Vascular Malformations of the Spine and Spinal Cord*: Anatomy, Classification, Treatment

'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.

Longitudinal Pulse-Synchronous Bouncing During Catheter Angiography-A Phenomenon Specific to Spinal Hemangioblastomas

BACKGROUND

Spinal hemangioblastomas are often evaluated with catheter angiography for both workup and treatment planning. We report a unique longitudinal pulse-synchronous bouncing phenomenon observed during their angiographic evaluation and consider the association of pulse-synchronous bouncing with syringomyelia, another pathologic feature associated with hemangioblastomas.

METHODS

Preoperative spinal angiograms and associated magnetic resonance imagings (MRIs) obtained over a 16-year period at a single institution were retrospectively evaluated. Magnetic resonance imaging (MRI) parameters included lesion and syrinx location and size. Angiograms were evaluated for bouncing phenomena. Student's t-test and Chi square test compared characteristics between groups. Linear regression analyses evaluated maximum amplitude of dynamic motion and any associated syrinx.

RESULTS

Nineteen hemangioblastoma patients had preoperative angiograms available for review. Eight exhibited bouncing behavior. Between the dynamic and nondynamic cohorts, there was no difference in presence or volume of syrinxes. Lesions in the dynamic cohort trended towards a cervical location (75% vs. 36.3%, P = 0.10). No significant correlation was found between bouncing amplitude and syrinx size (R2 = 0.023). Dural contact may be related to this dynamic behavior since other high-flow lesions like AVMs do not demonstrate this phenomenon, and AVMs are pial-based and more likely to contact stationary dura. Here, there were fewer lesions abutting the thecal sac in the dynamic cohort (50% vs. 81.8%, P = 0.14).

CONCLUSIONS

Though no significant relationship was established between this bouncing behavior and syrinx formation, noted trends included a greater range of motion for cervical lesions and limited motion in tumors abutting the thecal sac.

Arteriovenous shunts of the cervical spine: patient demographics, presentation, patterns of high-risk venous drainage, and updated classification

BACKGROUND

Intracranial dural arteriovenous (AV) fistula classifications focus on presence/absence of retrograde flow in the cortical veins of the brain as this angiographic finding portends a worse prognosis. However, prior categorization systems of AV shunts in the spine do not incorporate these features. We propose an updated classification for spinal shunting lesions that terms any shunting lesion with retrograde flow in any cortical vein of the brain or spinal cord medullary vein as "high risk". To present this classification, we analyzed our center's most recent experience with cervical spine shunting lesions.

METHODS

The electronic medical record at our institution was reviewed to identify shunting lesions of the cervical spine and patient demographics/presentation. Comprehensive craniospinal digital subtraction angiograms were evaluated to classify shunt location, type (arteriovenous malformation (AVM) vs arteriovenous fistula (AVF)), and presence of high-risk venous drainage.

RESULTS

Some 52 lesions were identified and categorized as pial/dural/epidural/paravertebral AVFs and intramedullary/extraspinal AVMs. Lesions were classified as high risk or not depending on the presence of retrograde flow into at least one vein that directly drains the spinal cord or brain. All patients who presented with either hemorrhage or infarct had underlying high-risk lesions. Additionally, 50% (17/34) of symptomatic patients with high-risk lesions presented with neurological extremity symptoms (OR=10.0, p=0.037) most of which fit a myelopathic pattern.

CONCLUSION

We present an updated classification system for shunting lesions of the spine that focuses on high-risk retrograde flow to the brain or spine in addition to anatomical location in order to better inform patient management.

Clarifying the clinical landscape of pediatric spinal arteriovenous shunts: an institutional experience and individual patient-data meta-analysis

BACKGROUND

Pediatric spinal arteriovenous shunts (SAVS) are rare lesions with heterogeneous pathogenesis and clinical manifestations.

OBJECTIVE

To evaluate the clinical characteristics, angioarchitecture, and technical/clinical outcomes in SAVS through a large single-center cohort analysis and meta-analysis of individual patient data.

METHODS

A retrospective institutional database identified children (aged 0-21 years) who underwent digital subtraction spinal angiography (DSA) for SAVS between January 1996 and July 2021. Clinical data were recorded to evaluate angioarchitecture, generate modified Aminoff-Logue gait disturbance scores (AL) and McCormick grades (MC), and assess outcomes. We then performed a systematic literature review following PRISMA-IPD (Preferred Reporting Items for Systematic Reviews and Meta-Analyses for individual patient data) guidelines, extracting similar data on individual patients for meta-analysis.

RESULTS

The cohort consisted of 28 children (M:F=11:17) with 32 SAVS lesions, with a mean age of 12.8±1.1 years at diagnosis. At presentation, SAVS were most highly concentrated in the cervical region (40.6%). Children had a median AL=2 and MC=2, with thoracolumbar AVS carrying the greatest disability. Among treated cases, complete obliteration was achieved in 48% of cases and median AL scores and MC grades both improved by one point. Systematic literature review identified 161 children (M:F=96:65) with 166 SAVS lesions with a mean age of 8.7±0.4 years. Among studies describing symptom chronicity, 37/51 (72.5%) of children presented acutely. At presentation, children had a median AL=4 and MC=3, with thoracolumbar AVS carrying the highest MC grades. After intervention, median AL and MC both improved by one point.

CONCLUSIONS

This study provides epidemiologic information on the location, onset, and presentation of the full spectrum of pediatric SAVS, highlighting the role of targeted treatment of high-risk features.

Autoimmune glial fibrillary acidic protein astrocytopathy complicated with low flow perimedullary arteriovenous fistula: a case report

Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy and low-flow perimedullary arteriovenous fistulas (PMAVFs) may cause longitudinal widespread myelopathy. We report a middle-aged male patient with autoimmune GFAP astrocytopathy complicated with low flow PMAVFs disease, presenting with lower extremity weakness and dysuria. Magnetic resonance imaging (MRI) of the spinal cord revealed a significant longitudinal extent of T2 high signal from T11 to L1, with the lesion located proximal to the vascular territory supplied by the anterior spinal artery. Multiple patchy abnormal signals were seen adjacent to the anterior and posterior horns of the lateral ventricles bilaterally and at the centers of the semi-ovals on MRI of the cranial brain, with iso signal in T1Flair, the high signal in T2WI, and no high signal seen in Diffusion Weighted Imaging (DWI). Subsequently, the presence of anti-GFAP antibodies was detected in the cerebrospinal fluid (CSF), and the diagnosis of autoimmune GFAP astrocytopathy in conjunction with low-flow PMAVFs was confirmed through spinal digital subtraction angiography (DSA). This case report aims to increase neurologists' awareness of this disease and avoid missed or misdiagnosed cases that may lead to delayed treatment.

Cervical myelitis: a practical approach to its differential diagnosis on MR imaging

BACKGROUND

 Differential diagnosis of non-compressive cervical myelopathy encompasses a broad spectrum of inflammatory, infectious, vascular, neoplastic, neurodegenerative, and metabolic etiologies. Although the speed of symptom onset and clinical course seem to be specific for certain neurological diseases, lesion pattern on MR imaging is a key player to confirm diagnostic considerations.

METHODS

 The differentiation between acute complete transverse myelitis and acute partial transverse myelitis makes it possible to distinguish between certain entities, with the latter often being the onset of multiple sclerosis. Typical medullary MRI lesion patterns include a) longitudinal extensive transverse myelitis, b) short-range ovoid and peripheral lesions, c) polio-like appearance with involvement of the anterior horns, and d) granulomatous nodular enhancement prototypes.

RESULTS AND CONCLUSION

 Cerebrospinal fluid analysis, blood culture tests, and autoimmune antibody testing are crucial for the correct interpretation of imaging findings. The combination of neuroradiological features and neurological and laboratory findings including cerebrospinal fluid analysis improves diagnostic accuracy.

KEY POINTS

  · The differentiation of medullary lesion patterns, i. e., longitudinal extensive transverse, short ovoid and peripheral, polio-like, and granulomatous nodular, facilitates the diagnosis of myelitis.. · Discrimination of acute complete and acute partial transverse myelitis makes it possible to categorize different entities, with the latter frequently being the overture of multiple sclerosis (MS).. · Neuromyelitis optica spectrum disorders (NMOSD) may start as short transverse myelitis and should not be mistaken for MS.. · The combination of imaging features and neurological and laboratory findings including cerebrospinal fluid analysis improves diagnostic accuracy.. · Additional brain imaging is mandatory in suspected demyelinating, systemic autoimmune, infectious, paraneoplastic, and metabolic diseases..

Case report: Surgical treatment and long-term successful outcome of a spinal intramedullary vascular malformation in a dog

A 3.5-year-old male intact Staffordshire terrier crossbreed dog was presented with a one-week history of progressive paraparesis with fecal and urinary incontinence. Neurological examination was consistent with a T3-L3 myelopathy. A magnetic resonance imaging study revealed the presence of a well-circumscribed hemorrhagic space-occupying lesion at the level of T12, suspected to be a vascular malformation, such as cavernoma or arteriovenous fistula, primary hematoma or hamartoma; less likely considerations included hemorrhagic inflammation or hemorrhagic primary or secondary neoplasia. A dorsal laminectomy, durotomy, and midline dorsal myelotomy were performed with a surgical microscope, and the vascular lesion was identified and removed. Histological examination of surgical samples yielded fibrin, hemorrhage, hematoidin pigment, and some neural tissue. Although a lining wall was visualized during surgery consistent with a vascular malformation, there was no histological confirmation of such a structure, hampering definitive classification of the lesion. There was no gross or histopathological evidence that would support a diagnosis of a hamartoma or benign neoplasia. The dog was paraplegic with intact nociception the day following surgery. Ambulation was recovered within 2 weeks. Progressive and complete recovery of neurological function was seen over the next 12 weeks. No recurrence of neurological dysfunction was seen over a 12-month follow-up period. Surgical treatment should be considered in dogs with spinal intramedullary vascular lesions which can have a successful long-term outcome.

Pericytes and vascular smooth muscle cells in central nervous system arteriovenous malformations

Previously considered passive support cells, mural cells-pericytes and vascular smooth muscle cells-have started to garner more attention in disease research, as more subclassifications, based on morphology, gene expression, and function, have been discovered. Central nervous system (CNS) arteriovenous malformations (AVMs) represent a neurovascular disorder in which mural cells have been shown to be affected, both in animal models and in human patients. To study consequences to mural cells in the context of AVMs, various animal models have been developed to mimic and predict human AVM pathologies. A key takeaway from recently published work is that AVMs and mural cells are heterogeneous in their molecular, cellular, and functional characteristics. In this review, we summarize the observed perturbations to mural cells in human CNS AVM samples and CNS AVM animal models, and we discuss various potential mechanisms relating mural cell pathologies to AVMs.

Spontaneous obliteration of a spinal perimedullary fistula

We herewith report a young patient who had an incidental spinal vascular malformation of the cervicomedullary junction discovered during a work-up for anosmia. Angiography demonstrated a perimedullary spinal arteriovenous fistula with supply from lateral spinal arteries arising from bilateral V3 level segmental arteries. It was decided to manage the patient conservatively with magnetic resonance imaging monitored biannually. On a recent follow-up magnetic resonance, nearly 10 years later, we noted a subtle change in caliber and imaging characteristics at the posterior margin of the cervical medullary junction. Repeat digital-subtraction angiography showed no evidence of early venous filling from the previously involved branches. Microcatheter exploration of the right lateral spinal artery confirmed spontaneous occlusion of the spinal perimedullary arteriovenous fistula, without any persistent shunting. Spontaneous resolution of a spinal vascular malformation is rare; this case demonstrates the dynamic nature of shunting vascular malformations and that spontaneous obliteration of arteriovenous shunts is possible.

Case report: Paralysis after epidural analgesia due to a hemorrhage of pure epidural venous hemangioma

Purpose

To report a case of sudden paralysis after epidural analgesia to raise awareness of the condition and the importance of early identification and appropriate treatment of extradural venous angiomas.

Clinical features

A 28-year-old man with myofascial pain syndrome experienced paraplegia after receiving an epidural block for pain relief, which was later discovered to be caused by hemorrhage from extradural venous angiomas. Decompression surgery was performed immediately and successfully. A follow-up examination was performed 5 months after surgery. The patient reported improvement in urinary retention. The muscle strength in both his lower extremities had recovered to 4 out of 5 but still exhibited considerable residual spasticity.

Conclusions

Before administering epidural analgesia to relieve undetermined pain, it is prudent to carefully weigh potential benefits against potential risks to patient health to minimize the likelihood of complications.

Thoracic epidural arteriovenous malformation causing rapidly progressive myelopathy and mimicking an acute transverse myelitis: A case report

Clinical symptoms of spinal arteriovenous malformations (AVMs) combined with acute spontaneous hemorrhage lack specificity, which leads to misdiagnosis and delays treatment. The current study aimed to analyze the causes of misdiagnosis and review the key points of diagnosis and treatment. We presented an extremely rare case of a 25-year-old man whose clinical characteristics mimicked acute transverse myelitis, suffering from rapidly and repeatedly progressive myelopathy with a mass. The pathological diagnosis of the mass was AVM; symptom-based surgical treatment with posterior decompression and the removal of epidural AVMs during the postoperative 12-month follow-up period were performed. The manual muscle testing grade score of the proximal and distal muscles in both lower limbs improved from 1 to 5, and the American Spinal Injury Association motor and sensation grade score improved from B to E. In the case of sudden or progressive spinal cord injury of unknown cause and acute spinal cord dysfunction, there might be a misdiagnosis. The key to a differential diagnosis is to take into account AVMs, and spontaneous hemorrhages and hematomas should also be suspected. Angiography and magnetic resonance imaging are very important for the diagnosis of AVM, and we hope to enhance clinicians' understanding of and vigilance for such diseases.

Clinical features and outcomes of perimedullary arteriovenous fistulas: comparison between micro- and macro-type lesions

BACKGROUND

Although the angioarchitecture of perimedullary arteriovenous fistulas (PMAVFs) is straightforward, their size and blood flow are highly heterogeneous. This study aimed to evaluate the differences in clinical features and outcomes of PMAVFs based on lesion size and blood flow.

METHODS

114 consecutive patients with PMAVFs from two institutes were retrospectively reviewed. The lesions were classified as either micro-PMAVFs (shunt point diameter <1 cm) or macro-PMAVFs (shunt point diameter ≥1 cm).

RESULTS

The patients with micro-PMAVFs were older at the first presentation (33.50 vs 13.50 years, p<0.001). Macro-PMAVFs were more commonly associated with spinal metameric arteriovenous shunts (6.9% vs 28.6%, p=0.003). Compared with the macro-PMAVFs, the micro-PMAVFs showed a significantly higher risk of gradual clinical deterioration after initial onset (73.6%/year vs 10.0%/year; HR 3.888, 95% CI 1.802 to 8.390, p=0.001). A total of 58.6% of the micro-PMAVFs were treated surgically, whereas 85.7% of the macro-PMAVFs were treated via endovascular approaches. Complete obliteration was 73.7% for the whole cohort, and was more common for the micro-PMAVFs than for the macro-PMAVFs (87.9% vs 58.9%, p=0.001). At the last follow-up, spinal function was significantly improved compared with the pretreatment status, and the rate of severe disability of patients with macro-PMAVFs was slightly but not significantly higher than that of patients with micro-PMAVFs (16.1% vs 8.6%, p=0.315) CONCLUSIONS: The clinical risks, treatment strategies and obliteration rates of PMAVFs differ based on their size and blood flow.

The recovery management of patients with operated extrame-dullary spinal arteriovenous fistula, evolution and socio-professional reintegration: case report and review of the litera-ture

Adequate therapeutic intervention performed in the case of extradural spinal AVM and an inten-sive recovery program allow the amelioration of neurological manifestations in a very high percentage. With the ultimate goal of practicing a trade, a good biological recovery is needed for social recovery. The effectiveness of strategies for professional integration and reintegration de-pends largely on the patient’s experiences before the onset of the disease. The paper aims to re-view the treatment, the evolution of patients with extradural spinal AV and the possibilities of socio-professional reintegration. Methods and analysis. A case presentation of a patient diag-nosed with extradural spinal AV fistula is proposed, along with a review of the current literature on the treatment of this pathology, the evolution and the possibilities of vocational recovery. The studies will be analysed and selected in two stages, in the first stage the titles and abstracts, in the second stage, the articles with full text will be analysed, selected and a narrative synthesis of the included studies will be made. Summary case. The 51-year-old urban patient, a profes-sional driving instructor who underwent endovascular and surgical treatment for extradural spinal AV fistula, is hospitalized for a moderate motor deficit, such as paraparesis, back pain, mechanical pain in the knees and gait disorders. The objectives of recovery are represented by neuromotor recovery and socio-professional reintegration. Conclusions. Spinal EAVFs are rare lesions with a low risk of bleeding; the clinical manifestations are determined by the compres-sion of the bone marrow; these being significantly improved after the endovascular and surgical treatment. Studies show a good long-term prognosis, which is determined by the absence of re-currences. An essential role in the integration of patients with disabilities in the socio-professional life is the identification of their deficiencies and their reorientation according to the outstanding abilities, the stimulation of the preserved skills. Keywords: rehabilitation, disc hernia, low back pain, paraplegia

The utility of intraoperative neurophysiological monitoring in surgical treatment for spinal arteriovenous malformations: a historical control study

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Postoperative neurological complications are not rare in surgical treatment for spinal arteriovenous malformations (SAVMs).

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An in-group analysis showed that the accuracy of IONM for detecting postoperative neurological complications was relatively high.

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Multimodal IONM may reduce postoperative neurological complications in the surgical treatment for SAVMs.

Objective

Methods

Results

Conclusions

Significance

Concomitant spinal dural arteriovenous fistula and nodular fasciitis in an adolescent: case report

Background

Spinal dural arteriovenous fistula (SDAVF) usually occurs during the 4^th to 6^th decades of life, and adolescent SDAVF is rarely reported. SDAVF arising around a tumor is also rare, and reported tumors are mostly schwannoma and lipoma.

Case presentation

We reported a 16-year-old male presented with progressive weakness and numbness of lower limbs for 3 months. A SDAVF was found, which was fed by right radicular arteries from segmental artery at L2 level and drained retrogradely into perimedullary veins. A concomitant spinal extradural nodular fasciitis at right L1/L2 intervertebral foramen was also noted. The SDAVF was completely obliterated by endovascular treatment and the tumor was debulked. The patient recovered well after the procedures.

Conclusions

Our case report suggests SDAVF can occur in adolescent. The concomitant presence with a nodular fasciitis indicates that although it usually arises in subcutaneous tissue but can rarely form on the dura of spine.

Resection of ruptured spinal pial arteriovenous fistula under ultrasound control: how I do it

BACKGROUND

Spinal pial arteriovenous fistulae are rare intradural superficial vascular lesion consisting in a direct shunt between spinal pial arteries and veins. The presentation of pial arteriovenous fistula is caused by venous congestion with spinal cord ischemia, mass effect, or hemorrhage. The treatment is surgery or endovascular procedure.

METHODS

We illustrate the case of thoracic pial arteriovenous fistula in a 66-year-old female operated with posterior midline approach and B-mode US.

CONCLUSION

Posterior midline approach with targeted laminotomy using high-speed drill affords an ideal surgical exposure. B-mode US is helpful to detect the fistula and study their relationship with the surrounding structures.

Spinal Vascular Shunts: A Patterned Approach

Spinal vascular shunts, including fistulas and malformations, are rare and complex vascular lesions for which multiple classification schemes have been proposed. The most widely adopted scheme consists of 4 types: type I, dural AVFs; type II, intramedullary glomus AVMs; type III, juvenile/metameric AVMs; and type IV, intradural perimedullary AVFs. MR imaging and angiography techniques permit detailed assessment of spinal arteriovenous shunts, though DSA is the criterion standard for delineating vascular anatomy and treatment planning. Diagnosis is almost exclusively based on imaging, and features often mimic more common pathologies. The radiologist's recognition of spinal vascular shunts may improve outcomes because patients may benefit from early intervention.

Acute Myelopathy: Vascular and Infectious Diseases

Vascular and infectious causes are rare but important causes of spinal cord injury. High suspicion for these processes is necessary, as symptoms may progress over hours to days, resulting in delayed presentation and diagnosis and worse outcomes. History and clinical examination findings can assist with localization of the affected vascular territory and spinal level, which will assist with focusing spinal imaging. Open and/or endovascular surgical management depends on the associated vascular abnormality. Infectious myelopathy treatment consists of targeted antimicrobial therapy when possible, infectious source control, and again, close monitoring for systemic complications.

Acute paraplegia in patient with spinal dural arteriovenous fistula after lumbar puncture and steroid administration: A case report

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Spinal dural arteriovenous fistula is an uncommon cause of longitudinal transverse myelitis.

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Spinal dural arteriovenous fistula can be easily misdiagnosed.

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It usually presents with venous congestive myelopathy symptoms and misdiagnosis is common.

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Prescence of flow voids on MRI should raise the suspicion of underlying fistula.

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Intravenous steroid and lumbar puncture may be associated with acute neurological deterioration.

Introduction and importance

Spinal dural arteriovenous fistula (SDAVF) is an uncommon cause of longitudinal extensive transverse myelitis (LETM). It usually presents with vague congestive myelopathy symptoms and diagnosis is usually difficult on initial presentation. Common daily neurological interventions can aggravate the underlying pathophysiology leading to undesirable acute neurological deterioration. Intravenous steroids administration and lumbar (LP) puncture as a diagnostic tool are amongst the most commonly reported aggravating interventions. This rare case presentation highlights this association with its negative impact on the patient outcome in misdiagnosed cases.

Case presentation

The authors present a sixty-eight-year-old male with paraplegia following steroid administration and LP for presumed inflammatory/autoimmune LETM in the setting of misdiagnosed SDAVF. The absence of flow voids on the conventional T2-weighted magnetic resonance image (MRI) lead to misdiagnosis. He had satisfactory neurological recovery few hours after surgical disconnection.

Clinical discussion

SDAVF is known to cause congestive myelopathy symptoms. Spinal angiogram is the gold standard for diagnosis. Although the exact mechanism is not fully understood, misdiagnosed cases like our case can develop severe neurological deterioration with steroid administration and lumbar puncture.

Conclusion

Although SDAVF is an uncommon cause of LETM, Clinicians should carefully exclude it before proceeding to steroid administration or performing LP as they can lead to devastating neurological deterioration.

Spinal cord arterio-venous shunts: From classification to therapeutic management

Spinal Cord Arterio-Venous shunts (SCAVSs) are a rare disease. The aim of this paper is to describe how we classify and consider management of SCAVSs in relation to the location of the shunt focusing mainly on intradural SCAVSs. The anatomical features of the SCAVSs together with data provided by MRI and CT scans allow identification of four types of SCAVSs: paraspinal, epidural, dural and intradural ones. Clinical and neuroradiologic characteristics are described for each entity as well as the therapeutic endovascular management at our institution between 2002 and 2020. The therapeutic management of SCAVSs, and in particular of intradural shunts, remains mainly based on endovascular treatment as a first-choice approach. Understanding properly the lesional and regional vascular anatomy is mandatory to plan an appropriate therapeutic strategy and obtain good clinical results stable at long term follow up.

Myelopathy secondary to an intramedullary arteriovenous malformation in a mature dog

A 2‐year‐old crossbreed dog was presented for evaluation of a 6‐week history of progressive paraparesis. Magnetic resonance imaging and computed tomography angiography of the thoracic and lumbar spinal cord disclosed multifocal, anomalous, small, vascular structures, distributed throughout the subarachnoid space of the included section of the spinal cord. An additional focal intramedullary lesion was identified extending from T9 to T10 to T12. Histopathological examination confirmed the presence of an intramedullary arteriovenous malformation affecting the thoracic spinal cord and leading to diffuse congestion and focal hemorrhages into the affected spinal cord.

Intramedullary tumours and tumour mimics

Spinal cord lesions are traditionally classified as either extradural or intradural extramedullary or of intramedullary origin. Intramedullary spinal cord tumours are histopathologically similar to cranial tumours with a diverse range of pathologies. Astrocytomas and ependymomas account for approximately 80% of all intramedullary tumours, with other primary and secondary lesions accounting for the remaining 20%. Magnetic resonance imaging is the preferred imaging modality for diagnosing and characterising spinal cord lesions; however, accurate characterisation of tumour histology can be challenging, and is further confounded by intramedullary non-neoplastic lesions, such as demyelinating vascular, inflammatory, infectious, or traumatic lesions. This review illustrates the spectrum of intramedullary tumours and tumour mimics with emphasis on the imaging findings.

Steroid-Associated Acute Clinical Worsening and Poor Outcome in Patients With Spinal Dural Arteriovenous Fistulas: A Prospective Cohort Study

STUDY DESIGN

A prospective cohort study.

OBJECTIVE

We conducted a prospective cohort study to identify the association between steroids and clinical worsening and compare outcomes between patients with and without preoperative steroid administration.

SUMMARY OF BACKGROUND DATA

Patients with spinal dural arteriovenous fistulas (SDAVFs) often were misdiagnosed and treated with steroids which led to acute worsening.

METHODS

Patients with angiographically confirmed SDAVFs were recruited consecutively between March 2013 and December 2014 in two referral centers. We reviewed the history of all the patients to identify those patients who were treated with steroids before exclusion of the fistulas. Modified Aminoff & Logue scale (mALS) was used to evaluate the spinal cord function at different time points: before and after steroid administration, before operation, and at 1-year follow-up. Paired t tests were used to assess the mALS of patients with steroid administration at different time points. Unpaired t tests and Pearson chi-square test were used to assess differences between patients with and without steroid administration.

RESULTS

Eighteen patients with (18.2%) and 81 patients without (81.8%) steroid administration were included in this study. At baseline, there were no difference between both patient groups, in regards to age, sex, duration, location of fistula, treatment, and preoperative mALS. Patients without steroid administration, however, had statistically significant better outcome according to their mALS at 1-year follow-up (P < 0.05).

CONCLUSION

Steroid administration can induce acute clinical worsening in patients with SDAVFs that may persist despite successful obliteration of the fistula and should thus be avoided.

LEVEL OF EVIDENCE

3.

Metameric spinal AVM: Long-term symptomatic relief achieved by embolization of the extradural component

BACKGROUND

Metameric spinal cord arteriovenous malformations (AVMs) are rare lesions characterized by an intradural and extradural component. They are difficult to treat surgically by the endovascular route. We report a case in which symptomatic relief was achieved by embolization of the extradural component only.

CASE PRESENTATION

A 35-year-old woman presented with acute worsening of back pain, weakness in the left leg and urinary retention. Spinal angiography showed a metameric spinal cord AVM with partial common venous drainage of the extradural and intradural components.

CONCLUSIONS

Targeted embolization of the extradural component led to dramatic improvement of the patient's symptoms, probably by achieving venous decongestion. She remains neurologically stable at two years' follow-up.

Enhanced recovery after surgery in intramedullary and extramedullary spinal cord lesions: perioperative considerations and recommendations

Enhanced recovery after surgery (ERAS) is an evidence-based approach developed to ameliorate the patient recovery process following surgical procedures. Employing a multimodal, multidisciplinary approach, ERAS implements strategies and treatment paradigms that have been shown to improve patient outcomes, reduce hospital length of stay, and ultimately reduce healthcare costs. With a substantial body of the literature supporting the implementation of ERAS in other surgical specialties, ERAS has only recently made its foray into spine surgery. Despite this, current studies are limited to spinal deformity and degenerative disease, with limited data regarding spinal cord surgery. This is due in part to the complex nature and rarity of spinal cord lesions, making the establishment of a formal ERAS protocol difficult. In developing an ERAS protocol, there must be a consensus on what factors are important to consider and implement. To address this, we reviewed the most recent advances in intramedullary and extramedullary spinal cord surgery in order to identify elements that influence patient outcomes. Using this information, the authors provide evidence-based recommendations with the intent of introducing a framework for future ERAS protocols with respect to treating spinal cord lesions.

Natural history of spinal cord arteriovenous shunts: an observational study

The natural history of intradural spinal cord arteriovenous shunts is unknown. We performed an observational study in a consecutive patient cohort with symptomatic intradural spinal cord arteriovenous shunts who were admitted to three institutes to investigate the clinical course of this complex disease, which would provide valuable evidence to inform clinical decision-making. The clinical course of patients with symptomatic intradural spinal cord arteriovenous shunts from initial presentation to occurrence of clinical deterioration, initiation of treatment, or last follow-up was analysed. Patients with at least 1 month of observation were included in this study. Clinical onset and deterioration patterns were divided into acute and gradual. Annual and cumulative rates of clinical deterioration as well as their risk factors were analysed using Kaplan-Meier life table analysis and Cox proportional hazards model. To assess risks and benefits of treatment, post-treatment clinical courses were further assessed. Four hundred and sixty-six patients with a mean observational period of 36.9 ± 58.8 months were included; 56.7% of patients presented with acute onset, of whom 77.3% experienced spontaneous recovery. Age of onset older than 28 years, initial modified Aminoff and Logue scale of >3, mid-thoracic lesions and non-ventral lesions were independent predictors of failure for spontaneous recovery. The annual risk of general, acute and gradual clinical deterioration after onset was 30.7%, 9.9% and 17.7%, respectively. Risk of deterioration was highest in the early period after initial onset. Acute onset was the only independent risk factor [hazard ratio 1.957 (95% confidence interval, CI 1.324–2.894); P = 0.0008] of acute deterioration and gradual onset was the strongest predictor [hazard ratio 2.350 (95% CI 1.711–3.229); P < 0.0001] of the gradual deterioration among all the stratifying factors. After invasive treatment, complete obliteration was achieved in 37.9% of patients (138 of 364) and improved or stable clinical status was noted in 80.8% of patients. Forty-two patients (11.5%) experienced permanent complications. Overall post-treatment deterioration rate was 8.4%/year, and 5.3%/year if permanent complications were excluded. The natural history of symptomatic spinal cord arteriovenous shunts is poor, especially in the early period after onset, and early intervention is thus recommended. Initial onset pattern significantly affects the natural history of the lesion, which prompts a differentiated treatment strategy.

Synchrotron radiation micro-tomography for high-resolution neurovascular network morphology investigation

There has been increasing interest in using high-resolution micro-tomography to investigate the morphology of neurovascular networks in the central nervous system, which remain difficult to characterize due to their microscopic size as well as their delicate and complex 3D structure. Synchrotron radiation X-ray imaging, which has emerged as a cutting-edge imaging technology with a high spatial resolution, provides a novel platform for the non-destructive imaging of microvasculature networks at a sub-micrometre scale. When coupled with computed tomography, this technique allows the characterization of the 3D morphology of vasculature. The current review focuses on recent progress in developing synchrotron radiation methodology and its application in probing neurovascular networks, especially the pathological changes associated with vascular abnormalities in various model systems. Furthermore, this tool represents a powerful imaging modality that improves our understanding of the complex biological interactions between vascular function and neuronal activity in both physiological and pathological states.

Location, length, and enhancement: systematic approach to differentiating intramedullary spinal cord lesions

Purpose

Intramedullary spinal cord abnormalities are often challenging to diagnose. Spinal cord biopsy is a high-risk procedure with the potential to cause permanent neurological injury. Magnetic resonance imaging is the modality of choice for diagnosis and preoperative assessment of patients with spinal cord abnormalities. The radiologist’s ability to narrow the differential diagnosis of spinal cord abnormalities has the potential to save patients from invasive approaches for diagnosis and also guide appropriate management.

Approach/methods

This article will provide a systematic approach to the evaluation of intramedullary spinal cord lesions—with emphasis on location, length and segment distribution, and enhancement pattern—to help narrow the differential diagnosis. In doing so, we will review various spinal cord pathologies, including demyelinating and metabolic conditions, neoplasms, and vascular lesions.

Summary/conclusion

Although intramedullary spinal cord abnormalities can be a challenge for the radiologist, a systematic approach to the differential diagnosis with a focus on lesion location, cord length and segment involvement, as well as enhancement pattern, can greatly help narrow the differential diagnosis, if not synch the diagnosis. This strategy will potentially obviate the need for an invasive approach to diagnosis and help guide treatment.

Teaching points

• Imaging diagnosis of intramedullary spinal cord lesions could obviate cord biopsy.

• Evaluation of cord lesions should focus on location, length, and enhancement pattern.

• In demyelination, the degree of cross-sectional involvement is a distinguishing feature.

Paraspinal arteriovenous fistula: Stuttgart classification based on experience and a review of the literature

The term "paraspinal arteriovenous shunts" (PAVSs) summarizes an inhomogeneous variety of rare vascular disorders. PAVSs have been observed as congenital or acquired lesions. The clinical course of PAVSs may be asymptomatic or present with life-threatening symptoms. Based on a collection of individual cases from three institutions and a literature evaluation, we propose the following classification: PAVSs that are part of a genetic syndrome are separated from "isolated" PAVSs. Isolated PAVSs are subdivided into "acquired", "traumatic" and "congenital" without an identifiable genetic hereditary disorder. The subgroups are differentiated by the route of venous drainage, being exclusively extraspinal or involving intraspinal veins. PAVSs associated to a genetic syndrome may either have a metameric link or occur together with a systemic genetic disorder. Again extra-vs intraspinal venous drainage is differentiated. The indication for treatment is based on individual circumstances (e.g. myelon compression, vascular bruit, high volume output cardiac failure). Most PAVSs can be treated by endovascular means using detachable coils, liquid embolic agents or stents and derivates.

Spinal cord

We first present a brief historic review of developments in the understanding of spinal cord clinical neuroanatomy and neurophysiology over the past 200 years. We then discuss the technical aspects that apply to the examination of the human spinal cord giving details on the interrelations between the spinal cord and the overlying structures, including the meninges and vertebrae. The subsequent discussion focuses on diseases of the spinal cord. Diseases that affect the spinal cord are vascular disease, diseases of spinal column, trauma, developmental abnormalities, central nervous system degenerative disease, inflammatory disease, metabolic and nutritional myelopathies, and tumors. We summarize our knowledge regarding general reactions of spinal cord tissue to disease, in particular Wallerian degeneration of descending/ascending tracts and axonal reaction. Two categories of disease will be covered in depth: vascular disease of the spinal cord, including a review of normal vascular anatomy, and diseases of the vertebral column that can affect the cord secondarily.

Cord Topographical Anatomy and its Role in Evaluating Intramedullary Lesions

Intramedullary spinal lesions present a wide differential diagnosis including infectious, inflammatory, traumatic, ischemic, benign, or malignant neoplastic etiologies. Using knowledge of anatomy and physiology within the spinal cord, many similar appearing entities can be parsed into a prioritized differential. The purpose of this article is to review anatomy and pathophysiology of the spinal cord, with subsequent discussion of how this knowledge can be used to differentiate several similar appearing intramedullary pathologic processes. Discussion includes the pathophysiology, imaging findings, and clinical pearls of several intramural lesions including infarct, demyelinating lesions, traumatic injury, neoplasm, vascular malformation, and metabolic processes such as subacute combined degeneration.

Magnetic Resonance Imaging and Clinical Features in Acute and Subacute Myelopathies

Differential diagnosis of acute and subacute transverse myelopathy includes inflammatory, infectious, vascular, metabolic and paraneoplastic etiologies. Information on the diagnostic approach to transverse myelopathy with regard to daily clinical practice is provided. The differentiation between five lesion patterns on magnetic resonance imaging (MRI) in myelitis may be helpful: (1) longitudinal extensive transverse myelitis, (2) short segment ovoid or peripherally located, (3) "polio-like", (4) granulomatous and (5) segmental with rash. A correlation with these imaging features is supported if the clinical course and neurological symptoms are known. Although the mean interval from onset to nadir of symptoms in spinal cord infarction is 1 h, an overlap with a fulminant course of myelitis is possible, and impaired diffusion may also occur in acute inflammatory processes. As a result, laboratory testing, including aquaporin-4 antibodies and cerebrospinal fluid analysis, is crucial for the correct interpretation of imaging findings. Moreover, the discrimination of acute complete and acute partial transverse myelitis is advantageous in order to identify diverse entities, the latter often being a precursor to multiple sclerosis. Additional brain imaging is mandatory in suspected demyelinating, infectious, neoplastic and systemic autoimmune disease. A symmetrical lesion pattern restricted to individual tracts or dorsal columns indicates subacute combined degeneration of the spinal cord and, in addition to deficiency syndromes, a paraneoplastic etiology should be considered.

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.

A Review of Vascular Abnormalities of the Spine

Patients with spinal vascular lesions present with unique symptoms and have important anatomical and physiologic changes that must be considered prior to treatment. In this mini-review, we provide an overview of normal spinal vascular anatomy and discuss several key spinal vascular lesions. We provide an overview of cavernous malformations, intradural arteriovenous malformations, perimedullary arteriovenous fistulas, and dural arteriovenous fistulas. Important considerations are addressed in terms of pathologic characterization, specific imaging findings, and treatment approaches.

Spinal arteriovenous fistulae: surgical management

Spinal vascular malformations include several types of pathologic entities with multiple variations in their neurologic presentation and risks. Spinal dural arteriovenous fistulae (SDAVF) are the most frequent type, and account for 70% of all lesions affecting the spinal cord. The nonspecific early neurologic symptoms of SDAVF often make early diagnosis of this clinical entity challenging, and a delay in diagnosis or appropriate treatment often has devastating consequences on spinal cord function. The lesion can invariably be obliterated with surgical occlusion of the intradural arterialized venous reflux, and progression of neurologic deficits is usually arrested and sometimes reversed.

Comparison of 3 Different Types of Spinal Arteriovenous Shunts below the Conus in Clinical Presentation, Radiologic Findings, and Outcomes

BACKGROUND AND PURPOSE

Spinal arteriovenous shunts below the conus constitute 3 types of lesions, which have previously been mainly described in case reports, given their rarity, and are sometimes misdiagnosed. The purpose of this study was to describe the features of each type and compare these types as to epidemiologic features, clinical and radiologic presentations, treatment, and outcomes in a consecutive series of 48 cases.

MATERIALS AND METHODS

The prospectively collected data bases of 2 referral centers for spinal vascular lesions were retrospectively reviewed. Spinal arteriovenous shunts below the conus were defined as all dural and intradural shunts below the conus medullaris. Clinical features, radiologic findings, treatment results, and clinical outcomes were assessed.

RESULTS

There were filum terminale arteriovenous fistulas in 11 patients (22.9%), radicular arteriovenous shunts in 7 patients (14.6%), and spinal dural arteriovenous fistulas in 30 patients (62.5%). Radicular arteriovenous shunts presented at a younger age (P = .017) and with a higher incidence of back pain symptoms (P = .037). A tethered spinal cord was found in 54.5% of patients with filum terminale arteriovenous fistulas and 23.3% of patients with spinal dural arteriovenous fistulas. After treatment, the angiographic complete obliteration rate was 89.4% and spinal function was improved significantly (P < .001).

CONCLUSIONS

Three groups of spinal arteriovenous shunts below the conus can be differentiated according to clinical and radiologic features. Filum terminale arteriovenous fistulas are frequently associated with dysraphic malformations, which may suggest a particular embryologic origin.

Intradural spinal varix: the "doughnut" sign on T 2 weighted MR and confirmation with gadolinium-enhanced arterial and blood pool MR angiography

Intradural spinal varices are rare lesions, with only three cases being previously reported in the literature. Previously described patients underwent MRI for non-specific low back pain and radiculopathy and were found to have an intradural lesion adjacent to the cauda equina, mimicking a nerve sheath tumour or ependymoma. Consideration of an intradural varix in the differential diagnosis of an intradural extramedullary spinal lesion is necessary to guide appropriate management. We report a case of an intradural spinal varix diagnosed with first-pass arterial and blood pool phase gadolinium-enhanced auto-triggered elliptic centric-ordered MR angiography. Digital subtraction angiography confirmed that there was no shunt but failed to demonstrate the varix. We reviewed the existing literature to look for common clinical and imaging features.

Stereotactic radiosurgery as a feasible treatment for intramedullary spinal arteriovenous malformations: a single-center observation

Spinal cord intramedullary arteriovenous malformations are rare. For patients suffering from either hemorrhage or myelopathy, surgical or endovascular interventions are indicated. However, complete eradication of the nidus is often difficult because of its intramedullary location and complex angioarchitecture. In this report, we evaluate the feasibility and safety of stereotactic radiosurgery as a treatment modality for intramedullary spinal arteriovenous malformations (AVMs). Between 2010 and 2014, we performed stereotactic radiosurgery to treat four patients with intramedullary AVM and one with spinal arteriovenous metameric syndrome (one woman and four men; age range, 31-66 years). Three patients presented with myelopathy, and two suffered hemorrhages. Nidi were located in the cervical (three cases) and thoracic (two cases) spinal cord regions. Based on the angioarchitecture, surgery and endovascular embolization were indicated. When both modalities were deemed hazardous, radiosurgery using CyberKnife™ was offered. Radiation using marginal doses of 18 Gy was administered in three fractions. The mean follow-up period was 37.2 months (range, 16-62 months). After treatment, two of the three patients with myelopathy experienced either improvement or stabilization of their symptoms and one experienced worsening of dysesthesia. In two patients with hemorrhage, symptoms improved in one and remained stable in the other. No further hemorrhagic episodes were evident during follow-up. Follow-up angiograms showed marked shrinkage of the nidus located in the thoracic spinal cord in one case and angiographic stabilization in the others. As a treatment modality for intramedullary AVMs, CyberKnife™ is safe and can be considered when surgery or endovascular therapy is not indicated. To determine optimum radiation doses and protocols for treating spinal AVMs, further studies with more patients and long-term follow-up are required.