Magnetic Resonance Imaging and Clinical Features in Acute and Subacute Myelopathies

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..

Progressive conus medullaris lesions are suggestive of intravascular large B-cell lymphoma

BACKGROUND AND PURPOSE

Spinal cord lesions are observed in 40% of all central nervous system lesions in intravascular large B-cell lymphoma (IVLBCL). However, because IVLBCL is a very rare disease, its clinical features are not well defined, which may delay appropriate diagnosis and treatment, whilst the acute to subacute course of brain lesions in patients with IVLBCL is well established. Therefore, this study aimed to clarify the clinical features of spinal cord lesions in patients with IVLBCL.

METHODS

The medical records of patients with IVLBCL admitted to our hospital between 2010 and 2020 were searched. The inclusion criteria were preceding neurological symptoms without non-neurological symptoms and pathologically confirmed IVLBCL in various organs. Clinical features of spinal cord involvement in patients with IVLBCL were assessed and distinguished from those of brain involvement.

RESULTS

Sixteen consecutive patients with IVLBCL were divided into two groups: six patients with spinal involvement (spinal cord type) and 10 patients with brain involvement (brain type). In the spinal cord type, four patients had chronic progression and two had subacute progression. Acute progression (0% vs. 80.0%) and sudden onset (0% vs. 50.0%) occurred significantly less frequently in the spinal cord than in the brain. All spinal cord lesions involved the conus medullaris.

CONCLUSIONS

Spinal cord involvement in IVLBCL has a predominantly chronic progressive course that is exclusive to brain involvement. Conus medullaris lesions are suggestive of IVLBCL and are useful for early and accurate diagnosis and treatment.

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.

Imaging Aspects of Toxic and Metabolic Myelopathies

Metabolic and toxic myelopathies usually occurs due to several different causes. Metabolic myelopathy usually occurs due to deficiency of a nutrient, such as vitamin B12. Toxic myelopathy occurs secondary to the exposure to an external toxic agent. Although they may have a difficult diagnosis, determination of the specific cause of myelopathy is of utmost importance, because many causes are amenable to treatment. Although they have many clinical, electrophysiologic, and neuropathologic similarities, imaging may aid in the suspicion of toxic or metabolic myelopathy. The aim of this article, is to review the imaging features of the main toxic and metabolic myelopathies.

Acute Disseminated Encephalomyelitis and Acute Encephalitis Following Vaccination Against SARS-CoV-2: Two Case Reports and Review of Literature

The spectrum of severe neurological complications following COVID-19 vaccination includes cerebrovascular events, inflammatory diseases of the CNS, cranial and peripheral nerve involvement and muscle affections. Post-vaccinal acute disseminated encephalomyelitis (ADEM) and acute encephalitis are rare. We report on a patient suffering from acute encephalitis and another with post-vaccinal monophasic ADEM. Beside imaging features typical for acute autoimmune associated inflammation, cranial MRI disclosed also transient haemorrhagic signal alterations in some cerebral lesions. To our best knowledge, this has not been mentioned before in literature. Competing causes were excluded by extensive laboratory investigations including serial CSF analysis. In line with the literature, repeated iv high-dosage corticosteroid therapy resulted in impressive improvement of neurological symptoms in both patients.

Non-traumatic acute myelopathies: Clinical and imaging features in a real world emergency setting

OBJECTIVE

The aetiologic diagnosis of non-traumatic acute myelopathies (AMs), and their differentiation from other mimicking conditions (i.e. 'mimics'), are clinically challenging, especially in the emergency setting. Here, we sought to identify: (i) red flags suggesting diagnoses alternative to AMs and (ii) clinical signs and magnetic resonance imaging (MRI) features differentiating non-compressive from compressive AMs.

MATERIALS AND METHODS

We retrospectively retrieved MRI scans of spinal cord dictated at emergency room from January 2016 to December 2020 in the suspicion of AMs. Patients with traumatic myelopathies and those with subacute/chronic myelopathies (i.e. MRI scans acquired >48 h from symptom onset) were excluded from analysis.

RESULTS

Our search retrieved 105 patients; after excluding 16 cases of traumatic myelopathies and 14 cases of subacute/chronic myelopathies, we identified 30 cases with non-compressive AMs, 30 cases with compressive AMs and 15 mimics. The presence of pyramidal signs (p = 0.012) and/or pain (p = 0.048) correctly identified 88% of cases with AMs. We failed to identify clinical indicators for distinguishing non-compressive and compressive AMs, although cases with inflammatory AMs were younger than cases with all the remaining conditions (p < 0.05). Different MRI patterns could be described according to the final diagnosis: among non-compressive AMs, inflammatory lesions were more often posterior or central; vascular malformation had a fairly widespread distribution; spine ischaemia was more often central. Anterior or lateral compression were more often associated with neoplasms and disc herniation , whereas hemorrhages and infections produced spine compression on all sides.

CONCLUSION

We propose a simple clinical indicator (i.e. pyramidal signs and/or pain) to distinguish AMs from their mimics in an emergency setting. Urgent spinal cord MRI remains essential to discriminate compressive and non-compressive aetiologies.

Spinal vascular lesions: anatomy, imaging techniques and treatment

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Vascular myelopathies include different aetiology and mechanism of damage.

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The level of the lesion and the localization within the SC correlates with the clinical symptoms.

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CT, MRI and angiography are essential for diagnosis and treatment playing a complementary role.

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MRI is the gold standard for the evaluation of spinal cord lesions.

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Spinal angiography is the gold standard for evaluation of spinal cord vasculature and vascular malformations.

Background

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.

Purpose

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.

Diagnostic approach in multiple sclerosis with MRI: an update

Although neurological examination and medical history are the first and most important steps towards the diagnosis of multiple sclerosis (MS), MRI has taken a prominent role in the diagnostic workflow especially since the implementation of McDonald criteria. However, before applying those on MR imaging features, other diseases must be excluded and MS should be favoured as the most likely diagnosis. For the prognosis the earliest possible and correct diagnosis of MS is crucial, since increasingly effective disease modifying therapies are available for the different forms of clinical manifestation and progression. This review deals with the significance of MRI in the diagnostic workup of MS with special regard to daily clinical practice. The recommended MRI protocols for baseline and follow-up examinations are summarized and typical MS lesion patterns ("green flags") in four defined CNS compartments are introduced. Pivotal is the recognition of neurological aspects as well as imaging findings atypical for MS ("red flags"). In addition, routinely assessment of Aquaporin-4-IgG antibodies specific for neuromyelitis optica spectrum disorders (NMOSD) as well as the knowledge of associated lesion patterns on MRI is recommended. Mistaken identity of such lesions with MS and consecutive implementation of disease modifying therapies for MS can worsen the course of NMOSD.

Subacute combined degeneration of the cervical and dorsal spinal cord in a 40-year-old male patient: A case report

Subacute combined degeneration of the spinal cord is a neurologic complication of vitamin B12 deficiency. It presents as a potentially reversible demyelination of the posterior and lateral columns of the cervical and dorsal spinal cord. We present the case of a 40-year-old male with progressive sensory and motor deficit from the lower extremities ascending to the mid-thoracic region. A combination of laboratory tests and magnetic resonance imaging confirmed the diagnosis of subacute degeneration of the spinal cord due to vitamin B12 deficiency.

Acute and subacute myelopathy

Myelopathy is a term referring to any pathologic process affecting the spinal cord, and encompasses a broad spectrum of etiologies. The first step is to categorize myelopathy, according to the time to reach maximum deficit. Myelopathies are commonly classified as acute, subacute or chronic, for which the etiologies are totally different. Myelopathy is considered acute when the symptoms progress to their nadir in maximum 21 days after onset. Due to heterogeneity in pathogenesis, and the overlap in the clinical and imaging presentation among etiologies, acute myelopathy is considered as a diagnostic dilemma. A simple and efficient algorithm for timely identification of the underlying cause is thus useful. In this review, we provide a simplified approach for the differential diagnosis among all causes of acute myelopathies, and describe the principal clinical and imaging features of the main etiologies in adults, including recently characterized antibody-mediated myelitis, and its mimics.

Free light chains kappa can differentiate between myelitis and noninflammatory myelopathy

OBJECTIVE

To test the hypothesis that the intrathecal synthesis of free light chain kappa (FLC-k) can be used as a CSF biomarker to differentiate patients with myelitis due to multiple sclerosis (MS), myelitis due to neuromyelitis optica spectrum disease (NMOSD), and noninflammatory myelopathy, we analyzed FLC-k in 26 patients with MS myelitis, 9 patients with NMOSD myelitis, and 14 patients with myelopathy.

METHODS

This is a retrospective monocentric cohort study. FLC-k were analyzed using the nephelometric Siemens FLC-k kit in paired samples of CSF and sera. Intrathecal fraction (IF) of FLC-k was plotted in a FLC-k quotient diagram.

RESULTS

Ninety-six percent of patients with MS myelitis had an intrathecal synthesis of FLC-k in comparison with 55.6% for NMOSD and 14.3% of patients with noninflammatory myelopathy. The locally synthesized absolute amount of FLC-k was significantly higher in patients with myelitis due to MS than in patients with NMOSD (p = 0.038) or noninflammatory myelopathy (p < 0.0001). The sensitivity of FLC-k synthesis to detect inflammation in patients with myelitis is 85.7%. Using a receiver operating characteristic analysis, FLC-k IF >78% can discriminate patients with myelitis due to MS and NMOSD with a sensitivity of 88.5% and a specificity of 88.9% CONCLUSIONS: With the hyperbolic reference range in quotient diagrams for FLC-k, it is possible to distinguish inflammatory myelitis from noninflammatory myelopathies. An FLC-k IF >78% can be a hint to suspect myelitis due to MS rather than NMOSD.

White Matter Lesions in Adults - a Differential Diagnostic Approach

OBJECTIVE

 Cerebral white matter lesions on MRI in adults are a common finding. On the one hand, they may correspond to a clinically incidental feature, be physiologically or age-associated, or on the other hand they may be the overture to a severe neurological disease. With regard to pathophysiological aspects, practical hints for the differential diagnostic interpretation of lesions in daily clinical practice are presented.

MATERIAL AND METHODS

 With special regard to the vascular architecture and supply of the cerebral white matter, physiological structures are schematically represented and pathophysiological processes are highlighted by comparative image analysis of equally angulated MR sequences.

RESULTS

 The most frequent vascular, inflammatory, metabolic, and neoplastic disease entities are presented on the basis of characteristic imaging findings and corresponding clinical- neurological constellations. The details of signal intensities and localization essential for differential diagnosis are highlighted.

CONCLUSION

 By means of comparative image analysis and the recognition of characteristic lesion patterns, taking into account anatomical principles and pathophysiological processes, the differential diagnostic classification of cerebral white matter lesions and associated diseases can be significantly facilitated. The additional consideration of clinical and laboratory findings is essential.

KEY POINTS

  · Cerebral white matter lesions can be a harmless secondary finding or overture to a severe neurological disease.. · The comparative image analysis of different sequences with identical angulation is crucial.. · With special regard to the vascular anatomy, different lesion patterns can be identified.. · The consideration of neurological and laboratory chemical constellations is essential for the differential diagnosis..

CITATION FORMAT

· Weidauer S, Wagner M, Hattingen E. White Matter Lesions in Adults - a Differential Diagnostic Approach. Fortschr Röntgenstr 2020; 192: 1154 - 1173.

Subacute combined degeneration: a case of pernicious anaemia without haematological manifestations

Vitamin B₁₂ deficiency can be caused by a diverse group of aetiologies. One of the less common of these is an autoimmune condition pernicious anaemia, so named after the most common physiological manifestation of B₁₂ deficiency: anaemia. However, B₁₂ is also necessary for nervous system function and its depletion can lead to dysfunction of the posterior columns of the spinal cord resulting in subacute combined degeneration (SCD). This disease, while debilitating in its acute phase, can usually be mostly if not fully reversed if caught early and treated appropriately. Early detection can prove challenging if there are no haematological manifestations of B₁₂ deficiency and the only guidance is the high index of suspicion. We present a case of pernicious anaemia leading to SCD without any clinical or laboratory findings of anaemia in this report.

CNS Infections in Immunoincompetent Patients : Neuroradiological and Clinical Features

In patients with immunodeficiency the pathogen spectrum of central nervous system (CNS) infections is broader and different from that of immunocompetent patients. Numerous opportunistic infections are characterized by a high prevalence of viral, bacterial and parasitic pathogens, and depend on the type of impaired immune defense, for example impaired T‑cell or monocyte function, monoclonal antibody treatment, and impaired granulocyte function. Neuroradiological features as well as laboratory findings are often different and versatile in comparison to immunocompetent individuals and pathognomonic imaging findings do not exist; however, knowledge of possible pathways of pathogens in the CNS and preferred tissue affection may help in narrowing down differential diagnoses. Therefore, knowledge of the type of patient and the performed immunomodulatory therapy is essential for the neuroradiological assessment and the differential diagnostic considerations. Moreover, parenchymal reactions in the sense of an immune reconstitution inflammatory syndrome (IRIS) can occur when immunocompetence is restored. This review focus on the most common pathologies in immunocompromised patients, and an overview of imaging features but also of pathology and clinical aspects is given. The synopsis of anamnestic information, clinical findings and structured analysis of the lesion pattern, its spread and short-term follow-up may increase the correct diagnostic classification; however, the gold standard is still determination of the pathogen in the cerebrospinal fluid (CSF), blood cultures or biopsies.

Acute extensive myelopathy after single heroin and cocaine exposure in a patient with toxicological evidence of long-term drug abstinence

Heroin-related myelopathy is an uncommon but often devastating complication of heroin intake. It is usually reported in individuals exposed to intravenous heroin after a variable drug-free period, leading to acute and complete spinal cord injury with poor long-term outcome. We describe an original case of acute longitudinally extensive transverse myelopathy following single heroin and cocaine intravenous exposure after a long period of abstinence confirmed by toxicological hair and retrospective urine drug analysis. This case could provide new insights in the understanding of this rare neurological complication.

Age-Related Measurements of the Myelin Water Fraction derived from 3D multi-echo GRASE reflect Myelin Content of the Cerebral White Matter

Myelin Water Fraction (MWF) measurements derived from quantitative Myelin Water Imaging (MWI) may detect demyelinating changes of the cerebral white matter (WM) microstructure. Here, we investigated age-related alterations of the MWF in normal aging brains of healthy volunteers utilizing two fast and clinically feasible 3D gradient and spin echo (GRASE) MWI sequences with 3 mm and 5 mm isotropic voxel size. In 45 healthy subjects (age range: 18–79 years), distinct regions of interest (ROI) were defined in the cerebral WM including corticospinal tracts. For the 3 mm sequence, significant correlations of the mean MWF with age were found for most ROIs (r < −0.8 for WM ROIs; r = −0.55 for splenium of corpus callosum; r = −0.75 for genu of corpus callosum; p < 0.001 for all ROIs). Similar correlations with age were found for the ROIs of the 5 mm sequence. No significant correlations were found for the corticospinal tract and the occipital WM (p > 0.05). Mean MWF values obtained from the 3 mm and 5 mm sequences were strongly comparable. The applied 3D GRASE MWI sequences were found to be sensitive for age-dependent myelin changes of the cerebral WM microstructure. The reported MWF values might be of substantial use as reference for further investigations in patient studies.

Central Nervous System Tuberculosis : Etiology, Clinical Manifestations and Neuroradiological Features

PURPOSE

As a result of multilateral migration and globalization in times of humanitarian crises, western countries face a possible increase in the incidence of central nervous system tuberculosis (CNS TB). The diagnosis of CNS TB is challenging and often delayed due to the manifold and often non-specific presentation of the disease. The aim of this review is to analyze and summarize imaging features and correlated clinical findings of CNS TB.

METHODS

The different manifestations of CNS TB are explained and illustrated by characteristic neuroradiological as well as neuropathological findings. An overview on diagnostic and therapeutic approaches is provided. For clarity, tables summarizing the lesion patterns, differential diagnoses and diagnostic hints are added.

RESULTS

The CNS TB can be manifested (1) diffuse as tuberculous meningitis (TBM), (2) localized as tuberculoma or (3) tuberculous abscess or (4) in extradural and intradural spinal infections. Information on clinical presentation, underlying pathology and the distinguishing features is demonstrated. The TBM is further described, which may lead to cranial nerve palsy, hydrocephalus and infarction due to associated arteritis of the basal perforators. The differential diagnoses are vast and include other infections, such as bacterial, viral or fungal meningoencephalitis, malignant causes or systemic inflammation with CNS. Complicating factors of diagnosis and treatment are HIV coinfection, multi-drug resistance and TB-associated immune reconstitution inflammatory syndrome (IRIS).

CONCLUSIONS

Neurologists and (neuro-)radiologists should be familiar with the neuroradiological presentation and the clinical course of CNS TB to ensure timely diagnosis and treatment.

Introduction to Neuroimaging

Primary care physicians are often tasked with evaluating neurologic symptoms, and imaging plays a critical role in neurologic diagnoses. Neuroradiology routinely employs advanced imaging modalities, and hence, determination of the appropriate imaging test and interpretation of findings in the clinical context can understandably be overwhelming. In this review article, we introduce resources that can guide physicians in the selection of neuroimaging tests and summarize guidelines on contrast agent administration. Key concepts on imaging techniques and terminology are reviewed, as is relevant for the primary care physician. We then present an overview of the typical imaging manifestations of brain pathologies, including stroke, traumatic injuries, infections, demyelinating and neurodegenerative processes, and neoplasms. Spine imaging is often considered for the evaluation of degenerative, infectious, or neoplastic etiologies, and the typical imaging findings in these scenarios are also summarized.

A practical approach to the diagnosis of spinal cord lesions

Every neurologist will be familiar with the patient with atypical spinal cord disease and the challenges of taking the diagnosis forward. This is predominantly because of the limited range of possible clinical and investigation findings making most individual features non-specific. The difficulty in obtaining a tissue diagnosis further contributes and patients are often treated empirically based on local prevalence and potential for reversibility. This article focuses on improving the diagnosis of adult non-traumatic, non-compressive spinal cord disorders. It is structured to start with the clinical presentation in order to be of practical use to the clinician. We aim, by combining the onset phenotype with the subsequent course, along with imaging and laboratory features, to improve the diagnostic process.