascular embolization of SDAVF up to December 2019 through PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials Results, CNKI, Wanfang Data, and SinoMed. The Chinese and English key words included: "SDAVF", "spinal dural arteriovenous fistula", "spinal AVM", "spinal vascular malformation and treatment". The included studies were evaluated using the Newcastle-Ottawa scale. The early failure rate, long-term recurrence, neurological recovery, and complications were evaluated and the clinical effects of the two methods in the treatment of SDAVF were compared by using RevMan 5.3 software. And a further subgroup analysis of the therapeutic effect of endovascular embolization with different embolic agents was conducted.

RESULTS

A total of 46 studies involving 1 958 cases of SDAVF were included, in which 935 cases were treated by microsurgery and 1 023 cases were treated by endovascular embolization. The funnel plot demonstrated that there was no publication bias. The results of meta-analysis showed that the incidence of early surgical failure was lower than that of endovascular embolization (OR=0.20, 95%CI: 0.13-0.30, P < 0.05), and the long-term recurrence was also lower than that of endovascular embolization (OR=0.36, 95%CI: 0.22-0.58, P < 0.05). The improvement of neurological function in the surgical patients is significantly higher than that in the patients treated with endovascular embolization (OR=2.86, 95%CI: 1.36-5.99, P < 0.05). There was no significant difference in the occurrence of complications in these two groups (OR=1.52, 95%CI: 0.88-2.64, P=0.14). In the cases of endovascular embolization, the risk of treatment failure or recurrence was higher with Onyx glue than with n-butyl 2-cyanoacrylate (NBCA), and the difference was statistically significant (OR=4.70, 95%CI: 1.55-14.28, P < 0.05).

CONCLUSION

Although the treatment of dural arteriovenous fistulas by intravascular embolization has been widely used, the clinical effect of microsurgery is still better than that of endovascular embolization. Large scale and high-quality randomized controlled trials are required to validate the efficacy and safety of endovascular treatment in SDAVF patients.

[Clinical outcomes following microsurgery and endovascular embolization in the management of spinal dural arteriovenous fistula: A meta-analysis study]

OBJECTIVE

To compare the clinical effect of microsurgery and endovascular embolization in the treatment of spinal dural arteriovenous fistula (SDAVF) by meta-analysis.

METHODS

A systematic review was performed to retrieve all relevant literature about surgical treatment or endovascular embolization of SDAVF up to December 2019 through PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials Results, CNKI, Wanfang Data, and SinoMed. The Chinese and English key words included: "SDAVF", "spinal dural arteriovenous fistula", "spinal AVM", "spinal vascular malformation and treatment". The included studies were evaluated using the Newcastle-Ottawa scale. The early failure rate, long-term recurrence, neurological recovery, and complications were evaluated and the clinical effects of the two methods in the treatment of SDAVF were compared by using RevMan 5.3 software. And a further subgroup analysis of the therapeutic effect of endovascular embolization with different embolic agents was conducted.

RESULTS

A total of 46 studies involving 1 958 cases of SDAVF were included, in which 935 cases were treated by microsurgery and 1 023 cases were treated by endovascular embolization. The funnel plot demonstrated that there was no publication bias. The results of meta-analysis showed that the incidence of early surgical failure was lower than that of endovascular embolization (OR=0.20, 95%CI: 0.13-0.30, P < 0.05), and the long-term recurrence was also lower than that of endovascular embolization (OR=0.36, 95%CI: 0.22-0.58, P < 0.05). The improvement of neurological function in the surgical patients is significantly higher than that in the patients treated with endovascular embolization (OR=2.86, 95%CI: 1.36-5.99, P < 0.05). There was no significant difference in the occurrence of complications in these two groups (OR=1.52, 95%CI: 0.88-2.64, P=0.14). In the cases of endovascular embolization, the risk of treatment failure or recurrence was higher with Onyx glue than with n-butyl 2-cyanoacrylate (NBCA), and the difference was statistically significant (OR=4.70, 95%CI: 1.55-14.28, P < 0.05).

CONCLUSION

Although the treatment of dural arteriovenous fistulas by intravascular embolization has been widely used, the clinical effect of microsurgery is still better than that of endovascular embolization. Large scale and high-quality randomized controlled trials are required to validate the efficacy and safety of endovascular treatment in SDAVF patients.

Spinal Dural Arteriovenous Fistula: A Mimic of Demyelinating Disease and Radiculopathy

Spinal dural arteriovenous fistula (SDAVF) is characterized by an abnormal connection between a radicular artery and the venous plexus producing spinal cord venous congestion. It manifests with nonspecific sensory and motor symptoms. We present three cases of SDAVF with different forms of presentation; in two cases, an autoimmune etiology was considered, and in the third case, the initial diagnosis was chronic radiculopathy. In all three cases, a serpentine enhancement was observed after the gadolinium in the dorsal region of the spinal cord corresponded to flow voids in T2-weighted images, which guided the diagnosis. SDAVF should be considered in atypical clinical presentations of radiculopathies or spinal cord syndromes, especially spinal conus or epicone syndrome. Likewise, it should be part of the differential diagnosis of spinal cord presentations of demyelinating diseases such as multiple sclerosis or neuromyelitis optica spectrum disorders.

Rapid Progression to Complete Paraplegia After Electroacupuncture in a Patient With Spinal Dural Arteriovenous Fistula: A Case Report

Spinal dural arteriovenous fistula (SDAVF) usually has an insidious clinical course, but 5–15% of the cases have acute exacerbations. In some cases, there is an abrupt progression to paraplegia following an epidural injection or anesthesia. Electroacupuncture is a form of acupuncture that applies a small electrical current to needles inserted at specific points in the body. It is widely used for its analgesic effect on back pain. In this study, we report a rare case of SDAVF in which the symptoms of a patient worsened rapidly to complete paraplegia within a few hours after applying electroacupuncture to his back. A 49-year-old man had rapid progression to complete paraplegia within a few hours of electroacupuncture on his back. MRI showed SDAVF and worsening of cord signal change. An emergency operation was performed to ligate the SDAVF. The patient was able to walk 1 month post-operatively. Most of the neurological deficits had disappeared by 1 year post-operatively, with normalization of MRI. Our case emphasizes that SDAVF patients should be careful when exposed to any circumstances that might affect the circulation around the dural arteriovenous fistula, such as electroacupuncture. Patients should also be warned in advance about the possibility of rapid exacerbation of neurological symptoms. Regardless of the severity of the neurological symptoms, immediate treatment is essential for recovery and a better outcome.

Longitudinally extensive transverse myelitis and Hepatitis C-a case report and literature review

Tractopathy lesions in the spinal cord associated with HCV infection, which normalized on MRI after antiviral treatment, are described. These specific MRI findings can be used in the diagnosis and treatment of secondary causes of transverse myelitis.

Vascular Spinal Cord Disorders

Vascular disorders of the spinal cord are uncommon yet under-recognized causes of myelopathy. Etiologies can be predominantly categorized into clinical and radiographic presentations of arterial ischemia, venous congestion/ischemia, hematomyelia, and extraparenchymal hemorrhage. While vascular myelopathies often produce significant morbidity, recent advances in the understanding and recognition of these disorders should continue to expedite diagnosis and proper management, and ideally improve patient outcomes. This article comprehensively reviews relevant spinal cord vascular anatomy, clinical features, radiographic findings, treatment, and prognosis of vascular disorders of the spinal cord.

Treatment strategy to maximize the treatment outcome of spinal dural arteriovenous fistula after initial endovascular embolization attempt at diagnostic angiography

Initial attempt of endovascular treatment (EVT) for spinal dural arteriovenous fistula (SDAVF) is preferred because of concurrent diagnosis and treatment. However, outcomes following further treatment with initial EVT are not well studied. We retrospectively reviewed 71 patients with SDAVF to evaluate treatment outcomes of SDAVF after an initial EVT attempt. Pretreatment and posttreatment functional states were assessed by the Aminoff-Logue scale (ALS). In the case of incomplete occlusion or recurrence, overall outcomes after further treatments were compared. Of the 71 patients, 56 underwent initial EVT. Complete occlusion was achieved by initial EVT in 37 of 56 patients (66.1%). Multiple feeders were more frequently observed in patients with incomplete occlusion than complete occlusion after initial EVT (73.7% vs. 27%, P < 0.001). Among 19 patients with incomplete occlusion upon initial EVT, 14 underwent additional surgery, 13 of whom (92.9%) obtained improved or stationary functional outcomes. Functional improvement was not observed in patients who had repeated EVT or follow-up without further treatment. Recurrence was observed in 8 of 37 patients with complete occlusion upon initial EVT. Additional surgery achieved improved functional outcomes in cases of incomplete occlusion of SDAVF after the initial EVT attempt or recurrence rather than repeated EVT or follow-up.

A case series of intracranial dural arteriovenous fistulae mimicking cervical myelitis: a diagnosis not to be missed

Objective

To describe the diagnostic features of intracranial dural arteriovenous fistulae (DAVF) presenting with cervical cord or brainstem swelling.

Methods

Retrospective case note and neuroimaging review of patients with angiographically confirmed DAVF diagnosed during January 2015–June 2020 at a tertiary neuroscience centre (Walton Centre NHS Foundation Trust, Liverpool, UK).

Results

Six intracranial DAVF causing cervical cord or brainstem oedema (all males aged 60–69 years) and 27 spinal DAVF (88% thoracolumbar) were detected over a 5.5-year period. Significantly more patients with intracranial DAVF received steroids for presumed inflammatory myelitis than those with spinal DAVF (5/6 vs 1/27, p = 0.0001, Fisher’s exact test). Several factors misled the treating clinicians: atypical rostral location of cord oedema (6/6); acute clinical deterioration (4/6); absence (3/6) or failure to recognise (3/6) subtle dilated perimedullary veins on MRI; intramedullary gadolinium enhancement (2/6); and elevated CSF protein (4/5). Acute deterioration followed steroid treatment in 4/5 patients. The following features may suggest DAVF rather than myelitis: older male patients (6/6), symptomatic progression over 4 or more weeks (6/6) and acellular CSF (5/5).

Conclusion

Intracranial DAVF are uncommon but often misdiagnosed and treated as myelitis, which can cause life-threatening deterioration. Neurologists must recognise suggestive features and consider angiography, especially in older male patients. Dilated perimedullary veins are an important clue to underlying DAVF, but may be invisible or easily missed on routine MRI sequences.

Neuroimaging of Spinal Cord and Cauda Equina Disorders

PURPOSE OF REVIEW

This article reviews the neuroimaging of disorders of the spinal cord and cauda equina, with a focus on MRI. An anatomic approach is used; diseases of the extradural, intradural-extramedullary, and intramedullary (parenchymal) compartments are considered, and both neoplastic and non-neoplastic conditions are covered. Differentiating imaging features are highlighted.

RECENT FINDINGS

Although T2-hyperintense signal abnormality of the spinal cord can have myriad etiologies, neuroimaging can provide specific diagnoses or considerably narrow the differential diagnosis in many cases. Intradural-extramedullary lesions compressing the spinal cord have a limited differential diagnosis and are usually benign; meningiomas and schwannomas are most common. Extradural lesions can often be specifically diagnosed. Disk herniations are the most commonly encountered mass of the epidural space. Cervical spondylotic myelopathy can cause a characteristic pattern of enhancement, which may be mistaken for an intrinsic myelopathy. A do-not-miss diagnosis of the extradural compartment is idiopathic spinal cord herniation, the appearance of which can overlap with arachnoid cysts and webs. Regarding intrinsic causes of myelopathy, the lesions of multiple sclerosis are characteristically short segment but can be confluent when multiple. Postcontrast MRI can be particularly helpful, including when attempting to differentiate the long-segment myelopathy of neurosarcoidosis and aquaporin-4 (AQP4)-IgG-seropositive neuromyelitis optica spectrum disorder (NMOSD) and when characterizing spinal cord tumors such as primary neoplasms and metastases. Spinal dural arteriovenous fistula is another do-not-miss diagnosis, with characteristic MRI features both precontrast and postcontrast. Tract-specific white matter involvement can be a clue for diseases such as subacute combined degeneration, paraneoplastic myelopathy, and radiation myelitis, whereas gray matter-specific involvement can suggest conditions such as cord infarct, viral myelitis, or myelin oligodendrocyte glycoprotein (MOG)-IgG associated disorder.

SUMMARY

Knowledge of the neuroimaging findings of the many causes of spinal cord and cauda equina dysfunction is critical for both neurologists and neuroradiologists. A structured approach to lesion compartmental location and imaging feature characterization is recommended.

Vascular Myelopathies

PURPOSE OF REVIEW

Neurologists should be able to identify clinical and neuroimaging features that distinguish vascular disorders from other causes of myelopathy.

RECENT FINDINGS

Although certain clinical features suggest a vascular etiology in acute and chronic myelopathy settings, accurate MRI interpretation within the clinical context is key. Recent studies have shown vascular myelopathies are frequently misdiagnosed as transverse myelitis, and recognition of this diagnostic pitfall is important. Many different vascular mechanisms can cause myelopathy; this article provides a comprehensive review that simplifies disease categories into arterial ischemia, venous congestion/ischemia, hematomyelia, and extraparenchymal hemorrhage.

SUMMARY

It is important to recognize and manage vascular disorders of the spinal cord as significant causes of acute, subacute, and progressive myelopathy.

Paralysis After Lumbar Interlaminar Epidural Steroid Injection in the Absence of Hematoma: A Case of Congestive Myelopathy Due to Spinal Dural Arteriovenous Fistula and a Review of the Literature

Paraplegia after interlaminar epidural steroid injection is a rare event and has typically been described after epidural hematoma or direct spinal cord injury. We present a case of an 87-yr-old man who experienced transient lower limb weakness after a lumbar interlaminar epidural steroid injection due to an alternative cause, congestive myelopathy related to an underlying vascular malformation, namely, a spinal dural arteriovenous fistula. This is a poorly recognized and potentially treatable cause of progressive myelopathy. We present this case and review the literature on paraplegia after epidural steroid injection due to spinal dural arteriovenous fistula. Notably, this case of paralysis occurred in association with the lowest volume of epidural injectate reported in the literature to date (4 ml); importantly, this volume is consistent with the current clinical practice guideline standards for the safe performance of interlaminar epidural steroid injections. Physicians should be aware of this potential complication of epidural steroid injection and remain vigilant for the possibility after a procedure, even when performed according to current practice standards.

Acquired Lumbosacral Spinal Dural Arteriovenous Fistula in Association with Degenerative Lumbosacral Disc Herniation and Spinal Canal Stenosis: Report of Two Cases and Review of the Literature

The authors describe two cases harboring lumbosacral spinal dural arteriovenous fistulas (SDAVFs) manifested with nonspecific initial symptoms, leading to misdiagnosis and unnecessary procedures. A curvilinear flow void in the lumbar region and thoracic cord congestion with subtle perimedullary flow voids were detected on magnetic resonance imaging (MRI) in both patients. Contrast-enhanced magnetic resonance angiography and spinal angiography confirmed the SDAVFs in the lower lumbar and sacral region. Both fistulas were located at the same level of disc herniation and spinal canal stenosis and supplied by branches of the internal iliac arteries (i.e., iliolumbar and lateral sacral arteries) with cranial drainage from the dilated vein of the filum terminale, corresponding to a curvilinear flow void, to the perimedullary veins. The first case was successfully treated with embolization. Another case had recanalization of the fistula 4 months after endovascular treatment and was successfully treated with surgical interruption of the fistula. Our two case reports may provide additional evidence supporting an acquired etiology of SDAVFs, probably secondary to lumbosacral disc herniation and spinal canal stenosis. The authors also reviewed literature about preexistent lumbosacral SDAVFs associated with disc herniation and spinal canal stenosis. From our review, the level of SDAVFs in most patients is correlated with the level of disc herniation, spondylolisthesis, and/or spinal stenosis.

Syringomyelia Associated with Spinal Dural Arteriovenous Fistula: Clinical and Radiological Improvement after Embolization

Spinal dural arteriovenous fistulae (AVF) are rare and can result in spinal cord dysfunction. We present one such case wherein the patient presented with a venous congestive myelopathy. Magnetic resonance imaging showed a syrinx formation, spinal cord edema, and flow voids. Digital subtraction angiography confirmed the dural AVF, which was treated with embolization. The syrinx disappeared, other spinal cord changes improved, and the patient had remarkable clinical improvement. The case is presented to draw attention to the rare formation of a syrinx in a spinal dural arteriovenous fistula and its disappearance after successful embolization.

Long-term surgical outcomes of patients with delayed diagnosis of spinal dural arteriovenous fistula

Spinal dural arteriovenous fistula (dAVF) is an extremely rare vascular entity that is usually misdiagnosed. We sought to determine the long-term clinical outcomes of patients undergoing microsurgical treatment for delayed diagnosis of spinal dAVF. This retrospective study identified patients with delayed diagnosed spinal dAVF at our institution from 2009 to 2018. Patients' data, including demographics, imaging, and follow-up data, were evaluated. This cohort included 65 consecutive patients with 68 dAVFs and a male-to-female ratio of 4:1 and a mean age of 53.5 ± 13.7 years. The presenting symptoms consisted of limb weakness (n = 42, 64.6%), paraparesis (n = 34, 52.3%), sphincter disturbances (n = 8, 12.3%), and pain (n = 13, 20.0%). The proportion of patients with each symptom significantly increased and patients experienced increased disability when the diagnosis was finalized. The mean length of delay of diagnosis was 20.7 ± 30.0 months. Surgery resulted in complete occlusion of the fistula on the first attempt in all patients. Three patients developed recurrent fistulas, and three died in the follow-up period. Improved motor function was achieved in 38 patients (59.5%). Other symptoms, such as sensory disorders, sphincter dysfunction, and pain, improved by 37.3%, 32.3%, and 66.7%, respectively. Patients with spinal dAVF usually exhibit progressive ascending myelopathy and often remain misdiagnosed for months to years. Some patients' increased disability cannot be reversed through surgery.

Clinical characteristics, misdiagnosis and outcomes of patients with low-flow spinal arteriovenous fistulas

OBJECTIVE

To describe the clinical characteristics, delay to diagnosis and post-intervention outcomes of patients with low-flow spinal arteriovenous fistulas (SAVFs).

METHODS

In this retrospective observational study, we reviewed all patients with low-flow SAVFs angiographically diagnosed at our institution between 2008 and 2018. Pre- and post-intervention disability levels were recorded using the modified Aminoff and Logue scale (mALS).

RESULTS

One-hundred and five patients were included. Median age was 62 years and 79% were male. Most patients (56%) presented to neurologists and 41% were misdiagnosed with myelitis. Patients underwent unnecessary treatment with corticosteroids (44%), other immunosuppressive therapies (8%) and spinal surgery (10%). Inappropriate corticosteroid treatment led to a precipitous clinical decline in 30% of patients exposed. Only 21% percent of patients were correctly diagnosed after initial evaluation; the median delay to diagnosis in the rest of the cohort was of 12 months (IQR 7 to 24 months). Longer delays to diagnosis were associated with higher levels of disability (p = .002). Treatment of SAVF was endovascular in 64% and surgical in 26%; 13% of patients required further intervention due to incomplete initial treatment or fistula recurrence. Greater than 6 months after intervention, disability scores were improved in 52% and stable in 43% of patients. In individual patients, pre- and post-intervention disability scores were strongly correlated (p < .001).

CONCLUSIONS

Low-flow SAVFs are associated with substantial disability and are frequently misdiagnosed. Timely diagnosis of SAVF needs to improve, as endovascular or surgical treatment results in stabilization or improvement of disability in the vast majority of patients.

Clinical and neuroimaging findings of spinal dural arteriovenous fistulas: How to avoid misdiagnosis of this disease

OBJECTIVE

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.

METHODS

Forty consecutive patients were retrospectively analyzed.

RESULTS

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.

CONCLUSIONS

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.

Unique Gadolinium Enhancement Pattern in Spinal Dural Arteriovenous Fistulas

Importance

Spinal dural arteriovenous fistula (sDAVF) is often misdiagnosed as an inflammatory or a neoplastic myelopathy, often because of intraparenchymal gadolinium enhancement on magnetic resonance imaging (MRI); proper early diagnosis is important because deficits are reversible and a delay in treatment is associated with permanent morbidity. Tortuous flow voids on MRI are not universally present; thus, recognition of a unique gadolinium enhancement pattern may also aid in the early recognition and treatment of sDAVF.

Objective

To describe a unique pattern of spinal cord gadolinium enhancement on MRI in sDAVF.

Design, Setting, and Participants

This retrospective evaluation included pretreatment MRIs from 80 patients referred to the Mayo Clinic, Rochester, Minnesota, from January 1, 1997, through December 31, 2017, with a confirmed diagnosis of sDAVF and a control group of 144 patients with alternative confirmed myelopathy diagnoses. All participants underwent a neurologic evaluation at the Mayo Clinic.

Main Outcomes and Measures

Evidence of at least 1 focal geographic nonenhancing area within a long segment of intense holocord gadolinium enhancement (termed the missing-piece sign) on MRI.

Results

Of 51 patients with an sDAVF and a pretreatment MRI with gadolinium enhancement, 44 (86%) had intraparenchymal contrast enhancement, and 19 of these patients (43%) displayed the characteristic missing-piece sign. Of these 19 patients, symptom onset occurred at a median age of 67 years (range, 27-80 years); 15 patients were men. Progressive myelopathy features affecting the lower extremities occurred during a median of 33 months (range, 1-84 months). Eleven patients (58%) received an alternative diagnosis before confirmation of sDAVF. Tortuous flow voids were present on T2-weighted MRI in 13 of 19 patients. More than 1 digital subtraction angiogram was required for 5 patients to confirm the diagnosis. The missing-piece sign was not seen in any patients from the control group.

Conclusions and Relevance

This unique gadolinium enhancement pattern in sDAVF was not found in a large control group of patients with other myelopathy. Identifying the missing-piece sign on MRI could potentially result in earlier time to angiography with improved outcomes for patients with an sDAVF.

Vascular Disorders of the Spinal Cord

PURPOSE OF REVIEW

Prompt recognition and timely management of vascular disorders of the spinal cord can improve patient outcomes. This article provides contemporary and practical knowledge about the most common vascular myelopathies.

RECENT FINDINGS

New studies have provided additional information on the risk factors and impact of neurologic monitoring on perioperative spinal cord infarction. Additionally, recent publications have provided information on the impact of misdiagnosis, corticosteroid treatment, and postoperative prognosis in the treatment of spinal dural arteriovenous fistulas and have discussed the outcome of patients with spinal arteriovenous malformations treated with embolization, surgery, and stereotactic radiosurgery. Finally, recent studies have provided information on the natural history and postoperative prognosis of spinal cavernous malformations and on the risk factors and surgical outcome of patients with spinal epidural hematomas.

SUMMARY

Diagnostic and therapeutic challenges are inherent in managing patients with vascular disorders of the spinal cord, and clinicians should have a thorough understanding of these disorders to facilitate optimal outcomes for patients with these potentially devastating illnesses. This article begins by reviewing functional vascular anatomy and subsequently describes the fundamental characteristics of both ischemic and hemorrhagic vascular myelopathies to equip clinicians with the knowledge to avoid common pitfalls.

Type I AV fistula of the thoracic spinal cord

Type I AV fistulas of the spinal cord are exceedingly rare. The average age at diagnosis is 50. Clinical presentation is often very non-specific, and sensory deficits and sphincter dysfunction may also occur. Neurological deterioration is generally gradual. Thus, failure to diagnosis frequently results in permanent disability. A 22-year-old female complained of a "muscle spasm" in the midline thoracic area with no history of trauma or prior occurrence. She also experienced bilateral lower extremity weakness/numbness and perianal anesthesia. She is a healthy female with no medical problems. Exam revealed lower extremity motor function of 1/5 as well as diminished sensation. A foley catheter was placed for urinary retention. The remainder of the neurological exam was normal. MRI demonstrated a lesion at the fourth thoracic level with significant cord compression. The patient was taken emergently to the operating room by neurosurgery. This case demonstrates a rare disorder occurring in a 22-year old female, far younger than the typical 50-year old patient. Moreover, the lesion was located in the thoracic rather than the typical lumbar cord. Symptoms may be misinterpreted as a peripheral nerve lesion and delay time to diagnosis. Early diagnosis remains critical to prevent permanent neurologic sequelae. AV fistula should remain high on the differential of patients presenting with back pain and focal neurologic complaints.

The Hybrid Assistive Limb® intervention for a postoperative patient with spinal dural arteriovenous fistula and chronic spinal cord injury: A case study

CONTEXT

The purpose of this report was to describe the improvement in walking ability using the Hybrid Assistive Limb® (HAL®) intervention in the case of a patient with paraplegia after spinal cord injury whose condition deteriorated because of a spinal dural arteriovenous fistula (SDAVF).

FINDINGS

A 48-year-old man started the HAL® intervention twice per week (total 10 sessions), after his neurologic improvement had plateaued from 3 to 6 months postoperatively for an SDAVF. During the HAL® intervention, the 10-m walk test (10MWT) without HAL® was performed before and after each session. An electromyography system was used to evaluate muscle activity of both the gluteus maximus (Gmax) and quadriceps femoris (Quad) muscles in synchronization with the Vicon motion capture system. The International Standards for Neurological and Functional Classification of Spinal Cord Injury (ISNCSCI) motor scores of the lower extremities and the Walking Index for Spinal Cord Injury II (WISCI II) score were also assessed to evaluate motor function. The HAL® intervention improved gait speed and cadence during the 10MWT. Before the intervention, both the Gmax and left Quad muscles were not activated. After the intervention, the right Gmax and both Quad muscles were activated in stance phase rhythmically according to the gait cycle. The ISNCSCI motor score also improved from 14 to 16, and the WISCI II scored improved from 7 to 12.

CONCLUSION/CLINICAL RELEVANCE

Our experience with this patient suggests that the HAL® can be an effective tool for improving functional ambulation in patients with chronic spinal cord injury.

Spinal Dural Arteriovenous Fistulas: Clinical Results and Quality of Life Assessment with Surgical Treatment as a Crucial Therapy. The Joint Experience of Two Centers

OBJECTIVE

Dorsal intradural arteriovenous fistulas (AVFs) consist of a direct connection between a radicular feeding artery and the coronal venous plexus; this direct connection leads to arterialization of the venous plexus, venous congestion, and myelopathy. Controversy still exists regarding the best treatment modality of spinal dural AVFs. Surgical disconnection of spinal dural AVFs is a straightforward procedure with a high success rate and virtually no risk of recurrence or incomplete treatment. To identify factors associated with the clinical progression of dorsal intradural AVFs and quantify the range of surgical outcomes in terms of neurologic improvement as well as patients' perception of quality of life (QOL).

METHODS

A retrospective observational study of 19 consecutive patients treated with surgery over a 10-year period was carried out. We analyzed surgical results and clinical outcomes. We also evaluated the impact of this disease and its sequelae on the patients' postoperative health-related QOL.

RESULTS

The surgical procedure showed good results in terms of neurologic improvement as well as patients' perception of QOL.

CONCLUSIONS

Our series confirmed that surgical obliteration of dorsal intradural AVFs is an effective and safe procedure. The results of this retrospective analysis make us believe that surgery, given its low morbidity and high success rate, represents a safe and effective first therapeutic option for these spinal vascular malformations. It could be considered to avoid unsuccessful endovascular attempts that could delay the definitive treatment of this disease. The surgical procedure showed good results in terms of neurologic improvement as well as patients' perception of QOL.

Dilated Vein of the Filum Terminale on MRI: A Marker for Deep Lumbar and Sacral Dural and Epidural Arteriovenous Fistulas

BACKGROUND AND PURPOSE

Conventional MR imaging can provide important clues regarding the location of a spinal vascular malformation. We hypothesized that a dilated vein of the filum terminale, identified as a curvilinear flow void on T2WI, could be an imaging marker for a lower lumbar (L3-L5) or sacral fistula.

MATERIALS AND METHODS

We retrospectively identified all spinal dural and spinal epidural arteriovenous fistulas from 2 large tertiary referral centers from 2005 to 2018. All patients had a lumbar spinal MR imaging and a conventional spinal angiography. Images were reviewed by 2 neuroradiologists who categorized the level of the arterial feeder to the fistula and the presence or absence of a dilated vein of the filum terminale on T2WI and T1 postcontrast images. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value of the presence of a dilated filum terminale vein for a deep lumbar or sacral fistula.

RESULTS

One hundred sixty-two patients were included. An enlarged filum terminale vein was identified in 39 patients. Sensitivity, specificity, positive predictive value, and negative predictive value of the presence of a dilated filum terminale vein for a deep lumbar or sacral fistula were 86%, 98.3%, 94.9%, and 95.1%, respectively.

CONCLUSIONS

The presence of a dilated vein of the filum terminale can accurately localize a spinal dural arteriovenous fistula/spinal epidural arteriovenous fistula to the lower lumbar or sacral spine in patients being evaluated for such lesions. This finding can be used to facilitate both noninvasive and conventional spinal angiography.

Spinal dural arteriovenous fistula: delay to radiological diagnosis and sources of radiological error

AIM

To highlight the magnetic resonance imaging (MRI) signs associated with spinal dural arteriovenous fistula (SDAVF) through categorisation of sources of radiological error and investigation of the delay to radiological diagnosis.

MATERIAL AND METHODS

This was a retrospective, observational study of cases referred to a neuroscience centre over 11 years. All patients who underwent spinal digital subtraction angiography (DSA) with a subsequent diagnosis of SDAVF were identified. Prior imaging was reviewed and compared with the formal reports issued.

RESULTS

Thirty-seven patients with SDAVF were initially imaged in seven institutions. Radiological abnormalities including intradural vessels (37/37, 100%), cord T2 signal change (34/37, 91.9%), and cord expansion (26/37, 70.2%) were present on prior MRI. These signs were not recognised in 22/37 (59.5%), 7/34 (20.5%), and 15/26 (57.7%) of cases, respectively. Increased T2 signal in the cord was the most commonly identified sign (27/34; 79.4%), but prompted either no diagnosis (7/34; 20.5%) or differential diagnoses including ischaemic, inflammatory, or neoplastic aetiologies or a syrinx in 11/34 (32.4%). An appropriate diagnosis was made on initial MRI in 15 patients (40.5%). The time from initial imaging to diagnosis was significantly delayed for those patients who did not have an arteriovenous vascular aetiology included in the initial differential diagnosis (281 (423.3) days versus 22 (15.7) days, p=0.03).

CONCLUSION

SDAVF have imaging features that are frequently missed or misinterpreted. This results in a significant delay to definitive diagnosis and therefore treatment.

Spinal dural arteriovenous fistula presenting with subarachnoid hemorrhage: A case report

RATIONALE

Subarachnoid hemorrhage (SAH) is a common and serious disease and one of the most important differential diagnoses in the emergency department.

PATIENT CONCERNS

A 39-year-old female patient with a 12 years' history of migraine, presented with a sudden headache combined with motor aphasia. Physical examination suggested probable positive neck resistance. SAH was confirmed by magnetic resonance imaging. In addition, spinal digital subtraction angiography and spinal vascular computed tomography angiography indicated spinal arteriovenous malformation (SAVM).

DIAGNOSES

The final diagnosis was spinal dural arteriovenous fistula presenting with SAH.

INTERVENTIONS

Following diagnosis, appropriate drugs were administered, but the therapeutic effect was poor. Then the patient was then transferred to a superior hospital where she was treated with interventional embolization.

OUTCOMES

Through 2 years of follow-up, intermittent migraine was found in the patient, but the symptoms of occipital pain, nausea, and vomiting did not occur again.

LESSONS

For patients who have been diagnosed with SAH but have no definite cause, we should pay attention to the etiological screening of SAH, and the possibility of the spinal cord SAH should be vigilant. The pain in the chest and back and the signs of spinal cord may be an important breakthrough in patients with spinal cord SAH, and medical history and physical examination are particularly important.

Spinal Cord Infarcts: Risk Factors, Management, and Prognosis

OPINION STATEMENT

There are no standard guidelines for treatment of spinal cord ischemia due to how rare it is and the diverse etiology and presentations involved. In addition, to date, there have been no large clinical trials examining ideal pharmacologic treatment options for spinal cord infarct. In our practice, we rely on hemodynamic augmentation initiated as soon as possible. Otherwise, treatment is usually geared towards the etiology of spinal cord ischemia. For instance, spinal cord ischemia occurring after aortic aneurysmal repair may improve with CSF drainage through a lumbar catheter in the periprocedural setting. Vertebral artery dissection should be treated with antithrombotics. If no clear etiology is found and there is evidence of atherosclerosis in other vascular beds, then management is focused on risk factor modification with blood pressure and glucose control, statins, and antithrombotics.

Spinal arteriovenous fistulas in adults: Management of a series of patients treated at a neurology department

OBJECTIVE

Spinal arteriovenous fístulas (SAVF), a rare type of vascular malformation, account for 3% of all spinal cord lesions. Without early treatment, the associated morbidity is high; furthermore, SAVF pose a major diagnostic challenge. Our purpose was to evaluate the clinical characteristics of SAVF and review their progress after treatment to determine whether it may be too late for treatment in some cases.

METHODS

We present a retrospective series of 10 patients diagnosed with SAVF and treated at a tertiary hospital during a 3-year period.

RESULTS

In our sample, SAVF were found to be significantly more frequent in men (80%). Mean age in our sample was 65.4 years. The most common initial symptom was intermittent claudication/paraparesis (70%). In most patients, symptoms appeared slowly and progressively. At the time of diagnosis, the most common symptoms were motor, sensory, and sphincter disorders. Mean time from symptom onset to diagnosis was 24.3 months. Initial diagnosis was erroneous in 60% of the patients. Spinal MRI was diagnostic in 90% of these cases and arteriography in 100%. The most common location of the fistula was the lower thoracic region and the most frequent type was dural (7 cases). All patients were treated with embolisation, surgery, or both and 70% improved after fistula closure regardless of progression time.

CONCLUSIONS

Diagnosis of SAVF is difficult and often delayed, which leads to poorer patient prognosis. We should have a high level of suspicion for SAVF in patients with intermittent claudication or paraparesis exacerbated by exercise. Early treatment should be started in these patients. Treatment should always aim to improve quality of life or stabilise symptoms, regardless of progression time.

Clinical presentation and treatment outcomes of spinal epidural arteriovenous fistulas

OBJECTIVE Spinal epidural arteriovenous fistulas (SEDAVFs) constitute a rare but treatable cause of vascular myelopathy and are a different subtype from the more common Type I spinal dural AVFs. The purpose of this study was to review a consecutive series of SEDAVFs from a single institution and report on the clinical presentations, functional status, and treatment outcomes. METHODS The authors identified all SEDAVFs treated at their institution from 2005 to 2015. SEDAVFs were defined as spinal AVFs in which the fistulous connection occurred in the epidural venous plexus. The clinical presentation, functional status, immediate treatment outcomes, and long-term neurological outcomes were analyzed. RESULTS Twenty-four patients with SEDAVFs were included in this study. The patients' mean age at presentation was 66.9 years. The most common presenting symptoms were pain and numbness (22 patients, 91.7%), followed by lower-extremity weakness (21 patients, 87.5%). The mean duration of symptoms prior to diagnosis was 11.8 months. Eighteen patients (75.0%) were treated with endovascular therapy alone, 4 (16.7) with surgery, and 2 (8.3%) with a combination of techniques. There was 1 major treatment-related complication (4.2%). Fifteen patients (62.5%) had improvement in disability, and 12 patients (54.5%) had improvement in sensory symptoms. CONCLUSIONS SEDAVFs often present with lower-extremity motor dysfunction and sensory symptoms. With the availability of newer liquid embolic agents, these lesions can be effectively treated with endovascular techniques. Surgery is also effective at treating these lesions, especially in situations where endovascular embolization fails or is not safe and in patients presenting with mass effect from compressive varices.

Endovascular management of spinal dural arteriovenous fistulas

Spinal dural arteriovenous fistulas (dAVF) are the most common subset of the larger group of spinal vascular malformations. In this chapter, we discuss the definition, epidemiology, clinical presentation, diagnosis, treatment, and outcomes of spinal dAVF. Special attention is given to clinical approach, imaging, and diagnosis with discussion of newer spinal magnetic resonance angiographic techniques. Endovascular management techniques are discussed, including technical and safety considerations for the performance of spinal angiography and various methods of embolization. Embolization media, including liquid embolics, particles, and coils, are introduced. Finally, clinical and imaging outcomes are discussed with attention to the clinical and imaging findings of dAVF recurrence.