Spinal vascular lesions: anatomy, imaging techniques and treatment

MR Imaging of Spinal Vascular Lesions

Spinal vascular lesions are an uncommon but important etiology for myelopathy. A high index of suspicion and appropriate protocol development are critical to correctly diagnose and direct management of these lesions. Contrast enhanced MR angiography should be considered for characterization of these lesions following anatomic image acquisition. When reporting on these cases, the presence of intramedullary spinal cord edema and blood products as well as potential arterial supply and venous drainage should be included.

Is the Atlantoaxial Level Overlooked in the Radiologic Interpretation of Cervical Magnetic Resonance Imaging?

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

The purpose of this study is to quantify the rate at which the atlantoaxial level is omitted from official cervical magnetic resonance imaging (MRI) radiologic reports and to identify potential missed pathology, emphasizing the need for improved standardization of evaluation.

SUMMARY OF BACKGROUND DATA

MRI is a readily utilized modality for evaluating the axial skeleton. In our experience, the atlantoaxial level of the cervical spine is often overlooked on MRI radiologic reports in the absence of trauma or obvious pathology.

METHODS

The preoperative MRIs and associated radiologic reports of 219 patients undergoing cervical decompression and fusion in a single year were collected. The inclusion or omission of distinct evaluation at the atlantoaxial level within each radiologic report was recorded. All imaging was then reviewed. The atlantoaxial level was specifically evaluated, and any pathology was noted and compared with the official radiologic reports. The rates of atlantoaxial evaluation omission from the radiologic reports and missed pathology at this level were primarily and secondarily reported.

RESULTS

MRI studies were performed at 101 different institutions, with reports issued by 126 individual radiologists. Specific documentation of atlantoaxial evaluation was noted in 32 (14.6%) radiology reports, with the remaining 187 cases (85.4%) including no mention of this level. Upon independent re-review of the imaging, pathology was noted at the atlantoaxial level in 18 patients (8.2%), totaling 19 abnormal findings. Such findings were absent from the official reports in 13 of these cases (5.9% of the total study population).

CONCLUSIONS

In our study, formal documentation was omitted from 85% of reports resulting in missed pathology in nearly 6% of cases. This study underscores the importance of thorough imaging interpretation and clinical correlation with patient symptoms. In addition, it highlights the need for standardized reporting of these studies to prevent potential morbidity associated with a missed diagnosis.

Three-Dimensional Exoscope-Assisted Occlusion of a Foraminal Intradural Left L5-S1 Arteriovenous Fistula-Operative Video

Spinal dural arteriovenous fistulas (dAVFs) are a rare type of spinal lesion that can cause severe clinical consequences.1 Early and accurate diagnosis and treatment are crucial to avoid severe complications such as radicular pain, weakness, sensory deficits, and loss of bowel and bladder control.2 Spinal dAVFs are commonly found in the lower thoracic or upper lumbar vertebrae. Spinal dAVFs are the most common spinal vascular malformations, of unknown cause, accounting for 70%-85 % of spinal shunts, with an annual incidence of 5-10 cases/1,000,000.3 Recently, they have been classified into extradural and intradural types, which may be further divided into dorsal and ventral lesions.4,5 Spine magnetic resonance imaging (MRI) is the most performed imaging study for suspected dAVF diagnosis.1 Catheter digital subtraction angiography (DSA) represents the gold-standard diagnosing technique. It provides critical information about the anatomy of the lesion, arterial inflow vessels, venous outflow, and endovascular treatment feasibility. DSA may also detect typical structures at risk during treatment.6 Surgical interruption of dAVF offers a complete cure, with low complication rates. Endovascular embolization might be safe and efficient, with high success rates, for selected vascular lesions.7,8 This video presents a rare case of left L5-S1 dAVF, surgically occluded with the aid of a three-dimensional (3D) exoscope (Video 1). There is little evidence about the application of the 3D exoscope in spinal vascular microsurgery, whereas it has been widely used and described in cranial surgery and spinal, degenerative, tumor, and traumatic surgery.9 In our experience, the advantages of this operating tool are the sharp color vividness, which allows adequate discrimination of anatomic structures, the distinct depth perception, the educational value for operating room attendants, and the ergonomics for surgeons. Ergonomics for surgeons, especially, is optimally adapted to spinal surgery, given the contraposed placement of surgeons and the disposition of screens during the operating procedure.

Hemorrhagic encephalopathies and myelopathies in dogs and cats: a focus on classification

The prevalence of hemorrhagic diseases of the central nervous system of dogs and cats is low compared to other diseases such as neoplasia and inflammation. However, the clinical consequences can be devastating. Several etiological and localization-based classification systems have been reported for intracerebral and spinal cord hemorrhage or hematomyelia in humans but similar systems do not exist in veterinary medicine. The authors propose an etiologic classification system for both intraparenchymal hemorrhagic encephalopathy and myelopathy following a review of the literature detailing the presentation, diagnosis, therapy, and prognosis of these diseases. A summary of the investigative and therapeutic approach to these cases is also provided.

Toward Functional PET Imaging of the Spinal Cord

At present, spinal cord imaging primarily uses magnetic resonance imaging (MRI) or computed tomography (CT), but the greater sensitivity of positron emission tomography (PET) techniques and the development of new radiotracers are paving the way for a new approach. The substantial rise in publications on PET radiotracers for spinal cord exploration indicates a growing interest in the functional and molecular imaging of this organ. The present review aimed to provide an overview of the various radiotracers used in this indication, in preclinical and clinical settings. Firstly, we outline spinal cord anatomy and associated target pathologies. Secondly, we present the state-of-the-art of spinal cord imaging techniques used in clinical practice, with their respective strengths and limitations. Thirdly, we summarize the literature on radiotracers employed in functional PET imaging of the spinal cord. In conclusion, we propose criteria for an ideal radiotracer for molecular spinal cord imaging, emphasizing the relevance of multimodal hybrid cameras, and particularly the benefits of PET-MRI integration.

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.

Clinical Approach to Myelopathy Diagnosis

OBJECTIVE

This article describes an integrative strategy to evaluate patients with suspected myelopathy, provides advice on diagnostic approach, and outlines the framework for the etiologic diagnosis of myelopathies.

LATEST DEVELOPMENTS

Advances in diagnostic neuroimaging techniques of the spinal cord and improved understanding of the immune pathogenic mechanisms associated with spinal cord disorders have expanded the knowledge of inflammatory and noninflammatory myelopathies. The discovery of biomarkers of disease, such as anti-aquaporin 4 and anti-myelin oligodendrocyte glycoprotein antibodies involved in myelitis and other immune-related mechanisms, the emergence and identification of infectious disorders that target the spinal cord, and better recognition of myelopathies associated with vascular pathologies have expanded our knowledge about the broad clinical spectrum of myelopathies.

ESSENTIAL POINTS

Myelopathies include a group of inflammatory and noninflammatory disorders of the spinal cord that exhibit a wide variety of motor, sensory, gait, and sensory disturbances and produce major neurologic disability. Both inflammatory and noninflammatory myelopathies comprise a broad spectrum of pathophysiologic mechanisms and etiologic factors that lead to specific clinical features and presentations. Knowledge of the clinical variety of myelopathies and understanding of strategies for the precise diagnosis, identification of etiologic factors, and implementation of therapies can help improve outcomes.

Sporadic Spinal Hamartoma in Adults: A Rare Pathologic Entity

BACKGROUND

Sporadic spinal hamartomas in adults are extremely rare tumor-like lesions, without defined guidelines of treatment. The aim of this study is to investigate the peculiar features of this pathologic entity to support a more accurate diagnosis and management.

METHODS

A comprehensive and detailed literature review of sporadic spinal hamartomas in adults, including a personal case, was performed. Demographic (sex and age), clinical (presenting symptoms), radiologic and pathologic (size, localization, dural and spinal cord relationship of lesion) features, as well as treatment (time to surgery, extent of resection, perioperative and postoperative complications) and outcome (clinical) data were analyzed.

RESULTS

Seven studies, including 7 patients, were eligible for the review. A personal case was also added. Sporadic adult spinal hamartomas equally affect males and females, in a range of age from 18 to 75 years; sensory radicular deficits were detected in all patients at clinical onset; thoracic segment (4/8) of the spine and intradural compartment (6/8) were most involved. All patients underwent surgery and just one experimented postoperative complication; gross total resection was achieved in only 3 patients, mainly in an extradural localization; clinical improvement at last follow-up was reported in all but 1 patient.

CONCLUSIONS

Spinal hamartomas in adults may sometimes account for progressive worsening of neurologic symptoms and lead to potentially irreversible neurologic deficit; therefore, prompt and adequate diagnosis and treatment are mandatory. Surgical resection represents the only curative treatment and is indicated for symptomatic lesions to achieve neurologic symptoms restoration or arrest/prevent their progressive deterioration.

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.

"Missing-piece" sign with dural arteriovenous fistula at craniocervical junction: A case report

OBJECTIVES

Spinal dural arteriovenous fistula (sDAVF) is a rare and often underdiagnosed spinal disease. Early diagnosis is required because the deficits are reversible and delays in treatment cause permanent morbidity. Although the abnormal vascular flow void is a critical radiographic feature of sDAVF, they are not always present. A characteristic enhancement pattern of sDAVF has been recently reported as the "missing-piece" sign which can lead to the early and correct diagnosis.

METHODS

We presented imaging findings, treatment decisions, and the outcome of a rare case of sDAVF, in which the "missing-piece" sign appeared atypical.

RESULTS

A 60-year-old woman developed numbness and weakness in her extremities. Spinal MRI revealed longitudinal hyperintensity in the T2-weighted image, extending from the thoracic level to medulla oblongata. At first, myelopathy with inflammation or tumor was suspected because of the lack of flow voids and vascular abnormalities in CT-angiography and MR-DSA. However, we administered intravenous methylprednisolone and her symptom got worse with the appearance of the "missing-piece" sign. Then, we successfully diagnosed sDAVF by angiography. The "missing-piece" sign was considered to derive from inconsistency of the intrinsic venous system of spinal cord, with the abrupt segments without enhancement. The same etiology was considered in our case.

CONCLUSIONS

Detecting the "missing-piece" sign can lead to the correct diagnosis of sDAVF, even if the sign appeared atypical.