Neuromyelitis optica - an update: 2007-2009

Neuromyelitis optica spectrum disorder in pediatrics. Case report

Introduction: Neuromyelitis optica is an inflammatory disorder of the central nervous system that accounts for 5% of demyelinating diseases in pediatrics. Its clinical presentation is variable and associated to the involved area of the central nervous system.Case presentation: This is the case of a 15-year-old patient who consulted several times for nonspecific neurological symptoms. During his last visit to the Clínica Universitaria Colombia in Bogotá, he presented with bilateral optic neuritis, associated with frontal and parietal headache. Immunophenotyping studies were carried out, reporting positive IgG anti-aquaporin 4 antibodies (anti-AQP4 antibody), thus leading to a diagnosis of seropositive neuromyelitis optica spectrum disorder (NMOSD). Management with methylprednisolone pulses was initiated with subsequent outpatient management with rituximab that allowed stabilizing the disease.Discussion: This is an interesting case due to its insidious and uncertain onset in a pediatric patient. It was possible to evaluate clinical and diagnostic differences in relation to its presentation in adults. NMOSD mediated by anti-AQP4 is rare; brain and bone marrow MRI are essential for diagnosis. The treatment of choice for acute conditions consists of high doses of methylprednisolone.Conclusion: This disorder may result in irreversible neurological damage; for this reason, high suspicion is required for early diagnosis and timely treatment.

Neuromyelitis optica-IgG testing in an Indian cohort with neuromyelitis optica and related demyelinating disorders: Our experience

BACKGROUND

Neuromyelitis optica (NMO) is an immune-mediated inflammatory demyelinating disorder of the central nervous system with a predilection for the optic nerves and the spinal cord. Immunopathological evidence suggests that the target antigen of the disease is aquaporin-4. An IgG antibody against this protein has been explored as a molecular marker for the disease and as a diagnostic tool due to its high sensitivity and specificity in various populations.

OBJECTIVE

To assess the value of NMO-IgG testing in Indian patients with clinical and magnetic resonance imaging features consistent with NMO and longitudinally extensive transverse myelitis (LETM).

MATERIALS AND METHODS

Forty-five patients with clinical and magnetic resonance imaging features consistent with NMO, LETM, and MS were tested for serum NMO-IgG. Of these patients, 22 patients satisfied revised (2006) Wingerchuk criteria for NMO (excluding NMO-IgG status) and 11 patients had LETM. Twelve patients satisfied the revised (2010) McDonald criteria for multiple sclerosis (MS).

RESULTS

Of the 21 patients, satisfying the criteria for NMO and for whom the test results were available, 17 were positive for NMO-IgG (80.9%), and of the 11 patients having LETM, 6 (54.5%) were positive for NMO-IgG. In one patient with NMO, the test result was not available. None of the 12 patients satisfying McDonald criteria for MS showed NMO-IgG seropositivity.

CONCLUSION

Our study suggests that it is worthwhile to pursue NMO-IgG testing as a diagnostic tool for patients with clinical and Magnetic Resonance Imaging (MRI) features consistent with NMO and LETM in the Indian population.

Phagocytized corpora amylacea as a histological hallmark of astrocytic injury in neuromyelitis optica

Neuromyelitis optica (NMO) is an inflammatory demyelinating and necrotizing disorder of the CNS that mainly affects the optic nerve and spinal cord. The etiology is still uncertain; however, the discovery of serum anti-aquaporin-4 (AQP4) autoantibody is becoming the center of attention, and a new hypothesis is emerging that NMO is essentially astrocytopathy provoked by this autoantibody. In this study, we focused on corpora amylacea (CA), glycoproteinaceous inclusions in astrocytic processes. We examined 57 lesions in nine cases of NMO spectrum disorder, and demonstrated that CA were phagocytized by macrophages in 42 lesions (74%) of eight cases, while phagocytized figures were not seen in unaffected areas. Phagocytized CA were frequently encountered in early-phase lesions still retaining myelin structures, while fewer or none were found in chronic destructive lesions. Moreover, phagocytized CA were significantly smaller in diameter than intact ones, and CA were decreased or absent in most lesions assessed. These findings suggest the following pathophysiological process: the astrocytes are affected at an early phase in NMO, CA are expelled from the astrocytes and phagocytized by macrophages finally leading to clearance. A phagocytized figure and subsequent loss of CA can be a histological hallmark of astrocytic injury of NMO.