Magnetic resonance imaging of acute intramedullary myelopathy: radiological differential diagnosis for the on-call radiologist

doi:10.1016/j.crad.2008.07.004

Clinical Radiology

Volume 64, Issue 1, January 2009, Pages 84-94

https://doi.org/10.1016/j.crad.2008.07.004 Get rights and content

Spinal cord disease is often viewed as having a poor outcome. Although in certain conditions this is true, non-traumatic myelopathy encompasses a vast array of diseases some of which are exquisitely responsive to treatment. Accurate diagnosis becomes important as damage is often progressive and long-term disability and morbidity is related to the degree of neurological impairment when the diagnosis is reached. Out-of-hours magnetic resonance imaging (MRI) is generally requested and performed to ascertain whether there is spinal cord compression; however, there are other causes of a cord syndrome, which are more subtle. This review aims to provide a summary of the imaging features of non-traumatic intramedullary spinal cord emergencies, many of which may appear radiologically similar.

Introduction

Spinal cord compression is perhaps the most common indication for out-of-hours MRI. In this situation, relatively inexperienced radiologists are often required to supervise the imaging and give a first opinion of the findings. Occasionally, these MRI studies performed on patients with an acute myelopathy will demonstrate intramedullary pathology rather than showing a compressive lesion (Figure 1, Figure 2). In this situation detailed knowledge of the anatomy of the cord and predilection of various diseases for different patterns of cord, brain, and extra-central nervous system (CNS) involvement, is of paramount importance.

The clinical information provided is also vital for MRI image interpretation in acute myelopathy. This is especially in regard to elucidating the likely pathological process from a list of what can be very similar imaging features. Of particular importance is the onset of symptoms differentiating vascular from inflammatory causes, which can be difficult on imaging alone. The patient's age and sex also help to narrow the differential. Accurate clinical examination will determine the likely anatomical location of lesions within the cord and provide clues to the nature of the underlying pathology. Knowledge of this enables better-targeted imaging and interpretation of incidental findings in the wrong location (Table 1).

The main causes of acute non-compressive myelopathy can be broadly classified into the following: inflammatory and autoimmune; infections; vascular; and others, including metabolic, radiation, and metastatic.

Although syringomyelia and primary cord tumours can result in similar imaging findings they do not often present acutely, so are not specifically covered in this review.

Section snippets

Inflammatory and autoimmune

Inflammatory and demyelinating myelopathy can be thought of as clinicopathological sequelae of a spectrum of disorders with a similar endpoint. These typically include viral and post-viral infections [enteroviruses, human immunodeficiency virus (HIV), human T-lymphotrophic virus -1 (HTLV-1), Epstein–Barr virus (EBV), cytomegalovirus (CMV), varicella zoster virus (VZV), acute disseminated encephalomyelitis (ADEM)], vasculitic/multisystem (systemic lupus erythematous, Bechet's sydrome, Sjogren's

Infection

On the whole, infectious myelopathy due to viral myelitis is equivalent in imaging terms to idiopathic transverse transverse myelitis. The diagnosis is reached by laboratory testing of the cerebrospinal fluid, serum serology, or by exclusion of other causes. Occasionally, however, the imaging is specific for other infectious causes. Being aware of and differentiating these is important as early treatment is vital.

Arterial infarction (Fig. 10)

Spinal cord infarcts most commonly affect the territory of the anterior spinal artery, involving the corticospinal and spinothalamic tracts.¹⁵ Although classically spared, impairment of proprioception may occur due to involvement of the inner part of the dorsal columns, which is also supplied by the anterior spinal artery, and may represent more extensive infarction.

Causes of cord ischaemia and infarction include aortic aneurysms, dissection, or surgery, vertebral artery dissection and

B12 deficiency (Fig. 13)

Subacute combined degeneration of the cord results from a deficit of vitamin B12 most often due to pernicious anaemia. A lack of B12 results in a paucity of both central and peripheral neuronal myelination. One small study showed MRI to be normal in 50% of cases pre-treatment. When abnormal, longitudinally orientated areas of high T2 signal are seen within the dorsal columns, occasionally resembling an inverted “V”. These typically will not enhance following gadolinium²³ and will resolve

Summary

There is a myriad of disease conditions that result in very similar imaging features consisting of poorly defined areas of high T2 and low T1 signal with slight enhancement and expansion of the cord. This description could represent anything from MS, through cord infarction, transverse myelitis to an astrocytoma. It is often not possible to give a definitive answer as to the cause, and the diagnosis is usually achieved from a combination of history, laboratory tests, and imaging. Imaging can

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Cited by (29)

Localization of macroscopically undetectable intramedullary hematoma by intraoperative epidural motor evoked potential
2022, Clinical Neurophysiology Practice
Citation Excerpt :
Intramedullary hematomas remain a diagnostic challenge, but they need to be considered as an uncommon cause of myelopathy (Leep Hunderfund and Wijdicks, 2009). The preferred imaging modality should be MRI (Sheerin et al., 2009). Early diagnosis is crucial and the treatment of choice should be surgical (Kreppel et al., 2003; Groen, 2004).
Intramedullary hematoma is an uncommon, serious neurological disease, representing a diagnostic challenge. The preferred treatment is surgical. In most of the cases the lesion can be identified macroscopically. Otherwise, finding the optimal place to perform myelotomy is demanding. Intraoperative neurophysiological monitoring plays an important role in preventing surgical complications, but its versatility for localization has not been studied so far.
The present case report describes a 17-year-old patient with flaccid right inferior monoparesis (later paraparesis), ipsilateral loss of proprioception and vibration sense, contralateral analgesia below the T10 dermatome level and urinary retention (Brown-Séquard syndrome). The MRI revealed an intramedullary hematoma at the level of T8-T9 vertebral bodies. Digital subtraction angiography did not identify any vascular malformation. Urgent surgical intervention was performed. In order to prevent any complication somatosensory-evoked potential (SSEP), transcranial and epidural motor-evoked potential (tcMEP, eMEP) recordings were planned. SSEP in response to right tibial nerve stimulation and tcMEP were absent bilaterally. From electrophysiological point of view, the eMEP revealed a total conduction block of the corticospinal tract. In the absence of typical macroscopic signs (discoloration, swelling, abnormal vascularization etc.), the small intramedullary hematoma could not be identified. Therefore, it was decided to adopt eMEP technique for mapping and localizing the conduction block intraoperatively by changing the distance between the two electrodes used for recording. The hematoma was precisely localized and successfully evacuated. Postoperatively, a slow but continuous improvement was noted.
Intraoperative neurophysiological monitoring has been suggested to play crucial role in spinal cord surgery. To our knowledge, this is the first case report using eMEP recording for guiding and localizing of an intramedullary hematoma. Beside the clear limitations of our study, it could result in a novel application of the aforementioned monitoring technique.
Spinal vascular lesions: anatomy, imaging techniques and treatment
2021, European Journal of Radiology Open
Citation Excerpt :
Detection of SDAVFs is tricky, due to nonspecific symptoms; diagnostic delays are common and significantly influence prognosis and good patients’ outcome. Classical MR imaging findings include, on T2 WI, centro-medullary spinal cord hyperintensity, as a result of intramedullary oedema affecting a long segment (LETM), and multiple flow voids from dilated veins on the cord surface [55], better recognized on heavily T2-weighted sequences as fast imaging employing steady-state acquisition (FIESTA) or 3D-TSE. Contrast administration may be useful in enhancing dilated and tortuous perimedullary veins, detecting small shunt [54], showing cord enhancement as consequence of the breakdown of the blood-spinal cord barrier due to venous hypertension (Fig. 8).
Vascular lesions of the spinal cord are rare but potentially devastating conditions whose accurate recognition critically determines the clinical outcome. Several conditions lead to myelopathy due to either arterial ischemia, venous congestion or bleeding within the cord. The clinical presentation varies, according with the different aetiology and mechanism of damage.
The aim is to provide a comprehensive review on the radiological features of the most common vascular myelopathies, passing through the knowledge of the vascular spinal anatomy and the clinical aspects of the different aetiologies, which is crucial to promptly address the diagnosis and the radiological assessment.
Enterovirus D68 infection in a cluster of children with acute flaccid myelitis, Buenos Aires, Argentina, 2016
2017, European Journal of Paediatric Neurology
Citation Excerpt :
Similar images may be observed in post-infectious or vascular disorders. Nevertheless, the clinical manifestations in our patients were not compatible with these conditions.1,10 Moreover, in the context of a cluster of patients with clinically similar features, a viral infection, including HEV-D68, should be considered.
To report a outbreak of 11 cases of acute asymmetric flaccid myelopathy due to spinal motor neuron injury.
Eleven children, six male, with a mean age of 3 years presented with acute flaccid myelitis. We analyzed clinical features, etiology, neuroradiological images, treatment, and outcome.
Nine children had bilateral and asymmetric flaccid myelitis of the upper limbs, 1 had upper limb monoplegia, and 1 presented with hemiparesis. The cranial nerves were involved in 6 patients and 4 required mechanical ventilation. In all cases acute flaccid myelitis co-occurred with upper airway infection and/or fever. Spinal cord magnetic resonance imaging was abnormal in all, showing 2 different patterns: A linear pattern involving the anterior horns and another that was more heterogeneous showing spinal cord expansion. The lesions were non-enhancing in all. In 5/11 patients involvement of the medulla oblongata and pons was also observed. None of the patients presented with supratentorial lesions. In 4/11 children, the human enterovirus subtype D68 (HEV-D68) was identified in the airway and in 1/11 in the cerebrospinal fluid as well. In the remaining patients different enterovirus species A, B, and C variants were detected, as well as rhinovirus in 1 and influenza in another. Ten children received treatment with intravenous immunoglobulin and steroids and 4 of these children also underwent plasma exchange. Treatment did not lead to clinical improvement.
In a patient with acute flaccid myelitis, HEV-D68 infection should be ruled out. Cases in which the virus was not detected were considered as “false negatives” as samples were collected late in course of the disease. The lack of response to anti-inflammatory and immunomodulatory treatment suggests a direct viral mechanism. This study is to our knowledge the first on an HEV-D68-infection-related cluster in Latin America.
Abnormal Spinal Cord Magnetic Resonance Signal: Approach to the Differential Diagnosis
2016, Seminars in Ultrasound, CT and MRI
Citation Excerpt :
In the absence of trauma, hemorrhagic changes in the cord should prompt the exclusion of an underlying tumor or vascular malformation (eg, cavernomas or dural arteriovenous fistulas) (Fig. 17). Overall, although the patterns of signal abnormalities can overlap with different processes, careful evaluation of the anatomical involvement can help with the differential diagnosis in most cases.29-33 Detailed description of inflammatory, infectious, demyelinating, vascular, metabolic, or malignant involvement of the spinal cord and imaging correlations are provided in the reviews dedicated to specific cord diseases of the current Seminars issue.
T2-hyperintense signal abnormalities within the spinal cord on magnetic resonance imaging can evoke a broad differential diagnosis and can present a diagnostic dilemma. Here, we review and provide a succinct and relevant differential diagnosis based on imaging patterns and anatomical or physiopathologic correlation. Clues and imaging pearls are provided focusing on inflammatory, infectious, demyelinating, vascular, and metabolic involvement of the spinal cord.
Imaging in Neurology
2016, Imaging in Neurology
Diagnostic Imaging: Spine
2015, Diagnostic Imaging: Spine

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Pictorial reviewMagnetic resonance imaging of acute intramedullary myelopathy: radiological differential diagnosis for the on-call radiologist

Introduction

Section snippets

Inflammatory and autoimmune

Infection

Arterial infarction (Fig. 10)

B12 deficiency (Fig. 13)

Summary

J Neurol Sci

Lancet

Imaging of the spinal cord

J Neurol Neurosurg Psychiatry

Idiopathic transverse myelitis: MR characteristics

AJNR Am J Neuroradiol

Acute transverse myelopathy: spinal and cranial MR study with clinical follow-up

AJNR Am J Neuroradiol

Multiple sclerosis in the spinal cord: MR appearance and correlation with clinical parameters

Radiology

Neuromyelitis optica

Spinal Cord

Acute disseminated encephalomyelitis

Postgrad Med J

Delayed MR imaging changes in acute disseminated encephalomyelitis

AJNR Am J Neuroradiol

MR of CNS sarcoidosis: correlation of imaging features to clinical symptoms and response to treatment

AJNR Am J Neuroradiol

Central nervous system sarcoidosis: follow-up at MR imaging during steroid therapy

Radiology

Pictorial review
Magnetic resonance imaging of acute intramedullary myelopathy: radiological differential diagnosis for the on-call radiologist