Focal compression of the upper left thoracic intersegmental arteries as a potential cause of spinal cord ischemia

Identification of specific causes of myelopathy in a large cohort of patients initially diagnosed with transverse myelitis

BACKGROUND AND OBJECTIVES

Identifying the etiologic diagnosis in patients presenting with myelopathy is essential in order to guide appropriate treatment and follow-up. We set out to examine the etiologic diagnosis after comprehensive clinical evaluation and diagnostic work-up in a large cohort of patients referred to our specialized myelopathy clinic, and to explore the demographic profiles and symptomatic evolution of specific etiologic diagnoses.

METHODS

In this retrospective study of patients referred to the Johns Hopkins Myelitis and Myelopathy Center between 2006 and 2021 for evaluation of "transverse myelitis", the final etiologic diagnosis determined after comprehensive evaluation in each patient was reviewed and validated. Demographic characteristics and temporal profile of symptom evolution were recorded.

RESULTS

Of 1193 included patients, 772 (65%) were determined to have an inflammatory myelopathy and 421 (35%) were determined to have a non-inflammatory myelopathy. Multiple sclerosis/clinically isolated syndrome (n = 221, 29%) and idiopathic myelitis (n = 149, 19%) were the most frequent inflammatory diagnoses, while spinal cord infarction (n = 197, 47%) and structural causes of myelopathy (n = 108, 26%) were the most frequent non-inflammatory diagnoses. Compared to patients with inflammatory myelopathies, patients with non-inflammatory myelopathies were more likely to be older, male and experience chronic symptom evolution (p < 0.001 for all). Hyperacute symptom evolution was most frequent in patients with spinal cord infarction (74%), while chronic symptom evolution was most frequent in patients with structural causes of myelopathy (81%), arteriovenous fistula or arteriovenous malformation (81%), myelopathy associated with rheumatologic disorder (71%), and sarcoidosis-associated myelopathy (61%).

CONCLUSIONS

Patients initially diagnosed with "transverse myelitis" are eventually found to have a more specific inflammatory or even non-inflammatory cause, potentially resulting in inappropriate treatment and follow-up. Demographic characteristics and temporal profile of symptom evolution may help inform a differential diagnosis in these patients. Etiological diagnosis of myelopathies would provide better therapeutic decisions.

Vascular Diseases of the Spinal Cord: Infarction, Hemorrhage, and Venous Congestive Myelopathy

Vascular pathologies of the spinal cord are rare and often overlooked. This article presents clinical and imaging approaches to the diagnosis and management of spinal vascular conditions most commonly encountered in clinical practice. Ischemia, infarction, hemorrhage, aneurysms, and vascular malformations of the spine and spinal cord are discussed. Pathophysiologic mechanisms, clinical classification schemes, clinical presentations, imaging findings, and treatment modalities are considered. Recent advances in genetic and syndromic vascular pathologies of the spinal cord are also discussed. Clinically relevant spinal vascular anatomy is reviewed in detail.

Spinal cord ischemia: aetiology, clinical syndromes and imaging features

INTRODUCTION

The purpose of this study was to analyse MR imaging features and lesion patterns as defined by compromised vascular territories, correlating them to different clinical syndromes and aetiological aspects.

METHODS

In a 19.8-year period, clinical records and magnetic resonance imaging (MRI) features of 55 consecutive patients suffering from spinal cord ischemia were evaluated.

RESULTS

Aetiologies of infarcts were arteriosclerosis of the aorta and vertebral arteries (23.6%), aortic surgery or interventional aneurysm repair (11%) and aortic and vertebral artery dissection (11%), and in 23.6%, aetiology remained unclear. Infarcts occurred in 38.2% at the cervical and thoracic level, respectively, and 49% of patients suffered from centromedullar syndrome caused by anterior spinal artery ischemia. MRI disclosed hyperintense pencil-like lesion pattern on T2WI in 98.2%, cord swelling in 40%, enhancement on post-contrast T1WI in 42.9% and always hyperintense signal on diffusion-weighted imaging (DWI) when acquired.

CONCLUSION

The most common clinical feature in spinal cord ischemia is a centromedullar syndrome, and in contrast to anterior spinal artery ischemia, infarcts in the posterior spinal artery territory are rare. The exclusively cervical location of the spinal sulcal artery syndrome seems to be a likely consequence of anterior spinal artery duplication which is observed preferentially here.

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.

Periconal arterial anastomotic circle and posterior lumbosacral watershed zone of the spinal cord

BACKGROUND

The existence of spinal cord watershed territories was suggested in the 1950s. Segmental infarcts within the junctional territories of adjacent radiculomedullary contributors and isolated spinal gray matter ischemia constitute two well-recognized types of watershed injury. This report describes the existence of another watershed territory related to the particular configuration of the spinal vasculature in the region of the conus medullaris.

METHODS

The anatomical bases underlying the concept of a posterior lumbosacral watershed zone are demonstrated with angiographic images obtained in a 16-year-old child. The clinical importance of this watershed zone is illustrated with MRI and angiographic data of three patients with a conus medullaris infarction.

RESULTS

In all three cases of spinal ischemia an intersegmental artery providing a significant radiculomedullary contribution for the lower cord was compromised by a compressive mechanism responsible for decreased spinal cord perfusion (diaphragmatic crus syndrome in two cases, disk herniation in one). The ischemic injury, located at the junction of the anterior and posterior spinal artery territories along the dorsal aspect of the conus medullaris, was consistent with a watershed mechanism. This zone is at risk because of the caudocranial direction of flow within the most caudal segment of the posterior spinal arterial network which, from a functional standpoint, depends on the anterior spinal artery.

CONCLUSIONS

The posterior thoracolumbar watershed zone of the spinal cord represents an area at increased risk of ischemic injury, particularly in the context of partial flow impairment related to arterial compression mechanisms.