Rapid onset transverse myelitis in adolescence: implications for pathogenesis and prognosis

Antecedent Minor Trauma and Hyperacute Presentations in Childhood Transverse Myelitis

INTRODUCTION

Fibrocartilaginous embolism and spinal cord infarction may resemble transverse myelitis with antecedent minor trauma (sporting activity or minor falls) or with hyperacute (<12-hour) presentation.

METHODS

Diagnostic criteria for fibrocartilaginous embolism and spinal cord infarction were applied to a 10-year (2007-2016) cohort of children aged 1 month to 16 years with transverse myelitis and clinical, laboratory, neuroimaging, and outcome data compared between those with and without antecedent minor trauma.

RESULTS

Thirty-two children of median age 8.9 (range 2.7-15.8) years were included; 19 (59%) were female. Falls at home, school, or play (6 children, 60%), swimming (2, 20%), physical education (1, 10%), and caning (1, 10%) were antecedent events in 10 (31%) children. Six (19%) had hyperacute presentations. One patient met spinal cord infarction criteria; none had fibrocartilaginous embolism. Children with transverse myelitis and antecedent minor trauma had single, short spinal cord lesions (median 3 vertebral bodies) but without a specific neuroimaging lesion pattern. None had intervertebral disc abnormalities or brain involvement and were negative for myelin oligodendrocyte and aquaporin 4 antibodies. Twenty-five (86%) of 29 had cerebrospinal fluid inflammation, and 30 (94%) received immunotherapy. Thirty (97%) were followed for a median of 3.6 (0.1-10.2) years, with good outcome (modified Rankin Scale score 0-1) in the majority (80%). Four (75%) with hyperacute presentation had a good outcome (modified Rankin Scale score 0-1), but the patient with spinal cord infarction was the most disabled (modified Rankin Scale score 4).

CONCLUSION

Minor trauma or hyperacute presentations does not always indicate fibrocartilaginous embolism or spinal cord infarction. Children with minor trauma preceding transverse myelitis have a distinct clinicoradiologic syndrome, with good outcome following immunotherapy.

[A case of sudden-onset transverse myelopathy suspected to be caused by fibrocartilaginous embolism]

A 44-year-old male was admitted to our hospital because of sudden weakness and sensory loss in both legs following left scapular pain. He had a history of lower back pain but no vascular risk factors. Neurological examination on admission revealed flaccid paraplegia, a loss of both pinprick and vibratory sensations below the Th6 level, and bladder and rectal disturbances. Tendon reflexes were absent in both lower limbs. Diffusion-weighted imaging performed 5 hours after onset revealed an extensive high-intensity lesion at the Th2-6 spine levels, accompanied by a vague high intensity on T₂-weighted images. CT angiography showed no abnormalities of the aorta or the artery of Adamkiewicz. Laboratory test results were normal and there was no evidence of coagulopathy. Autoantibodies, including anti-aquaporin-4 and anti-myelin oligodendrocyte glycoprotein antibodies, were negative. The cerebrospinal fluid test was normal. The lesion had expanded to the whole thoracic cord and was markedly swollen on T₂-weighted imaging at 5 days after onset. Immunotherapies, including intravenous methylprednisolone pulse therapy and plasma exchange, were ineffective. Although there was no evidence of any source of embolism, we found degenerative calcified changes in the fibrocartilage of the intervertebral discs, with Schmorl's nodes in the thoracic spines. We clinically diagnosed the patient with spinal cord infarction caused by fibrocartilaginous embolism. He developed deep vein thrombosis and was treated with edoxaban. His neurological symptoms did not improve during 55 days of hospitalization. In a case with sudden-onset myelopathy, fibrocartilaginous embolism should be considered.

Spinal cord infarction with ipsilateral segmental neuropathic pain and flaccid paralysis. A functional role for human afferent ventral root small sensory fibres

This paper illustrates the cases of two patients with an acute onset of right brachial neuropathic pain, flaccid paralysis and contralateral thermal and thermal pain hypoesthesia, without posterior column impairment nor pyramidal signs below the segmental lesion. MRI showed right sided spinal cord infarction, in the anterior spinal artery territory between C1 and C5 in one patient and between C3 and C7 in the other. Contact Heat Evoked Potentials and Quantitative Thermal Sensory testing are consistent with contralateral, but not ipsilateral, spinothalamic tract involvement. Electromyographic results established ipsilateral segmental denervation and somatosensory evoked responses were consistent with dorsal column sparing. Unilateral anterior cervical spinal cord infarction may present with acute ipsilateral segmental neuropathic pain, lower motor neurone-type weakness, contralateral thermoanalgesia and no pyramidal signs. The ipsilateral pain provides novel evidence that in some instances, ventral roots can play a role in nociception in humans. The infarcted territory may result from occlusion of a sulcal commissural artery or a number of more proximal vessels (including a single or duplicated anterior spinal artery, vertebral arteries or feeding radicular arteries).

Childhood idiopathic spinal cord infarction: Description of 7 cases and review of the literature

OBJECTIVES

To describe the clinical course, neuroimaging findings and functional outcome of idiopathic spinal cord infarction (SCI) in adolescents.

METHODS

Retrospective and descriptive analyses of seven patients with idiopathic SCI and 50 additional cases from the literature were included. Data collected concerned clinical presentation, MRI findings, initial diagnosis, treatments and functional outcome at the last medical visit.

RESULTS

Mean age at presentation was 13.2years (range 13-15). All patients presented a sudden and painful acute myelopathy with <24h time to maximal symptoms manifestation. A suspected trigger related to a minor effort was reported in 3/7 cases. Six patients presented with paraplegia, one with paraparesis. All had bladder dysfunction needing catheterization. Three patients had an initial misdiagnosis. Initial MRI was considered as normal in 2 cases. In the 5 other cases, T2-weighted-MR images showed hyperintensity within the thoracolumbar spinal cord, affecting mostly the anterior spinal artery territory. Evidence for associated spinal growth dystrophy were present in 6/7 cases. Mean follow-up time was 27.4months (range 3-46): 2 patients recovered autonomous ambulation, 4 patients regained walking ability with aids and one child (the shortest follow-up) remained wheelchair-dependent. A neurogenic bladder was still reported in 6/7 children at the last visit. Complementary analyses with literature cases were consistent with the findings obtained in our cohort.

CONCLUSION

Idiopathic SCI typically occurs in adolescence with a rapid onset and painful acute myelopathy. The MRI shows a T2-hyperintense signal within the spinal cord and provides evidence for an ischemic mechanism. Etiology remains unclear in most cases even though some specific risk factors for this age must play an important role in the pathogenesis, such as mechanical constraints on the immature spine.

Acute asymmetrical spinal infarct secondary to fibrocartilaginous embolism

INTRODUCTION

Spinal cord infarction is extremely rare in childhood and can result from a wide range of causes. Fibrocartilaginous embolism can give rise to spinal stroke and mimic non-vascular disease such as acute transverse myelitis.

CASE

We report two children who suffered an asymmetrical spinal cord infarction due to fibrocartilaginous embolism. The clinical presentation, radiological findings, and pathophysiology of fibrocartilaginous embolism are described. Each patient demonstrated marked clinical improvement after receiving extensive physical therapy and rehabilitation. One child demonstrated complete clinical recovery. The other had persistent asymmetrical foot weakness and distal sensory deficits.

CONCLUSION

We outline the key clinical and radiographic features that enable spinal cord infarction to be differentiated from transverse myelitis. Prognosis depends on many factors such as extent and type of injury, level of the cord affected, and age at the time of spinal cord infarction.

Acute myelopathy with normal imaging

A 17-year-old girl presented with rapidly progressive quadriparesis and ventilatory failure. The clinical findings indicated a spinal level, but the diagnosis of myelopathy was not supported by her initial spinal imaging and cerebrospinal fluid studies. She had completed treatment for Guillain-Barré syndrome before a follow-up spinal imaging study showed interval expansion and enhancement of the cervical cord.

Spinal cord infarction following minor trauma in children: fibrocartilaginous embolism as a putative cause

Spinal cord infarctions following seemingly innocuous trauma in children are rare, devastating events. In the majority of these cases, the pathophysiology is enigmatic. The authors present 3 cases of pediatric spinal cord infarction that followed minor trauma. An analysis of the clinical, radiographic, and laboratory features of these cases suggests that thromboembolism of the nucleus pulposus into the spinal cord microcirculation is the likely mechanism. A review of the human and veterinary literature supports this notion. To the authors' knowledge, this is the largest pediatric series of myelopathy due to thromboembolism of the nucleus pulposus reported to date, and it is the first report of this condition occurring in an infant.

Inflammatory, vascular, and infectious myelopathies in children

Acute nontraumatic myelopathies of childhood include inflammatory, infectious, and vascular etiologies. Inflammatory immune-mediated disorders of the spinal cord can be categorized as idiopathic isolated transverse myelitis, neuromyelitis optica, and multiple sclerosis. In recent years, human T-cell lymphotropic virus type 1, West Nile virus, enterovirus-71, and Lyme disease have been increasingly recognized as infectious etiologies of myelopathy, and poliomyelitis remains an important etiology in world regions where vaccination programs have not been universally available. Vascular etiologies include vasculopathies (systemic lupus erythematosus, small vessel primary angiitis of the central nervous system), arteriovenous malformations, and spinal cord infarction (fibrocartilaginous embolism, diffuse hypoxic ischemia-mediated infarction). Vascular myelopathies are less common than inflammatory and infectious myelopathies, but are more likely to lead to devastating clinical deficits. Current therapeutic strategies include acute anti-inflammatory treatment and rehabilitation. Stem cell transplantation, nerve graft implantation, and stimulation of endogenous repair mechanisms represent promising strategies for spinal cord repair.

The demographic, clinical, and magnetic resonance imaging (MRI) features of transverse myelitis in children

The authors collected demographic, clinical, and neuroimaging data prospectively on 38 children with transverse myelitis. One child died during the illness. The female:male ratio was 1.2:1 for children under age 10 years and 2.6:1 over age 10 years. Twenty-eight (74%) reported a prodromal event. Twenty-two patients (58%) had longitudinally extensive transverse myelitis, 9 (24%) had focal lesions, and 5 (13%) had both. Twenty of 33 with brain imaging (61%) had brain lesions; 7 fulfilled McDonald criteria for dissemination in space. Seven of 22 (36%) tested had cerebrospinal fluid oligoclonal banding, 6 of whom had brain lesions. Serum neuromyelitis optica IgG antibodies were absent in all 20 of the children for whom this test was available. At follow-up (mean 3.2 ± 2.0 years), 16% are wheelchair-dependent, 22% have persisting bladder dysfunction, and 13% have been diagnosed with multiple sclerosis.

Acquired transverse myelopathy in children in the United Kingdom--a 2 year prospective study

AIMS

To define the incidence, describe presentation, management and outcome and identify prognostic factors in Acquired Transverse Myelopathy (ATM) in children under 16 years.

METHODS

A prospective population-based surveillance study, involving all consultant paediatric neurologists in the United Kingdom from 1 July 2002 to 30 June 2004.

RESULTS AND DISCUSSION

Response rate was 91%, and 60 children were reported, of whom 41 were included. Median age was 9 years. The incidence of ATM in children under 16 years in confirmed cases is at least 1.72 per million children per year. There was a previously unrecognised male predominance (M:F 25:16). Early evaluation of bladder function is sometimes omitted. MR imaging should include whole spine and brain to maximise diagnostic information. Despite the use of high dose steroids, 25% of cases were left with significant sequelae. Outcome data was available for 36 children in whom recovery was defined as 'complete' in 19, 'good' in 8, 'fair' in 3 and 'poor' in 6. Significant positive prognostic factors were preceding infection, start of recovery within a week of onset, age less than 10 years, and lumbosacral spinal level on clinical assessment. Significant negative predictors were flaccid legs at presentation, sphincter involvement and rapid progression from onset to nadir within 24h.

Anterior spinal artery syndrome in a girl with Down syndrome: case report and literature review

BACKGROUND/OBJECTIVE

Anterior spinal artery syndrome is an extremely rare cause of acute ischemic cord infarction in children. It is caused by hypoperfusion of the anterior spinal artery, leading to ischemia in the anterior two thirds of the spinal cord. The presentation is usually with an acute and painful myelopathy with impaired bladder and bowel control. Pain and temperature sensation below the lesion are lost, whereas vibration and position sense is intact because of the preservation of the posterior columns.

METHODS

Case report.

RESULTS

A 16-year-old girl with Down syndrome presented with urinary retention and acute complete flaccid paralysis of the legs with absent deep tendon and abdominal reflexes. Magnetic resonance imaging showed a signal abnormality in the anterior half of the thoracic cord from T5 to T12, consistent with anterior spinal artery infarction.

CONCLUSIONS

Pediatricians should consider anterior spinal artery syndrome in the child who presents with acute, painful myelopathy. We summarize the etiology, neurological findings and outcomes of 19 children found in the literature with anterior spinal artery syndrome.

Acute transverse myelitis and acute disseminated encephalomyelitis in childhood: spectrum or separate entities?

The clinical and radiological features of childhood acute transverse myelitis are compared to those of acute disseminated encephalomyelitis with spinal cord involvement in 22 children with acute transverse myelitis and 12 children with acute disseminated encephalomyelitis with spinal cord involvement. Children with acute transverse myelitis were more likely to have a sensory level (55%) and areflexia. Sixty-eight percent of the children with acute transverse myelitis, and 92% of children with acute disseminated encephalomyelitis had longitudinally extensive transverse myelitis. Demyelination was more extensive in acute disseminated encephalomyelitis (mean 15.6 vertebral segments) than in acute transverse myelitis (mean 8.0 vertebral segments). The outcome was normal to good in 82% with acute transverse myelitis and in 100% with acute disseminated encephalomyelitis. Persistent bladder dysfunction was uncommon in both. Poor prognostic factors in acute transverse myelitis are flaccid paraparesis, respiratory failure, and age less than 6 months. These clinical and radiological differences suggest acute transverse myelitis and acute disseminated encephalomyelitis are separate entities.

Multiple sclerosis in children: clinical diagnosis, therapeutic strategies, and future directions

The onset of multiple sclerosis (MS) in childhood poses diagnostic and therapeutic challenges, particularly if the symptoms of the first demyelinating event resemble acute disseminated encephalomyelitis (ADEM). MRI is an invaluable diagnostic tool but it lacks the specificity to distinguish ADEM from the first attack of MS. Advanced MRI techniques might have the required specificity to reveal whether the loss of integrity in non-lesional tissue occurs as a fundamental feature of MS. Although the onset of MS in childhood typically predicts a favourable short-term prognosis, some children are severely disabled, either physically or cognitively, and more than 50% are predicted to enter the secondary-progressive phase of the disease by the age of 30 years. Immunomodulatory therapies for MS and their safe application in children can improve long-term prognosis. Genetic and environmental factors, such as viral infection, might be uniquely amenable to study in paediatric patients with MS. Understanding the immunological consequences of these putative exposures will shed light on the early pathological changes in MS.

Ischemic spinal cord infarction in children without vertebral fracture

Spinal cord infarction in children is a rare condition that is becoming more widely recognized. There are few reports in the pediatric literature characterizing etiology, diagnosis, treatment, and prognosis. The risk factors for pediatric ischemic spinal cord infarction include obstruction of blood flow associated with cardiovascular compromise or malformation, iatrogenic or traumatic vascular injury, cerebellar herniation, thrombotic or embolic disease, infection, and vasculitis. In many children, the cause of spinal cord ischemia in the absence of vertebral fracture is unknown. Imaging diagnosis of spinal cord ischemia is often difficult, due to the small transverse area of the cord, cerebrospinal fluid artifact, and inadequate resolution of magnetic resonance imaging. Physical therapy is the most important treatment option. The prognosis is dependent on the level of spinal cord damage, early identification and reversal of ischemia, and follow-up with intensive physical therapy and medical support. In addition to summarizing the literature regarding spinal cord infarction in children without vertebral fracture, this review article adds two cases to the literature that highlight the difficulties and controversies in the management of this condition.

Discriminatory features of acute transverse myelitis: a retrospective analysis of 45 patients

Acute transverse myelitis (ATM) is a pathogenetically heterogeneous inflammatory disorder of the spinal cord. Therefore, the identification of clinical and paraclinical features providing clues of the underlying etiologies is needed. The clinical presentation, blood and cerebrospinal fluid (CSF) findings as well as magnetic resonance imaging (MRI) and neurophysiological features were retrospectively analyzed in 45 unselected consecutive patients with ATM. Parainfectious ATM was diagnosed in 38% of patients. The underlying infectious agent, however, was identified only in a minority of patients. In 36% of patients, the etiology remained uncertain ("idiopathic" ATM) and in 22% ATM was the first manifestation of possible multiple sclerosis (ATM-MS) according to recently published diagnostic criteria. Spinal cord MRI showed signal alterations in 96% of the patients. In ATM-MS, monosegmental involvement of the spinal cord was most frequent while spinal cord involvement of two or more segments was more common in ATM of other etiologies. Of particular note, neurophysiological examinations showed evidence of peripheral nervous system (PNS) involvement in 27% of patients with ATM but not in patients with ATM-MS. Therefore, neurophysiological evidence of PNS involvement may provide additional discriminatory features between ATM-MS and ATM of other etiologies.

Fibrocartilaginous embolism—an uncommon cause of spinal cord infarction: a case report and review of the literature11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated

Fibrocartilaginous embolism is a rare cause of spinal cord infarction. It is postulated that an acute vertical disk herniation of the nucleus pulposus material can lead to spinal cord infarction by a retrograde embolization to the central artery. An increased intradiskal pressure resulting from axial loading of the vertebral column with a concomitant Valsalva maneuver is thought to be the initiating event for the embolus. We present a previously healthy 16-year-old boy with sudden onset of back pain and progressive paraparesis within 36 hours after lifting exercises in a squat position. His clinical presentation and neuroimaging studies were consistent with spinal cord infarction resulting from a central artery embolus at the T8 spinal cord level. Laboratory investigation showed no evidence of infectious, autoimmune, inflammatory, or neoplastic causes. Although no histologic confirmation was obtained, lack of evidence for other plausible diagnoses in the setting of his clinical presentation and in the magnetic resonance imaging findings made fibrocartilaginous embolism myelopathy the most likely diagnosis. We postulated that some cases of transverse myelitis might actually be fibrocartilaginous embolism, making it a more prevalent cause of an acute myelopathy than commonly recognized. Relevant literature and current theories regarding the pathogenesis of fibrocartilaginous embolism myelopathy are reviewed.

Childhood autoimmune neurologic diseases of the central nervous system

An autoimmune mechanism for ADEM and MS can be supported by the similar patterns of pathologic changes seen in both diseases with the animal model EAE induced by inoculating animals with nervous tissue and the occurrence of ADEM in patients exposed to nervous tissue during vaccination. Whereas there are no universally agreed-upon criteria for the diagnosis of ADEM, a combination of prodromal illness or preceding vaccination, MRI signs of demyelination, and an acute presentation of neurologic symptoms are the triad most commonly looked for in making the diagnosis of ADEM. An ever-increasing number of infections and vaccinations (nonspecific URIs being most common) has been associated with ADEM. Fever and encephalopathy are seen frequently at presentation. Seizures also are common, as are cranial nerve abnormalities and motor symptoms. A mild pleocytosis or protein elevation is found in the majority of patients with ADEM. Intrathecal IgG synthesis and oligoclonal bands are relatively infrequent but should not be considered inconsistent with the diagnosis of ADEM. White matter changes on T2 in a bilateral although asymmetric distribution with relative sparing of the periventricular region with or without deep gray matter involvement is consistent and to some a requirement for the diagnosis. Low-dose steroids have no beneficial effect in the treatment of ADEM and may be contraindicated. High-dose steroids may have a beneficial effect, particularly in more prolonged illnesses, although the evidence is primarily anecdotal. If steroids are used to improve morbidity, 30 mg/kg/d of methylprednisolone for three to five days is the dose with a six-week taper to reduce the risk of recurrence. The prodromal infection may be a major factor in the ultimate mortality and morbidity of the disease. The current mortality of ADEM is quite low. Whether or not this is an effect of different triggering agents or changes in medical care cannot be determined. In larger series of patients with ADEM, 10% to 20% of children experience some sort of recurrence with the majority occurring in the initial one to two months after the first event. This is sometimes associated with steroid withdrawal. A second group of children have a late second recurrence that clinically may not be MS but a recurrence of ADEM, although longer follow-up may change that assessment. Two months should be allowed before a second relapse is considered a manifestation of MS, whereas a second attack also may occur years after an initial attack of ADEM and still be consistent with ADEM recurrence. MS does occur during childhood, with the youngest children at the least risk, and risk increasing with age. The criteria of Poser et al can be used to diagnose MS in childhood [40]. The presentation of MS in childhood is most often sensory, motor, and brainstem signs and symptoms. A relapsing-remitting course is most common with a first relapse occurring in the year after presentation. MRI findings in MS typically show periventricular changes. Oligoclonal bands and CSF IgG synthesis are found in the majority. Treatments of childhood MS have not been studied adequately, but, when treatments studied in adults are used in children, they are well tolerated. Efficacy has not been shown. The long-term outcome of MS in childhood can be either severe or benign with no clear consensus that childhood MS is either a less or more severe disease than the adult form. ATM and ON treatments and outcomes are particularly difficult to evaluate because of the heterogeneity of populations included in case series and the small numbers reported. Steroids are used with anecdotal reports of their superiority to nontreatment. Outcome in ATM often can be poor, whereas in ON it rarely is. A multinational collaborative effort to study and collect the large numbers necessary to address the important questions in these childhood autoimmune disorders would be of great benefit and the only way likely to demonstrate good evidenced-based medicine practiced in this field.

MRI findings in acute idiopathic transverse myelopathy in children

OBJECTIVE

To describe the clinical and MRI findings in three children with acute idiopathic myelopathy (AIM).

MATERIALS AND METHODS

Retrospective review of the clinical presentation, MRI findings and outcome of three patients diagnosed with acute idiopathic transverse myelitis.

RESULTS

Of note was the swift onset of symptoms in all patients, without any preceding illness or history of vaccination in two of the patients, and the rapid resolution of symptoms on steroid therapy in all the patients. MRI showed T2-weighted hyperintensity and patchy enhancement with gadolinium, but the extensive cord involvement did not correlate with the severity of presentation or outcome.

CONCLUSIONS

Our findings do not support that MRI evidence alone of diffuse myelopathy is a predictor of poor outcome in childhood AIM.

Myelitis

Acute transverse myelitis (ATM) with moderate symptomatology and smaller multiple magnetic resonance imaging lesions is often caused by multiple sclerosis. Severe ATM with extensive magnetic resonance imaging lesions with or without associated meningitis often has a viral cause, particularly in the younger age groups, whereas vascular disorders may prevail among older patients. Previously, one had to rely on indirect evidence such as viral serology or viral identification in throat washings to confirm a diagnosis of myelitis. Thus, mycoplasma myelitis may occur coincident with a mycoplasma pneumonia. Viral myelitis is now often diagnosed by specific polymerase chain reaction of the cerebrospinal fluid, for echovirus, Coxsackie virus, mumps virus, herpes simplex virus or varicella-zoster virus, but an autoimmune component may still be important. An anterior horn syndrome may be produced by the tick-borne encephalomyelitis virus. Severe ATM may also be a postinfectious or postvaccinal disorder [i.e. a partial acute disseminated encephalomyelitis (ADEM)]. Neuromyelitis optica, a combination of severe myelitis and optic neuritis, is often a manifestation of ADEM or systemic lupus erythematosus. Many of these disorders are potentially treatable with specific antiviral agents or immunosuppression. 'Idiopathic' ATM is probably a consequence of inadequate examination and follow up. The differential diagnoses-viral myelitis, multiple sclerosis, ADEM, neuromyelitis optica, spinal arteriovenous malformation and arteritis-should be considered and are usually identified by a rapid diagnostic work-up, leaving few ATM cases undiagnosed.