Anterior spinal artery stroke demonstrated by echo-planar DWI

Isolated Infarctions of the Conus Medullaris: Clinical Features and Outcomes

OBJECTIVE

This study aims to describe the clinical features and outcomes of patients with isolated infarctions of the conus medullaris, and to identify factors associated with poor functional outcomes.

MATERIALS AND METHODS

We performed a systematic review and retrospective analysis on the clinical characteristics and outcomes of patients with isolated conus medullaris infarctions reported in literature over the past 30 years.

RESULTS

We analyzed a total of 19 cases; 18 identified in literature from January 1991 to June 2021, together with our patient. Their median age was 56 years (range 28-79), with twice as many females as males. Pain was prominent at onset (15/19, 79%), only a third had vascular risk factors (7/19, 37%), and half had no significant preceding activities or events (9/19, 47%). Almost all experienced paraplegia or paraparesis (16/19, 84%), in which upper motor neuron features were rare (3/19, 16%). The underlying cause was unknown in half (10/19, 53%). Functional outcomes appeared fair, with nearly half being capable of unassisted ambulation (9/11, 82%). Patients with vascular risk factors (67% vs 13%, p = 0.024) or with identified underlying causes (78% vs 13%, p = 0.007) were less likely to walk unassisted.

CONCLUSION

Isolated conus medullaris but should be considered in patients with acute cauda equina syndrome, especially in females. Patients with vascular risk factors, or with known causes of infarction, are less likely to walk unassisted. DWI sequences should be included in conventional MRI sequences when evaluating patients with acute cauda equina syndrome.

Sulcal artery syndrome: A Three-patient series and review of literature

OBJECTIVE

This study aims to describe the clinical characteristics of patients with sulcal artery syndrome, and between those with vertebral artery dissection against those without.

METHODS

We report three cases of sulcal artery syndrome without vertebral artery dissection, performed a systematic review and retrospective analysis of the characteristics of patients with sulcal artery syndrome in available literature, and compared the clinical features of those with vertebral artery dissection against those without.

RESULTS

We report 3 patients with sulcal artery syndrome, and analysed them with 17 other cases identified in literature between January 1990 till April 2020. The mean age was 47 years (range 10-80), with twice as many males as females. Pain at onset was a prominent feature (17/18, 94.4%). Preceding trauma occurred in less than half (7/18, 38.9%). Most had cervical cord infarctions (18/20, 90%), often over the high cervical cord (16/18, 88.9%). Good functional recovery (mRS 0-2) was observed in 86.7% (13/15). While vertebral artery dissection was the leading aetiology (11/20, 55.5%), about half of the cases were due to other causes. Cervical cord involvement was significantly associated with vertebral artery dissection (p = 0.026).

CONCLUSION

Sulcal artery syndrome should be suspected in patients with acute hemicord syndrome, especially in males with cervical cord involvement or pain at onset. High cervical cord involvement was strongly suggestive of underlying vertebral artery dissection. Additionally, DWI sequences are useful when evaluating acute myelopathies, and its inclusion in conventional MRI sequences is supported in prevailing literature.

Acute Spinal Cord Infarction Presenting With Chest Pain and Neurogenic Shock: A Case Report

BACKGROUND

Spinal cord infarction (SCI) is rare, accounting for approximately 1% of strokes.

CASE REPORT

We present the case of a 63-year-old male who presented to the emergency department (ED) with chest pain and acute-onset generalized weakness and was ultimately diagnosed with SCI secondary to suspected occlusion of the artery of Adamkiewicz. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: SCI may present diagnostic challenges, with its predilection for mimicking other major emergency conditions, such as acute aortic dissection, aortic aneurysm rupture, spinal cord compressive myelopathy, or transverse myelitis. Its consequences are often significantly disabling initially, though patients may experience subsequent clinical improvement. It is important to include SCI in the differential for patients with chest or back pain coupled with neurologic symptoms.

Diagnostic and Prognostic Relevance of Magnetic Resonance Imaging and Electrophysiological Findings in Acute Spinal Ischemia

OBJECTIVE

Our purpose was to classify the rare entity of spontaneous spinal ischemia with clinical, magnetic resonance-tomographic, and electrophysiological parameters to determine criteria for outcome prediction.

METHODS

We analyzed the stroke registry database of the University Hospital Mannheim, Germany, from 2004 to 2010 for patients with a diagnosis of vascular spinal cord ischemia.

RESULTS

Ten patients were identified (mean age 65 years [range 50-83], 5 women). In 5 patients an etiology was found. Spinal diffusion-weighted magnetic resonance imaging revealed acute ischemia in 7 patients at initial imaging and this diagnosis was confirmed during the first week in the remaining 3 patients. Electrophysiological studies showed abnormal motor evoked potentials (MEPs) in 8 patients and abnormal somatosensory evoked potentials (SSEPs) in 7 patients. After rehabilitation, 5 patients had regained walking ability, whereas 5 patients stayed wheelchair bound. All patients with unfavorable outcome (American Spinal Injury Association (ASIA) Impairment score [AIS] score of ≤C) showed severe pyramidal tract lesions in MEPs during the first week. All patients with normal MEPs had an excellent outcome (AIS of E, P < .05).

CONCLUSIONS

Diffusion-weighted imaging (DWI) is a useful tool to confirm acute spinal ischemia suspected in patients within the first days after symptom onset. Poor outcome was associated with severe electrophysiological abnormalities in MEPs and SSEPs. Normal MEPs were significantly predictive of an excellent prognosis. A multimodal diagnostic approach combining DWI and electrophysiological evaluation facilitates the prediction of the individual clinical outcome.

Spinal cord ischemia: practical imaging tips, pearls, and pitfalls

Ischemia of the spinal cord is a rare entity with a poor prognosis. Brain ischemia is no longer a diagnostic challenge; on the contrary, ischemia of the spinal cord remains difficult, particularly in children. In this article, we illustrate the principal causes in children and adults, clinical presentation, different techniques for the diagnosis by MR imaging (diffusion, spinal MR angiography, and 1.5 versus 3T), pathophysiology, and differential diagnosis. We will discuss current knowledge, perspectives, and pitfalls.

MRI in transverse myelitis

Transverse myelitis is an acute inflammatory disease of the spinal cord, characterized by rapid onset of bilateral neurological symptoms. Weakness, sensory disturbance, and autonomic dysfunction evolve over hours or days, most progressing to maximal clinical severity within 10 days of onset. At maximal clinical severity, half will have a paraparesis, and almost all patients have sensory disturbance and bladder dysfunction. Residual disability is divided equally between severe, moderate and minimal or none. The causes of transverse myelitis are diverse; etiologies implicated include demyelinating conditions, collagen vascular disease, and parainfectious causes, however, despite extensive diagnostic work-up many cases are considered idiopathic. Due to heterogeneity in pathogenesis, and the similarity of its clinical presentation with those of various noninflammatory myelopathies, transverse myelitis has frequently been viewed as a diagnostic dilemma. However, as targeted therapies to optimize patient outcome develop, timely identification of the underlying etiology is becoming increasingly important. In this review, we describe the imaging and clinical features of idiopathic and disease-associated transverse myelitis and its major differentials, with discussion of how MR imaging features assist in the identification of various sub-types of transverse myelitis. We will also discuss the potential for advanced MR techniques to contribute to diagnosis and prognostication.

Diffusion weighted imaging with trace diffusion weighted imaging, the apparent diffusion coefficient and exponential images in the diagnosis of spinal cord infarction

A 73-year-old man, with a history of hypertension and left supraclavicular fossa arteriovenous malformation with multiple previous uncomplicated vessel embolisation procedures, presented with acute spastic quadriparesis and urinary retention following upper limb angiography and embolisation. There was no evidence of preceding infection or neurological disease prior to the event. Cerebrospinal fluid analysis was unremarkable. MRI of the cervical spine with a 1.5 Tesla magnet performed 13 hours from symptom onset revealed bilateral paramedian intramedullary T2-weighted signal change without gadolinium enhancement limited to the grey matter with corresponding diffusion restriction extending from C5-6 down to the mid-T1. The diagnosis of cervical spinal cord infarction (SCI) was made and the patient was given regular aspirin and atorvastatin. On follow-up at 3 months, there was modest improvement with respect to his quadriparesis and was walking unaided. An extensive literature review on the role of MRI in SCI is discussed.

Neuroimaging in acute transverse myelitis

Transverse myelitis is an acute inflammatory condition. A relatively rare condition, the diversity of causes makes it an important diagnostic challenge. An approach to the classification and work-up standardizes diagnostic criteria and terminology to facilitate clinical research, and forms a useful tool in the clinical work-up for patients at presentation. Its pathogenesis can be grouped into four categories. Imaging appearances can be nonspecific; however, the morphology of cord involvement, enhancement pattern, and presence of coexistent abnormalities on MR imaging can provide clues as to the causes. Neuroimaging is important in identifying subgroups that may benefit from specific treatment.

Restricted diffusion in spinal cord infarction demonstrated by magnetic resonance line scan diffusion imaging

BACKGROUND AND PURPOSE

We report on the use of line scan diffusion magnetic resonance imaging in the evaluation of spinal cord infarctions.

METHODS

Data on 19 patients with clinical findings consistent with spinal cord infarctions and abnormal findings on line scan diffusion imaging were reviewed. The Apparent Diffusion Coefficient (ADC) measurements for the normal spinal cord and for the areas of abnormality were calculated from trace ADC maps.

RESULTS

Restricted diffusion was found in all 19 patients. Absolute ADC values in the ischemic area ranged between 395.4 and 575.8 × 10(-6) mm(2)/s, with ADC ratios ranging between 39.4% and 57.4%.

CONCLUSIONS

Line scan diffusion imaging is technically feasible and appears to be a reliable method to diagnose spinal cord infarction in the acute setting.

Diffusion-weighted imaging, diffusion-tensor imaging, and fiber tractography of the spinal cord

In the brain, diffusion-weighted imaging (DWI) is an established and reliable method for the characterization of neurologic lesions. Although the diagnostic value of DWI in the early detection of ischemia has not diminished with time, many new clinical applications of DWI have also emerged. Diffusion-tensor imaging and fiber tractography have more recently been developed and optimized, allowing quantification of the magnitude and direction of diffusion along three principal eigenvectors. Diffusion-tensor imaging and fiber tractography are proving to be useful in clinical neuroradiology practice, with application to several categories of disease, and to be a powerful research tool. This article describes some of the applications of DWI and diffusion-tensor imaging in the evaluation of the diseases of the spinal cord.

Spinal cord lesions in patients with neuromyelitis optica: a retrospective long-term MRI follow-up study

Neuromyelitis optica (NMO) is characterised by a particular pattern of the optic nerves and the spinal cord. Long-term MRI follow-up studies of spinal NMO lesions are rare, or limited by short observation periods. In nine patients with definite NMO or recurrent longitudinally extensive transverse myelitis (LETM) with NMO-IgG serum antibodies, repeated MRI examinations of the spine were carried out over a period of up to 11 years and evaluated regarding the changes over time in this retrospective study. In eight patients spinal cord lesions were located centrally, involving the grey and white matter. In the first examination after clinical onset changes resembled a stroke of the anterior spinal artery in two patients. Symmetrical signal alterations within the grey matter were observed. In one patient this pattern was transient, but it remained in the other. During the chronic stage, either a variable degree of spinal cord atrophy and high signal alterations, or almost complete remission of the lesions, was observed. Spinal MRI of patients with NMO myelitis can resemble a stroke. MRI of acute NMO stages did not allow a prediction of the clinical outcome. To a variable degree, NMO left behind typical defects which correlated with the clinical outcome.

Clinical applications of diffusion tensor tractography of the spinal cord

Diffusion tensor imaging (DTI) can visualize the white matter tracts in vivo. The aim of this study was to assess the clinical utility of DTI in patients with diseases of the spinal cord. Fourteen subjects underwent magnetic resonance imaging of the spine at 1.5 T. Preliminary diagnosis of the patients suggested traumatic, tumorous, ischemic or inflammatory lesions of the spinal cord. In addition to T2-weighted images, DTI was performed with the gradients in 30 orthogonal directions. Maps of the apparent diffusion coefficient and of fractional anisotropy were reconstructed. Diffusion tensor imaging showed a clear displacement and deformation of the white matter tracts at the level of the pathological lesions in the spinal cord. This capability of diffusion tensor imaging to reliably display secondary alterations to the white matter tracts caused by the primary lesion has the potential to be of great utility for treatment planning and follow-up.

Temporal evolution of spinal cord infarction in an in vivo experimental study of canine models characterized by diffusion-weighted imaging

PURPOSE

To determine the temporal evolution of diffusion abnormalities of in vivo experimental spinal cord infarction.

MATERIALS AND METHODS

Guided by a digital subtract angiography (DSA) monitor, an agent of 1:1 match of lipiodol and diatrizoate meglumine was injected into bilateral T9-11 intercostal arteries of six dogs to embolize the spinal branches of intercostal arteries and establish the canine spinal cord infarction models. The progression of experimental spinal cord infarction was followed by dynamic MRI, including diffusion-weighted imaging (DWI) on a 1.5 Tesla MR system from one hour to 168 hours postembolization. Apparent diffusion coefficient (ADC) values were calculated and analyzed. At the end of the MRI experiments, the spinal cords of the animals were fixed for histology.

RESULTS

A total of six experimental models were successfully established. In all cases, DWI images showed slight hyperintensity within one hour postembolization, whereas only four cases presented slight hyperintensity on T2-weighted images. ADC values of spinal cord infarction lesions decreased rapidly at early stage (several hours to 24 hours) and then increased gradually.

CONCLUSION

The temporal evolution of diffusion abnormality of experimental spinal cord infarction may help us better understand various DWI signals in the process of spinal cord infarction.

Diffusion-weighted MR imaging (DWI) in spinal cord ischemia

INTRODUCTION

Spinal cord infarction is a rare clinical diagnosis characterized by a sudden onset of paralysis, bowel and bladder dysfunction, and loss of pain and temperature perception, with preservation of proprioception and vibration sense. Magnetic resonance imaging (MRI) usually demonstrates intramedullary hyperintensity on T2-weighted MR images with cord enlargement. However, in approximately 45% of patients, MR shows no abnormality. Diffusion-weighted MR imaging (DWI) has been widely used for the evaluation of a variety of brain disorders, especially for acute stroke. Preliminary data suggest that DWI has the potential to be useful in the early detection of spinal infarction.

METHODS

We performed DWI, using navigated, interleaved, multishot echo planar imaging (IEPI), in a series of six patients with a clinical suspicion of acute spinal cord ischemia.

RESULTS

In all patients, high signal was observed on isotropic DWI images with low ADC values (0.23 and 0.86x10(-3) cm(2)/s), indicative of restricted diffusion.

CONCLUSION

We analyzed the imaging findings from conventional MR sequences and diffusion-weighted MR sequences in six patients with spinal cord infarction, compared the findings with those in published series, and discuss the value of DWI in spinal cord ischemia based on current experience. Although the number of patients with described DWI findings totals only 23, the results of previously published studies and those of our study suggest that DWI has the potential to be a useful and feasible technique for the detection of spinal infarction.

Diffusion-Weighted Imaging Distinguishes Recurrent Epidermoid Neoplasm From Postoperative Arachnoid Cyst in the Lumbosacral Spine

Diffusion-weighted imaging can be used to distinguish epidermoid tumor from arachnoid cyst in the intracranial compartment. We report the use of diffusion-weighted imaging in a postoperative spine to successfully distinguish a recurrent epidermoid tumor from arachnoid cyst in a noninvasive manner. Our case illustrates the value of this readily available sequence presently not generally used in the clinical evaluation of spinal pathology.

[Acute tetraparesis of cerebral origin]

INTRODUCTION

Thrombolytic treatment in the early stage of ischemic cerebral attacks requires rapid confirmation of the diagnosis and topographic localization. Unusual clinical features can lead to misdiagnosis with the risk of delaying optimal therapeutic management.

OBSERVATION

We report the cases of two patients who experienced acute tetraparesis without any associated encephalic sign, consistent with the diagnosis of spinal cord injury. Cervical magnetic resonance imaging (MRI) was normal. Conversely, cerebral MRI displayed in both cases bilateral hemispheric infarction. Two ischemic lesions were revealed in the territory of both anterior cerebral arteries in the first patient, while the second patient had a bilateral infarction in the posterior arms of both internal capsules.

CONCLUSION

In case of tetraparesis, emergency spinal cord MRI should be performed to rule out neurosurgical etiologies and ischemia. If negative, cerebral MRI should be performed at the same time to look for early cerebral infarction in both hemispheres and determine the indication for thrombolysis.

Diffusion MRI in spinal dural arterio-venous fistula: a case report

STUDY DESIGN

Case report.

OBJECTIVES

Brain diffusion magnetic resonance imaging (MRI) and apparent diffusion coefficient (ADC) maps are useful to differentiate vasogenic and cytotoxic oedema during cerebovascular diseases. We investigate spinal cord diffusion MRI and ADC maps before and after treatment in one case of spinal dural arteriovenous fistula.

SETTING

University of Bordeaux, France.

METHODS

We used spinal cord diffusion MRI.

RESULTS

We found a vasogenic oedema that disappears after treatment.

CONCLUSION

This case report confirms the interest of spinal cord diffusion and ADC maps to differentiate vasogenic and cytotoxic oedema at the spinal cord level.

Spinal cord infarction demonstrated by diffusion-weighted magnetic resonance imaging

Spinal cord infarction is a rare entity of varying etiology although most often associated with atherosclerotic aortic disease. Definitive diagnosis of (idiopathic) spinal cord infarction in the acute stage and in the absence of demonstrable predisposing factors is not always possible even with MRI. Diffusion-weighted MRI (dwMRI) may provide valuable information in the evaluation of spinal cord ischemia. A 45-year-old woman presented with idiopathic spinal cord infarction manifesting as sudden onset of paraparesis and sphincter dysfunction. Both T2-weighted and line-scan dwMRI revealed hyperintense signals in the dorsal part of the spinal conus. Apparent diffusion coefficient values were significantly low in the lesion, suggesting cytotoxic edema compatible with acute ischemia. The clinical course and other radiographic findings were also compatible with idiopathic spinal cord infarction. Diffusion-weighted MRI is an important diagnostic tool for examining patients with suspected spinal cord ischemia.

Diffusion-weighted MR imaging in acute spinal cord ischemia

We report diffusion-weighted (DW) MR findings for acute spinal cord ischemia in a 56-year-old patient. MR imaging obtained approximately 3 h after symptom onset demonstrated an area of hyperintensity on DW images, but no conspicuous signal abnormality on T2-weighted images in the conus medullaris. DW imaging of the spinal cord can contribute to the early detection of spinal cord vascular compromise.

Diffusion-weighted MRI and the evaluation of spinal cord axonal integrity following injury and treatment

Diffusion-based magnetic resonance imaging (MRI) (DWI) has been shown experimentally to detect both injury and functionally significant neuroprotection of injured spinal cord white matter that would otherwise go undetected with conventional MRI techniques. The diffusion of water in the central nervous system (CNS) is thought to be affected by both its location (intracellular or extracellular), and by diffusion barriers formed by cell membranes and myelin sheaths. There is, however, controversy concerning how to obtain, interpret, and present DWI data. Computer simulations and MR microscopy have been helpful in resolving some of these issues, as well as determining exact histologic correlates to DWI findings.

Diffusion imaging of the human spinal cord and the vertebral column

During the last decade, diffusion-weighted imaging (DWI) has matured from an experimental tool to a clinically useful modality that has not only significantly impacted the diagnosis of (acute) cerebral stroke but has also shown utility in other abnormalities of the brain. Although DWI should be equally sensitive to changes in the spine, it has been used far less frequently in this region of the body. This is mainly because of the inhomogeneous magnetic environment, the small size of the spinal cord, and increased motion in and around the spine. However, once these limitations are overcome, a whole range of applications can be envisioned. Already now, DWI promises to be able to differentiate between benign and malignant vertebral compression fractures. As in the brain, the immediate reduction of diffusivity following ischemic damage in the spinal cord may provide an early identification of patients with infarction. The study of diffusion anisotropy may open new avenues for the detection and better understanding of damage to the long fiber tracts with important clinical implications for disorders like multiple sclerosis and amyotrophic lateral sclerosis. It may also be possible to address, in a more refined manner, mechanisms of damage such as occur with spondylotic myelopathy. To lay the basis for future research in these areas, we will discuss the most appropriate DWI methods for the spine. Following an overview of the basic principles of DWI and associated pitfalls, the most commonly used imaging methods are addressed. Finally, experimental and clinical applications in the spinal cord and the vertebral column and their clinical relevance thus far are reviewed.

Diffusion-weighted MRI in acute spinal cord ischaemia

Acute spinal cord ischaemia is often undetectable with conventional MRI. Diffusion-weighted MRI (DWI) has been difficult to use in the spine because of susceptibility artefacts. We assessed the diagnostic value of echoplanar DWI for early confirmation of spinal cord ischaemia. We performed conventional MRI and DWI in two men and three women, aged 54-75 years with clinically suspected acute spinal cord ischaemia. Imaging was performed 9-46 h after the onset of symptoms, and 2-9 days later to assess the extent of ischaemic signal change. Spatial resolution of DWI within the spine using standard equipment was poor, but in all patients, early DWI revealed areas of high signal indicating decreased diffusion, confirmed by measurement of apparent diffusion coefficients. Follow-up MRI showed high signal on T2-weighted images and contrast enhancement at the expected levels. Neurological deficits corresponded with radiological findings in four patients: various syndromes, including isolated bilateral weakness or sensory change and combined deficits, were found. Echoplanar DWI may be helpful for confirmation of spinal cord ischaemia in the acute stage, but follow-up T2-weighted images have superior spatial resolution and correlation with clinical findings and lesion extent.

Case report: spinal cord infarction demonstrated on diffusion-weighted MR imaging with a single-shot fast spin-echo sequence

We describe the diffusion-weighted (DW) MR imaging findings in three cases of spinal cord infarction using a recently developed single-shot fast spin-echo (SSFSE) technique. The SSFSE-DW MR images, which were obtained 20 hours, 3 days, and 18 days, respectively, after the ischemic event, demonstrated conspicuous areas of hyperintensity in the affected portions. Follow-up DW MR images, obtained in two of the patients at 17 days and 3 months, respectively, showed persistent decreased apparent diffusion coefficient values. SSFSE-DW imaging of the spinal cord may provide additional information for assessment of ischemic changes.

Case report: diffusion-weighted MRI in anterior spinal artery stroke of the cervical spinal cord

The authors present a case of anterior spinal artery stroke demonstrated by diffusion-weighted MRI (DWI) using single-shot echo-planar imaging. DWI clearly demonstrated hyperintensity with a decreased apparent diffusion coefficient (ADC) at 26 hours after onset. At 28 days, there was persistent hyperintensity with an increased ADC, corresponding to T2-weighted hyperintensity in the whole spinal gray matter at the C2-C7 vertebral level. DWI provided satisfactory images and was helpful for diagnosing and evaluating anterior spinal artery stroke.