Dados do Trabalho

Título

Diagnóstico de Neuromielite Óptica, em paciente com Miastenia Gravis

RESUMO

Apresentação do Caso:
G.C.D.S, started at 29 years of age, floating weakness in arms and legs, prevailing in the proximal muscles, associated with intermitent diplopia and ptosis. Reported worsening of symptoms with stress and warm weather. Electroneuromyography with repetitive nervous stimulation at 3 hz showed a 25.4% decrease in amplitude; she was then diagnosed with myasthenia gravis (MG), and started treatment with pyridostigmine, azathioprine and prednisone and thymectomy was performed. Evolved with good response to treatment with control of symptoms;
10 years later, during an interruption of azathioprine use, she noticed recurrent paresthesias in the arms and developed sudden visual acuity loss of the left eye; fundoscopy with optic disk with low-defined margins and pale color suggestive of optic neuritis;
Treatment with pulsotherapy with methylprednisone 1g for 5 days in hospital was performed, with partial improvement of visual acuity;
Brain MRI: smooth signal change and apparent enhancement by contrast of the left optic nerve. Cervical MRI: focus of signal change in the vertebral cord, most evident at the bulb and at the level of C2, C4 and C5, without significant enhancement by contrast; dosage of anti-aquaporin 4 IgG: reagent 1:20; receiving a diagnosis of neuromyelitis optic (NMO);
Discussão:
MG and NMO are immune-mediated disorders with low prevalence in the general population.
MG is a neuromuscular disorder associated with the presence of anti–acetylcholine receptor antibodies (Achr-Ab) and characterised by fluctuating muscle weakness.
NMO is an inflammatory disease of the central nervous system that mainly affects the spinal cord and optic nerve, and is associated with presence of anti–aquaporin-4 antibodies (AQP4-AB) in 60%-80% of patients.
Both AQP4-AB-positive NMO and Achr-AB-positive MG are associated with other autoimmune diseases and autoantibodies, both organ-specific and systemic. Despite the rarity of MG and NMO, several cases and small series of patients with both disorders have been reported over the years.
Aqp4-NMO is recognized to be associated with other autoimmune manifestations in about 25%–50% of cases, both organ-specific and systemic.
Conclusão:
Clinicians should have a low threshold to screen for comorbid autoimmune disease in patients with MG and NMO, in which non-invasive testing for antibodies is specific and allows for early treatment and better outcomes.

Palavras Chave

Miastenia Gravis; Neuromielite optica

Área

Neuroimunologia