[Encephalopathy and neuromyelitis optica: the importance of recognising atypical symptoms]

Neuromyelitis optica (NMO), or Devic's disease, is an autoimmune, inflammatory and demyelinating disease of the central nervous system which mainly and characteristically involves the optic nerve and the spinal cord. Anti-aquaporin-4 (AQ-4) antibodies are a specific biomarker of the entity and, since their discovery, both the number of symptoms and the radiological data about the disease have progressively increased, and the concept of clinical spectrum of NMO has been defined.

A 66-year-old female diagnosed with NMO after suffering attacks of optic neuritis and recurrent myelitis, and showing positive for AQ-4 antibodies. The patient presented a diminished level of consciousness, and magnetic resonance imaging of the head revealed a number of lesions in the white matter, without contrast enhancement, which resolved without treatment. One month later, her general state had declined and was accompanied by symptoms of confusion and blindness. A magnetic resonance imaging scan showed new lesions in the white matter and an increase in the size of those already present. The patient was diagnosed as suffering from encephalopathy within the context of NMO and she was treated with intravenous immunoglobulins and corticoids, which resulted in a clinical and radiological improvement.

Since the discovery of AQ-4 antibodies, there has been an increase in the number of clinical and radiological manifestations of NMO beyond involvement of the optic nerve and the spinal cord, including manifestations in the brain. It is important to recognise them in order to make an early diagnosis, to avoid unnecessary complementary tests and to establish the most suitable treatment.