Demyelinating and infectious diseases of the spinal cord

Pediatric Spinal Cord Diseases

Spinal cord diseases in pediatric patients are highly variable in terms of presentation, pathology, and prognosis. Not only do they differ with respect to each other but so too with their adult equivalents. Some of the most common diseases are autoimmune (ie, multiple sclerosis, acute disseminated encephalomyelitis, and acute transverse myelitis), congenital (ie, dysraphism with spina bifida, split cord malformation, and tethered cord syndrome), tumor (ie, juvenile pilocytic astrocytoma, ependymoma, and hem-angioblastoma), and vascular (ie, cavernous malformations, arteriovenous malformations, and dural arteriovenous fistulas) in nature. These each require their own niche treatment paradigm and prognosis. Furthermore, presentation of different spinal cord diseases in children can be difficult to discern without epidemiologic and imaging data. Interpretation of these data is crucial to facilitating a timely and accurate diagnosis. Correspondingly, the aim of this review was to highlight the most pertinent features of the most common spinal cord diseases in the pediatric population.

Magnetic resonance imaging in enterovirus-71, myelin oligodendrocyte glycoprotein antibody, aquaporin-4 antibody, and multiple sclerosis-associated myelitis in children

AIM

We used magnetic resonance imaging (MRI) to compare the neuroimaging of children with their first episode of clinical enterovirus 71-associated transverse myelitis (EV71-TM), myelin oligodendrocyte glycoprotein antibody positive transverse myelitis (MOG-TM), aquaporin-4 antibody positive transverse myelitis (AQP4-TM), transverse myelitis in multiple sclerosis (MS-TM), and unclassified transverse myelitis (UNC-TM).

METHOD

We performed a retrospective blinded radiological assessment and compared the neuroimaging of 52 children (32 females, 20 males; mean age 9y 8mo, SD 5y 5mo, range 5mo-17y) presenting with their first episode of myelitis caused by EV71-TM (n=11), MOG-TM (n=10), AQP4-TM (n=9), MS-TM (n=13), and UNC-TM (n=9).

RESULTS

In the EV71-TM group, lesions were distributed throughout the cord and enhancement of nerve roots (ventral and dorsal) was common. The MOG-TM group had lesions distributed throughout the cord and most commonly longitudinally extensive transverse myelitis and lesions involving the grey matter alone on axial scans. The AQP4-TM group had lesions distributed in the cervicothoracic spine, cavitation, and contrast enhancing lesions. All patients with AQP4-TM had an abnormal brain MRI scan. The MS-TM group characteristically had multiple short segment lesions of the cord involving the cervicothoracic spine. The UNC-TM group did not have distinctive spinal MRI findings but had a relative paucity of lesions on their brain MRI scans.

INTERPRETATION

There are neuroimaging findings that are helpful in differentiating between myelitis associated with EV71, MOG, AQP4, and multiple sclerosis in children. These features may be useful early in the presentation of transverse myelitis while awaiting infectious/immunological testing, and/or further demyelinating events.

WHAT THIS PAPER ADDS

Magnetic resonance imaging can help identify aetiologies for children presenting with a first episode of myelitis. Entervirus-71-associated myelitis lesions are distributed throughout the cord and enhancement of nerve roots is common. Lesions distributed throughout the cord are commonly seen in myelin oligodendrocyte-associated myelitis. Aquaporin-4-associated myelitis lesions are distributed in the cervicothoracic spine, cavitation and contrast enhancing lesions are common. Short segment lesions in the cervicothoracic spine are commonly seen in multiple sclerosis-associated myelitis.

Acquired pathology of the pediatric spine and spinal cord

Pediatric spine pathology poses a diagnostic challenge for radiologists. Acquired spine pathology often yields nonspecific signs and symptoms in children, especially in the younger age groups, and diagnostic delay can carry significant morbidity. This review is focused on some of the more common diagnostic dilemmas we face when attempting to evaluate and diagnose acquired pediatric spine anomalies in daily practice. An understanding of some of the key differentiating features of these disease processes in conjunction with pertinent history, physical exam, and advanced imaging techniques can indicate the correct diagnosis.

Longitudinally extensive myelopathy in children

When children present with acute myelopathy manifested by sensory, motor, or bowel and bladder symptoms, MRI of the neuraxis with contrast agent is the most important imaging study to obtain. Although occasionally normal, MRI often demonstrates signal abnormality within the spinal cord. Classically, longitudinally extensive transverse myelitis (≥3 vertebral bodies in length) has been described with neuromyelitis optica (NMO), but alternative diagnoses should be considered. This pictorial essay reviews the differential diagnoses that may present with longitudinally extensive spinal cord signal abnormalities. Multiple inflammatory, infectious, vascular, metabolic and neurodegenerative etiologies can present with a myelopathy. Thus, radiologists can assist in the diagnosis by familiarizing themselves with the spectrum of diseases in childhood that result in longitudinally extensive signal abnormalities in the absence of trauma.

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.