Neuromyélite optique de devic associée à une tuberculose pulmonaire

Tuberculous Myelopathy Associated with Longitudinally Extensive Lesion: A Clinicoradiological Review of Reported Cases

Acute transverse myelitis is an inflammatory disorder of the spinal cord in which there is no evidence of spinal cord compression. Longitudinally extensive transverse myelitis (LETM) is a specific subtype of acute transverse myelitis that usually affects three or more vertebral levels and produces marked neurological deficits. While the most-common cause of LETM is neuromyelitis optica or neuromyelitis optica spectrum disorder, there are rare cases of other causes mimicking this condition, including tuberculosis (TB). We sought to review the clinicoradiological features of TB myelopathy associated with longitudinally extensive lesion, which may mimic LETM, in the English literature. We searched the PubMed, Google Scholar, Web of Science, and Scopus databases for relevant articles using search terms including “longitudinally extensive transverse myelitis,” “tuberculosis,” “TB spinal cord,” and various combinations of these expressions. Full-text papers were selected without limiting the publication year. We also examined the reference lists of key papers to identify further articles that are potentially relevant. We found 10 cases in 7 papers describing TB myelopathy associated with longitudinally extensive lesion. The demographics, clinical features, relevant cerebrospinal fluid findings, and radiological findings were compiled and summarized. TB myelopathy associated with longitudinally extensive lesion is very rare, with no documented prevalence. Early and accurate diagnosis is important since the condition is potentially treatable.

Longitudinally extensive transverse myelitis with pulmonary tuberculosis: Two case reports

RATIONALE

Longitudinally extensive transverse myelitis (LETM) is characterized by contiguous inflammatory lesions of spinal cord extending to ≥3 vertebral segments. The etiology of LETM is complicated, including various infection, autoimmune disease, and so on. Neuromyelitis optic spectrum disorder (NMOSD) is the most common cause of LETM. Several case reports have suggested the associations between NMOSD and pulmonary tuberculosis (PTB).

PATIENT CONCERNS

Patient 1, a 20-year-old woman who had a past history of PTB, presented with weakness, numbness, and pain in the limbs. The serum anti-aquaporin-4 antibody (AQP4-Ab) was strongly positive, and the magnetic resonance imaging (MRI) scan of cervical and thoracic spinal cord after admission to the hospital revealed hyperintensity lesions extending from C3 to T8 on T2-weighted (T2W) image, T1-weighted (T1W) image, and fluid-attenuated inversion recovery (FLAIR) image. Patient 2, a 21-year-old woman who had a past medical history of PTB without receiving any treatment, presented for numbness in bilateral lower limbs and in the chest. The anti-AQP4-Ab was negative both in the serum and in the cerebral spinal fluid (CSF) of the patient. The MRI scan during hospitalization of cervical and thoracic spinal cord revealed diffuse hyperintense signal extending C3 to T11 on T2W and FLAIR images and hypointense signal on T1W image.

DIAGNOSIS

The first patient was diagnosed with anti-AQP4-Ab positive NMOSD, while the second case was an anti-AQP4-Ab negative LETM patient.

INTERVENTIONS

Both of the patients received a combination of corticosteroid and anti-tuberculosis (isonicotinyl hydrazide 0.3 g/d, rifampin 0.45 g/d, pyrazinamide 1 g/d, and ethambutol 1 g/d) treatment.

OUTCOMES

The patients were followed up for up to 1 year. The Expanded Disability Status Scale (EDSS) of both patients were decreased and the lesion size in the spinal cord was significantly reduced at the time point of the follow-up.

LESSONS

Combination of anti-tuberculosis and corticosteroid treatment may have better prognosis for patient of LETM with PTB.

Association between neuromyelitis optica and tuberculosis in a Chinese population

Background

A number of reports have described the presence of tuberculosis (TB) in neuromyelitis optica (NMO) patients. However, a definite association between the two conditions has not been conclusively demonstrated.

Methods

To investigate the association between NMO and TB in a Chinese population, we performed a retrospective review of hospital records of NMO patients, control patients and tuberculosis meningitis (TBM) patients from January 1, 1995 to December 31, 2011.

Results

The frequency of preceding/simultaneous active pulmonary TB (PTB) was not significantly different between NMO patients (1.1%) and control groups (2.3% in myasthenia gravis, 1.1% in polymyositis or dermatomyositis, zero in idiopathic facial palsy and viral meningitis/meningoencephalitis). NMO cases differed from TBM cases in terms of demographics, course (recurrent or monophasic), cerebrospinal fluid analysis and magnetic resonance images. Two TBM patients shared partial clinical features with NMO (one of the TBM patients had a longitudinal extensive spinal cord lesion involving the holocord, and the other had optic neuritis before anti-tuberculosis treatment). NMO antibodies were only detected in NMO patients and not in TBM patients with myelitis or optic neuritis.

Conclusions

We could not confirm previous suggestions of the association between PTB and NMO. Direct infection of the central nervous system by TB may mimic NMO in some respects, but whether NMO-like symptoms that develop during the course of TB should be considered and diagnosed as NMO is open to discussion.

A serological analysis of viral and bacterial infections associated with neuromyelitis optica

To evaluate the role of infections in the development of neuromyelitis optica (NMO), 19 patients positive for anti-aquaporin-4 antibody were screened for 24 viral and bacterial infections. Serological evidence of recent viral infection was found in 7 of 15 patients screened during the acute phase of the neurologic illness, which was a significantly more frequent rate of infection than seen in the control group of 33 patients with neurodegenerative, metabolic, or vertebral diseases (47% versus 15%). Mumps virus and human herpes viruses were the frequent causal agents, although there was no statistical difference in frequency between the two groups. Most patients with identified recent infection had monophasic or recurrent myelitis without evidence of optic nerve involvement and small number of total clinical relapses. Disease history tended to be shorter in patients with identified recent infection than those without, and an expanded long spinal cord lesion in magnetic resonance imaging was rarely found in patients with identified recent infection, although statistical significance could not be shown. These findings indicate that, not single, but various viral infections, can be associated with the development of NMO during the early stages of the illness, although the exact pathogenesis of NMO has yet to be clarified.

The clinical spectrum and immunobiology of parainfectious neuromyelitis optica (Devic) syndromes

In a subgroup of patients with neuromyelitis optica (NMO), a severe inflammatory demyelinating disorder of autoimmune origin characterized by recurrent attacks of optic neuritis and longitudinally extensive transverse myelitis, a parainfectious pathogenesis may play a central role. We systematically evaluated such reports in the literature published between 1975 and 2009 in order to characterize parainfectious NMO syndromes. Identified were 25 cases, whereof 11 were in association with viral and 14 with bacterial pathogens. Sufficient clinical and paraclinical information was available in 16 patients (11 women). Median age was 8 years for children and 32 years for adults. Acute febrile illness preceding or in close relation with neurological symptoms was most common and the association with varicella-zoster virus and Mycobacterium pneumonia most frequent. In the majority, the course was monophasic (88%) and disability sustained (with complete recovery in only 25%). Seven patients fulfilled the revised NMO diagnosis criteria of 2006; none was seropositve for aquaporin-4 antibodies. Immune mechanisms potentially involved in parainfectious NMO syndromes include bystander activation, molecular mimicry, and the exacerbation of a pre-existing central nervous system (CNS) disorder by a systemic infection. However, current studies are not sufficient to define the place of parainfectious NMO syndromes within the spectrum of inflammatory disorders of the CNS.

Neuromyelitis optica pathogenesis and aquaporin 4

Neuromyelitis optica (NMO) is a severe, debilitating human disease that predominantly features immunopathology in the optic nerves and the spinal cord. An IgG1 autoantibody (NMO-IgG) that binds aquaporin 4 (AQP4) has been identified in the sera of a significant number of NMO patients, as well as in patients with two related neurologic conditions, bilateral optic neuritis (ON), and longitudinal extensive transverse myelitis (LETM), that are generally considered to lie within the NMO spectrum of diseases. NMO-IgG is not the only autoantibody found in NMO patient sera, but the correlation of pathology in central nervous system (CNS) with tissues that normally express high levels of AQP4 suggests NMO-IgG might be pathogenic. If this is the case, it is important to identify and understand the mechanism(s) whereby an immune response is induced against AQP4. This review focuses on open questions about the "events" that need to be understood to determine if AQP4 and NMO-IgG are involved in the pathogenesis of NMO. These questions include: 1) How might AQP4-specific T and B cells be primed by either CNS AQP4 or peripheral pools of AQP4? 2) Do the different AQP4-expressing tissues and perhaps the membrane structural organization of AQP4 influence NMO-IgG binding efficacy and thus pathogenesis? 3) Does prior infection, genetic predisposition, or underlying immune dysregulation contribute to a confluence of events which lead to NMO in select individuals? A small animal model of NMO is essential to demonstrate whether AQP4 is indeed the incipient autoantigen capable of inducing NMO-IgG formation and NMO. If the NMO model is consistent with the human disease, it can be used to examine how changes in AQP4 expression and blood-brain barrier (BBB) integrity, both of which can be regulated by CNS inflammation, contribute to inductive events for anti-AQP4-specific immune response. In this review, we identify reagents and experimental questions that need to be developed and addressed to enhance our understanding of the pathogenesis of NMO. Finally, dysregulation of tolerance associated with autoimmune disease appears to have a role in NMO. Animal models would allow manipulation of hormone levels, B cell growth factors, and other elements known to increase the penetrance of autoimmune disease. Thus an AQP4 animal model would provide a means to manipulate events which are now associated with NMO and thus demonstrate what set of events or multiplicity of events can push the anti-AQP4 response to be pathogenic.

La neuromyélite optique au Maroc

INTRODUCTION

Optic neuromyelitis or Devic's syndrome associates optic neuritis and myelitis. It can have a monophasic or relapsing course. The limits of this entity remain controversial.

METHODS

We analyzed the results of a retrospective series of Moroccan patients with Devic's syndrome defined on the basis of Wingerchuk's criteria.

RESULTS

Six women and three men were retained for study; average age was 39 years. Three patients presented with a monophasic form and six with relapsing disease. CSF analysis was abnormal in five. Brain MRI was normal in eight. Signal abnormalities extended over more than three vertebrae in eight patients. Infections were associated with neurological features in half of the patients.

DISCUSSION

Our results are in agreement with those of large series in the literature regarding the clinical, imaging, and laboratory findings and disease course. We also noted that infections were more frequently associated with Devic's syndrome in our patients.

CONCLUSION

Our study reports the results of the first North African series of Devic's syndrome patients. We suggest that this syndrome is particular in our context due to the high frequency and diversity of associated infections.