Idiopathic acute transverse myelitis: Application of the recent diagnostic criteria

Partial acute transverse myelitis is a predictor of multiple sclerosis in children

Background:

Acute transverse myelitis (ATM) in children is a rare and often severe disease for which there are few known prognostic factors, particularly the subsequent risk of multiple sclerosis (MS) diagnosis.

Objectives:

To determine the clinical course and prognostic factors after a first episode of ATM in children.

Methods:

Thirty children below 16 years of age diagnosed with a first neurological episode of ATM were included retrospectively. Clinical evaluation, treatment, laboratory, and MRI data were collected.

Results:

Median age at onset was 11 years (range 3–15 years). Follow-up data were available for a median of 4 years (range 0.5–16.7 years). Five patients subsequently had a diagnosis of MS (17%), which was associated with acute partial transverse myelitis (odds ratio 5; 95% confidence interval 2.3–11), with a 60% probability of having a relapse at five years ( p < 0.01). The 2011 Verhey criteria correctly identified MS in children with the highest specificity (96%) and sensitivity (80%).

Conclusion:

Acute partial transverse myelitis and brain MRI abnormalities at initial presentation are significantly predictive of a subsequent diagnosis of MS in children with ATM. These findings suggest that closer brain MRI monitoring after acute partial transverse myelitis might make the earlier introduction of disease-modifying therapies possible.

MRI in transverse myelitis

Transverse myelitis is an acute inflammatory disease of the spinal cord, characterized by rapid onset of bilateral neurological symptoms. Weakness, sensory disturbance, and autonomic dysfunction evolve over hours or days, most progressing to maximal clinical severity within 10 days of onset. At maximal clinical severity, half will have a paraparesis, and almost all patients have sensory disturbance and bladder dysfunction. Residual disability is divided equally between severe, moderate and minimal or none. The causes of transverse myelitis are diverse; etiologies implicated include demyelinating conditions, collagen vascular disease, and parainfectious causes, however, despite extensive diagnostic work-up many cases are considered idiopathic. Due to heterogeneity in pathogenesis, and the similarity of its clinical presentation with those of various noninflammatory myelopathies, transverse myelitis has frequently been viewed as a diagnostic dilemma. However, as targeted therapies to optimize patient outcome develop, timely identification of the underlying etiology is becoming increasingly important. In this review, we describe the imaging and clinical features of idiopathic and disease-associated transverse myelitis and its major differentials, with discussion of how MR imaging features assist in the identification of various sub-types of transverse myelitis. We will also discuss the potential for advanced MR techniques to contribute to diagnosis and prognostication.

Transverse myelitis and acute motor sensory axonal neuropathy due to Legionella pneumophila: a case report

Guillain-Barré syndrome is a rapidly progressive symmetrical muscle weakness associated with acute inflammatory disease. Transverse myelitis (TM) is the inflammation of the spinal cord characterized by rapidly evolving muscle weakness in the lower extremities, defects in sensory level and sphincter dysfunction. Guillain-Barré syndrome, and TM association occurs very rarely in childhood. A 7-year-old girl presented with complaints of neck pain, spout-style vomiting, cough, shortness of breath, and acute paraparesis with sensory and sphincter disturbance. The patient was intubated because of increased respiratory distress. A positive direct fluorescein antigen test in bronchoalveolar lavage confirmed Legionella pneumophila infection. Imaging and neurophysiologic studies were diagnostic for TM with acute motor and sensory axonal neuropathy. She was treated with a combination of high-dose methylprednisolone and intravenous immunoglobulins, and we observed incomplete recovery. The presented case is the first child with concomitant TM and acute motor and sensory axonal neuropathy related to L. pneumophila infection.

Prognostic indicators of acute transverse myelitis in 39 children

BACKGROUND

The Transverse Myelitis Consortium Working Group has proposed new diagnostic criteria for acute transverse myelitis. The purpose of the present study is to evaluate the relations between clinical variables and functional prognosis using new criteria.

METHODS

We reviewed 39 Chinese cases meeting the new criteria, recorded clinical epidemiological data, and followed activities of daily living measuring scale (Modified Barthel Index).

RESULTS

Thirty-nine children met new criteria for definite acute transverse myelitis in the past 14 years between 1995 and 2008. Mean follow-up time was 102.7 months. Conversion to multiple sclerosis occurred in two patients (5.1%). Those children with a short time to maximal deficits, long time of peak neurological impairment and initial time of treatment, increased protein levels of the cerebrospinal fluid, and secondary infection were more likely to have residual neurological deficits, resulting in lower qualities of life (P = 0.005, P = 0.003, P = 0.011, P = 0.0012, P = 0.000, respectively).

CONCLUSIONS

A short time to maximal deficits, long time of peak neurological impairment and initial time of treatment, increased protein levels of cerebrospinal fluid, and secondary infection played important roles in predicting poor prognosis.

Clinical and biomarker assessment of demyelinating events suggesting multiple sclerosis

BACKGROUND

Initial demyelinating event (IDE) diagnosis and prognosis are not straightforward.

OBJECTIVE

To identify potential diagnostic markers and outcome predictors of IDEs suggestive of multiple sclerosis (MS), that is, clinically isolated syndromes (CISs).

METHODS

Clinically isolated syndrome cases (i.e., subjects with an IDE compatible with MS onset and no alternative explanation) with at least 1.5 years' follow-up were retrospectively identified. All cases underwent clinical, neurophysiological, MRI, and cerebrospinal fluid (CSF) assessment, including exploratory tau, 14-3-3, and cystatin C testing. CIS recovery, conversion to MS, and long-term neurological disability were used as outcome measures. Patients with neuromyelitis optica spectrum disorders, idiopathic acute transverse myelitis (IATM), Creutzfeldt-Jacob disease, and non-inflammatory/non-neurodegenerative disorders served as controls for CSF analysis.

RESULTS

Forty-six CIS cases were included. Severe presentation was associated with incomplete recovery, while presence of at least 3 periventricular lesions on baseline MRI correlated with MS conversion. Initial pyramidal tract involvement, incomplete CIS recovery, and number of relapses predicted neurological disability. CSF tau, 14-3-3, and cystatin C did not correlate with any outcome measure. CIS cases had significantly lower tau and cystatin C levels compared to IATM.

CONCLUSIONS

An extensive diagnostic evaluation of patients with an IDE is worthwhile to make prognostic predictions. More robust molecular biomarkers are needed.

Idiopathic acute transverse myelitis: outcome and conversion to multiple sclerosis in a large series

BACKGROUND

In 2002, the Transverse Myelitis Consortium Working Group (TMCWG) proposed the diagnostic criteria for idiopathic acute transverse myelitis (IATM) to delimit and unify this group of patients. This study aimed to describe the conversion rate to multiple sclerosis (MS) and variables associated with conversion, and to analyze functional outcome and prognostic factors associated with functional recovery in patients who fulfilled the current TMCWG criteria for definite and possible IATM.

METHODS

Eighty-seven patients diagnosed with IATM between 1989 and 2011 were retrospectively reviewed. Two patients with positive neuromyelitis optica IgG serum antibodies were excluded. Epidemiological, clinical, laboratory, magnetic resonance imaging (MRI) data and outcome of 85 patients were analyzed.

RESULTS

Eleven (13%) patients converted to MS after a median follow-up of 2.9 years (interquartile range 1.0-4.8). Early-age onset of symptoms was related to conversion to MS. Only 9.4% of patients with IATM were unable to walk unassisted at the end of follow-up. Urinary sphincter dysfunction (odds ratio [OR] 3.37, 95% confidence interval [CI] 1.04-10.92) and longitudinally extensive transverse myelitis (LETM) on MRI (OR 12.34, 95% CI 3.38-45.00) were associated with a poorer outcome (Rankin ≥ 2).

CONCLUSIONS

At least 13% of patients who fulfill the TMCWG criteria for definite and possible IATM will convert to MS. Functional recovery in IATM is poorer in patients with urinary sphincter dysfunction at admission or LETM on MRI.

Compressive myelopathy: magnetic resonance imaging findings simulating idiopathic acute transverse myelopathy

OBJECTIVE

To provide magnetic resonance imaging (MRI) findings of compressive myelopathy simulating idiopathic acute transverse myelopathy (ATM).

MATERIALS AND METHODS

From 19,416 patients who had spinal MRI from 1 September 2004 to 10 July 2011, the patients who met inclusion criteria were enrolled as follows: (1) definable cord compression, (2) long-segmental intramedullary T2-high signal intensity (HSI) extending more than 2 vertebral segments, and (3) no history of trauma, malignancy, or demyelinating disease. The characteristics of T2-HSI and contrast enhancement pattern were analyzed. The patients' clinical information was collected in the process.

RESULTS

Thirteen patients (10 men, 3 women; mean age, 52.8 years; age range, 43-77 years) were included in this study. Twelve patients had cervical cord compression and one had thoracic compression. Common findings of T2-HSI included fusiform shape (100 %) with cord swelling (92.3 %), cord compression in midline location (76.9 %), diffuse distribution occupying more than two-thirds of the cross-sectional dimension of the cord in axial image (84.6 %), and focal and peripheral enhancement (63.6 %). Intravenous corticosteroid was administered to four patients, including two patients following decompressive surgery, and interval decrease in T2-HSI was seen in three patients, but with residual lesions at cord compression level.

CONCLUSIONS

Spinal cord compression can induce long-segmental cord signal change, such as idiopathic ATM.

Transverse myelitis

Transverse myelitis (TM) includes a pathobiologically heterogeneous syndrome characterized by acute or subacute spinal cord dysfunction resulting in paresis, a sensory level, and autonomic (bladder, bowel, and sexual) impairment below the level of the lesion. Etiologies for TM can be broadly classified as parainfectious, paraneoplastic, drug/toxin-induced, systemic autoimmune disorders, and acquired demyelinating diseases. We discuss the clinical evaluation, workup, and acute and long-term management of patients with TM. Additionally, we briefly discuss various disease entities that may cause TM and their salient distinguishing features, as well as disorders that may mimic TM.

Diagnóstico diferencial das lesões inflamatórias e infecciosas do cone medular utilizando a ressonância magnética

O cone medular é frequentemente acometido por lesões de etiologia inflamatória e infecciosa, muitas vezes de difícil diferenciação devido a história clínica e exame físico semelhantes entre as diversas entidades. A ressonância magnética apresenta alta sensibilidade na detecção de lesões no cone medular e tem importante papel no diagnóstico e controle evolutivo. Este ensaio iconográfico com casos selecionados dos arquivos do nosso serviço tem como objetivo demonstrar achados de imagem que possam auxiliar no diagnóstico de uma etiologia específica entre as doenças inflamatórias e infecciosas e na diferenciação com doenças de outras etiologias como neoplasias e causas vasculares. Características como padrão de realce, presença de cistos, edema, além do acometimento de outras regiões do sistema nervoso central são importantes para esta diferenciação, podendo definir uma etiologia específica quando associadas ao quadro clínico e laboratorial.

Acute necrotizing encephalopathy (ANE1): rare autosomal-dominant disorder presenting as acute transverse myelitis

The term "acute transverse myelitis (ATM)" comprises various non-traumatic disorders that eventually can be associated with a focal myelopathy. Patients characteristically present with an acutely occurring paraparesis/plegia and require a comprehensive and timely diagnostic work up for the initiation of an appropriate treatment. We present a case of a 36-year-old female patient with a rare genetic disorder (ANE1: Acute Necrotizing Encephalopathy due to a RANBP2 mutation) who presented with an acute quadriplegia. Following an acute pulmonal infection, she rapidly (< 24 h) developed a severe quadriplegia (total motor score 38) with some facial sensory symptoms (perioral hypoesthesia). Magnetic resonance imaging (MRI) revealed a combination of longitudinal extensive transverse myelitis and symmetrical thalamic lesions. A work-up for infectious and systemic diseases was negative; specifically, no findings related to multiple sclerosis, neuromyelitis optica or vascular disorders. After empirical high dose steroid treatment and rehabilitation therapy, the patient gained almost normal gait and upper limb function. She was found to carry an autosomal-dominant missense mutation in the RANBP2 gene predisposing for ANE. Gene segregation was confirmed in other family members that had been affected by other episodes of acute steroid-responsive encephalopathies. We propose that a redefined diagnostic workup of ATM might include ANE1, as the frequency of this rare disorder might be underestimated.

Acute Transverse Myelitis Associated with Buserelin Use during IVF

A healthy woman undergoing in vitro fertilization (IVF) developed acute transverse myelitis (ATM) following the use of Buserelin. ATM has a multifactorial etiology and may develop as a result of the activation of immune responses. Infectious agents have been postulated as possible triggers of an immune response (Sá, 2009). Gonadotropin-releasing agonists may have a similar role and trigger the acceleration of preexisting disease by the activation of immune responses (Ho et al., 1995, and Umesaki et al., 1999).

Analysis of prognostic factors associated with longitudinally extensive transverse myelitis

OBJECTIVE

The aim of this study is to report the clinical profile and outcome of longitudinally extensive transverse myelitis (LETM).

METHODS

We prospectively studied adult patients who presented with LETM from January 2008 to December 2011. Information on demographic, clinical course, magnetic resonance imaging (MRI) and outcome was collected. HLA-DRB1 genotype was compared with those of 225 normal controls and patients with MS (228) and neuromyelitis optica (NMO) (22).

RESULTS

In total, 23 patients (16 female) with a median age of 44.5 years (range: 20-77 years) were included. Most (74%) had moderate-severe disability at nadir (48% non-ambulatory), normal/non-multiple sclerosis (MS) brain MRI (96%) and a median MRI cord lesion of 5 vertebral segments (range: 3-19). Laboratory analysis showed cerebrospinal fluid pleocytosis (45%), NMO-IgG (9%), antinuclear antibodies (70%), and genotype HLA-DRB1*13 (57%). The frequency of DRB1*13 genotype was higher compared with controls (p=0.002), MS (p=0.001) and NMO (p=0.003) patients. After a median follow-up of 32 months, one patient converted to MS, two had relapsing LETM with NMO-IgG, and 20 remained as idiopathic with recurrences in four (20%). Twelve (52%) patients recovered with minimal disability (Expanded Disability Status Scale (EDSS) ≤2.5) and three (13%) remained wheelchair dependent. Disability at nadir was associated with the final outcome and extension of the spinal cord lesion with risk of recurrence. Recurrence was not associated with worse outcome.

CONCLUSIONS

Inflammatory LETM is mostly idiopathic with a good outcome. It includes a relatively homogenous group of patients with an overrepresentation of the HLA-DRB1*13 genotype. EDSS at nadir is a predictor of the final outcome and extension of the myelitis of the recurrence risk.

[Inflammatory diseases of the spinal column and the myelon]

Inflammatory diseases of the spine and the spinal cord (myelon) can be caused by a wide range of pathological conditions. Except for degenerative inflammatory diseases of the spine, infectious and autoimmune disorders are relatively rare. The latter can also be a significant source of pain and disability, especially if these hard to diagnose conditions go untreated. In cases of advanced disease some entities, such as spondylodiscitis or rheumatoid arthritis can cause severe neurological impairment especially by progressive intraspinal spread. Inflammation of the myelon cannot be depicted with conventional radiographs in general and by computed tomography only occasionally. In these cases magnetic resonance imaging is the method of choice to detect early abnormalities of the myelon and to provide detailed information for the differential diagnosis.

Neuroimaging in acute transverse myelitis

Transverse myelitis is an acute inflammatory condition. A relatively rare condition, the diversity of causes makes it an important diagnostic challenge. An approach to the classification and work-up standardizes diagnostic criteria and terminology to facilitate clinical research, and forms a useful tool in the clinical work-up for patients at presentation. Its pathogenesis can be grouped into four categories. Imaging appearances can be nonspecific; however, the morphology of cord involvement, enhancement pattern, and presence of coexistent abnormalities on MR imaging can provide clues as to the causes. Neuroimaging is important in identifying subgroups that may benefit from specific treatment.

Immune mediated diseases and immune modulation in the neurocritical care unit

This chapter will review the spectrum of immune-mediated diseases that affect the nervous system and may result in an admission to the neurological intensive care unit. Immunomodulatory strategies to treat acute exacerbations of neurological diseases caused by aberrant immune responses are discussed, but strategies for long-term immunosuppression are not presented. The recommendations for therapeutic intervention are based on a synthesis of the literature, and include recommendations by the Cochrane Collaborative, the American Academy of Neurology, and other key organizations. References from recent publications are provided for the disorders and therapies in which randomized clinical trials and large evidenced-based reviews do not exist. The chapter concludes with a brief review of the mechanisms of action, dosing, and side effects of commonly used immunosuppressive strategies in the neurocritical care unit.

[Acute transverse myelitis in Buenos Aires, Argentina. A retrospective cohort study of 8 years follow up]

INTRODUCTION

Epidemiological studies on acute transverse myelitis (ATM) in South America are scarce. The aim of our study was to describe demographic, clinical and para-clinical features of patients with ATM in a health care organisation in Buenos Aires. A further objective was to determine the aetiologies of ATM.

METHODS

All patients diagnosed with ATM between June 1, 2002 and June 30, 2010 were retrospectively identified, using the Transverse Myelitis Consortium Working Group criteria.

RESULTS

A total of 40 patients diagnosed with ATM, (24 females, 60%) were included. The mean follow-up was 57 ± 8 months. The principal cause of myelitis found was ATM secondary to demyelinating disease (55%). Idiopathic ATM was diagnosed in 15 (37.5%) cases in the sample. The majority of patients had an extensive cord lesion (50%) detectable with spinal MRI.

CONCLUSION

There are few epidemiological studies concerning ATM in Argentina, and we believe that it is important to be aware of the manner in which this condition manifests itself in this region. We would therefore be able to compare them with studies previously published in other countries.

Acute disseminated encephalomyelitis and its place amongst other acute inflammatory demyelinating CNS disorders

The diagnosis of acute inflammatory demyelinating CNS conditions is complex and this is reflected in variations in how cohorts are defined across studies. For some conditions the diagnosis relies on whether it is monophasic or relapsing, in others the anatomical site of inflammation is used as a means of categorisation. Clinical features such as precipitants, gender and age may affect the probability of certain diagnoses, but are not highly accurate. Exclusive features for the pathology are identifiable for some but not all conditions, and are seldom available during life. Specific markers such as antibodies are informative and new developments in this area are likely in the near future. This review outlines the features and classification of acute disseminated encephalomyelitis and contrasts it with other related conditions before attempting to define a pragmatic organisation of these conditions based upon present evidence.

Immune-mediated myelitis associated with hepatitis virus infections

Virus-induced spinal cord damage results from a cytolytic effect on anterior horn cells or from predominantly cellular immune-mediated damage of long white matter tracts. Infection with the hepatitis virus group, most notably hepatitis C virus, has infrequently been associated with the occurrence of myelitis. The pathogenesis of hepatitis virus-associated myelitis has not been clarified: virus-induced autoimmunity (humoral or cell-mediated, possibly vasculitic) seems the most likely disease mechanism. Limited available information offers no evidence of direct hepatitis virus infection of the spinal cord. Virus neuropenetration may occur after virus-infected mononuclear cells penetrate the blood-brain barrier, but a true neurolytic effect has not been demonstrated. Attacks of acute myelitis usually respond favorably to immunomodulatory therapy. Antiviral therapy plays no confirmed role in the treatment of acute bouts of myelitis, but may limit the relapsing course of HCV-associated myelitis.

Acute transverse myelitis in demyelinating diseases among the Chinese

The aim of the study was to characterize the demographic, clinical, and prognostic features of Chinese patients with acute transverse myelitis (ATM). The clinical data from ATM patients in a demyelinating disease database were analyzed retrospectively. Sixty-seven ATM patients with a follow-up duration longer than 2 years were identified. The frequency of neuromyelitis optica-related ATM (NMO-ATM) was high in our cohort (40.3%). Recurrent ATM (R-ATM), with a female predominance, was common in total idiopathic ATM (69.0%, 20/29). In R-ATM with longitudinally extensive spinal cord lesions (LESCLs), the high seropositivity of NMO-IgG, spinal cord lesions mostly involved the central gray matter and severer long-term disability were similar to NMO-ATM. In RTM without LESCLs, low seropositivity of NMO-IgG, preferentially involvement of the peripheral white matter and relative better neurological recovery were consistent with multiple sclerosis-related ATM (MS-ATM). The transition rates to MS in patients with acute partial transverse myelitis (APTM) and acute complete transverse myelitis (ACTM) were not significant (16.7 vs. 6.3%, P = 0.753), while LESCLs (OR = 11.4, P = 0.028) were significantly correlated with transition to NMO. The presence of LESCLs was the only variable showing a higher risk for reaching Rankin 3 (hazard ratio: 2.5, 95% CI: 1.0-6.1). Chinese patients with ATM had demographic, clinical, and prognostic features different from those in Western populations. Idiopathic R-ATM, common in Chinese, is a heterogeneous entity that shares partial clinical, spinal MRI and prognostic features with MS-ATM and NMO-ATM. The length of spinal cord lesion, rather than APTM/ACTM, may be a prognostic factor associated with clinical outcome and long-term disability in our population.

Rituximab in the treatment of severe lupus myelopathy

Lupus myelopathy (LM) is a rare but critical condition, and the prognosis is grim for patients with severe initial motor deficits despite aggressive conventional immunosuppressive therapy. In this report, six recent-onset severe LM patients with lower extremity muscle strength less than or equal to grade 3 were treated with rituximab combined with pulse methylprednisolone. Four patients showed complete myelopathy response at 12 months. The safety profile of rituximab was tolerable, with urinary tract infection as the most frequent adverse event. Preliminary data indicated that rituximab could be beneficial in preventing permanent neurological damage in severe LM.

Optical coherence tomography evaluation of retinal nerve fiber layer in longitudinally extensive transverse myelitis

OBJECTIVE: To compare optical coherence tomography (OCT) measurements on the retinal nerve fiber layer (RNFL) of healthy controls and patients with longitudinally extensive transverse myelitis (LETM) without previous optic neuritis. METHOD: Twenty-six eyes from 26 patients with LETM and 26 control eyes were subjected to automated perimetry and OCT for comparison of RNFL measurements. RESULTS: The mean deviation values from perimetry were significantly lower in patients with LETM than in controls (p<0.0001). RNFL measurements in the nasal quadrant and in the 3-o'clock segment were significantly smaller in LETM eyes than in controls. (p=0.04 and p=0.006, respectively). No significantly differences in other RNFL measurements were found. CONCLUSION: Patients with LETM may present localized RNFL loss, particularly on the nasal side of the optic disc, associated with slight visual field defects, even in the absence of previous episodes of optic neuritis. These findings emphasize the fact that patients with LETM may experience attacks of subclinical optic nerve damage.

Primary HIV infection with acute transverse myelitis

Primary HIV infection (PHI) is associated with various neurological disorders. However, acute transverse myelitis (ATM) complicating PHI has not been reported after the introduction of the combination antiretroviral therapy (cART). We encountered one patient with known PHI with clinical presentation of ATM. Treatment with cART and corticosteroids successfully improved symptoms, and no recurrence was noted after discontinuation of cART. In conclusion, concurrent use of cART and corticosteroids was effective against PHI accompanied by ATM and could be withdrawn after improvement of ATM.

Predictive factors for multiple sclerosis in patients with clinically isolated spinal cord syndrome

OBJECTIVES

To identify predictors of conversion to definite multiple sclerosis (MS) in patients with a cord clinically isolated syndrome.

METHODS

The predictive values for conversion to MS of clinical, magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) variables in 114 patients with acute partial myelitis confirmed by a spinal cord lesion on MRI were studied. Other causes of cord syndromes were excluded.

RESULTS

MS was diagnosed in 78 patients (86%) during 4.0 ± 1.9 years of follow-up. Some 67 of these patients had a second clinical episode. The diagnosis of isolated myelitis was maintained for 36 patients, 78% of whom (28 cases) were followed for at least 2 years, comparable to the MS patients. Age, bladder involvement, ≥ 2 cord lesions on MRI, ≥ 9 brain lesions, ≥ 3 periventricular lesions and intrathecal IgG synthesis predicted conversion to clinically definite MS. Multivariate logistic analysis identified three predictors of MS diagnosis: age ≤ 40 years, inflammatory CSF and ≥ 3 periventricular lesions on brain MRI.

CONCLUSION

Two out of three baseline factors (age, periventricular lesions and inflammatory CSF) predicted conversion to MS with better accuracy than the revised McDonald criteria for dissemination in space.

[Imaging of demyelinating and neoplastic diseases of the spinal cord]

The clinical symptoms of myelopathy are variable and non-specific. Demyelinating as well as neoplastic spinal cord diseases can cause paresthesia, progressive sensomotoric deficits and bowel and bladder dysfunction. Imaging of the spine, especially with magnetic resonance imaging (MRI), is an essential component in the diagnostic assessment of myelopathy and makes a substantial contribution to achieving the correct diagnosis. Although intramedullary neoplasms are far less common than demyelinating spinal cord diseases, radiologists should be familiar with the three most common entities, astrocytoma, ependymoma and hemangioblastoma, which represent over 70% of all spinal cord neoplasms. An early diagnosis and therapy is essential with neoplastic and demyelinating spinal cord diseases to hold residual neurological deficits as low as possible.

[Imaging of non-traumatic and non-tumoral cord lesions]

There is a wide range of spinal cord pathologies (vascular, inflammatory, infectious, metabolic, degenerative). They present clinically as acute partial or complete cord syndromes, or chronic myelopathies (more than 4 weeks in duration). MRI examination should be undertaken with a very strict protocol. Spinal cord lesions should be evaluated with regards to their T1W and T2W signal characteristics, involvement of grey and/or white matter, axial and sagittal extension, cord volume changes, contrast uptake and associated lesions (perimedullary, radicular or brain). The correlation of MR imaging features with clinical and biological data (blood and CSF) should suggest a differential diagnosis.

The epidemiology of transverse myelitis

Transverse myelitis is a neurological disorder causing acute spinal cord injury as a result of acute inflammation, often associated with para infectious processes and autoimmune disease. The purpose of this article is to review the literature on the geoepidemiology of transverse myelitis and assess its environmental associations. Articles from 1981 to 2009 were reviewed in Pub Med along with potential causes such as autoimmune disease (focusing on systemic lupus erythematosus (SLE), antiphospholipid antibody syndrome (APS), and Sjogren's), infection, vaccination, and intoxication.

Clinically isolated acute transverse myelitis: prognostic features and incidence

Demyelinating acute transverse myelitis may be the first presentation of multiple sclerosis or remain a clinically isolated syndrome. North Canterbury, New Zealand provides a well circumscribed population to study acute transverse myelitis. Objective: to identify prognostic features, clinical outcomes and incidence of ATM in North Canterbury, New Zealand. All patients with acute transverse myelitis as a first neurological presentation diagnosed from January 2001 to December 2005 at a single institution providing all neurological care for North Canterbury were assessed for clinical data, MRI findings, cerebrospinal fluid results and clinical outcomes. CHAMPS, Barkhof/Tintore and Swanton criteria were applied to brain MRI. Sixty-one patients were identified with a mean duration of follow-up of 30 ± 17 months. Fifty percent of patients with ATM with brain lesions by CHAMPS criteria converted to clinically definite multiple sclerosis. No patients with idiopathic acute transverse myelitis converted to clinically definite multiple sclerosis. There was a strong association with conversion to clinically definite multiple sclerosis and abnormal brain MRI by CHAMPS criteria (hazard ratio, 5.63; 1.83—17.3), Barkhof/Tintore criteria (hazard ratio, 6.43; 2.31—17.9) and Swanton criteria (hazard ratio, 4.53; 1.67—12.3). The age standardized annual incidence of acute transverse myelitis was 24.6 (18.2—31.1) per million, of definite and possible idiopathic acute transverse myelitis was 6.2 (2.9—9.6) per million, and of acute transverse myelitis with brain lesions was 4.7 (1.9—7.6) per million. Patients with idiopathic acute transverse myelitis are at low risk for conversion to clinically definite multiple sclerosis. Abnormal brain MRI by CHAMPS criteria is a sensitive predictor of conversion to clinically definite multiple sclerosis. The annual incidence of acute transverse multiple sclerosis in North Canterbury, New Zealand is significantly higher than previously reported.

[Acute myelitis associated with systemic diseases]

Myelitis secondary to systemic disease is a rare condition but clinical involvement is frequently severe. In case of a well-known systemic disease before myelitis diagnosis is relatively easy to perform. On contrary, when the systemic disease is not known previously the management is more difficult. This is of importance for therapeutical considerations. In the present paper we review the topic of acute myelitis secondary to systemic diseases.

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.

Long-term outcome of acute and subacute myelopathies

We aimed to evaluate the long-term (>2 years) outcome of acute and subacute myelopathies (ASM). We systematically followed-up consecutive patients presenting with a first episode of ASM, defined by spinal cord symptoms with an onset <3 weeks and duration >or=48 h. Patients with compressive or traumatic spinal cord lesions are excluded from this report. Our cohort consisted of 170 patients (median age 39.0 years, median duration of follow-up 73.2 months). The death rate was 8.8%, Lipton and Teasdall's functional score was bad or fair in 38.2%, and 37.1% of the survivors who worked when the ASM occurred were unable to carry on with the same profession. Unfavorable functional outcome was more frequent when (1) symptoms were initially severe, (2) the lesion was located centrally on spinal cord MRI and (3) the etiology was neuromyelitis optica (NMO) or systemic disease (SD). In one-third of patients the etiology at the end of follow-up differed from the etiology suspected after the initial diagnostic workup. Over half of patients initially diagnosed with myelopathy of undetermined cause subsequently developed multiple sclerosis, NMO or SD. ASM is a severe condition with a bad or fair functional outcome and a major impact on professional activity in one-third of the patients. Central lesions on spinal cord MRI and etiologies such as NMO or SD are associated with a worse functional outcome. Finally, a long-term follow-up is important given the large number of causes that are identified at a distance from the initial event.