Cerebral cortex impairment in neuromyelitis optica spectrum disorder: A case report and literature review.

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disorder of the central nervous system that usually presents with acute myelitis and/or optic neuritis. Cortical lesions used to be regarded as "red flags" of NMOSD, and indicated the possibility of alternative diagnoses. We recently had reported a NMOSD patient with weakness in both lower limbs resulting from cortical damage, which was usually attributed to spinal cord lesions. Surprisingly, we identified another patient bearing an uncanny resemblance of imaging manifestations. Cases of NMOSD with cortical impairment reported in the English language literature were reviewed and the demographic characteristics, clinical features, response to treatment, and imaging findings of these cases were analyzed.

RESULTS

Our literature review identified other nine cases excluding our previously reported one. All patients had abnormal magnetic resonance imaging (MRI) signals findings in the cortex and leptomeninges. Eight cases reported symptoms of specific cortical impairments. Seven cases underwent follow-up MRI examination and all displayed normal images. Three cases had a previous history of Sjögren's syndrome.

CONCLUSIONS

Cortical impairment with leptomeningeal enhancement can be considered an imaging performance component of NMOSD. Serious damage to the blood-brain barrier and Aquaporin-4 antibody (AQP4) may be involved in the process of cortical and leptomeningeal damage. We identified the frontal lobes as being the most susceptible area, especially the cortex adjacent to the cerebral falx. NMOSD cortical lesions may be reversed by methylprednisolone and immunosuppressant treatment.