Background：The discovery of aquaporin-4 (AQP4) antibody was a major advance since it indicated that neuromyelitis optica (NMO) is an independent disease distinct from multiplesclerosis. Thereafter, a broad spectrum of disorders in which AQP4 antibody could be found were grouped together and termed as neuromyelitis optica spectrum disorder (NMOSD).Recently, scholars have proposed that the condition of AQP4 antibody-positivity in patients
should be considered as autoimmune AQP4 channelopathy, of which NMOSD should be regarded as a part.
Methods: We describe a 41-year-old woman with encephalopathy who presented withstrange behaviour, disorganized language, and other psychiatric symptoms. Cerebral magnetic resonance imaging (MRI) revealed that lesions were located in the bilateral hypothalamus,thalamus, corpus callosum, and periependymal surfaces of the third and lateral ventricles.Serum and cerebrospinal fluid (CSF) were tested for AQP4-antibody using a commercial fixed cell-based assay.
Results: AQP4 antibodies were positive in both the cerebrospinal fluid and serum; however, autoimmune encephalitis antibodies were negative.
Conclusion: For patients with acute or subacute onset of encephalopathy, with lesions in theareas where AQP4 were enriched, AQP4 antibody assay should be a routine test. Moreoverfor an appropriate representation of the disease, the description autoimmune aquaporin-4 channelopathy should be used.