COVID-19-Associated Myelitis Involving the Dorsal and Lateral White Matter Tracts: A Case Series and Review of the Literature

Motor Neuron Diseases and Central Nervous System Tractopathies: Clinical-Radiologic Correlation and Diagnostic Approach

White matter tracts within the central nervous system are organized into ascending and descending pathways that transmit sensory input and motor output, respectively. Tractopathy, or damage to these tracts, can impair sensory or motor functions. Motor neuron diseases are pathologic processes affecting the upper or lower motor neurons. Amyotrophic lateral sclerosis (ALS) is the most common form of acquired motor neuron disease. Traditionally, ALS has affected upper and lower motor neurons of the extremities, torso, and head and neck. There are several ALS variants, some of which affect only the upper motor neurons (eg, primary lateral sclerosis), lower motor neurons (eg, progressive muscular atrophy), or motor neurons of the head and neck (eg, progressive bulbar palsy). Characteristic imaging features of ALS include abnormal T2 hyperintensity within the brain along the corticospinal tract, as well as cortical susceptibility signal intensity along the precentral gyrus, termed the "motor band" sign. Spinal muscular atrophy is a less common primary motor neuron disease and appears on images as atrophy of the anterior horn of the spinal cord, as well as proximal muscle atrophy. In addition to pure motor neuron diseases, there are numerous toxic and metabolic conditions, genetic disorders, infectious diseases, and immune-mediated disorders that can secondarily affect the corticospinal tracts (corticospinal tractopathies), producing symptoms of upper motor neuron injury. These tractopathies are visible at MRI as T2-hyperintense lesions along varying segments of the corticospinal tract. A comprehensive diagnostic approach that integrates clinical symptoms with radiologic and laboratory findings is crucial to distinguish among these varied conditions. ©RSNA, 2024 Supplemental material is available for this article.

COVID-19 Neuroimaging Update: Pathophysiology, Acute Findings, and Post-Acute Developments

COVID-19 has prominent effects on the nervous system with important manifestations on neuroimaging. In this review, we discuss the neuroimaging appearance of acute COVID-19 that became evident during the early stages of the pandemic. We highlight the underlying pathophysiology mediating nervous system effects and neuroimaging appearances including systemic inflammatory response such as cytokine storm, coagulopathy, and para/post-infections immune mediated phenomena. We also discuss the nervous system manifestations of COVID-19 and the role of imaging as the pandemic has evolved over time, including related to the development of vaccines and the emergence of post-acute sequalae such as long COVID.

'Grasshopper sign': the novel imaging of post-COVID-19 myelopathy with delayed longitudinal white matter abnormalities

Introduction

Recently, there have been a few reports of atypical post-coronavirus disease 2019 (COVID-19) myelopathy manifesting tract-specific lesions similar to those due to vitamin B12 deficiency. However, the precise characteristics of imaging or clinical course remain not well understood.

Methods

A retrospective analysis of the clinical and imaging characteristics of four patients who were referred to our hospital with a unique post-COVID-19 myelopathy was performed.

Results

Four-to-six weeks following COVID-19 infection in the summer of 2023, four middle-aged men developed paraparesis, hypo/dysesthesia and bladder/bowel disturbance, suggesting myelopathy. Although spinal MRI showed no abnormalities in the early stages, tract-specific longitudinal lesions along the dorsal and lateral columns became apparent as the symptoms progressed. Owing to the lack of MRI findings at the early stage, all cases were challenging to diagnose. However, the patients remained partially responsive to aggressive immunosuppressive therapies, even in the advanced stage.

Discussion

We termed these tract-specific longitudinal lesions in the presented case series 'Grasshopper sign' because brain coronal and spine axial MRI findings looked like a grasshopper's antennae and face. Early identification of the characteristic MRI abnormality could allow for early intervention using intensive immunosuppressive therapy, which could improve patient outcomes.

Spontaneous spinal epidural haematoma following COVID-19 vaccination: a case report

Introduction

COVID-19 vaccination side effects are rare but important medical situations. Spine-affecting side effects are amongst the rarest, but exceedingly important. Haemorrhagic spinal manifestations of COVID-19 and its vaccines are less reported with little knowledge about them.

Case presentation

An 80-year-old male who received his first shot of the COVID-19 vaccine had developed COVID-19 pneumonia, weakness, and sensory problems in his legs followed by sphincter incontinence within 5 days period. MRI showed a spontaneous epidural spinal epidural haematoma (SSEDH) in T10-L1. He underwent laminectomy and haematoma evacuation. One month follow-up showed no clinical improvement.

Discussion

To our knowledge, this was the first post-vaccination SSEDH and second in haemorrhagic spinal complications following COVID-19 vaccination. Considering the neuropathogenesis pathway of COVID-19 and its vaccines, there are common mechanisms of action that could potentially justify post-vaccination SSEDH such as seen in COVID-19 infection, itself. Early Neurosurgical intervention and better preoperative neurological status could be a beneficial modifier for favourable clinical outcomes.

Conclusion

SSEDH and COVID-19 vaccine coincidence is a rare clinical event, still no solid association could be scientifically explained. Further studies are required for a reliable pathophysiologic association. Early diagnosis, interdisciplinary medical approach, and faster intervention are the cornerstone of the treatment paradigm.

Three Types of Demyelination, Perivenous, Confluent, and Perineuronal Nets-Rich in a COVID-19 Patient With Meningoencephalomyelitis

Neurologic symptoms are common in COVID-19, and a variety of neuropathological changes have been reported. One of the important neuropathological findings is demyelination. However, the underlying pathogenesis of demyelination remained poorly understood. We witnessed a case of COVID-19 with distinct types of demyelination in the cerebrum, medulla oblongata, and spinal canal, who died of sepsis. The postmortem examination showed the solitary massive demyelination in the medulla oblongata. The massive lesion was filled with components of perineuronal nets. In the spinal canal, confluent demyelination in bilateral lateral and dorsal funiculi was detected over the entire length from C1 to S5, which was maximum at the level of cervical spinal canal stenosis. Demyelination in the cerebrum was mainly perivenular, and augmented in the area of lacunar infarcts and dilated perivascular spaces. Considering the distribution patterns of the following three types of demyelination, the traces of viral spreading could be highlighted. Discontinuous perivenous demyelination in the cerebrum showed the result of hematogenous spreading. Longitudinal confluent demyelination of the spinal cord should be the picturesque of the trace of axonal spreading. The distribution of demyelination was possibly modified by the underlying diseases, diabetes mellitus, hypertension, and spinal canal stenosis.

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..

Inpatient rehabilitation outcomes in patients with the new diagnosis of COVID-19 tractopathy: a case series

STUDY DESIGN

Retrospective Case Series.

OBJECTIVES

Describe the inpatient rehabilitation outcomes of four patients with COVID-19 tractopathy.

SETTING

Olmsted County, Minnesota, United States of America.

METHODS

Retrospective review of medical records was performed to collect patient data.

RESULTS

Four individuals (n = 4, 3 men and 1 woman, mean age 58.25 years [range 56-61]) completed inpatient rehabilitation during the COVID-19 pandemic. All presented after COVID-19 infection and were admitted to acute care with progressive paraparesis. None were able to ambulate on admission to acute care. All received extensive evaluations which were largely negative except for mildly elevated CSF protein and MRI findings of longitudinally extensive T2 hyperintensity signal changes in the lateral (n = 3) and dorsal (n = 1) columns. All patients experienced incomplete spastic paraparesis. All patients experienced neurogenic bowel dysfunction; a majority experienced neuropathic pain (n = 3); half experienced impaired proprioception (n = 2); and a minority experienced neurogenic bladder dysfunction (n = 1). Between rehabilitation admission and discharge, the median improvement in lower extremity motor score was 5 (0-28). All patients were discharged home, but only one was a functional ambulator at time of discharge.

CONCLUSION

While the underlying mechanism is yet to be elucidated, in rare cases a COVID-19 infection can lead to a tractopathy, presenting as weakness, sensory deficits, spasticity, neuropathic pain, and neurogenic bladder/bowel. Patients with COVID-19 tractopathy would benefit from inpatient rehabilitation to enhance their functional mobility and independence.

Transverse myelitis in children and adults

Transverse myelitis is a noncompressive myelopathy of inflammatory origin. The causes are broad, ranging from infective or toxic to immuno-mediated etiology. They can be manifestations of systemic diseases, such as sarcoidosis and systemic lupus erythematous, or phenotypes of neuroinflammation; in a portion of cases, the etiology remains unknown, leading to the designation idiopathic. The clinical presentation of transverse myelitis depends on the level of spinal cord damage and may include sensorimotor deficits and autonomic dysfunction. The age of onset of the disorder can impact the symptoms and outcomes of affected patients, with differences in manifestation and prognosis between children and adults. Spinal cord magnetic resonance imaging and cerebrospinal fluid examination are the main diagnostic tools that can guide clinicians in the diagnostic process, even though the search for antibodies that target the structural components of the neural tissue (anti-aquaporin4 antibodies and anti-myelin-oligodendrocyte antibodies) helps in the distinction among the immune-mediated phenotypes. Management and outcomes depend on the underlying cause, with different probabilities of relapse according to the phenotypes. Hence, immunosuppression is often recommended for the immune-mediated diseases that may have a higher risk of recurrence. Age at onset has implications for the choice of treatment.

Neuroimaging features in inflammatory myelopathies: A review

Spinal cord involvement can be observed in the course of immune-mediated disorders. Although multiple sclerosis (MS) represents the leading cause of inflammatory myelopathy, an increasing number of alternative etiologies must be now considered in the diagnostic work-up of patients presenting with myelitis. These include antibody-mediated disorders and cytotoxic T cell-mediated diseases targeting central nervous system (CNS) antigens, and systemic autoimmune conditions with secondary CNS involvement. Even though clinical features are helpful to orient the diagnostic suspicion (e.g., timing and severity of myelopathy symptoms), the differential diagnosis of inflammatory myelopathies is often challenging due to overlapping features. Moreover, noninflammatory etiologies can sometimes mimic an inflammatory process. In this setting, magnetic resonance imaging (MRI) is becoming a fundamental tool for the characterization of spinal cord damage, revealing a pictorial scenario which is wider than the clinical manifestations. The characterization of spinal cord lesions in terms of longitudinal extension, location on axial plane, involvement of the white matter and/or gray matter, and specific patterns of contrast enhancement, often allows a proper differentiation of these diseases. For instance, besides classical features, such as the presence of longitudinally extensive spinal cord lesions in patients with aquaporin-4-IgG positive neuromyelitis optica spectrum disorder (AQP4+NMOSD), novel radiological signs (e.g., H sign, trident sign) have been recently proposed and successfully applied for the differential diagnosis of inflammatory myelopathies. In this review article, we will discuss the radiological features of spinal cord involvement in autoimmune disorders such as MS, AQP4+NMOSD, myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), and other recently characterized immune-mediated diseases. The identification of imaging pitfalls and mimics that can lead to misdiagnosis will also be examined. Since spinal cord damage is a major cause of irreversible clinical disability, the recognition of these radiological aspects will help clinicians achieve a correct and prompt diagnosis, treat early with disease-specific treatment and improve patient outcomes.

Neurologic complications of coronavirus and other respiratory viral infections

In humans, several respiratory viruses can have neurologic implications affecting both central and peripheral nervous system. Neurologic manifestations can be linked to viral neurotropism and/or indirect effects of the infection due to endothelitis with vascular damage and ischemia, hypercoagulation state with thrombosis and hemorrhages, systemic inflammatory response, autoimmune reactions, and other damages. Among these respiratory viruses, recent and huge attention has been given to the coronaviruses, especially the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic started in 2020. Besides the common respiratory symptoms and the lung tropism of SARS-CoV-2 (COVID-19), neurologic manifestations are not rare and often present in the severe forms of the infection. The most common acute and subacute symptoms and signs include headache, fatigue, myalgia, anosmia, ageusia, sleep disturbances, whereas clinical syndromes include mainly encephalopathy, ischemic stroke, seizures, and autoimmune peripheral neuropathies. Although the pathogenetic mechanisms of COVID-19 in the various acute neurologic manifestations are partially understood, little is known about long-term consequences of the infection. These consequences concern both the so-called long-COVID (characterized by the persistence of neurological manifestations after the resolution of the acute viral phase), and the onset of new neurological symptoms that may be linked to the previous infection.